linux/drivers/pci/setup-res.c
Ard Biesheuvel 729e3a669d PCI: Decline to resize resources if boot config must be preserved
The _DSM #5 method in the ACPI host bridge object tells us whether the OS
must preserve the resource assignments done by firmware. If this is the
case, we should not permit drivers to resize BARs on the fly. Make
pci_resize_resource() take this into account.

Link: https://lore.kernel.org/r/20210109095353.13417-1-ardb@kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org	# v5.4+
2021-01-12 16:39:52 -06:00

508 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Support routines for initializing a PCI subsystem
*
* Extruded from code written by
* Dave Rusling (david.rusling@reo.mts.dec.com)
* David Mosberger (davidm@cs.arizona.edu)
* David Miller (davem@redhat.com)
*
* Fixed for multiple PCI buses, 1999 Andrea Arcangeli <andrea@suse.de>
*
* Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
* 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;
/* 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, &region, 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/43147B3D.1030309@vc.cvut.cz/
*/
if (!(res->flags & IORESOURCE_ROM_ENABLE))
return;
reg = dev->rom_base_reg;
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, "BAR %d: error updating (%#08x != %#08x)\n",
resno, 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, "BAR %d: error updating (high %#08x != %#08x)\n",
resno, 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];
struct resource *root, *conflict;
if (res->flags & IORESOURCE_UNSET) {
pci_info(dev, "can't claim BAR %d %pR: no address assigned\n",
resource, 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, "can't claim BAR %d %pR: no compatible bridge window\n",
resource, res);
res->flags |= IORESOURCE_UNSET;
return -EINVAL;
}
conflict = request_resource_conflict(root, res);
if (conflict) {
pci_info(dev, "can't claim BAR %d %pR: address conflict with %s %pR\n",
resource, 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;
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 (res->flags & IORESOURCE_IO)
root = &ioport_resource;
else
root = &iomem_resource;
}
pci_info(dev, "BAR %d: trying firmware assignment %pR\n",
resno, res);
conflict = request_resource_conflict(root, res);
if (conflict) {
pci_info(dev, "BAR %d: %pR conflicts with %s %pR\n",
resno, 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;
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, "BAR %d: can't assign %pR (bogus alignment)\n",
resno, 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, "BAR %d: no space for %pR\n", resno, res);
ret = pci_revert_fw_address(res, dev, resno, size);
}
if (ret < 0) {
pci_info(dev, "BAR %d: failed to assign %pR\n", resno, res);
return ret;
}
res->flags &= ~IORESOURCE_UNSET;
res->flags &= ~IORESOURCE_STARTALIGN;
pci_info(dev, "BAR %d: assigned %pR\n", resno, 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;
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, "BAR %d: can't reassign an unassigned resource %pR\n",
resno, 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, "BAR %d: %pR (failed to expand by %#llx)\n",
resno, res, (unsigned long long) addsize);
return ret;
}
res->flags &= ~IORESOURCE_UNSET;
res->flags &= ~IORESOURCE_STARTALIGN;
pci_info(dev, "BAR %d: reassigned %pR (expanded by %#llx)\n",
resno, 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;
pci_info(dev, "BAR %d: releasing %pR\n", resno, 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;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
old_cmd = cmd;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
if (!(mask & (1 << i)))
continue;
r = &dev->resource[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, "can't enable device: BAR %d %pR not assigned\n",
i, r);
return -EINVAL;
}
if (!r->parent) {
pci_err(dev, "can't enable device: BAR %d %pR not claimed\n",
i, 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;
}