// SPDX-License-Identifier: GPL-2.0
/*
* Support routines for initializing a PCI subsystem
*
* Extruded from code written by
* Dave Rusling ([email protected])
* David Mosberger ([email protected])
* David Miller ([email protected])
*
* Fixed for multiple PCI buses, 1999 Andrea Arcangeli <[email protected]>
*
* Nov 2000, Ivan Kokshaysky <[email protected]>
* Resource sorting
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include <linux/slab.h>
#include "pci.h"
static void pci_std_update_resource(struct pci_dev *dev, int resno)
{
struct pci_bus_region region;
bool disable;
u16 cmd;
u32 new, check, mask;
int reg;
struct resource *res = dev->resource + resno;
const char *res_name = pci_resource_name(dev, resno);
/* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
if (dev->is_virtfn)
return;
/*
* Ignore resources for unimplemented BARs and unused resource slots
* for 64 bit BARs.
*/
if (!res->flags)
return;
if (res->flags & IORESOURCE_UNSET)
return;
/*
* Ignore non-moveable resources. This might be legacy resources for
* which no functional BAR register exists or another important
* system resource we shouldn't move around.
*/
if (res->flags & IORESOURCE_PCI_FIXED)
return;
pcibios_resource_to_bus(dev->bus, ®ion, res);
new = region.start;
if (res->flags & IORESOURCE_IO) {
mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
} else if (resno == PCI_ROM_RESOURCE) {
mask = PCI_ROM_ADDRESS_MASK;
} else {
mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
}
if (resno < PCI_ROM_RESOURCE) {
reg = PCI_BASE_ADDRESS_0 + 4 * resno;
} else if (resno == PCI_ROM_RESOURCE) {
/*
* Apparently some Matrox devices have ROM BARs that read
* as zero when disabled, so don't update ROM BARs unless
* they're enabled. See
* https://lore.kernel.org/r/[email protected]/
* But we must update ROM BAR for buggy devices where even a
* disabled ROM can conflict with other BARs.
*/
if (!(res->flags & IORESOURCE_ROM_ENABLE) &&
!dev->rom_bar_overlap)
return;
reg = dev->rom_base_reg;
if (res->flags & IORESOURCE_ROM_ENABLE)
new |= PCI_ROM_ADDRESS_ENABLE;
} else
return;
/*
* We can't update a 64-bit BAR atomically, so when possible,
* disable decoding so that a half-updated BAR won't conflict
* with another device.
*/
disable = (res->flags & IORESOURCE_MEM_64) && !dev->mmio_always_on;
if (disable) {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
pci_write_config_word(dev, PCI_COMMAND,
cmd & ~PCI_COMMAND_MEMORY);
}
pci_write_config_dword(dev, reg, new);
pci_read_config_dword(dev, reg, &check);
if ((new ^ check) & mask) {
pci_err(dev, "%s: error updating (%#010x != %#010x)\n",
res_name, new, check);
}
if (res->flags & IORESOURCE_MEM_64) {
new = region.start >> 16 >> 16;
pci_write_config_dword(dev, reg + 4, new);
pci_read_config_dword(dev, reg + 4, &check);
if (check != new) {
pci_err(dev, "%s: error updating (high %#010x != %#010x)\n",
res_name, new, check);
}
}
if (disable)
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
void pci_update_resource(struct pci_dev *dev, int resno)
{
if (resno <= PCI_ROM_RESOURCE)
pci_std_update_resource(dev, resno);
#ifdef CONFIG_PCI_IOV
else if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
pci_iov_update_resource(dev, resno);
#endif
}
int pci_claim_resource(struct pci_dev *dev, int resource)
{
struct resource *res = &dev->resource[resource];
const char *res_name = pci_resource_name(dev, resource);
struct resource *root, *conflict;
if (res->flags & IORESOURCE_UNSET) {
pci_info(dev, "%s %pR: can't claim; no address assigned\n",
res_name, res);
return -EINVAL;
}
/*
* If we have a shadow copy in RAM, the PCI device doesn't respond
* to the shadow range, so we don't need to claim it, and upstream
* bridges don't need to route the range to the device.
*/
if (res->flags & IORESOURCE_ROM_SHADOW)
return 0;
root = pci_find_parent_resource(dev, res);
if (!root) {
pci_info(dev, "%s %pR: can't claim; no compatible bridge window\n",
res_name, res);
res->flags |= IORESOURCE_UNSET;
return -EINVAL;
}
conflict = request_resource_conflict(root, res);
if (conflict) {
pci_info(dev, "%s %pR: can't claim; address conflict with %s %pR\n",
res_name, res, conflict->name, conflict);
res->flags |= IORESOURCE_UNSET;
return -EBUSY;
}
return 0;
}
EXPORT_SYMBOL(pci_claim_resource);
void pci_disable_bridge_window(struct pci_dev *dev)
{
/* MMIO Base/Limit */
pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
/* Prefetchable MMIO Base/Limit */
pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
}
/*
* Generic function that returns a value indicating that the device's
* original BIOS BAR address was not saved and so is not available for
* reinstatement.
*
* Can be over-ridden by architecture specific code that implements
* reinstatement functionality rather than leaving it disabled when
* normal allocation attempts fail.
*/
resource_size_t __weak pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx)
{
return 0;
}
static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
int resno, resource_size_t size)
{
struct resource *root, *conflict;
resource_size_t fw_addr, start, end;
const char *res_name = pci_resource_name(dev, resno);
fw_addr = pcibios_retrieve_fw_addr(dev, resno);
if (!fw_addr)
return -ENOMEM;
start = res->start;
end = res->end;
res->start = fw_addr;
res->end = res->start + size - 1;
res->flags &= ~IORESOURCE_UNSET;
root = pci_find_parent_resource(dev, res);
if (!root) {
/*
* If dev is behind a bridge, accesses will only reach it
* if res is inside the relevant bridge window.
*/
if (pci_upstream_bridge(dev))
return -ENXIO;
/*
* On the root bus, assume the host bridge will forward
* everything.
*/
if (res->flags & IORESOURCE_IO)
root = &ioport_resource;
else
root = &iomem_resource;
}
pci_info(dev, "%s: trying firmware assignment %pR\n", res_name, res);
conflict = request_resource_conflict(root, res);
if (conflict) {
pci_info(dev, "%s %pR: conflicts with %s %pR\n", res_name, res,
conflict->name, conflict);
res->start = start;
res->end = end;
res->flags |= IORESOURCE_UNSET;
return -EBUSY;
}
return 0;
}
/*
* We don't have to worry about legacy ISA devices, so nothing to do here.
* This is marked as __weak because multiple architectures define it; it should
* eventually go away.
*/
resource_size_t __weak pcibios_align_resource(void *data,
const struct resource *res,
resource_size_t size,
resource_size_t align)
{
return res->start;
}
static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
int resno, resource_size_t size, resource_size_t align)
{
struct resource *res = dev->resource + resno;
resource_size_t min;
int ret;
min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
/*
* First, try exact prefetching match. Even if a 64-bit
* prefetchable bridge window is below 4GB, we can't put a 32-bit
* prefetchable resource in it because pbus_size_mem() assumes a
* 64-bit window will contain no 32-bit resources. If we assign
* things differently than they were sized, not everything will fit.
*/
ret = pci_bus_alloc_resource(bus, res, size, align, min,
IORESOURCE_PREFETCH | IORESOURCE_MEM_64,
pcibios_align_resource, dev);
if (ret == 0)
return 0;
/*
* If the prefetchable window is only 32 bits wide, we can put
* 64-bit prefetchable resources in it.
*/
if ((res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) ==
(IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) {
ret = pci_bus_alloc_resource(bus, res, size, align, min,
IORESOURCE_PREFETCH,
pcibios_align_resource, dev);
if (ret == 0)
return 0;
}
/*
* If we didn't find a better match, we can put any memory resource
* in a non-prefetchable window. If this resource is 32 bits and
* non-prefetchable, the first call already tried the only possibility
* so we don't need to try again.
*/
if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64))
ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
pcibios_align_resource, dev);
return ret;
}
static int _pci_assign_resource(struct pci_dev *dev, int resno,
resource_size_t size, resource_size_t min_align)
{
struct pci_bus *bus;
int ret;
bus = dev->bus;
while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
if (!bus->parent || !bus->self->transparent)
break;
bus = bus->parent;
}
return ret;
}
int pci_assign_resource(struct pci_dev *dev, int resno)
{
struct resource *res = dev->resource + resno;
const char *res_name = pci_resource_name(dev, resno);
resource_size_t align, size;
int ret;
if (res->flags & IORESOURCE_PCI_FIXED)
return 0;
res->flags |= IORESOURCE_UNSET;
align = pci_resource_alignment(dev, res);
if (!align) {
pci_info(dev, "%s %pR: can't assign; bogus alignment\n",
res_name, res);
return -EINVAL;
}
size = resource_size(res);
ret = _pci_assign_resource(dev, resno, size, align);
/*
* If we failed to assign anything, let's try the address
* where firmware left it. That at least has a chance of
* working, which is better than just leaving it disabled.
*/
if (ret < 0) {
pci_info(dev, "%s %pR: can't assign; no space\n", res_name, res);
ret = pci_revert_fw_address(res, dev, resno, size);
}
if (ret < 0) {
pci_info(dev, "%s %pR: failed to assign\n", res_name, res);
return ret;
}
res->flags &= ~IORESOURCE_UNSET;
res->flags &= ~IORESOURCE_STARTALIGN;
pci_info(dev, "%s %pR: assigned\n", res_name, res);
if (resno < PCI_BRIDGE_RESOURCES)
pci_update_resource(dev, resno);
return 0;
}
EXPORT_SYMBOL(pci_assign_resource);
int pci_reassign_resource(struct pci_dev *dev, int resno,
resource_size_t addsize, resource_size_t min_align)
{
struct resource *res = dev->resource + resno;
const char *res_name = pci_resource_name(dev, resno);
unsigned long flags;
resource_size_t new_size;
int ret;
if (res->flags & IORESOURCE_PCI_FIXED)
return 0;
flags = res->flags;
res->flags |= IORESOURCE_UNSET;
if (!res->parent) {
pci_info(dev, "%s %pR: can't reassign; unassigned resource\n",
res_name, res);
return -EINVAL;
}
/* already aligned with min_align */
new_size = resource_size(res) + addsize;
ret = _pci_assign_resource(dev, resno, new_size, min_align);
if (ret) {
res->flags = flags;
pci_info(dev, "%s %pR: failed to expand by %#llx\n",
res_name, res, (unsigned long long) addsize);
return ret;
}
res->flags &= ~IORESOURCE_UNSET;
res->flags &= ~IORESOURCE_STARTALIGN;
pci_info(dev, "%s %pR: reassigned; expanded by %#llx\n",
res_name, res, (unsigned long long) addsize);
if (resno < PCI_BRIDGE_RESOURCES)
pci_update_resource(dev, resno);
return 0;
}
void pci_release_resource(struct pci_dev *dev, int resno)
{
struct resource *res = dev->resource + resno;
const char *res_name = pci_resource_name(dev, resno);
pci_info(dev, "%s %pR: releasing\n", res_name, res);
if (!res->parent)
return;
release_resource(res);
res->end = resource_size(res) - 1;
res->start = 0;
res->flags |= IORESOURCE_UNSET;
}
EXPORT_SYMBOL(pci_release_resource);
int pci_resize_resource(struct pci_dev *dev, int resno, int size)
{
struct resource *res = dev->resource + resno;
struct pci_host_bridge *host;
int old, ret;
u32 sizes;
u16 cmd;
/* Check if we must preserve the firmware's resource assignment */
host = pci_find_host_bridge(dev->bus);
if (host->preserve_config)
return -ENOTSUPP;
/* Make sure the resource isn't assigned before resizing it. */
if (!(res->flags & IORESOURCE_UNSET))
return -EBUSY;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & PCI_COMMAND_MEMORY)
return -EBUSY;
sizes = pci_rebar_get_possible_sizes(dev, resno);
if (!sizes)
return -ENOTSUPP;
if (!(sizes & BIT(size)))
return -EINVAL;
old = pci_rebar_get_current_size(dev, resno);
if (old < 0)
return old;
ret = pci_rebar_set_size(dev, resno, size);
if (ret)
return ret;
res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
/* Check if the new config works by trying to assign everything. */
if (dev->bus->self) {
ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
if (ret)
goto error_resize;
}
return 0;
error_resize:
pci_rebar_set_size(dev, resno, old);
res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
return ret;
}
EXPORT_SYMBOL(pci_resize_resource);
int pci_enable_resources(struct pci_dev *dev, int mask)
{
u16 cmd, old_cmd;
int i;
struct resource *r;
const char *r_name;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
old_cmd = cmd;
pci_dev_for_each_resource(dev, r, i) {
if (!(mask & (1 << i)))
continue;
r_name = pci_resource_name(dev, i);
if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
continue;
if ((i == PCI_ROM_RESOURCE) &&
(!(r->flags & IORESOURCE_ROM_ENABLE)))
continue;
if (r->flags & IORESOURCE_UNSET) {
pci_err(dev, "%s %pR: not assigned; can't enable device\n",
r_name, r);
return -EINVAL;
}
if (!r->parent) {
pci_err(dev, "%s %pR: not claimed; can't enable device\n",
r_name, r);
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (cmd != old_cmd) {
pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
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