// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015 - 2016 Cavium, Inc.
*/
#include <linux/bitfield.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/pci-acpi.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include "../pci.h"
#if defined(CONFIG_PCI_HOST_THUNDER_PEM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
#define PEM_CFG_WR 0x28
#define PEM_CFG_RD 0x30
/*
* Enhanced Configuration Access Mechanism (ECAM)
*
* N.B. This is a non-standard platform-specific ECAM bus shift value. For
* standard values defined in the PCI Express Base Specification see
* include/linux/pci-ecam.h.
*/
#define THUNDER_PCIE_ECAM_BUS_SHIFT 24
struct thunder_pem_pci {
u32 ea_entry[3];
void __iomem *pem_reg_base;
};
static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
u64 read_val, tmp_val;
struct pci_config_window *cfg = bus->sysdata;
struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
if (devfn != 0 || where >= 2048)
return PCIBIOS_DEVICE_NOT_FOUND;
/*
* 32-bit accesses only. Write the address to the low order
* bits of PEM_CFG_RD, then trigger the read by reading back.
* The config data lands in the upper 32-bits of PEM_CFG_RD.
*/
read_val = where & ~3ull;
writeq(read_val, pem_pci->pem_reg_base + PEM_CFG_RD);
read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
read_val >>= 32;
/*
* The config space contains some garbage, fix it up. Also
* synthesize an EA capability for the BAR used by MSI-X.
*/
switch (where & ~3) {
case 0x40:
read_val &= 0xffff00ff;
read_val |= 0x00007000; /* Skip MSI CAP */
break;
case 0x70: /* Express Cap */
/*
* Change PME interrupt to vector 2 on T88 where it
* reads as 0, else leave it alone.
*/
if (!(read_val & (0x1f << 25)))
read_val |= (2u << 25);
break;
case 0xb0: /* MSI-X Cap */
/* TableSize=2 or 4, Next Cap is EA */
read_val &= 0xc00000ff;
/*
* If Express Cap(0x70) raw PME vector reads as 0 we are on
* T88 and TableSize is reported as 4, else TableSize
* is 2.
*/
writeq(0x70, pem_pci->pem_reg_base + PEM_CFG_RD);
tmp_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
tmp_val >>= 32;
if (!(tmp_val & (0x1f << 25)))
read_val |= 0x0003bc00;
else
read_val |= 0x0001bc00;
break;
case 0xb4:
/* Table offset=0, BIR=0 */
read_val = 0x00000000;
break;
case 0xb8:
/* BPA offset=0xf0000, BIR=0 */
read_val = 0x000f0000;
break;
case 0xbc:
/* EA, 1 entry, no next Cap */
read_val = 0x00010014;
break;
case 0xc0:
/* DW2 for type-1 */
read_val = 0x00000000;
break;
case 0xc4:
/* Entry BEI=0, PP=0x00, SP=0xff, ES=3 */
read_val = 0x80ff0003;
break;
case 0xc8:
read_val = pem_pci->ea_entry[0];
break;
case 0xcc:
read_val = pem_pci->ea_entry[1];
break;
case 0xd0:
read_val = pem_pci->ea_entry[2];
break;
default:
break;
}
read_val >>= (8 * (where & 3));
switch (size) {
case 1:
read_val &= 0xff;
break;
case 2:
read_val &= 0xffff;
break;
default:
break;
}
*val = read_val;
return PCIBIOS_SUCCESSFUL;
}
static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct pci_config_window *cfg = bus->sysdata;
if (bus->number < cfg->busr.start ||
bus->number > cfg->busr.end)
return PCIBIOS_DEVICE_NOT_FOUND;
/*
* The first device on the bus is the PEM PCIe bridge.
* Special case its config access.
*/
if (bus->number == cfg->busr.start)
return thunder_pem_bridge_read(bus, devfn, where, size, val);
return pci_generic_config_read(bus, devfn, where, size, val);
}
/*
* Some of the w1c_bits below also include read-only or non-writable
* reserved bits, this makes the code simpler and is OK as the bits
* are not affected by writing zeros to them.
*/
static u32 thunder_pem_bridge_w1c_bits(u64 where_aligned)
{
u32 w1c_bits = 0;
switch (where_aligned) {
case 0x04: /* Command/Status */
case 0x1c: /* Base and I/O Limit/Secondary Status */
w1c_bits = 0xff000000;
break;
case 0x44: /* Power Management Control and Status */
w1c_bits = 0xfffffe00;
break;
case 0x78: /* Device Control/Device Status */
case 0x80: /* Link Control/Link Status */
case 0x88: /* Slot Control/Slot Status */
case 0x90: /* Root Status */
case 0xa0: /* Link Control 2 Registers/Link Status 2 */
w1c_bits = 0xffff0000;
break;
case 0x104: /* Uncorrectable Error Status */
case 0x110: /* Correctable Error Status */
case 0x130: /* Error Status */
case 0x160: /* Link Control 4 */
w1c_bits = 0xffffffff;
break;
default:
break;
}
return w1c_bits;
}
/* Some bits must be written to one so they appear to be read-only. */
static u32 thunder_pem_bridge_w1_bits(u64 where_aligned)
{
u32 w1_bits;
switch (where_aligned) {
case 0x1c: /* I/O Base / I/O Limit, Secondary Status */
/* Force 32-bit I/O addressing. */
w1_bits = 0x0101;
break;
case 0x24: /* Prefetchable Memory Base / Prefetchable Memory Limit */
/* Force 64-bit addressing */
w1_bits = 0x00010001;
break;
default:
w1_bits = 0;
break;
}
return w1_bits;
}
static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
struct pci_config_window *cfg = bus->sysdata;
struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
u64 write_val, read_val;
u64 where_aligned = where & ~3ull;
u32 mask = 0;
if (devfn != 0 || where >= 2048)
return PCIBIOS_DEVICE_NOT_FOUND;
/*
* 32-bit accesses only. If the write is for a size smaller
* than 32-bits, we must first read the 32-bit value and merge
* in the desired bits and then write the whole 32-bits back
* out.
*/
switch (size) {
case 1:
writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
read_val >>= 32;
mask = ~(0xff << (8 * (where & 3)));
read_val &= mask;
val = (val & 0xff) << (8 * (where & 3));
val |= (u32)read_val;
break;
case 2:
writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
read_val >>= 32;
mask = ~(0xffff << (8 * (where & 3)));
read_val &= mask;
val = (val & 0xffff) << (8 * (where & 3));
val |= (u32)read_val;
break;
default:
break;
}
/*
* By expanding the write width to 32 bits, we may
* inadvertently hit some W1C bits that were not intended to
* be written. Calculate the mask that must be applied to the
* data to be written to avoid these cases.
*/
if (mask) {
u32 w1c_bits = thunder_pem_bridge_w1c_bits(where);
if (w1c_bits) {
mask &= w1c_bits;
val &= ~mask;
}
}
/*
* Some bits must be read-only with value of one. Since the
* access method allows these to be cleared if a zero is
* written, force them to one before writing.
*/
val |= thunder_pem_bridge_w1_bits(where_aligned);
/*
* Low order bits are the config address, the high order 32
* bits are the data to be written.
*/
write_val = (((u64)val) << 32) | where_aligned;
writeq(write_val, pem_pci->pem_reg_base + PEM_CFG_WR);
return PCIBIOS_SUCCESSFUL;
}
static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
struct pci_config_window *cfg = bus->sysdata;
if (bus->number < cfg->busr.start ||
bus->number > cfg->busr.end)
return PCIBIOS_DEVICE_NOT_FOUND;
/*
* The first device on the bus is the PEM PCIe bridge.
* Special case its config access.
*/
if (bus->number == cfg->busr.start)
return thunder_pem_bridge_write(bus, devfn, where, size, val);
return pci_generic_config_write(bus, devfn, where, size, val);
}
static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg,
struct resource *res_pem)
{
struct thunder_pem_pci *pem_pci;
resource_size_t bar4_start;
pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
if (!pem_pci)
return -ENOMEM;
pem_pci->pem_reg_base = devm_ioremap(dev, res_pem->start, 0x10000);
if (!pem_pci->pem_reg_base)
return -ENOMEM;
/*
* The MSI-X BAR for the PEM and AER interrupts is located at
* a fixed offset from the PEM register base. Generate a
* fragment of the synthesized Enhanced Allocation capability
* structure here for the BAR.
*/
bar4_start = res_pem->start + 0xf00000;
pem_pci->ea_entry[0] = lower_32_bits(bar4_start) | 2;
pem_pci->ea_entry[1] = lower_32_bits(res_pem->end - bar4_start) & ~3u;
pem_pci->ea_entry[2] = upper_32_bits(bar4_start);
cfg->priv = pem_pci;
return 0;
}
#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
#define PEM_RES_BASE 0x87e0c0000000ULL
#define PEM_NODE_MASK GENMASK_ULL(45, 44)
#define PEM_INDX_MASK GENMASK_ULL(26, 24)
#define PEM_MIN_DOM_IN_NODE 4
#define PEM_MAX_DOM_IN_NODE 10
static void thunder_pem_reserve_range(struct device *dev, int seg,
struct resource *r)
{
resource_size_t start = r->start, end = r->end;
struct resource *res;
const char *regionid;
regionid = kasprintf(GFP_KERNEL, "PEM RC:%d", seg);
if (!regionid)
return;
res = request_mem_region(start, end - start + 1, regionid);
if (res)
res->flags &= ~IORESOURCE_BUSY;
else
kfree(regionid);
dev_info(dev, "%pR %s reserved\n", r,
res ? "has been" : "could not be");
}
static void thunder_pem_legacy_fw(struct acpi_pci_root *root,
struct resource *res_pem)
{
int node = acpi_get_node(root->device->handle);
int index;
if (node == NUMA_NO_NODE)
node = 0;
index = root->segment - PEM_MIN_DOM_IN_NODE;
index -= node * PEM_MAX_DOM_IN_NODE;
res_pem->start = PEM_RES_BASE | FIELD_PREP(PEM_NODE_MASK, node) |
FIELD_PREP(PEM_INDX_MASK, index);
res_pem->flags = IORESOURCE_MEM;
}
static int thunder_pem_acpi_init(struct pci_config_window *cfg)
{
struct device *dev = cfg->parent;
struct acpi_device *adev = to_acpi_device(dev);
struct acpi_pci_root *root = acpi_driver_data(adev);
struct resource *res_pem;
int ret;
res_pem = devm_kzalloc(&adev->dev, sizeof(*res_pem), GFP_KERNEL);
if (!res_pem)
return -ENOMEM;
ret = acpi_get_rc_resources(dev, "CAVA02B", root->segment, res_pem);
/*
* If we fail to gather resources it means that we run with old
* FW where we need to calculate PEM-specific resources manually.
*/
if (ret) {
thunder_pem_legacy_fw(root, res_pem);
/*
* Reserve 64K size PEM specific resources. The full 16M range
* size is required for thunder_pem_init() call.
*/
res_pem->end = res_pem->start + SZ_64K - 1;
thunder_pem_reserve_range(dev, root->segment, res_pem);
res_pem->end = res_pem->start + SZ_16M - 1;
/* Reserve PCI configuration space as well. */
thunder_pem_reserve_range(dev, root->segment, &cfg->res);
}
return thunder_pem_init(dev, cfg, res_pem);
}
const struct pci_ecam_ops thunder_pem_ecam_ops = {
.bus_shift = THUNDER_PCIE_ECAM_BUS_SHIFT,
.init = thunder_pem_acpi_init,
.pci_ops = {
.map_bus = pci_ecam_map_bus,
.read = thunder_pem_config_read,
.write = thunder_pem_config_write,
}
};
#endif
#ifdef CONFIG_PCI_HOST_THUNDER_PEM
static int thunder_pem_platform_init(struct pci_config_window *cfg)
{
struct device *dev = cfg->parent;
struct platform_device *pdev = to_platform_device(dev);
struct resource *res_pem;
if (!dev->of_node)
return -EINVAL;
/*
* The second register range is the PEM bridge to the PCIe
* bus. It has a different config access method than those
* devices behind the bridge.
*/
res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res_pem) {
dev_err(dev, "missing \"reg[1]\"property\n");
return -EINVAL;
}
return thunder_pem_init(dev, cfg, res_pem);
}
static const struct pci_ecam_ops pci_thunder_pem_ops = {
.bus_shift = THUNDER_PCIE_ECAM_BUS_SHIFT,
.init = thunder_pem_platform_init,
.pci_ops = {
.map_bus = pci_ecam_map_bus,
.read = thunder_pem_config_read,
.write = thunder_pem_config_write,
}
};
static const struct of_device_id thunder_pem_of_match[] = {
{
.compatible = "cavium,pci-host-thunder-pem",
.data = &pci_thunder_pem_ops,
},
{ },
};
static struct platform_driver thunder_pem_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = thunder_pem_of_match,
.suppress_bind_attrs = true,
},
.probe = pci_host_common_probe,
};
builtin_platform_driver(thunder_pem_driver);
#endif
#endif
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