// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) Microsoft Corporation.
*
* Author:
* Jake Oshins <[email protected]>
*
* This driver acts as a paravirtual front-end for PCI Express root buses.
* When a PCI Express function (either an entire device or an SR-IOV
* Virtual Function) is being passed through to the VM, this driver exposes
* a new bus to the guest VM. This is modeled as a root PCI bus because
* no bridges are being exposed to the VM. In fact, with a "Generation 2"
* VM within Hyper-V, there may seem to be no PCI bus at all in the VM
* until a device as been exposed using this driver.
*
* Each root PCI bus has its own PCI domain, which is called "Segment" in
* the PCI Firmware Specifications. Thus while each device passed through
* to the VM using this front-end will appear at "device 0", the domain will
* be unique. Typically, each bus will have one PCI function on it, though
* this driver does support more than one.
*
* In order to map the interrupts from the device through to the guest VM,
* this driver also implements an IRQ Domain, which handles interrupts (either
* MSI or MSI-X) associated with the functions on the bus. As interrupts are
* set up, torn down, or reaffined, this driver communicates with the
* underlying hypervisor to adjust the mappings in the I/O MMU so that each
* interrupt will be delivered to the correct virtual processor at the right
* vector. This driver does not support level-triggered (line-based)
* interrupts, and will report that the Interrupt Line register in the
* function's configuration space is zero.
*
* The rest of this driver mostly maps PCI concepts onto underlying Hyper-V
* facilities. For instance, the configuration space of a function exposed
* by Hyper-V is mapped into a single page of memory space, and the
* read and write handlers for config space must be aware of this mechanism.
* Similarly, device setup and teardown involves messages sent to and from
* the PCI back-end driver in Hyper-V.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci-ecam.h>
#include <linux/delay.h>
#include <linux/semaphore.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/hyperv.h>
#include <linux/refcount.h>
#include <linux/irqdomain.h>
#include <linux/acpi.h>
#include <linux/sizes.h>
#include <asm/mshyperv.h>
/*
* Protocol versions. The low word is the minor version, the high word the
* major version.
*/
#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (minor)))
#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16)
#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff)
enum pci_protocol_version_t {
PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */
PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */
PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3), /* Vibranium */
PCI_PROTOCOL_VERSION_1_4 = PCI_MAKE_VERSION(1, 4), /* WS2022 */
};
#define CPU_AFFINITY_ALL -1ULL
/*
* Supported protocol versions in the order of probing - highest go
* first.
*/
static enum pci_protocol_version_t pci_protocol_versions[] = {
PCI_PROTOCOL_VERSION_1_4,
PCI_PROTOCOL_VERSION_1_3,
PCI_PROTOCOL_VERSION_1_2,
PCI_PROTOCOL_VERSION_1_1,
};
#define PCI_CONFIG_MMIO_LENGTH 0x2000
#define CFG_PAGE_OFFSET 0x1000
#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
#define MAX_SUPPORTED_MSI_MESSAGES 0x400
#define STATUS_REVISION_MISMATCH 0xC0000059
/* space for 32bit serial number as string */
#define SLOT_NAME_SIZE 11
/*
* Size of requestor for VMbus; the value is based on the observation
* that having more than one request outstanding is 'rare', and so 64
* should be generous in ensuring that we don't ever run out.
*/
#define HV_PCI_RQSTOR_SIZE 64
/*
* Message Types
*/
enum pci_message_type {
/*
* Version 1.1
*/
PCI_MESSAGE_BASE = 0x42490000,
PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0,
PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1,
PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4,
PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5,
PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6,
PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7,
PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8,
PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9,
PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA,
PCI_EJECT = PCI_MESSAGE_BASE + 0xB,
PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC,
PCI_REENABLE = PCI_MESSAGE_BASE + 0xD,
PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE,
PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF,
PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10,
PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11,
PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12,
PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13,
PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14,
PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15,
PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16,
PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17,
PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */
PCI_BUS_RELATIONS2 = PCI_MESSAGE_BASE + 0x19,
PCI_RESOURCES_ASSIGNED3 = PCI_MESSAGE_BASE + 0x1A,
PCI_CREATE_INTERRUPT_MESSAGE3 = PCI_MESSAGE_BASE + 0x1B,
PCI_MESSAGE_MAXIMUM
};
/*
* Structures defining the virtual PCI Express protocol.
*/
union pci_version {
struct {
u16 minor_version;
u16 major_version;
} parts;
u32 version;
} __packed;
/*
* Function numbers are 8-bits wide on Express, as interpreted through ARI,
* which is all this driver does. This representation is the one used in
* Windows, which is what is expected when sending this back and forth with
* the Hyper-V parent partition.
*/
union win_slot_encoding {
struct {
u32 dev:5;
u32 func:3;
u32 reserved:24;
} bits;
u32 slot;
} __packed;
/*
* Pretty much as defined in the PCI Specifications.
*/
struct pci_function_description {
u16 v_id; /* vendor ID */
u16 d_id; /* device ID */
u8 rev;
u8 prog_intf;
u8 subclass;
u8 base_class;
u32 subsystem_id;
union win_slot_encoding win_slot;
u32 ser; /* serial number */
} __packed;
enum pci_device_description_flags {
HV_PCI_DEVICE_FLAG_NONE = 0x0,
HV_PCI_DEVICE_FLAG_NUMA_AFFINITY = 0x1,
};
struct pci_function_description2 {
u16 v_id; /* vendor ID */
u16 d_id; /* device ID */
u8 rev;
u8 prog_intf;
u8 subclass;
u8 base_class;
u32 subsystem_id;
union win_slot_encoding win_slot;
u32 ser; /* serial number */
u32 flags;
u16 virtual_numa_node;
u16 reserved;
} __packed;
/**
* struct hv_msi_desc
* @vector: IDT entry
* @delivery_mode: As defined in Intel's Programmer's
* Reference Manual, Volume 3, Chapter 8.
* @vector_count: Number of contiguous entries in the
* Interrupt Descriptor Table that are
* occupied by this Message-Signaled
* Interrupt. For "MSI", as first defined
* in PCI 2.2, this can be between 1 and
* 32. For "MSI-X," as first defined in PCI
* 3.0, this must be 1, as each MSI-X table
* entry would have its own descriptor.
* @reserved: Empty space
* @cpu_mask: All the target virtual processors.
*/
struct hv_msi_desc {
u8 vector;
u8 delivery_mode;
u16 vector_count;
u32 reserved;
u64 cpu_mask;
} __packed;
/**
* struct hv_msi_desc2 - 1.2 version of hv_msi_desc
* @vector: IDT entry
* @delivery_mode: As defined in Intel's Programmer's
* Reference Manual, Volume 3, Chapter 8.
* @vector_count: Number of contiguous entries in the
* Interrupt Descriptor Table that are
* occupied by this Message-Signaled
* Interrupt. For "MSI", as first defined
* in PCI 2.2, this can be between 1 and
* 32. For "MSI-X," as first defined in PCI
* 3.0, this must be 1, as each MSI-X table
* entry would have its own descriptor.
* @processor_count: number of bits enabled in array.
* @processor_array: All the target virtual processors.
*/
struct hv_msi_desc2 {
u8 vector;
u8 delivery_mode;
u16 vector_count;
u16 processor_count;
u16 processor_array[32];
} __packed;
/*
* struct hv_msi_desc3 - 1.3 version of hv_msi_desc
* Everything is the same as in 'hv_msi_desc2' except that the size of the
* 'vector' field is larger to support bigger vector values. For ex: LPI
* vectors on ARM.
*/
struct hv_msi_desc3 {
u32 vector;
u8 delivery_mode;
u8 reserved;
u16 vector_count;
u16 processor_count;
u16 processor_array[32];
} __packed;
/**
* struct tran_int_desc
* @reserved: unused, padding
* @vector_count: same as in hv_msi_desc
* @data: This is the "data payload" value that is
* written by the device when it generates
* a message-signaled interrupt, either MSI
* or MSI-X.
* @address: This is the address to which the data
* payload is written on interrupt
* generation.
*/
struct tran_int_desc {
u16 reserved;
u16 vector_count;
u32 data;
u64 address;
} __packed;
/*
* A generic message format for virtual PCI.
* Specific message formats are defined later in the file.
*/
struct pci_message {
u32 type;
} __packed;
struct pci_child_message {
struct pci_message message_type;
union win_slot_encoding wslot;
} __packed;
struct pci_incoming_message {
struct vmpacket_descriptor hdr;
struct pci_message message_type;
} __packed;
struct pci_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
} __packed;
struct pci_packet {
void (*completion_func)(void *context, struct pci_response *resp,
int resp_packet_size);
void *compl_ctxt;
struct pci_message message[];
};
/*
* Specific message types supporting the PCI protocol.
*/
/*
* Version negotiation message. Sent from the guest to the host.
* The guest is free to try different versions until the host
* accepts the version.
*
* pci_version: The protocol version requested.
* is_last_attempt: If TRUE, this is the last version guest will request.
* reservedz: Reserved field, set to zero.
*/
struct pci_version_request {
struct pci_message message_type;
u32 protocol_version;
} __packed;
/*
* Bus D0 Entry. This is sent from the guest to the host when the virtual
* bus (PCI Express port) is ready for action.
*/
struct pci_bus_d0_entry {
struct pci_message message_type;
u32 reserved;
u64 mmio_base;
} __packed;
struct pci_bus_relations {
struct pci_incoming_message incoming;
u32 device_count;
struct pci_function_description func[];
} __packed;
struct pci_bus_relations2 {
struct pci_incoming_message incoming;
u32 device_count;
struct pci_function_description2 func[];
} __packed;
struct pci_q_res_req_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
u32 probed_bar[PCI_STD_NUM_BARS];
} __packed;
struct pci_set_power {
struct pci_message message_type;
union win_slot_encoding wslot;
u32 power_state; /* In Windows terms */
u32 reserved;
} __packed;
struct pci_set_power_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
union win_slot_encoding wslot;
u32 resultant_state; /* In Windows terms */
u32 reserved;
} __packed;
struct pci_resources_assigned {
struct pci_message message_type;
union win_slot_encoding wslot;
u8 memory_range[0x14][6]; /* not used here */
u32 msi_descriptors;
u32 reserved[4];
} __packed;
struct pci_resources_assigned2 {
struct pci_message message_type;
union win_slot_encoding wslot;
u8 memory_range[0x14][6]; /* not used here */
u32 msi_descriptor_count;
u8 reserved[70];
} __packed;
struct pci_create_interrupt {
struct pci_message message_type;
union win_slot_encoding wslot;
struct hv_msi_desc int_desc;
} __packed;
struct pci_create_int_response {
struct pci_response response;
u32 reserved;
struct tran_int_desc int_desc;
} __packed;
struct pci_create_interrupt2 {
struct pci_message message_type;
union win_slot_encoding wslot;
struct hv_msi_desc2 int_desc;
} __packed;
struct pci_create_interrupt3 {
struct pci_message message_type;
union win_slot_encoding wslot;
struct hv_msi_desc3 int_desc;
} __packed;
struct pci_delete_interrupt {
struct pci_message message_type;
union win_slot_encoding wslot;
struct tran_int_desc int_desc;
} __packed;
/*
* Note: the VM must pass a valid block id, wslot and bytes_requested.
*/
struct pci_read_block {
struct pci_message message_type;
u32 block_id;
union win_slot_encoding wslot;
u32 bytes_requested;
} __packed;
struct pci_read_block_response {
struct vmpacket_descriptor hdr;
u32 status;
u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
} __packed;
/*
* Note: the VM must pass a valid block id, wslot and byte_count.
*/
struct pci_write_block {
struct pci_message message_type;
u32 block_id;
union win_slot_encoding wslot;
u32 byte_count;
u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
} __packed;
struct pci_dev_inval_block {
struct pci_incoming_message incoming;
union win_slot_encoding wslot;
u64 block_mask;
} __packed;
struct pci_dev_incoming {
struct pci_incoming_message incoming;
union win_slot_encoding wslot;
} __packed;
struct pci_eject_response {
struct pci_message message_type;
union win_slot_encoding wslot;
u32 status;
} __packed;
static int pci_ring_size = VMBUS_RING_SIZE(SZ_16K);
/*
* Driver specific state.
*/
enum hv_pcibus_state {
hv_pcibus_init = 0,
hv_pcibus_probed,
hv_pcibus_installed,
hv_pcibus_removing,
hv_pcibus_maximum
};
struct hv_pcibus_device {
#ifdef CONFIG_X86
struct pci_sysdata sysdata;
#elif defined(CONFIG_ARM64)
struct pci_config_window sysdata;
#endif
struct pci_host_bridge *bridge;
struct fwnode_handle *fwnode;
/* Protocol version negotiated with the host */
enum pci_protocol_version_t protocol_version;
struct mutex state_lock;
enum hv_pcibus_state state;
struct hv_device *hdev;
resource_size_t low_mmio_space;
resource_size_t high_mmio_space;
struct resource *mem_config;
struct resource *low_mmio_res;
struct resource *high_mmio_res;
struct completion *survey_event;
struct pci_bus *pci_bus;
spinlock_t config_lock; /* Avoid two threads writing index page */
spinlock_t device_list_lock; /* Protect lists below */
void __iomem *cfg_addr;
struct list_head children;
struct list_head dr_list;
struct msi_domain_info msi_info;
struct irq_domain *irq_domain;
struct workqueue_struct *wq;
/* Highest slot of child device with resources allocated */
int wslot_res_allocated;
bool use_calls; /* Use hypercalls to access mmio cfg space */
};
/*
* Tracks "Device Relations" messages from the host, which must be both
* processed in order and deferred so that they don't run in the context
* of the incoming packet callback.
*/
struct hv_dr_work {
struct work_struct wrk;
struct hv_pcibus_device *bus;
};
struct hv_pcidev_description {
u16 v_id; /* vendor ID */
u16 d_id; /* device ID */
u8 rev;
u8 prog_intf;
u8 subclass;
u8 base_class;
u32 subsystem_id;
union win_slot_encoding win_slot;
u32 ser; /* serial number */
u32 flags;
u16 virtual_numa_node;
};
struct hv_dr_state {
struct list_head list_entry;
u32 device_count;
struct hv_pcidev_description func[] __counted_by(device_count);
};
struct hv_pci_dev {
/* List protected by pci_rescan_remove_lock */
struct list_head list_entry;
refcount_t refs;
struct pci_slot *pci_slot;
struct hv_pcidev_description desc;
bool reported_missing;
struct hv_pcibus_device *hbus;
struct work_struct wrk;
void (*block_invalidate)(void *context, u64 block_mask);
void *invalidate_context;
/*
* What would be observed if one wrote 0xFFFFFFFF to a BAR and then
* read it back, for each of the BAR offsets within config space.
*/
u32 probed_bar[PCI_STD_NUM_BARS];
};
struct hv_pci_compl {
struct completion host_event;
s32 completion_status;
};
static void hv_pci_onchannelcallback(void *context);
#ifdef CONFIG_X86
#define DELIVERY_MODE APIC_DELIVERY_MODE_FIXED
#define FLOW_HANDLER handle_edge_irq
#define FLOW_NAME "edge"
static int hv_pci_irqchip_init(void)
{
return 0;
}
static struct irq_domain *hv_pci_get_root_domain(void)
{
return x86_vector_domain;
}
static unsigned int hv_msi_get_int_vector(struct irq_data *data)
{
struct irq_cfg *cfg = irqd_cfg(data);
return cfg->vector;
}
#define hv_msi_prepare pci_msi_prepare
/**
* hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current
* affinity.
* @data: Describes the IRQ
*
* Build new a destination for the MSI and make a hypercall to
* update the Interrupt Redirection Table. "Device Logical ID"
* is built out of this PCI bus's instance GUID and the function
* number of the device.
*/
static void hv_arch_irq_unmask(struct irq_data *data)
{
struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
struct hv_retarget_device_interrupt *params;
struct tran_int_desc *int_desc;
struct hv_pcibus_device *hbus;
const struct cpumask *dest;
cpumask_var_t tmp;
struct pci_bus *pbus;
struct pci_dev *pdev;
unsigned long flags;
u32 var_size = 0;
int cpu, nr_bank;
u64 res;
dest = irq_data_get_effective_affinity_mask(data);
pdev = msi_desc_to_pci_dev(msi_desc);
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
int_desc = data->chip_data;
if (!int_desc) {
dev_warn(&hbus->hdev->device, "%s() can not unmask irq %u\n",
__func__, data->irq);
return;
}
local_irq_save(flags);
params = *this_cpu_ptr(hyperv_pcpu_input_arg);
memset(params, 0, sizeof(*params));
params->partition_id = HV_PARTITION_ID_SELF;
params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;
params->int_entry.msi_entry.address.as_uint32 = int_desc->address & 0xffffffff;
params->int_entry.msi_entry.data.as_uint32 = int_desc->data;
params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
(hbus->hdev->dev_instance.b[4] << 16) |
(hbus->hdev->dev_instance.b[7] << 8) |
(hbus->hdev->dev_instance.b[6] & 0xf8) |
PCI_FUNC(pdev->devfn);
params->int_target.vector = hv_msi_get_int_vector(data);
if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
/*
* PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
* HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
* with >64 VP support.
* ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED
* is not sufficient for this hypercall.
*/
params->int_target.flags |=
HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {
res = 1;
goto out;
}
cpumask_and(tmp, dest, cpu_online_mask);
nr_bank = cpumask_to_vpset(¶ms->int_target.vp_set, tmp);
free_cpumask_var(tmp);
if (nr_bank <= 0) {
res = 1;
goto out;
}
/*
* var-sized hypercall, var-size starts after vp_mask (thus
* vp_set.format does not count, but vp_set.valid_bank_mask
* does).
*/
var_size = 1 + nr_bank;
} else {
for_each_cpu_and(cpu, dest, cpu_online_mask) {
params->int_target.vp_mask |=
(1ULL << hv_cpu_number_to_vp_number(cpu));
}
}
res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),
params, NULL);
out:
local_irq_restore(flags);
/*
* During hibernation, when a CPU is offlined, the kernel tries
* to move the interrupt to the remaining CPUs that haven't
* been offlined yet. In this case, the below hv_do_hypercall()
* always fails since the vmbus channel has been closed:
* refer to cpu_disable_common() -> fixup_irqs() ->
* irq_migrate_all_off_this_cpu() -> migrate_one_irq().
*
* Suppress the error message for hibernation because the failure
* during hibernation does not matter (at this time all the devices
* have been frozen). Note: the correct affinity info is still updated
* into the irqdata data structure in migrate_one_irq() ->
* irq_do_set_affinity(), so later when the VM resumes,
* hv_pci_restore_msi_state() is able to correctly restore the
* interrupt with the correct affinity.
*/
if (!hv_result_success(res) && hbus->state != hv_pcibus_removing)
dev_err(&hbus->hdev->device,
"%s() failed: %#llx", __func__, res);
}
#elif defined(CONFIG_ARM64)
/*
* SPI vectors to use for vPCI; arch SPIs range is [32, 1019], but leaving a bit
* of room at the start to allow for SPIs to be specified through ACPI and
* starting with a power of two to satisfy power of 2 multi-MSI requirement.
*/
#define HV_PCI_MSI_SPI_START 64
#define HV_PCI_MSI_SPI_NR (1020 - HV_PCI_MSI_SPI_START)
#define DELIVERY_MODE 0
#define FLOW_HANDLER NULL
#define FLOW_NAME NULL
#define hv_msi_prepare NULL
struct hv_pci_chip_data {
DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR);
struct mutex map_lock;
};
/* Hyper-V vPCI MSI GIC IRQ domain */
static struct irq_domain *hv_msi_gic_irq_domain;
/* Hyper-V PCI MSI IRQ chip */
static struct irq_chip hv_arm64_msi_irq_chip = {
.name = "MSI",
.irq_set_affinity = irq_chip_set_affinity_parent,
.irq_eoi = irq_chip_eoi_parent,
.irq_mask = irq_chip_mask_parent,
.irq_unmask = irq_chip_unmask_parent
};
static unsigned int hv_msi_get_int_vector(struct irq_data *irqd)
{
return irqd->parent_data->hwirq;
}
/*
* @nr_bm_irqs: Indicates the number of IRQs that were allocated from
* the bitmap.
* @nr_dom_irqs: Indicates the number of IRQs that were allocated from
* the parent domain.
*/
static void hv_pci_vec_irq_free(struct irq_domain *domain,
unsigned int virq,
unsigned int nr_bm_irqs,
unsigned int nr_dom_irqs)
{
struct hv_pci_chip_data *chip_data = domain->host_data;
struct irq_data *d = irq_domain_get_irq_data(domain, virq);
int first = d->hwirq - HV_PCI_MSI_SPI_START;
int i;
mutex_lock(&chip_data->map_lock);
bitmap_release_region(chip_data->spi_map,
first,
get_count_order(nr_bm_irqs));
mutex_unlock(&chip_data->map_lock);
for (i = 0; i < nr_dom_irqs; i++) {
if (i)
d = irq_domain_get_irq_data(domain, virq + i);
irq_domain_reset_irq_data(d);
}
irq_domain_free_irqs_parent(domain, virq, nr_dom_irqs);
}
static void hv_pci_vec_irq_domain_free(struct irq_domain *domain,
unsigned int virq,
unsigned int nr_irqs)
{
hv_pci_vec_irq_free(domain, virq, nr_irqs, nr_irqs);
}
static int hv_pci_vec_alloc_device_irq(struct irq_domain *domain,
unsigned int nr_irqs,
irq_hw_number_t *hwirq)
{
struct hv_pci_chip_data *chip_data = domain->host_data;
int index;
/* Find and allocate region from the SPI bitmap */
mutex_lock(&chip_data->map_lock);
index = bitmap_find_free_region(chip_data->spi_map,
HV_PCI_MSI_SPI_NR,
get_count_order(nr_irqs));
mutex_unlock(&chip_data->map_lock);
if (index < 0)
return -ENOSPC;
*hwirq = index + HV_PCI_MSI_SPI_START;
return 0;
}
static int hv_pci_vec_irq_gic_domain_alloc(struct irq_domain *domain,
unsigned int virq,
irq_hw_number_t hwirq)
{
struct irq_fwspec fwspec;
struct irq_data *d;
int ret;
fwspec.fwnode = domain->parent->fwnode;
fwspec.param_count = 2;
fwspec.param[0] = hwirq;
fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
if (ret)
return ret;
/*
* Since the interrupt specifier is not coming from ACPI or DT, the
* trigger type will need to be set explicitly. Otherwise, it will be
* set to whatever is in the GIC configuration.
*/
d = irq_domain_get_irq_data(domain->parent, virq);
return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
}
static int hv_pci_vec_irq_domain_alloc(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs,
void *args)
{
irq_hw_number_t hwirq;
unsigned int i;
int ret;
ret = hv_pci_vec_alloc_device_irq(domain, nr_irqs, &hwirq);
if (ret)
return ret;
for (i = 0; i < nr_irqs; i++) {
ret = hv_pci_vec_irq_gic_domain_alloc(domain, virq + i,
hwirq + i);
if (ret) {
hv_pci_vec_irq_free(domain, virq, nr_irqs, i);
return ret;
}
irq_domain_set_hwirq_and_chip(domain, virq + i,
hwirq + i,
&hv_arm64_msi_irq_chip,
domain->host_data);
pr_debug("pID:%d vID:%u\n", (int)(hwirq + i), virq + i);
}
return 0;
}
/*
* Pick the first cpu as the irq affinity that can be temporarily used for
* composing MSI from the hypervisor. GIC will eventually set the right
* affinity for the irq and the 'unmask' will retarget the interrupt to that
* cpu.
*/
static int hv_pci_vec_irq_domain_activate(struct irq_domain *domain,
struct irq_data *irqd, bool reserve)
{
int cpu = cpumask_first(cpu_present_mask);
irq_data_update_effective_affinity(irqd, cpumask_of(cpu));
return 0;
}
static const struct irq_domain_ops hv_pci_domain_ops = {
.alloc = hv_pci_vec_irq_domain_alloc,
.free = hv_pci_vec_irq_domain_free,
.activate = hv_pci_vec_irq_domain_activate,
};
static int hv_pci_irqchip_init(void)
{
static struct hv_pci_chip_data *chip_data;
struct fwnode_handle *fn = NULL;
int ret = -ENOMEM;
chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
if (!chip_data)
return ret;
mutex_init(&chip_data->map_lock);
fn = irq_domain_alloc_named_fwnode("hv_vpci_arm64");
if (!fn)
goto free_chip;
/*
* IRQ domain once enabled, should not be removed since there is no
* way to ensure that all the corresponding devices are also gone and
* no interrupts will be generated.
*/
hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
fn, &hv_pci_domain_ops,
chip_data);
if (!hv_msi_gic_irq_domain) {
pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
goto free_chip;
}
return 0;
free_chip:
kfree(chip_data);
if (fn)
irq_domain_free_fwnode(fn);
return ret;
}
static struct irq_domain *hv_pci_get_root_domain(void)
{
return hv_msi_gic_irq_domain;
}
/*
* SPIs are used for interrupts of PCI devices and SPIs is managed via GICD
* registers which Hyper-V already supports, so no hypercall needed.
*/
static void hv_arch_irq_unmask(struct irq_data *data) { }
#endif /* CONFIG_ARM64 */
/**
* hv_pci_generic_compl() - Invoked for a completion packet
* @context: Set up by the sender of the packet.
* @resp: The response packet
* @resp_packet_size: Size in bytes of the packet
*
* This function is used to trigger an event and report status
* for any message for which the completion packet contains a
* status and nothing else.
*/
static void hv_pci_generic_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct hv_pci_compl *comp_pkt = context;
comp_pkt->completion_status = resp->status;
complete(&comp_pkt->host_event);
}
static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
u32 wslot);
static void get_pcichild(struct hv_pci_dev *hpdev)
{
refcount_inc(&hpdev->refs);
}
static void put_pcichild(struct hv_pci_dev *hpdev)
{
if (refcount_dec_and_test(&hpdev->refs))
kfree(hpdev);
}
/*
* There is no good way to get notified from vmbus_onoffer_rescind(),
* so let's use polling here, since this is not a hot path.
*/
static int wait_for_response(struct hv_device *hdev,
struct completion *comp)
{
while (true) {
if (hdev->channel->rescind) {
dev_warn_once(&hdev->device, "The device is gone.\n");
return -ENODEV;
}
if (wait_for_completion_timeout(comp, HZ / 10))
break;
}
return 0;
}
/**
* devfn_to_wslot() - Convert from Linux PCI slot to Windows
* @devfn: The Linux representation of PCI slot
*
* Windows uses a slightly different representation of PCI slot.
*
* Return: The Windows representation
*/
static u32 devfn_to_wslot(int devfn)
{
union win_slot_encoding wslot;
wslot.slot = 0;
wslot.bits.dev = PCI_SLOT(devfn);
wslot.bits.func = PCI_FUNC(devfn);
return wslot.slot;
}
/**
* wslot_to_devfn() - Convert from Windows PCI slot to Linux
* @wslot: The Windows representation of PCI slot
*
* Windows uses a slightly different representation of PCI slot.
*
* Return: The Linux representation
*/
static int wslot_to_devfn(u32 wslot)
{
union win_slot_encoding slot_no;
slot_no.slot = wslot;
return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func);
}
static void hv_pci_read_mmio(struct device *dev, phys_addr_t gpa, int size, u32 *val)
{
struct hv_mmio_read_input *in;
struct hv_mmio_read_output *out;
u64 ret;
/*
* Must be called with interrupts disabled so it is safe
* to use the per-cpu input argument page. Use it for
* both input and output.
*/
in = *this_cpu_ptr(hyperv_pcpu_input_arg);
out = *this_cpu_ptr(hyperv_pcpu_input_arg) + sizeof(*in);
in->gpa = gpa;
in->size = size;
ret = hv_do_hypercall(HVCALL_MMIO_READ, in, out);
if (hv_result_success(ret)) {
switch (size) {
case 1:
*val = *(u8 *)(out->data);
break;
case 2:
*val = *(u16 *)(out->data);
break;
default:
*val = *(u32 *)(out->data);
break;
}
} else
dev_err(dev, "MMIO read hypercall error %llx addr %llx size %d\n",
ret, gpa, size);
}
static void hv_pci_write_mmio(struct device *dev, phys_addr_t gpa, int size, u32 val)
{
struct hv_mmio_write_input *in;
u64 ret;
/*
* Must be called with interrupts disabled so it is safe
* to use the per-cpu input argument memory.
*/
in = *this_cpu_ptr(hyperv_pcpu_input_arg);
in->gpa = gpa;
in->size = size;
switch (size) {
case 1:
*(u8 *)(in->data) = val;
break;
case 2:
*(u16 *)(in->data) = val;
break;
default:
*(u32 *)(in->data) = val;
break;
}
ret = hv_do_hypercall(HVCALL_MMIO_WRITE, in, NULL);
if (!hv_result_success(ret))
dev_err(dev, "MMIO write hypercall error %llx addr %llx size %d\n",
ret, gpa, size);
}
/*
* PCI Configuration Space for these root PCI buses is implemented as a pair
* of pages in memory-mapped I/O space. Writing to the first page chooses
* the PCI function being written or read. Once the first page has been
* written to, the following page maps in the entire configuration space of
* the function.
*/
/**
* _hv_pcifront_read_config() - Internal PCI config read
* @hpdev: The PCI driver's representation of the device
* @where: Offset within config space
* @size: Size of the transfer
* @val: Pointer to the buffer receiving the data
*/
static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where,
int size, u32 *val)
{
struct hv_pcibus_device *hbus = hpdev->hbus;
struct device *dev = &hbus->hdev->device;
int offset = where + CFG_PAGE_OFFSET;
unsigned long flags;
/*
* If the attempt is to read the IDs or the ROM BAR, simulate that.
*/
if (where + size <= PCI_COMMAND) {
memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size);
} else if (where >= PCI_CLASS_REVISION && where + size <=
PCI_CACHE_LINE_SIZE) {
memcpy(val, ((u8 *)&hpdev->desc.rev) + where -
PCI_CLASS_REVISION, size);
} else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <=
PCI_ROM_ADDRESS) {
memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where -
PCI_SUBSYSTEM_VENDOR_ID, size);
} else if (where >= PCI_ROM_ADDRESS && where + size <=
PCI_CAPABILITY_LIST) {
/* ROM BARs are unimplemented */
*val = 0;
} else if ((where >= PCI_INTERRUPT_LINE && where + size <= PCI_INTERRUPT_PIN) ||
(where >= PCI_INTERRUPT_PIN && where + size <= PCI_MIN_GNT)) {
/*
* Interrupt Line and Interrupt PIN are hard-wired to zero
* because this front-end only supports message-signaled
* interrupts.
*/
*val = 0;
} else if (where + size <= CFG_PAGE_SIZE) {
spin_lock_irqsave(&hbus->config_lock, flags);
if (hbus->use_calls) {
phys_addr_t addr = hbus->mem_config->start + offset;
hv_pci_write_mmio(dev, hbus->mem_config->start, 4,
hpdev->desc.win_slot.slot);
hv_pci_read_mmio(dev, addr, size, val);
} else {
void __iomem *addr = hbus->cfg_addr + offset;
/* Choose the function to be read. (See comment above) */
writel(hpdev->desc.win_slot.slot, hbus->cfg_addr);
/* Make sure the function was chosen before reading. */
mb();
/* Read from that function's config space. */
switch (size) {
case 1:
*val = readb(addr);
break;
case 2:
*val = readw(addr);
break;
default:
*val = readl(addr);
break;
}
/*
* Make sure the read was done before we release the
* spinlock allowing consecutive reads/writes.
*/
mb();
}
spin_unlock_irqrestore(&hbus->config_lock, flags);
} else {
dev_err(dev, "Attempt to read beyond a function's config space.\n");
}
}
static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev)
{
struct hv_pcibus_device *hbus = hpdev->hbus;
struct device *dev = &hbus->hdev->device;
u32 val;
u16 ret;
unsigned long flags;
spin_lock_irqsave(&hbus->config_lock, flags);
if (hbus->use_calls) {
phys_addr_t addr = hbus->mem_config->start +
CFG_PAGE_OFFSET + PCI_VENDOR_ID;
hv_pci_write_mmio(dev, hbus->mem_config->start, 4,
hpdev->desc.win_slot.slot);
hv_pci_read_mmio(dev, addr, 2, &val);
ret = val; /* Truncates to 16 bits */
} else {
void __iomem *addr = hbus->cfg_addr + CFG_PAGE_OFFSET +
PCI_VENDOR_ID;
/* Choose the function to be read. (See comment above) */
writel(hpdev->desc.win_slot.slot, hbus->cfg_addr);
/* Make sure the function was chosen before we start reading. */
mb();
/* Read from that function's config space. */
ret = readw(addr);
/*
* mb() is not required here, because the
* spin_unlock_irqrestore() is a barrier.
*/
}
spin_unlock_irqrestore(&hbus->config_lock, flags);
return ret;
}
/**
* _hv_pcifront_write_config() - Internal PCI config write
* @hpdev: The PCI driver's representation of the device
* @where: Offset within config space
* @size: Size of the transfer
* @val: The data being transferred
*/
static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where,
int size, u32 val)
{
struct hv_pcibus_device *hbus = hpdev->hbus;
struct device *dev = &hbus->hdev->device;
int offset = where + CFG_PAGE_OFFSET;
unsigned long flags;
if (where >= PCI_SUBSYSTEM_VENDOR_ID &&
where + size <= PCI_CAPABILITY_LIST) {
/* SSIDs and ROM BARs are read-only */
} else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) {
spin_lock_irqsave(&hbus->config_lock, flags);
if (hbus->use_calls) {
phys_addr_t addr = hbus->mem_config->start + offset;
hv_pci_write_mmio(dev, hbus->mem_config->start, 4,
hpdev->desc.win_slot.slot);
hv_pci_write_mmio(dev, addr, size, val);
} else {
void __iomem *addr = hbus->cfg_addr + offset;
/* Choose the function to write. (See comment above) */
writel(hpdev->desc.win_slot.slot, hbus->cfg_addr);
/* Make sure the function was chosen before writing. */
wmb();
/* Write to that function's config space. */
switch (size) {
case 1:
writeb(val, addr);
break;
case 2:
writew(val, addr);
break;
default:
writel(val, addr);
break;
}
/*
* Make sure the write was done before we release the
* spinlock allowing consecutive reads/writes.
*/
mb();
}
spin_unlock_irqrestore(&hbus->config_lock, flags);
} else {
dev_err(dev, "Attempt to write beyond a function's config space.\n");
}
}
/**
* hv_pcifront_read_config() - Read configuration space
* @bus: PCI Bus structure
* @devfn: Device/function
* @where: Offset from base
* @size: Byte/word/dword
* @val: Value to be read
*
* Return: PCIBIOS_SUCCESSFUL on success
* PCIBIOS_DEVICE_NOT_FOUND on failure
*/
static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct hv_pcibus_device *hbus =
container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
struct hv_pci_dev *hpdev;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
if (!hpdev)
return PCIBIOS_DEVICE_NOT_FOUND;
_hv_pcifront_read_config(hpdev, where, size, val);
put_pcichild(hpdev);
return PCIBIOS_SUCCESSFUL;
}
/**
* hv_pcifront_write_config() - Write configuration space
* @bus: PCI Bus structure
* @devfn: Device/function
* @where: Offset from base
* @size: Byte/word/dword
* @val: Value to be written to device
*
* Return: PCIBIOS_SUCCESSFUL on success
* PCIBIOS_DEVICE_NOT_FOUND on failure
*/
static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
struct hv_pcibus_device *hbus =
container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
struct hv_pci_dev *hpdev;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
if (!hpdev)
return PCIBIOS_DEVICE_NOT_FOUND;
_hv_pcifront_write_config(hpdev, where, size, val);
put_pcichild(hpdev);
return PCIBIOS_SUCCESSFUL;
}
/* PCIe operations */
static struct pci_ops hv_pcifront_ops = {
.read = hv_pcifront_read_config,
.write = hv_pcifront_write_config,
};
/*
* Paravirtual backchannel
*
* Hyper-V SR-IOV provides a backchannel mechanism in software for
* communication between a VF driver and a PF driver. These
* "configuration blocks" are similar in concept to PCI configuration space,
* but instead of doing reads and writes in 32-bit chunks through a very slow
* path, packets of up to 128 bytes can be sent or received asynchronously.
*
* Nearly every SR-IOV device contains just such a communications channel in
* hardware, so using this one in software is usually optional. Using the
* software channel, however, allows driver implementers to leverage software
* tools that fuzz the communications channel looking for vulnerabilities.
*
* The usage model for these packets puts the responsibility for reading or
* writing on the VF driver. The VF driver sends a read or a write packet,
* indicating which "block" is being referred to by number.
*
* If the PF driver wishes to initiate communication, it can "invalidate" one or
* more of the first 64 blocks. This invalidation is delivered via a callback
* supplied by the VF driver by this driver.
*
* No protocol is implied, except that supplied by the PF and VF drivers.
*/
struct hv_read_config_compl {
struct hv_pci_compl comp_pkt;
void *buf;
unsigned int len;
unsigned int bytes_returned;
};
/**
* hv_pci_read_config_compl() - Invoked when a response packet
* for a read config block operation arrives.
* @context: Identifies the read config operation
* @resp: The response packet itself
* @resp_packet_size: Size in bytes of the response packet
*/
static void hv_pci_read_config_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct hv_read_config_compl *comp = context;
struct pci_read_block_response *read_resp =
(struct pci_read_block_response *)resp;
unsigned int data_len, hdr_len;
hdr_len = offsetof(struct pci_read_block_response, bytes);
if (resp_packet_size < hdr_len) {
comp->comp_pkt.completion_status = -1;
goto out;
}
data_len = resp_packet_size - hdr_len;
if (data_len > 0 && read_resp->status == 0) {
comp->bytes_returned = min(comp->len, data_len);
memcpy(comp->buf, read_resp->bytes, comp->bytes_returned);
} else {
comp->bytes_returned = 0;
}
comp->comp_pkt.completion_status = read_resp->status;
out:
complete(&comp->comp_pkt.host_event);
}
/**
* hv_read_config_block() - Sends a read config block request to
* the back-end driver running in the Hyper-V parent partition.
* @pdev: The PCI driver's representation for this device.
* @buf: Buffer into which the config block will be copied.
* @len: Size in bytes of buf.
* @block_id: Identifies the config block which has been requested.
* @bytes_returned: Size which came back from the back-end driver.
*
* Return: 0 on success, -errno on failure
*/
static int hv_read_config_block(struct pci_dev *pdev, void *buf,
unsigned int len, unsigned int block_id,
unsigned int *bytes_returned)
{
struct hv_pcibus_device *hbus =
container_of(pdev->bus->sysdata, struct hv_pcibus_device,
sysdata);
struct {
struct pci_packet pkt;
char buf[sizeof(struct pci_read_block)];
} pkt;
struct hv_read_config_compl comp_pkt;
struct pci_read_block *read_blk;
int ret;
if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
return -EINVAL;
init_completion(&comp_pkt.comp_pkt.host_event);
comp_pkt.buf = buf;
comp_pkt.len = len;
memset(&pkt, 0, sizeof(pkt));
pkt.pkt.completion_func = hv_pci_read_config_compl;
pkt.pkt.compl_ctxt = &comp_pkt;
read_blk = (struct pci_read_block *)&pkt.pkt.message;
read_blk->message_type.type = PCI_READ_BLOCK;
read_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
read_blk->block_id = block_id;
read_blk->bytes_requested = len;
ret = vmbus_sendpacket(hbus->hdev->channel, read_blk,
sizeof(*read_blk), (unsigned long)&pkt.pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event);
if (ret)
return ret;
if (comp_pkt.comp_pkt.completion_status != 0 ||
comp_pkt.bytes_returned == 0) {
dev_err(&hbus->hdev->device,
"Read Config Block failed: 0x%x, bytes_returned=%d\n",
comp_pkt.comp_pkt.completion_status,
comp_pkt.bytes_returned);
return -EIO;
}
*bytes_returned = comp_pkt.bytes_returned;
return 0;
}
/**
* hv_pci_write_config_compl() - Invoked when a response packet for a write
* config block operation arrives.
* @context: Identifies the write config operation
* @resp: The response packet itself
* @resp_packet_size: Size in bytes of the response packet
*/
static void hv_pci_write_config_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct hv_pci_compl *comp_pkt = context;
comp_pkt->completion_status = resp->status;
complete(&comp_pkt->host_event);
}
/**
* hv_write_config_block() - Sends a write config block request to the
* back-end driver running in the Hyper-V parent partition.
* @pdev: The PCI driver's representation for this device.
* @buf: Buffer from which the config block will be copied.
* @len: Size in bytes of buf.
* @block_id: Identifies the config block which is being written.
*
* Return: 0 on success, -errno on failure
*/
static int hv_write_config_block(struct pci_dev *pdev, void *buf,
unsigned int len, unsigned int block_id)
{
struct hv_pcibus_device *hbus =
container_of(pdev->bus->sysdata, struct hv_pcibus_device,
sysdata);
struct {
struct pci_packet pkt;
char buf[sizeof(struct pci_write_block)];
u32 reserved;
} pkt;
struct hv_pci_compl comp_pkt;
struct pci_write_block *write_blk;
u32 pkt_size;
int ret;
if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
return -EINVAL;
init_completion(&comp_pkt.host_event);
memset(&pkt, 0, sizeof(pkt));
pkt.pkt.completion_func = hv_pci_write_config_compl;
pkt.pkt.compl_ctxt = &comp_pkt;
write_blk = (struct pci_write_block *)&pkt.pkt.message;
write_blk->message_type.type = PCI_WRITE_BLOCK;
write_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
write_blk->block_id = block_id;
write_blk->byte_count = len;
memcpy(write_blk->bytes, buf, len);
pkt_size = offsetof(struct pci_write_block, bytes) + len;
/*
* This quirk is required on some hosts shipped around 2018, because
* these hosts don't check the pkt_size correctly (new hosts have been
* fixed since early 2019). The quirk is also safe on very old hosts
* and new hosts, because, on them, what really matters is the length
* specified in write_blk->byte_count.
*/
pkt_size += sizeof(pkt.reserved);
ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size,
(unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
ret = wait_for_response(hbus->hdev, &comp_pkt.host_event);
if (ret)
return ret;
if (comp_pkt.completion_status != 0) {
dev_err(&hbus->hdev->device,
"Write Config Block failed: 0x%x\n",
comp_pkt.completion_status);
return -EIO;
}
return 0;
}
/**
* hv_register_block_invalidate() - Invoked when a config block invalidation
* arrives from the back-end driver.
* @pdev: The PCI driver's representation for this device.
* @context: Identifies the device.
* @block_invalidate: Identifies all of the blocks being invalidated.
*
* Return: 0 on success, -errno on failure
*/
static int hv_register_block_invalidate(struct pci_dev *pdev, void *context,
void (*block_invalidate)(void *context,
u64 block_mask))
{
struct hv_pcibus_device *hbus =
container_of(pdev->bus->sysdata, struct hv_pcibus_device,
sysdata);
struct hv_pci_dev *hpdev;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
if (!hpdev)
return -ENODEV;
hpdev->block_invalidate = block_invalidate;
hpdev->invalidate_context = context;
put_pcichild(hpdev);
return 0;
}
/* Interrupt management hooks */
static void hv_int_desc_free(struct hv_pci_dev *hpdev,
struct tran_int_desc *int_desc)
{
struct pci_delete_interrupt *int_pkt;
struct {
struct pci_packet pkt;
u8 buffer[sizeof(struct pci_delete_interrupt)];
} ctxt;
if (!int_desc->vector_count) {
kfree(int_desc);
return;
}
memset(&ctxt, 0, sizeof(ctxt));
int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;
int_pkt->message_type.type =
PCI_DELETE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
int_pkt->int_desc = *int_desc;
vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt),
0, VM_PKT_DATA_INBAND, 0);
kfree(int_desc);
}
/**
* hv_msi_free() - Free the MSI.
* @domain: The interrupt domain pointer
* @info: Extra MSI-related context
* @irq: Identifies the IRQ.
*
* The Hyper-V parent partition and hypervisor are tracking the
* messages that are in use, keeping the interrupt redirection
* table up to date. This callback sends a message that frees
* the IRT entry and related tracking nonsense.
*/
static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
unsigned int irq)
{
struct hv_pcibus_device *hbus;
struct hv_pci_dev *hpdev;
struct pci_dev *pdev;
struct tran_int_desc *int_desc;
struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq);
struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
pdev = msi_desc_to_pci_dev(msi);
hbus = info->data;
int_desc = irq_data_get_irq_chip_data(irq_data);
if (!int_desc)
return;
irq_data->chip_data = NULL;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
if (!hpdev) {
kfree(int_desc);
return;
}
hv_int_desc_free(hpdev, int_desc);
put_pcichild(hpdev);
}
static void hv_irq_mask(struct irq_data *data)
{
pci_msi_mask_irq(data);
if (data->parent_data->chip->irq_mask)
irq_chip_mask_parent(data);
}
static void hv_irq_unmask(struct irq_data *data)
{
hv_arch_irq_unmask(data);
if (data->parent_data->chip->irq_unmask)
irq_chip_unmask_parent(data);
pci_msi_unmask_irq(data);
}
struct compose_comp_ctxt {
struct hv_pci_compl comp_pkt;
struct tran_int_desc int_desc;
};
static void hv_pci_compose_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct compose_comp_ctxt *comp_pkt = context;
struct pci_create_int_response *int_resp =
(struct pci_create_int_response *)resp;
if (resp_packet_size < sizeof(*int_resp)) {
comp_pkt->comp_pkt.completion_status = -1;
goto out;
}
comp_pkt->comp_pkt.completion_status = resp->status;
comp_pkt->int_desc = int_resp->int_desc;
out:
complete(&comp_pkt->comp_pkt.host_event);
}
static u32 hv_compose_msi_req_v1(
struct pci_create_interrupt *int_pkt,
u32 slot, u8 vector, u16 vector_count)
{
int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = slot;
int_pkt->int_desc.vector = vector;
int_pkt->int_desc.vector_count = vector_count;
int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
/*
* Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
* hv_irq_unmask().
*/
int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
return sizeof(*int_pkt);
}
/*
* The vCPU selected by hv_compose_multi_msi_req_get_cpu() and
* hv_compose_msi_req_get_cpu() is a "dummy" vCPU because the final vCPU to be
* interrupted is specified later in hv_irq_unmask() and communicated to Hyper-V
* via the HVCALL_RETARGET_INTERRUPT hypercall. But the choice of dummy vCPU is
* not irrelevant because Hyper-V chooses the physical CPU to handle the
* interrupts based on the vCPU specified in message sent to the vPCI VSP in
* hv_compose_msi_msg(). Hyper-V's choice of pCPU is not visible to the guest,
* but assigning too many vPCI device interrupts to the same pCPU can cause a
* performance bottleneck. So we spread out the dummy vCPUs to influence Hyper-V
* to spread out the pCPUs that it selects.
*
* For the single-MSI and MSI-X cases, it's OK for hv_compose_msi_req_get_cpu()
* to always return the same dummy vCPU, because a second call to
* hv_compose_msi_msg() contains the "real" vCPU, causing Hyper-V to choose a
* new pCPU for the interrupt. But for the multi-MSI case, the second call to
* hv_compose_msi_msg() exits without sending a message to the vPCI VSP, so the
* original dummy vCPU is used. This dummy vCPU must be round-robin'ed so that
* the pCPUs are spread out. All interrupts for a multi-MSI device end up using
* the same pCPU, even though the vCPUs will be spread out by later calls
* to hv_irq_unmask(), but that is the best we can do now.
*
* With Hyper-V in Nov 2022, the HVCALL_RETARGET_INTERRUPT hypercall does *not*
* cause Hyper-V to reselect the pCPU based on the specified vCPU. Such an
* enhancement is planned for a future version. With that enhancement, the
* dummy vCPU selection won't matter, and interrupts for the same multi-MSI
* device will be spread across multiple pCPUs.
*/
/*
* Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
* by subsequent retarget in hv_irq_unmask().
*/
static int hv_compose_msi_req_get_cpu(const struct cpumask *affinity)
{
return cpumask_first_and(affinity, cpu_online_mask);
}
/*
* Make sure the dummy vCPU values for multi-MSI don't all point to vCPU0.
*/
static int hv_compose_multi_msi_req_get_cpu(void)
{
static DEFINE_SPINLOCK(multi_msi_cpu_lock);
/* -1 means starting with CPU 0 */
static int cpu_next = -1;
unsigned long flags;
int cpu;
spin_lock_irqsave(&multi_msi_cpu_lock, flags);
cpu_next = cpumask_next_wrap(cpu_next, cpu_online_mask, nr_cpu_ids,
false);
cpu = cpu_next;
spin_unlock_irqrestore(&multi_msi_cpu_lock, flags);
return cpu;
}
static u32 hv_compose_msi_req_v2(
struct pci_create_interrupt2 *int_pkt, int cpu,
u32 slot, u8 vector, u16 vector_count)
{
int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2;
int_pkt->wslot.slot = slot;
int_pkt->int_desc.vector = vector;
int_pkt->int_desc.vector_count = vector_count;
int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
int_pkt->int_desc.processor_array[0] =
hv_cpu_number_to_vp_number(cpu);
int_pkt->int_desc.processor_count = 1;
return sizeof(*int_pkt);
}
static u32 hv_compose_msi_req_v3(
struct pci_create_interrupt3 *int_pkt, int cpu,
u32 slot, u32 vector, u16 vector_count)
{
int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE3;
int_pkt->wslot.slot = slot;
int_pkt->int_desc.vector = vector;
int_pkt->int_desc.reserved = 0;
int_pkt->int_desc.vector_count = vector_count;
int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
int_pkt->int_desc.processor_array[0] =
hv_cpu_number_to_vp_number(cpu);
int_pkt->int_desc.processor_count = 1;
return sizeof(*int_pkt);
}
/**
* hv_compose_msi_msg() - Supplies a valid MSI address/data
* @data: Everything about this MSI
* @msg: Buffer that is filled in by this function
*
* This function unpacks the IRQ looking for target CPU set, IDT
* vector and mode and sends a message to the parent partition
* asking for a mapping for that tuple in this partition. The
* response supplies a data value and address to which that data
* should be written to trigger that interrupt.
*/
static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
struct hv_pcibus_device *hbus;
struct vmbus_channel *channel;
struct hv_pci_dev *hpdev;
struct pci_bus *pbus;
struct pci_dev *pdev;
const struct cpumask *dest;
struct compose_comp_ctxt comp;
struct tran_int_desc *int_desc;
struct msi_desc *msi_desc;
/*
* vector_count should be u16: see hv_msi_desc, hv_msi_desc2
* and hv_msi_desc3. vector must be u32: see hv_msi_desc3.
*/
u16 vector_count;
u32 vector;
struct {
struct pci_packet pci_pkt;
union {
struct pci_create_interrupt v1;
struct pci_create_interrupt2 v2;
struct pci_create_interrupt3 v3;
} int_pkts;
} __packed ctxt;
bool multi_msi;
u64 trans_id;
u32 size;
int ret;
int cpu;
msi_desc = irq_data_get_msi_desc(data);
multi_msi = !msi_desc->pci.msi_attrib.is_msix &&
msi_desc->nvec_used > 1;
/* Reuse the previous allocation */
if (data->chip_data && multi_msi) {
int_desc = data->chip_data;
msg->address_hi = int_desc->address >> 32;
msg->address_lo = int_desc->address & 0xffffffff;
msg->data = int_desc->data;
return;
}
pdev = msi_desc_to_pci_dev(msi_desc);
dest = irq_data_get_effective_affinity_mask(data);
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
channel = hbus->hdev->channel;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
if (!hpdev)
goto return_null_message;
/* Free any previous message that might have already been composed. */
if (data->chip_data && !multi_msi) {
int_desc = data->chip_data;
data->chip_data = NULL;
hv_int_desc_free(hpdev, int_desc);
}
int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC);
if (!int_desc)
goto drop_reference;
if (multi_msi) {
/*
* If this is not the first MSI of Multi MSI, we already have
* a mapping. Can exit early.
*/
if (msi_desc->irq != data->irq) {
data->chip_data = int_desc;
int_desc->address = msi_desc->msg.address_lo |
(u64)msi_desc->msg.address_hi << 32;
int_desc->data = msi_desc->msg.data +
(data->irq - msi_desc->irq);
msg->address_hi = msi_desc->msg.address_hi;
msg->address_lo = msi_desc->msg.address_lo;
msg->data = int_desc->data;
put_pcichild(hpdev);
return;
}
/*
* The vector we select here is a dummy value. The correct
* value gets sent to the hypervisor in unmask(). This needs
* to be aligned with the count, and also not zero. Multi-msi
* is powers of 2 up to 32, so 32 will always work here.
*/
vector = 32;
vector_count = msi_desc->nvec_used;
cpu = hv_compose_multi_msi_req_get_cpu();
} else {
vector = hv_msi_get_int_vector(data);
vector_count = 1;
cpu = hv_compose_msi_req_get_cpu(dest);
}
/*
* hv_compose_msi_req_v1 and v2 are for x86 only, meaning 'vector'
* can't exceed u8. Cast 'vector' down to u8 for v1/v2 explicitly
* for better readability.
*/
memset(&ctxt, 0, sizeof(ctxt));
init_completion(&comp.comp_pkt.host_event);
ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
ctxt.pci_pkt.compl_ctxt = ∁
switch (hbus->protocol_version) {
case PCI_PROTOCOL_VERSION_1_1:
size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
hpdev->desc.win_slot.slot,
(u8)vector,
vector_count);
break;
case PCI_PROTOCOL_VERSION_1_2:
case PCI_PROTOCOL_VERSION_1_3:
size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,
cpu,
hpdev->desc.win_slot.slot,
(u8)vector,
vector_count);
break;
case PCI_PROTOCOL_VERSION_1_4:
size = hv_compose_msi_req_v3(&ctxt.int_pkts.v3,
cpu,
hpdev->desc.win_slot.slot,
vector,
vector_count);
break;
default:
/* As we only negotiate protocol versions known to this driver,
* this path should never hit. However, this is it not a hot
* path so we print a message to aid future updates.
*/
dev_err(&hbus->hdev->device,
"Unexpected vPCI protocol, update driver.");
goto free_int_desc;
}
ret = vmbus_sendpacket_getid(hpdev->hbus->hdev->channel, &ctxt.int_pkts,
size, (unsigned long)&ctxt.pci_pkt,
&trans_id, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret) {
dev_err(&hbus->hdev->device,
"Sending request for interrupt failed: 0x%x",
comp.comp_pkt.completion_status);
goto free_int_desc;
}
/*
* Prevents hv_pci_onchannelcallback() from running concurrently
* in the tasklet.
*/
tasklet_disable_in_atomic(&channel->callback_event);
/*
* Since this function is called with IRQ locks held, can't
* do normal wait for completion; instead poll.
*/
while (!try_wait_for_completion(&comp.comp_pkt.host_event)) {
unsigned long flags;
/* 0xFFFF means an invalid PCI VENDOR ID. */
if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) {
dev_err_once(&hbus->hdev->device,
"the device has gone\n");
goto enable_tasklet;
}
/*
* Make sure that the ring buffer data structure doesn't get
* freed while we dereference the ring buffer pointer. Test
* for the channel's onchannel_callback being NULL within a
* sched_lock critical section. See also the inline comments
* in vmbus_reset_channel_cb().
*/
spin_lock_irqsave(&channel->sched_lock, flags);
if (unlikely(channel->onchannel_callback == NULL)) {
spin_unlock_irqrestore(&channel->sched_lock, flags);
goto enable_tasklet;
}
hv_pci_onchannelcallback(hbus);
spin_unlock_irqrestore(&channel->sched_lock, flags);
udelay(100);
}
tasklet_enable(&channel->callback_event);
if (comp.comp_pkt.completion_status < 0) {
dev_err(&hbus->hdev->device,
"Request for interrupt failed: 0x%x",
comp.comp_pkt.completion_status);
goto free_int_desc;
}
/*
* Record the assignment so that this can be unwound later. Using
* irq_set_chip_data() here would be appropriate, but the lock it takes
* is already held.
*/
*int_desc = comp.int_desc;
data->chip_data = int_desc;
/* Pass up the result. */
msg->address_hi = comp.int_desc.address >> 32;
msg->address_lo = comp.int_desc.address & 0xffffffff;
msg->data = comp.int_desc.data;
put_pcichild(hpdev);
return;
enable_tasklet:
tasklet_enable(&channel->callback_event);
/*
* The completion packet on the stack becomes invalid after 'return';
* remove the ID from the VMbus requestor if the identifier is still
* mapped to/associated with the packet. (The identifier could have
* been 're-used', i.e., already removed and (re-)mapped.)
*
* Cf. hv_pci_onchannelcallback().
*/
vmbus_request_addr_match(channel, trans_id, (unsigned long)&ctxt.pci_pkt);
free_int_desc:
kfree(int_desc);
drop_reference:
put_pcichild(hpdev);
return_null_message:
msg->address_hi = 0;
msg->address_lo = 0;
msg->data = 0;
}
/* HW Interrupt Chip Descriptor */
static struct irq_chip hv_msi_irq_chip = {
.name = "Hyper-V PCIe MSI",
.irq_compose_msi_msg = hv_compose_msi_msg,
.irq_set_affinity = irq_chip_set_affinity_parent,
#ifdef CONFIG_X86
.irq_ack = irq_chip_ack_parent,
#elif defined(CONFIG_ARM64)
.irq_eoi = irq_chip_eoi_parent,
#endif
.irq_mask = hv_irq_mask,
.irq_unmask = hv_irq_unmask,
};
static struct msi_domain_ops hv_msi_ops = {
.msi_prepare = hv_msi_prepare,
.msi_free = hv_msi_free,
};
/**
* hv_pcie_init_irq_domain() - Initialize IRQ domain
* @hbus: The root PCI bus
*
* This function creates an IRQ domain which will be used for
* interrupts from devices that have been passed through. These
* devices only support MSI and MSI-X, not line-based interrupts
* or simulations of line-based interrupts through PCIe's
* fabric-layer messages. Because interrupts are remapped, we
* can support multi-message MSI here.
*
* Return: '0' on success and error value on failure
*/
static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
{
hbus->msi_info.chip = &hv_msi_irq_chip;
hbus->msi_info.ops = &hv_msi_ops;
hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
MSI_FLAG_PCI_MSIX);
hbus->msi_info.handler = FLOW_HANDLER;
hbus->msi_info.handler_name = FLOW_NAME;
hbus->msi_info.data = hbus;
hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode,
&hbus->msi_info,
hv_pci_get_root_domain());
if (!hbus->irq_domain) {
dev_err(&hbus->hdev->device,
"Failed to build an MSI IRQ domain\n");
return -ENODEV;
}
dev_set_msi_domain(&hbus->bridge->dev, hbus->irq_domain);
return 0;
}
/**
* get_bar_size() - Get the address space consumed by a BAR
* @bar_val: Value that a BAR returned after -1 was written
* to it.
*
* This function returns the size of the BAR, rounded up to 1
* page. It has to be rounded up because the hypervisor's page
* table entry that maps the BAR into the VM can't specify an
* offset within a page. The invariant is that the hypervisor
* must place any BARs of smaller than page length at the
* beginning of a page.
*
* Return: Size in bytes of the consumed MMIO space.
*/
static u64 get_bar_size(u64 bar_val)
{
return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)),
PAGE_SIZE);
}
/**
* survey_child_resources() - Total all MMIO requirements
* @hbus: Root PCI bus, as understood by this driver
*/
static void survey_child_resources(struct hv_pcibus_device *hbus)
{
struct hv_pci_dev *hpdev;
resource_size_t bar_size = 0;
unsigned long flags;
struct completion *event;
u64 bar_val;
int i;
/* If nobody is waiting on the answer, don't compute it. */
event = xchg(&hbus->survey_event, NULL);
if (!event)
return;
/* If the answer has already been computed, go with it. */
if (hbus->low_mmio_space || hbus->high_mmio_space) {
complete(event);
return;
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* Due to an interesting quirk of the PCI spec, all memory regions
* for a child device are a power of 2 in size and aligned in memory,
* so it's sufficient to just add them up without tracking alignment.
*/
list_for_each_entry(hpdev, &hbus->children, list_entry) {
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO)
dev_err(&hbus->hdev->device,
"There's an I/O BAR in this list!\n");
if (hpdev->probed_bar[i] != 0) {
/*
* A probed BAR has all the upper bits set that
* can be changed.
*/
bar_val = hpdev->probed_bar[i];
if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
bar_val |=
((u64)hpdev->probed_bar[++i] << 32);
else
bar_val |= 0xffffffff00000000ULL;
bar_size = get_bar_size(bar_val);
if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
hbus->high_mmio_space += bar_size;
else
hbus->low_mmio_space += bar_size;
}
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
complete(event);
}
/**
* prepopulate_bars() - Fill in BARs with defaults
* @hbus: Root PCI bus, as understood by this driver
*
* The core PCI driver code seems much, much happier if the BARs
* for a device have values upon first scan. So fill them in.
* The algorithm below works down from large sizes to small,
* attempting to pack the assignments optimally. The assumption,
* enforced in other parts of the code, is that the beginning of
* the memory-mapped I/O space will be aligned on the largest
* BAR size.
*/
static void prepopulate_bars(struct hv_pcibus_device *hbus)
{
resource_size_t high_size = 0;
resource_size_t low_size = 0;
resource_size_t high_base = 0;
resource_size_t low_base = 0;
resource_size_t bar_size;
struct hv_pci_dev *hpdev;
unsigned long flags;
u64 bar_val;
u32 command;
bool high;
int i;
if (hbus->low_mmio_space) {
low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
low_base = hbus->low_mmio_res->start;
}
if (hbus->high_mmio_space) {
high_size = 1ULL <<
(63 - __builtin_clzll(hbus->high_mmio_space));
high_base = hbus->high_mmio_res->start;
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* Clear the memory enable bit, in case it's already set. This occurs
* in the suspend path of hibernation, where the device is suspended,
* resumed and suspended again: see hibernation_snapshot() and
* hibernation_platform_enter().
*
* If the memory enable bit is already set, Hyper-V silently ignores
* the below BAR updates, and the related PCI device driver can not
* work, because reading from the device register(s) always returns
* 0xFFFFFFFF (PCI_ERROR_RESPONSE).
*/
list_for_each_entry(hpdev, &hbus->children, list_entry) {
_hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command);
command &= ~PCI_COMMAND_MEMORY;
_hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command);
}
/* Pick addresses for the BARs. */
do {
list_for_each_entry(hpdev, &hbus->children, list_entry) {
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
bar_val = hpdev->probed_bar[i];
if (bar_val == 0)
continue;
high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64;
if (high) {
bar_val |=
((u64)hpdev->probed_bar[i + 1]
<< 32);
} else {
bar_val |= 0xffffffffULL << 32;
}
bar_size = get_bar_size(bar_val);
if (high) {
if (high_size != bar_size) {
i++;
continue;
}
_hv_pcifront_write_config(hpdev,
PCI_BASE_ADDRESS_0 + (4 * i),
4,
(u32)(high_base & 0xffffff00));
i++;
_hv_pcifront_write_config(hpdev,
PCI_BASE_ADDRESS_0 + (4 * i),
4, (u32)(high_base >> 32));
high_base += bar_size;
} else {
if (low_size != bar_size)
continue;
_hv_pcifront_write_config(hpdev,
PCI_BASE_ADDRESS_0 + (4 * i),
4,
(u32)(low_base & 0xffffff00));
low_base += bar_size;
}
}
if (high_size <= 1 && low_size <= 1) {
/*
* No need to set the PCI_COMMAND_MEMORY bit as
* the core PCI driver doesn't require the bit
* to be pre-set. Actually here we intentionally
* keep the bit off so that the PCI BAR probing
* in the core PCI driver doesn't cause Hyper-V
* to unnecessarily unmap/map the virtual BARs
* from/to the physical BARs multiple times.
* This reduces the VM boot time significantly
* if the BAR sizes are huge.
*/
break;
}
}
high_size >>= 1;
low_size >>= 1;
} while (high_size || low_size);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
}
/*
* Assign entries in sysfs pci slot directory.
*
* Note that this function does not need to lock the children list
* because it is called from pci_devices_present_work which
* is serialized with hv_eject_device_work because they are on the
* same ordered workqueue. Therefore hbus->children list will not change
* even when pci_create_slot sleeps.
*/
static void hv_pci_assign_slots(struct hv_pcibus_device *hbus)
{
struct hv_pci_dev *hpdev;
char name[SLOT_NAME_SIZE];
int slot_nr;
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if (hpdev->pci_slot)
continue;
slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot));
snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser);
hpdev->pci_slot = pci_create_slot(hbus->bridge->bus, slot_nr,
name, NULL);
if (IS_ERR(hpdev->pci_slot)) {
pr_warn("pci_create slot %s failed\n", name);
hpdev->pci_slot = NULL;
}
}
}
/*
* Remove entries in sysfs pci slot directory.
*/
static void hv_pci_remove_slots(struct hv_pcibus_device *hbus)
{
struct hv_pci_dev *hpdev;
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if (!hpdev->pci_slot)
continue;
pci_destroy_slot(hpdev->pci_slot);
hpdev->pci_slot = NULL;
}
}
/*
* Set NUMA node for the devices on the bus
*/
static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus)
{
struct pci_dev *dev;
struct pci_bus *bus = hbus->bridge->bus;
struct hv_pci_dev *hv_dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
hv_dev = get_pcichild_wslot(hbus, devfn_to_wslot(dev->devfn));
if (!hv_dev)
continue;
if (hv_dev->desc.flags & HV_PCI_DEVICE_FLAG_NUMA_AFFINITY &&
hv_dev->desc.virtual_numa_node < num_possible_nodes())
/*
* The kernel may boot with some NUMA nodes offline
* (e.g. in a KDUMP kernel) or with NUMA disabled via
* "numa=off". In those cases, adjust the host provided
* NUMA node to a valid NUMA node used by the kernel.
*/
set_dev_node(&dev->dev,
numa_map_to_online_node(
hv_dev->desc.virtual_numa_node));
put_pcichild(hv_dev);
}
}
/**
* create_root_hv_pci_bus() - Expose a new root PCI bus
* @hbus: Root PCI bus, as understood by this driver
*
* Return: 0 on success, -errno on failure
*/
static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
{
int error;
struct pci_host_bridge *bridge = hbus->bridge;
bridge->dev.parent = &hbus->hdev->device;
bridge->sysdata = &hbus->sysdata;
bridge->ops = &hv_pcifront_ops;
error = pci_scan_root_bus_bridge(bridge);
if (error)
return error;
pci_lock_rescan_remove();
hv_pci_assign_numa_node(hbus);
pci_bus_assign_resources(bridge->bus);
hv_pci_assign_slots(hbus);
pci_bus_add_devices(bridge->bus);
pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
}
struct q_res_req_compl {
struct completion host_event;
struct hv_pci_dev *hpdev;
};
/**
* q_resource_requirements() - Query Resource Requirements
* @context: The completion context.
* @resp: The response that came from the host.
* @resp_packet_size: The size in bytes of resp.
*
* This function is invoked on completion of a Query Resource
* Requirements packet.
*/
static void q_resource_requirements(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct q_res_req_compl *completion = context;
struct pci_q_res_req_response *q_res_req =
(struct pci_q_res_req_response *)resp;
s32 status;
int i;
status = (resp_packet_size < sizeof(*q_res_req)) ? -1 : resp->status;
if (status < 0) {
dev_err(&completion->hpdev->hbus->hdev->device,
"query resource requirements failed: %x\n",
status);
} else {
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
completion->hpdev->probed_bar[i] =
q_res_req->probed_bar[i];
}
}
complete(&completion->host_event);
}
/**
* new_pcichild_device() - Create a new child device
* @hbus: The internal struct tracking this root PCI bus.
* @desc: The information supplied so far from the host
* about the device.
*
* This function creates the tracking structure for a new child
* device and kicks off the process of figuring out what it is.
*
* Return: Pointer to the new tracking struct
*/
static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
struct hv_pcidev_description *desc)
{
struct hv_pci_dev *hpdev;
struct pci_child_message *res_req;
struct q_res_req_compl comp_pkt;
struct {
struct pci_packet init_packet;
u8 buffer[sizeof(struct pci_child_message)];
} pkt;
unsigned long flags;
int ret;
hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL);
if (!hpdev)
return NULL;
hpdev->hbus = hbus;
memset(&pkt, 0, sizeof(pkt));
init_completion(&comp_pkt.host_event);
comp_pkt.hpdev = hpdev;
pkt.init_packet.compl_ctxt = &comp_pkt;
pkt.init_packet.completion_func = q_resource_requirements;
res_req = (struct pci_child_message *)&pkt.init_packet.message;
res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS;
res_req->wslot.slot = desc->win_slot.slot;
ret = vmbus_sendpacket(hbus->hdev->channel, res_req,
sizeof(struct pci_child_message),
(unsigned long)&pkt.init_packet,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
goto error;
if (wait_for_response(hbus->hdev, &comp_pkt.host_event))
goto error;
hpdev->desc = *desc;
refcount_set(&hpdev->refs, 1);
get_pcichild(hpdev);
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_add_tail(&hpdev->list_entry, &hbus->children);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
return hpdev;
error:
kfree(hpdev);
return NULL;
}
/**
* get_pcichild_wslot() - Find device from slot
* @hbus: Root PCI bus, as understood by this driver
* @wslot: Location on the bus
*
* This function looks up a PCI device and returns the internal
* representation of it. It acquires a reference on it, so that
* the device won't be deleted while somebody is using it. The
* caller is responsible for calling put_pcichild() to release
* this reference.
*
* Return: Internal representation of a PCI device
*/
static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
u32 wslot)
{
unsigned long flags;
struct hv_pci_dev *iter, *hpdev = NULL;
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry(iter, &hbus->children, list_entry) {
if (iter->desc.win_slot.slot == wslot) {
hpdev = iter;
get_pcichild(hpdev);
break;
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
return hpdev;
}
/**
* pci_devices_present_work() - Handle new list of child devices
* @work: Work struct embedded in struct hv_dr_work
*
* "Bus Relations" is the Windows term for "children of this
* bus." The terminology is preserved here for people trying to
* debug the interaction between Hyper-V and Linux. This
* function is called when the parent partition reports a list
* of functions that should be observed under this PCI Express
* port (bus).
*
* This function updates the list, and must tolerate being
* called multiple times with the same information. The typical
* number of child devices is one, with very atypical cases
* involving three or four, so the algorithms used here can be
* simple and inefficient.
*
* It must also treat the omission of a previously observed device as
* notification that the device no longer exists.
*
* Note that this function is serialized with hv_eject_device_work(),
* because both are pushed to the ordered workqueue hbus->wq.
*/
static void pci_devices_present_work(struct work_struct *work)
{
u32 child_no;
bool found;
struct hv_pcidev_description *new_desc;
struct hv_pci_dev *hpdev;
struct hv_pcibus_device *hbus;
struct list_head removed;
struct hv_dr_work *dr_wrk;
struct hv_dr_state *dr = NULL;
unsigned long flags;
dr_wrk = container_of(work, struct hv_dr_work, wrk);
hbus = dr_wrk->bus;
kfree(dr_wrk);
INIT_LIST_HEAD(&removed);
/* Pull this off the queue and process it if it was the last one. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
while (!list_empty(&hbus->dr_list)) {
dr = list_first_entry(&hbus->dr_list, struct hv_dr_state,
list_entry);
list_del(&dr->list_entry);
/* Throw this away if the list still has stuff in it. */
if (!list_empty(&hbus->dr_list)) {
kfree(dr);
continue;
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (!dr)
return;
mutex_lock(&hbus->state_lock);
/* First, mark all existing children as reported missing. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry(hpdev, &hbus->children, list_entry) {
hpdev->reported_missing = true;
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
/* Next, add back any reported devices. */
for (child_no = 0; child_no < dr->device_count; child_no++) {
found = false;
new_desc = &dr->func[child_no];
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) &&
(hpdev->desc.v_id == new_desc->v_id) &&
(hpdev->desc.d_id == new_desc->d_id) &&
(hpdev->desc.ser == new_desc->ser)) {
hpdev->reported_missing = false;
found = true;
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (!found) {
hpdev = new_pcichild_device(hbus, new_desc);
if (!hpdev)
dev_err(&hbus->hdev->device,
"couldn't record a child device.\n");
}
}
/* Move missing children to a list on the stack. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
do {
found = false;
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if (hpdev->reported_missing) {
found = true;
put_pcichild(hpdev);
list_move_tail(&hpdev->list_entry, &removed);
break;
}
}
} while (found);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
/* Delete everything that should no longer exist. */
while (!list_empty(&removed)) {
hpdev = list_first_entry(&removed, struct hv_pci_dev,
list_entry);
list_del(&hpdev->list_entry);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
put_pcichild(hpdev);
}
switch (hbus->state) {
case hv_pcibus_installed:
/*
* Tell the core to rescan bus
* because there may have been changes.
*/
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->bridge->bus);
hv_pci_assign_numa_node(hbus);
hv_pci_assign_slots(hbus);
pci_unlock_rescan_remove();
break;
case hv_pcibus_init:
case hv_pcibus_probed:
survey_child_resources(hbus);
break;
default:
break;
}
mutex_unlock(&hbus->state_lock);
kfree(dr);
}
/**
* hv_pci_start_relations_work() - Queue work to start device discovery
* @hbus: Root PCI bus, as understood by this driver
* @dr: The list of children returned from host
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
struct hv_dr_state *dr)
{
struct hv_dr_work *dr_wrk;
unsigned long flags;
bool pending_dr;
if (hbus->state == hv_pcibus_removing) {
dev_info(&hbus->hdev->device,
"PCI VMBus BUS_RELATIONS: ignored\n");
return -ENOENT;
}
dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
if (!dr_wrk)
return -ENOMEM;
INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
dr_wrk->bus = hbus;
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* If pending_dr is true, we have already queued a work,
* which will see the new dr. Otherwise, we need to
* queue a new work.
*/
pending_dr = !list_empty(&hbus->dr_list);
list_add_tail(&dr->list_entry, &hbus->dr_list);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (pending_dr)
kfree(dr_wrk);
else
queue_work(hbus->wq, &dr_wrk->wrk);
return 0;
}
/**
* hv_pci_devices_present() - Handle list of new children
* @hbus: Root PCI bus, as understood by this driver
* @relations: Packet from host listing children
*
* Process a new list of devices on the bus. The list of devices is
* discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
* whenever a new list of devices for this bus appears.
*/
static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
struct pci_bus_relations *relations)
{
struct hv_dr_state *dr;
int i;
dr = kzalloc(struct_size(dr, func, relations->device_count),
GFP_NOWAIT);
if (!dr)
return;
dr->device_count = relations->device_count;
for (i = 0; i < dr->device_count; i++) {
dr->func[i].v_id = relations->func[i].v_id;
dr->func[i].d_id = relations->func[i].d_id;
dr->func[i].rev = relations->func[i].rev;
dr->func[i].prog_intf = relations->func[i].prog_intf;
dr->func[i].subclass = relations->func[i].subclass;
dr->func[i].base_class = relations->func[i].base_class;
dr->func[i].subsystem_id = relations->func[i].subsystem_id;
dr->func[i].win_slot = relations->func[i].win_slot;
dr->func[i].ser = relations->func[i].ser;
}
if (hv_pci_start_relations_work(hbus, dr))
kfree(dr);
}
/**
* hv_pci_devices_present2() - Handle list of new children
* @hbus: Root PCI bus, as understood by this driver
* @relations: Packet from host listing children
*
* This function is the v2 version of hv_pci_devices_present()
*/
static void hv_pci_devices_present2(struct hv_pcibus_device *hbus,
struct pci_bus_relations2 *relations)
{
struct hv_dr_state *dr;
int i;
dr = kzalloc(struct_size(dr, func, relations->device_count),
GFP_NOWAIT);
if (!dr)
return;
dr->device_count = relations->device_count;
for (i = 0; i < dr->device_count; i++) {
dr->func[i].v_id = relations->func[i].v_id;
dr->func[i].d_id = relations->func[i].d_id;
dr->func[i].rev = relations->func[i].rev;
dr->func[i].prog_intf = relations->func[i].prog_intf;
dr->func[i].subclass = relations->func[i].subclass;
dr->func[i].base_class = relations->func[i].base_class;
dr->func[i].subsystem_id = relations->func[i].subsystem_id;
dr->func[i].win_slot = relations->func[i].win_slot;
dr->func[i].ser = relations->func[i].ser;
dr->func[i].flags = relations->func[i].flags;
dr->func[i].virtual_numa_node =
relations->func[i].virtual_numa_node;
}
if (hv_pci_start_relations_work(hbus, dr))
kfree(dr);
}
/**
* hv_eject_device_work() - Asynchronously handles ejection
* @work: Work struct embedded in internal device struct
*
* This function handles ejecting a device. Windows will
* attempt to gracefully eject a device, waiting 60 seconds to
* hear back from the guest OS that this completed successfully.
* If this timer expires, the device will be forcibly removed.
*/
static void hv_eject_device_work(struct work_struct *work)
{
struct pci_eject_response *ejct_pkt;
struct hv_pcibus_device *hbus;
struct hv_pci_dev *hpdev;
struct pci_dev *pdev;
unsigned long flags;
int wslot;
struct {
struct pci_packet pkt;
u8 buffer[sizeof(struct pci_eject_response)];
} ctxt;
hpdev = container_of(work, struct hv_pci_dev, wrk);
hbus = hpdev->hbus;
mutex_lock(&hbus->state_lock);
/*
* Ejection can come before or after the PCI bus has been set up, so
* attempt to find it and tear down the bus state, if it exists. This
* must be done without constructs like pci_domain_nr(hbus->bridge->bus)
* because hbus->bridge->bus may not exist yet.
*/
wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
pdev = pci_get_domain_bus_and_slot(hbus->bridge->domain_nr, 0, wslot);
if (pdev) {
pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
pci_unlock_rescan_remove();
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_del(&hpdev->list_entry);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
memset(&ctxt, 0, sizeof(ctxt));
ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
sizeof(*ejct_pkt), 0,
VM_PKT_DATA_INBAND, 0);
/* For the get_pcichild() in hv_pci_eject_device() */
put_pcichild(hpdev);
/* For the two refs got in new_pcichild_device() */
put_pcichild(hpdev);
put_pcichild(hpdev);
/* hpdev has been freed. Do not use it any more. */
mutex_unlock(&hbus->state_lock);
}
/**
* hv_pci_eject_device() - Handles device ejection
* @hpdev: Internal device tracking struct
*
* This function is invoked when an ejection packet arrives. It
* just schedules work so that we don't re-enter the packet
* delivery code handling the ejection.
*/
static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
{
struct hv_pcibus_device *hbus = hpdev->hbus;
struct hv_device *hdev = hbus->hdev;
if (hbus->state == hv_pcibus_removing) {
dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n");
return;
}
get_pcichild(hpdev);
INIT_WORK(&hpdev->wrk, hv_eject_device_work);
queue_work(hbus->wq, &hpdev->wrk);
}
/**
* hv_pci_onchannelcallback() - Handles incoming packets
* @context: Internal bus tracking struct
*
* This function is invoked whenever the host sends a packet to
* this channel (which is private to this root PCI bus).
*/
static void hv_pci_onchannelcallback(void *context)
{
const int packet_size = 0x100;
int ret;
struct hv_pcibus_device *hbus = context;
struct vmbus_channel *chan = hbus->hdev->channel;
u32 bytes_recvd;
u64 req_id, req_addr;
struct vmpacket_descriptor *desc;
unsigned char *buffer;
int bufferlen = packet_size;
struct pci_packet *comp_packet;
struct pci_response *response;
struct pci_incoming_message *new_message;
struct pci_bus_relations *bus_rel;
struct pci_bus_relations2 *bus_rel2;
struct pci_dev_inval_block *inval;
struct pci_dev_incoming *dev_message;
struct hv_pci_dev *hpdev;
unsigned long flags;
buffer = kmalloc(bufferlen, GFP_ATOMIC);
if (!buffer)
return;
while (1) {
ret = vmbus_recvpacket_raw(chan, buffer, bufferlen,
&bytes_recvd, &req_id);
if (ret == -ENOBUFS) {
kfree(buffer);
/* Handle large packet */
bufferlen = bytes_recvd;
buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
if (!buffer)
return;
continue;
}
/* Zero length indicates there are no more packets. */
if (ret || !bytes_recvd)
break;
/*
* All incoming packets must be at least as large as a
* response.
*/
if (bytes_recvd <= sizeof(struct pci_response))
continue;
desc = (struct vmpacket_descriptor *)buffer;
switch (desc->type) {
case VM_PKT_COMP:
lock_requestor(chan, flags);
req_addr = __vmbus_request_addr_match(chan, req_id,
VMBUS_RQST_ADDR_ANY);
if (req_addr == VMBUS_RQST_ERROR) {
unlock_requestor(chan, flags);
dev_err(&hbus->hdev->device,
"Invalid transaction ID %llx\n",
req_id);
break;
}
comp_packet = (struct pci_packet *)req_addr;
response = (struct pci_response *)buffer;
/*
* Call ->completion_func() within the critical section to make
* sure that the packet pointer is still valid during the call:
* here 'valid' means that there's a task still waiting for the
* completion, and that the packet data is still on the waiting
* task's stack. Cf. hv_compose_msi_msg().
*/
comp_packet->completion_func(comp_packet->compl_ctxt,
response,
bytes_recvd);
unlock_requestor(chan, flags);
break;
case VM_PKT_DATA_INBAND:
new_message = (struct pci_incoming_message *)buffer;
switch (new_message->message_type.type) {
case PCI_BUS_RELATIONS:
bus_rel = (struct pci_bus_relations *)buffer;
if (bytes_recvd < sizeof(*bus_rel) ||
bytes_recvd <
struct_size(bus_rel, func,
bus_rel->device_count)) {
dev_err(&hbus->hdev->device,
"bus relations too small\n");
break;
}
hv_pci_devices_present(hbus, bus_rel);
break;
case PCI_BUS_RELATIONS2:
bus_rel2 = (struct pci_bus_relations2 *)buffer;
if (bytes_recvd < sizeof(*bus_rel2) ||
bytes_recvd <
struct_size(bus_rel2, func,
bus_rel2->device_count)) {
dev_err(&hbus->hdev->device,
"bus relations v2 too small\n");
break;
}
hv_pci_devices_present2(hbus, bus_rel2);
break;
case PCI_EJECT:
dev_message = (struct pci_dev_incoming *)buffer;
if (bytes_recvd < sizeof(*dev_message)) {
dev_err(&hbus->hdev->device,
"eject message too small\n");
break;
}
hpdev = get_pcichild_wslot(hbus,
dev_message->wslot.slot);
if (hpdev) {
hv_pci_eject_device(hpdev);
put_pcichild(hpdev);
}
break;
case PCI_INVALIDATE_BLOCK:
inval = (struct pci_dev_inval_block *)buffer;
if (bytes_recvd < sizeof(*inval)) {
dev_err(&hbus->hdev->device,
"invalidate message too small\n");
break;
}
hpdev = get_pcichild_wslot(hbus,
inval->wslot.slot);
if (hpdev) {
if (hpdev->block_invalidate) {
hpdev->block_invalidate(
hpdev->invalidate_context,
inval->block_mask);
}
put_pcichild(hpdev);
}
break;
default:
dev_warn(&hbus->hdev->device,
"Unimplemented protocol message %x\n",
new_message->message_type.type);
break;
}
break;
default:
dev_err(&hbus->hdev->device,
"unhandled packet type %d, tid %llx len %d\n",
desc->type, req_id, bytes_recvd);
break;
}
}
kfree(buffer);
}
/**
* hv_pci_protocol_negotiation() - Set up protocol
* @hdev: VMBus's tracking struct for this root PCI bus.
* @version: Array of supported channel protocol versions in
* the order of probing - highest go first.
* @num_version: Number of elements in the version array.
*
* This driver is intended to support running on Windows 10
* (server) and later versions. It will not run on earlier
* versions, as they assume that many of the operations which
* Linux needs accomplished with a spinlock held were done via
* asynchronous messaging via VMBus. Windows 10 increases the
* surface area of PCI emulation so that these actions can take
* place by suspending a virtual processor for their duration.
*
* This function negotiates the channel protocol version,
* failing if the host doesn't support the necessary protocol
* level.
*/
static int hv_pci_protocol_negotiation(struct hv_device *hdev,
enum pci_protocol_version_t version[],
int num_version)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_version_request *version_req;
struct hv_pci_compl comp_pkt;
struct pci_packet *pkt;
int ret;
int i;
/*
* Initiate the handshake with the host and negotiate
* a version that the host can support. We start with the
* highest version number and go down if the host cannot
* support it.
*/
pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
version_req = (struct pci_version_request *)&pkt->message;
version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
for (i = 0; i < num_version; i++) {
version_req->protocol_version = version[i];
ret = vmbus_sendpacket(hdev->channel, version_req,
sizeof(struct pci_version_request),
(unsigned long)pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (!ret)
ret = wait_for_response(hdev, &comp_pkt.host_event);
if (ret) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed to request version: %d",
ret);
goto exit;
}
if (comp_pkt.completion_status >= 0) {
hbus->protocol_version = version[i];
dev_info(&hdev->device,
"PCI VMBus probing: Using version %#x\n",
hbus->protocol_version);
goto exit;
}
if (comp_pkt.completion_status != STATUS_REVISION_MISMATCH) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed version request: %#x",
comp_pkt.completion_status);
ret = -EPROTO;
goto exit;
}
reinit_completion(&comp_pkt.host_event);
}
dev_err(&hdev->device,
"PCI pass-through VSP failed to find supported version");
ret = -EPROTO;
exit:
kfree(pkt);
return ret;
}
/**
* hv_pci_free_bridge_windows() - Release memory regions for the
* bus
* @hbus: Root PCI bus, as understood by this driver
*/
static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus)
{
/*
* Set the resources back to the way they looked when they
* were allocated by setting IORESOURCE_BUSY again.
*/
if (hbus->low_mmio_space && hbus->low_mmio_res) {
hbus->low_mmio_res->flags |= IORESOURCE_BUSY;
vmbus_free_mmio(hbus->low_mmio_res->start,
resource_size(hbus->low_mmio_res));
}
if (hbus->high_mmio_space && hbus->high_mmio_res) {
hbus->high_mmio_res->flags |= IORESOURCE_BUSY;
vmbus_free_mmio(hbus->high_mmio_res->start,
resource_size(hbus->high_mmio_res));
}
}
/**
* hv_pci_allocate_bridge_windows() - Allocate memory regions
* for the bus
* @hbus: Root PCI bus, as understood by this driver
*
* This function calls vmbus_allocate_mmio(), which is itself a
* bit of a compromise. Ideally, we might change the pnp layer
* in the kernel such that it comprehends either PCI devices
* which are "grandchildren of ACPI," with some intermediate bus
* node (in this case, VMBus) or change it such that it
* understands VMBus. The pnp layer, however, has been declared
* deprecated, and not subject to change.
*
* The workaround, implemented here, is to ask VMBus to allocate
* MMIO space for this bus. VMBus itself knows which ranges are
* appropriate by looking at its own ACPI objects. Then, after
* these ranges are claimed, they're modified to look like they
* would have looked if the ACPI and pnp code had allocated
* bridge windows. These descriptors have to exist in this form
* in order to satisfy the code which will get invoked when the
* endpoint PCI function driver calls request_mem_region() or
* request_mem_region_exclusive().
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus)
{
resource_size_t align;
int ret;
if (hbus->low_mmio_space) {
align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0,
(u64)(u32)0xffffffff,
hbus->low_mmio_space,
align, false);
if (ret) {
dev_err(&hbus->hdev->device,
"Need %#llx of low MMIO space. Consider reconfiguring the VM.\n",
hbus->low_mmio_space);
return ret;
}
/* Modify this resource to become a bridge window. */
hbus->low_mmio_res->flags |= IORESOURCE_WINDOW;
hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY;
pci_add_resource(&hbus->bridge->windows, hbus->low_mmio_res);
}
if (hbus->high_mmio_space) {
align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space));
ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev,
0x100000000, -1,
hbus->high_mmio_space, align,
false);
if (ret) {
dev_err(&hbus->hdev->device,
"Need %#llx of high MMIO space. Consider reconfiguring the VM.\n",
hbus->high_mmio_space);
goto release_low_mmio;
}
/* Modify this resource to become a bridge window. */
hbus->high_mmio_res->flags |= IORESOURCE_WINDOW;
hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY;
pci_add_resource(&hbus->bridge->windows, hbus->high_mmio_res);
}
return 0;
release_low_mmio:
if (hbus->low_mmio_res) {
vmbus_free_mmio(hbus->low_mmio_res->start,
resource_size(hbus->low_mmio_res));
}
return ret;
}
/**
* hv_allocate_config_window() - Find MMIO space for PCI Config
* @hbus: Root PCI bus, as understood by this driver
*
* This function claims memory-mapped I/O space for accessing
* configuration space for the functions on this bus.
*
* Return: 0 on success, -errno on failure
*/
static int hv_allocate_config_window(struct hv_pcibus_device *hbus)
{
int ret;
/*
* Set up a region of MMIO space to use for accessing configuration
* space.
*/
ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1,
PCI_CONFIG_MMIO_LENGTH, 0x1000, false);
if (ret)
return ret;
/*
* vmbus_allocate_mmio() gets used for allocating both device endpoint
* resource claims (those which cannot be overlapped) and the ranges
* which are valid for the children of this bus, which are intended
* to be overlapped by those children. Set the flag on this claim
* meaning that this region can't be overlapped.
*/
hbus->mem_config->flags |= IORESOURCE_BUSY;
return 0;
}
static void hv_free_config_window(struct hv_pcibus_device *hbus)
{
vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
}
static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs);
/**
* hv_pci_enter_d0() - Bring the "bus" into the D0 power state
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_enter_d0(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_bus_d0_entry *d0_entry;
struct hv_pci_compl comp_pkt;
struct pci_packet *pkt;
bool retry = true;
int ret;
enter_d0_retry:
/*
* Tell the host that the bus is ready to use, and moved into the
* powered-on state. This includes telling the host which region
* of memory-mapped I/O space has been chosen for configuration space
* access.
*/
pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
d0_entry = (struct pci_bus_d0_entry *)&pkt->message;
d0_entry->message_type.type = PCI_BUS_D0ENTRY;
d0_entry->mmio_base = hbus->mem_config->start;
ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),
(unsigned long)pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (!ret)
ret = wait_for_response(hdev, &comp_pkt.host_event);
if (ret)
goto exit;
/*
* In certain case (Kdump) the pci device of interest was
* not cleanly shut down and resource is still held on host
* side, the host could return invalid device status.
* We need to explicitly request host to release the resource
* and try to enter D0 again.
*/
if (comp_pkt.completion_status < 0 && retry) {
retry = false;
dev_err(&hdev->device, "Retrying D0 Entry\n");
/*
* Hv_pci_bus_exit() calls hv_send_resource_released()
* to free up resources of its child devices.
* In the kdump kernel we need to set the
* wslot_res_allocated to 255 so it scans all child
* devices to release resources allocated in the
* normal kernel before panic happened.
*/
hbus->wslot_res_allocated = 255;
ret = hv_pci_bus_exit(hdev, true);
if (ret == 0) {
kfree(pkt);
goto enter_d0_retry;
}
dev_err(&hdev->device,
"Retrying D0 failed with ret %d\n", ret);
}
if (comp_pkt.completion_status < 0) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed D0 Entry with status %x\n",
comp_pkt.completion_status);
ret = -EPROTO;
goto exit;
}
ret = 0;
exit:
kfree(pkt);
return ret;
}
/**
* hv_pci_query_relations() - Ask host to send list of child
* devices
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_query_relations(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_message message;
struct completion comp;
int ret;
/* Ask the host to send along the list of child devices */
init_completion(&comp);
if (cmpxchg(&hbus->survey_event, NULL, &comp))
return -ENOTEMPTY;
memset(&message, 0, sizeof(message));
message.type = PCI_QUERY_BUS_RELATIONS;
ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),
0, VM_PKT_DATA_INBAND, 0);
if (!ret)
ret = wait_for_response(hdev, &comp);
/*
* In the case of fast device addition/removal, it's possible that
* vmbus_sendpacket() or wait_for_response() returns -ENODEV but we
* already got a PCI_BUS_RELATIONS* message from the host and the
* channel callback already scheduled a work to hbus->wq, which can be
* running pci_devices_present_work() -> survey_child_resources() ->
* complete(&hbus->survey_event), even after hv_pci_query_relations()
* exits and the stack variable 'comp' is no longer valid; as a result,
* a hang or a page fault may happen when the complete() calls
* raw_spin_lock_irqsave(). Flush hbus->wq before we exit from
* hv_pci_query_relations() to avoid the issues. Note: if 'ret' is
* -ENODEV, there can't be any more work item scheduled to hbus->wq
* after the flush_workqueue(): see vmbus_onoffer_rescind() ->
* vmbus_reset_channel_cb(), vmbus_rescind_cleanup() ->
* channel->rescind = true.
*/
flush_workqueue(hbus->wq);
return ret;
}
/**
* hv_send_resources_allocated() - Report local resource choices
* @hdev: VMBus's tracking struct for this root PCI bus
*
* The host OS is expecting to be sent a request as a message
* which contains all the resources that the device will use.
* The response contains those same resources, "translated"
* which is to say, the values which should be used by the
* hardware, when it delivers an interrupt. (MMIO resources are
* used in local terms.) This is nice for Windows, and lines up
* with the FDO/PDO split, which doesn't exist in Linux. Linux
* is deeply expecting to scan an emulated PCI configuration
* space. So this message is sent here only to drive the state
* machine on the host forward.
*
* Return: 0 on success, -errno on failure
*/
static int hv_send_resources_allocated(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_resources_assigned *res_assigned;
struct pci_resources_assigned2 *res_assigned2;
struct hv_pci_compl comp_pkt;
struct hv_pci_dev *hpdev;
struct pci_packet *pkt;
size_t size_res;
int wslot;
int ret;
size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
? sizeof(*res_assigned) : sizeof(*res_assigned2);
pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
if (!pkt)
return -ENOMEM;
ret = 0;
for (wslot = 0; wslot < 256; wslot++) {
hpdev = get_pcichild_wslot(hbus, wslot);
if (!hpdev)
continue;
memset(pkt, 0, sizeof(*pkt) + size_res);
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) {
res_assigned =
(struct pci_resources_assigned *)&pkt->message;
res_assigned->message_type.type =
PCI_RESOURCES_ASSIGNED;
res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
} else {
res_assigned2 =
(struct pci_resources_assigned2 *)&pkt->message;
res_assigned2->message_type.type =
PCI_RESOURCES_ASSIGNED2;
res_assigned2->wslot.slot = hpdev->desc.win_slot.slot;
}
put_pcichild(hpdev);
ret = vmbus_sendpacket(hdev->channel, &pkt->message,
size_res, (unsigned long)pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (!ret)
ret = wait_for_response(hdev, &comp_pkt.host_event);
if (ret)
break;
if (comp_pkt.completion_status < 0) {
ret = -EPROTO;
dev_err(&hdev->device,
"resource allocated returned 0x%x",
comp_pkt.completion_status);
break;
}
hbus->wslot_res_allocated = wslot;
}
kfree(pkt);
return ret;
}
/**
* hv_send_resources_released() - Report local resources
* released
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_send_resources_released(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_child_message pkt;
struct hv_pci_dev *hpdev;
int wslot;
int ret;
for (wslot = hbus->wslot_res_allocated; wslot >= 0; wslot--) {
hpdev = get_pcichild_wslot(hbus, wslot);
if (!hpdev)
continue;
memset(&pkt, 0, sizeof(pkt));
pkt.message_type.type = PCI_RESOURCES_RELEASED;
pkt.wslot.slot = hpdev->desc.win_slot.slot;
put_pcichild(hpdev);
ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,
VM_PKT_DATA_INBAND, 0);
if (ret)
return ret;
hbus->wslot_res_allocated = wslot - 1;
}
hbus->wslot_res_allocated = -1;
return 0;
}
#define HVPCI_DOM_MAP_SIZE (64 * 1024)
static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE);
/*
* PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0
* as invalid for passthrough PCI devices of this driver.
*/
#define HVPCI_DOM_INVALID 0
/**
* hv_get_dom_num() - Get a valid PCI domain number
* Check if the PCI domain number is in use, and return another number if
* it is in use.
*
* @dom: Requested domain number
*
* return: domain number on success, HVPCI_DOM_INVALID on failure
*/
static u16 hv_get_dom_num(u16 dom)
{
unsigned int i;
if (test_and_set_bit(dom, hvpci_dom_map) == 0)
return dom;
for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) {
if (test_and_set_bit(i, hvpci_dom_map) == 0)
return i;
}
return HVPCI_DOM_INVALID;
}
/**
* hv_put_dom_num() - Mark the PCI domain number as free
* @dom: Domain number to be freed
*/
static void hv_put_dom_num(u16 dom)
{
clear_bit(dom, hvpci_dom_map);
}
/**
* hv_pci_probe() - New VMBus channel probe, for a root PCI bus
* @hdev: VMBus's tracking struct for this root PCI bus
* @dev_id: Identifies the device itself
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_probe(struct hv_device *hdev,
const struct hv_vmbus_device_id *dev_id)
{
struct pci_host_bridge *bridge;
struct hv_pcibus_device *hbus;
u16 dom_req, dom;
char *name;
int ret;
bridge = devm_pci_alloc_host_bridge(&hdev->device, 0);
if (!bridge)
return -ENOMEM;
hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
if (!hbus)
return -ENOMEM;
hbus->bridge = bridge;
mutex_init(&hbus->state_lock);
hbus->state = hv_pcibus_init;
hbus->wslot_res_allocated = -1;
/*
* The PCI bus "domain" is what is called "segment" in ACPI and other
* specs. Pull it from the instance ID, to get something usually
* unique. In rare cases of collision, we will find out another number
* not in use.
*
* Note that, since this code only runs in a Hyper-V VM, Hyper-V
* together with this guest driver can guarantee that (1) The only
* domain used by Gen1 VMs for something that looks like a physical
* PCI bus (which is actually emulated by the hypervisor) is domain 0.
* (2) There will be no overlap between domains (after fixing possible
* collisions) in the same VM.
*/
dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4];
dom = hv_get_dom_num(dom_req);
if (dom == HVPCI_DOM_INVALID) {
dev_err(&hdev->device,
"Unable to use dom# 0x%x or other numbers", dom_req);
ret = -EINVAL;
goto free_bus;
}
if (dom != dom_req)
dev_info(&hdev->device,
"PCI dom# 0x%x has collision, using 0x%x",
dom_req, dom);
hbus->bridge->domain_nr = dom;
#ifdef CONFIG_X86
hbus->sysdata.domain = dom;
hbus->use_calls = !!(ms_hyperv.hints & HV_X64_USE_MMIO_HYPERCALLS);
#elif defined(CONFIG_ARM64)
/*
* Set the PCI bus parent to be the corresponding VMbus
* device. Then the VMbus device will be assigned as the
* ACPI companion in pcibios_root_bridge_prepare() and
* pci_dma_configure() will propagate device coherence
* information to devices created on the bus.
*/
hbus->sysdata.parent = hdev->device.parent;
hbus->use_calls = false;
#endif
hbus->hdev = hdev;
INIT_LIST_HEAD(&hbus->children);
INIT_LIST_HEAD(&hbus->dr_list);
spin_lock_init(&hbus->config_lock);
spin_lock_init(&hbus->device_list_lock);
hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0,
hbus->bridge->domain_nr);
if (!hbus->wq) {
ret = -ENOMEM;
goto free_dom;
}
hdev->channel->next_request_id_callback = vmbus_next_request_id;
hdev->channel->request_addr_callback = vmbus_request_addr;
hdev->channel->rqstor_size = HV_PCI_RQSTOR_SIZE;
ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
hv_pci_onchannelcallback, hbus);
if (ret)
goto destroy_wq;
hv_set_drvdata(hdev, hbus);
ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions,
ARRAY_SIZE(pci_protocol_versions));
if (ret)
goto close;
ret = hv_allocate_config_window(hbus);
if (ret)
goto close;
hbus->cfg_addr = ioremap(hbus->mem_config->start,
PCI_CONFIG_MMIO_LENGTH);
if (!hbus->cfg_addr) {
dev_err(&hdev->device,
"Unable to map a virtual address for config space\n");
ret = -ENOMEM;
goto free_config;
}
name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance);
if (!name) {
ret = -ENOMEM;
goto unmap;
}
hbus->fwnode = irq_domain_alloc_named_fwnode(name);
kfree(name);
if (!hbus->fwnode) {
ret = -ENOMEM;
goto unmap;
}
ret = hv_pcie_init_irq_domain(hbus);
if (ret)
goto free_fwnode;
ret = hv_pci_query_relations(hdev);
if (ret)
goto free_irq_domain;
mutex_lock(&hbus->state_lock);
ret = hv_pci_enter_d0(hdev);
if (ret)
goto release_state_lock;
ret = hv_pci_allocate_bridge_windows(hbus);
if (ret)
goto exit_d0;
ret = hv_send_resources_allocated(hdev);
if (ret)
goto free_windows;
prepopulate_bars(hbus);
hbus->state = hv_pcibus_probed;
ret = create_root_hv_pci_bus(hbus);
if (ret)
goto free_windows;
mutex_unlock(&hbus->state_lock);
return 0;
free_windows:
hv_pci_free_bridge_windows(hbus);
exit_d0:
(void) hv_pci_bus_exit(hdev, true);
release_state_lock:
mutex_unlock(&hbus->state_lock);
free_irq_domain:
irq_domain_remove(hbus->irq_domain);
free_fwnode:
irq_domain_free_fwnode(hbus->fwnode);
unmap:
iounmap(hbus->cfg_addr);
free_config:
hv_free_config_window(hbus);
close:
vmbus_close(hdev->channel);
destroy_wq:
destroy_workqueue(hbus->wq);
free_dom:
hv_put_dom_num(hbus->bridge->domain_nr);
free_bus:
kfree(hbus);
return ret;
}
static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct vmbus_channel *chan = hdev->channel;
struct {
struct pci_packet teardown_packet;
u8 buffer[sizeof(struct pci_message)];
} pkt;
struct hv_pci_compl comp_pkt;
struct hv_pci_dev *hpdev, *tmp;
unsigned long flags;
u64 trans_id;
int ret;
/*
* After the host sends the RESCIND_CHANNEL message, it doesn't
* access the per-channel ringbuffer any longer.
*/
if (chan->rescind)
return 0;
if (!keep_devs) {
struct list_head removed;
/* Move all present children to the list on stack */
INIT_LIST_HEAD(&removed);
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry)
list_move_tail(&hpdev->list_entry, &removed);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
/* Remove all children in the list */
list_for_each_entry_safe(hpdev, tmp, &removed, list_entry) {
list_del(&hpdev->list_entry);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
/* For the two refs got in new_pcichild_device() */
put_pcichild(hpdev);
put_pcichild(hpdev);
}
}
ret = hv_send_resources_released(hdev);
if (ret) {
dev_err(&hdev->device,
"Couldn't send resources released packet(s)\n");
return ret;
}
memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet));
init_completion(&comp_pkt.host_event);
pkt.teardown_packet.completion_func = hv_pci_generic_compl;
pkt.teardown_packet.compl_ctxt = &comp_pkt;
pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT;
ret = vmbus_sendpacket_getid(chan, &pkt.teardown_packet.message,
sizeof(struct pci_message),
(unsigned long)&pkt.teardown_packet,
&trans_id, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0) {
/*
* The completion packet on the stack becomes invalid after
* 'return'; remove the ID from the VMbus requestor if the
* identifier is still mapped to/associated with the packet.
*
* Cf. hv_pci_onchannelcallback().
*/
vmbus_request_addr_match(chan, trans_id,
(unsigned long)&pkt.teardown_packet);
return -ETIMEDOUT;
}
return 0;
}
/**
* hv_pci_remove() - Remove routine for this VMBus channel
* @hdev: VMBus's tracking struct for this root PCI bus
*/
static void hv_pci_remove(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus;
hbus = hv_get_drvdata(hdev);
if (hbus->state == hv_pcibus_installed) {
tasklet_disable(&hdev->channel->callback_event);
hbus->state = hv_pcibus_removing;
tasklet_enable(&hdev->channel->callback_event);
destroy_workqueue(hbus->wq);
hbus->wq = NULL;
/*
* At this point, no work is running or can be scheduled
* on hbus-wq. We can't race with hv_pci_devices_present()
* or hv_pci_eject_device(), it's safe to proceed.
*/
/* Remove the bus from PCI's point of view. */
pci_lock_rescan_remove();
pci_stop_root_bus(hbus->bridge->bus);
hv_pci_remove_slots(hbus);
pci_remove_root_bus(hbus->bridge->bus);
pci_unlock_rescan_remove();
}
hv_pci_bus_exit(hdev, false);
vmbus_close(hdev->channel);
iounmap(hbus->cfg_addr);
hv_free_config_window(hbus);
hv_pci_free_bridge_windows(hbus);
irq_domain_remove(hbus->irq_domain);
irq_domain_free_fwnode(hbus->fwnode);
hv_put_dom_num(hbus->bridge->domain_nr);
kfree(hbus);
}
static int hv_pci_suspend(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
enum hv_pcibus_state old_state;
int ret;
/*
* hv_pci_suspend() must make sure there are no pending work items
* before calling vmbus_close(), since it runs in a process context
* as a callback in dpm_suspend(). When it starts to run, the channel
* callback hv_pci_onchannelcallback(), which runs in a tasklet
* context, can be still running concurrently and scheduling new work
* items onto hbus->wq in hv_pci_devices_present() and
* hv_pci_eject_device(), and the work item handlers can access the
* vmbus channel, which can be being closed by hv_pci_suspend(), e.g.
* the work item handler pci_devices_present_work() ->
* new_pcichild_device() writes to the vmbus channel.
*
* To eliminate the race, hv_pci_suspend() disables the channel
* callback tasklet, sets hbus->state to hv_pcibus_removing, and
* re-enables the tasklet. This way, when hv_pci_suspend() proceeds,
* it knows that no new work item can be scheduled, and then it flushes
* hbus->wq and safely closes the vmbus channel.
*/
tasklet_disable(&hdev->channel->callback_event);
/* Change the hbus state to prevent new work items. */
old_state = hbus->state;
if (hbus->state == hv_pcibus_installed)
hbus->state = hv_pcibus_removing;
tasklet_enable(&hdev->channel->callback_event);
if (old_state != hv_pcibus_installed)
return -EINVAL;
flush_workqueue(hbus->wq);
ret = hv_pci_bus_exit(hdev, true);
if (ret)
return ret;
vmbus_close(hdev->channel);
return 0;
}
static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg)
{
struct irq_data *irq_data;
struct msi_desc *entry;
int ret = 0;
if (!pdev->msi_enabled && !pdev->msix_enabled)
return 0;
msi_lock_descs(&pdev->dev);
msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) {
irq_data = irq_get_irq_data(entry->irq);
if (WARN_ON_ONCE(!irq_data)) {
ret = -EINVAL;
break;
}
hv_compose_msi_msg(irq_data, &entry->msg);
}
msi_unlock_descs(&pdev->dev);
return ret;
}
/*
* Upon resume, pci_restore_msi_state() -> ... -> __pci_write_msi_msg()
* directly writes the MSI/MSI-X registers via MMIO, but since Hyper-V
* doesn't trap and emulate the MMIO accesses, here hv_compose_msi_msg()
* must be used to ask Hyper-V to re-create the IOMMU Interrupt Remapping
* Table entries.
*/
static void hv_pci_restore_msi_state(struct hv_pcibus_device *hbus)
{
pci_walk_bus(hbus->bridge->bus, hv_pci_restore_msi_msg, NULL);
}
static int hv_pci_resume(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
enum pci_protocol_version_t version[1];
int ret;
hbus->state = hv_pcibus_init;
hdev->channel->next_request_id_callback = vmbus_next_request_id;
hdev->channel->request_addr_callback = vmbus_request_addr;
hdev->channel->rqstor_size = HV_PCI_RQSTOR_SIZE;
ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
hv_pci_onchannelcallback, hbus);
if (ret)
return ret;
/* Only use the version that was in use before hibernation. */
version[0] = hbus->protocol_version;
ret = hv_pci_protocol_negotiation(hdev, version, 1);
if (ret)
goto out;
ret = hv_pci_query_relations(hdev);
if (ret)
goto out;
mutex_lock(&hbus->state_lock);
ret = hv_pci_enter_d0(hdev);
if (ret)
goto release_state_lock;
ret = hv_send_resources_allocated(hdev);
if (ret)
goto release_state_lock;
prepopulate_bars(hbus);
hv_pci_restore_msi_state(hbus);
hbus->state = hv_pcibus_installed;
mutex_unlock(&hbus->state_lock);
return 0;
release_state_lock:
mutex_unlock(&hbus->state_lock);
out:
vmbus_close(hdev->channel);
return ret;
}
static const struct hv_vmbus_device_id hv_pci_id_table[] = {
/* PCI Pass-through Class ID */
/* 44C4F61D-4444-4400-9D52-802E27EDE19F */
{ HV_PCIE_GUID, },
{ },
};
MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table);
static struct hv_driver hv_pci_drv = {
.name = "hv_pci",
.id_table = hv_pci_id_table,
.probe = hv_pci_probe,
.remove = hv_pci_remove,
.suspend = hv_pci_suspend,
.resume = hv_pci_resume,
};
static void __exit exit_hv_pci_drv(void)
{
vmbus_driver_unregister(&hv_pci_drv);
hvpci_block_ops.read_block = NULL;
hvpci_block_ops.write_block = NULL;
hvpci_block_ops.reg_blk_invalidate = NULL;
}
static int __init init_hv_pci_drv(void)
{
int ret;
if (!hv_is_hyperv_initialized())
return -ENODEV;
ret = hv_pci_irqchip_init();
if (ret)
return ret;
/* Set the invalid domain number's bit, so it will not be used */
set_bit(HVPCI_DOM_INVALID, hvpci_dom_map);
/* Initialize PCI block r/w interface */
hvpci_block_ops.read_block = hv_read_config_block;
hvpci_block_ops.write_block = hv_write_config_block;
hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate;
return vmbus_driver_register(&hv_pci_drv);
}
module_init(init_hv_pci_drv);
module_exit(exit_hv_pci_drv);
MODULE_DESCRIPTION("Hyper-V PCI");
MODULE_LICENSE("GPL v2");
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