linux-stable.git/drivers/pci/devres.c, branch v6.15

PCI: Check BAR index for validity

2025-03-14T15:35:12+00:00

Many functions in PCI use accessor macros such as pci_resource_len(),
which take a BAR index. That index, however, is never checked for
validity, potentially resulting in undefined behavior by overflowing the
array pci_dev.resource in the macro pci_resource_n().

Since many users of those macros directly assign the accessed value to
an unsigned integer, the macros cannot be changed easily anymore to
return -EINVAL for invalid indexes. Consequently, the problem has to be
mitigated in higher layers.

Add pci_bar_index_valid(). Use it where appropriate.

Link: https://lore.kernel.org/r/20250312080634.13731-4-phasta@kernel.org
Closes: https://lore.kernel.org/all/adb53b1f-29e1-3d14-0e61-351fd2d3ff0d@linux.intel.com/
Reported-by: Bingbu Cao 
Signed-off-by: Philipp Stanner 
[kwilczynski: correct if-statement condition the pci_bar_index_is_valid()
helper function uses, tidy up code comments]
Signed-off-by: Krzysztof Wilczyński 
[bhelgaas: fix typo]
Signed-off-by: Bjorn Helgaas

PCI: Fix wrong length of devres array

2025-03-14T09:22:24+00:00

The array for the iomapping cookie addresses has a length of
PCI_STD_NUM_BARS. This constant, however, only describes standard BARs;
while PCI can allow for additional, special BARs.

The total number of PCI resources is described by constant
PCI_NUM_RESOURCES, which is also used in, e.g., pci_select_bars().

Thus, the devres array has so far been too small.

Change the length of the devres array to PCI_NUM_RESOURCES.

Link: https://lore.kernel.org/r/20250312080634.13731-3-phasta@kernel.org
Fixes: bbaff68bf4a4 ("PCI: Add managed partial-BAR request and map infrastructure")
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Krzysztof Wilczyński 
Cc: stable@vger.kernel.org	# v6.11+

PCI: Restore original INTX_DISABLE bit by pcim_intx()

2025-01-27T18:55:12+00:00

pcim_intx() tries to restore the INTx bit at removal via devres, but there
is a chance that it restores a wrong value.

Because the value to be restored is blindly assumed to be the negative of
the enable argument, when a driver calls pcim_intx() unnecessarily for the
already enabled state, it'll restore to the disabled state in turn.  That
is, the function assumes the case like:

  // INTx == 1
  pcim_intx(pdev, 0); // old INTx value assumed to be 1 -> correct

but it might be like the following, too:

  // INTx == 0
  pcim_intx(pdev, 0); // old INTx value assumed to be 1 -> wrong

Also, when a driver calls pcim_intx() multiple times with different enable
argument values, the last one will win no matter what value it is.  This
can lead to inconsistency, e.g.

  // INTx == 1
  pcim_intx(pdev, 0); // OK
  ...
  pcim_intx(pdev, 1); // now old INTx wrongly assumed to be 0

This patch addresses those inconsistencies by saving the original INTx
state at the first pcim_intx() call.  For that, get_or_create_intx_devres()
is folded into pcim_intx() caller side; it allows us to simply check the
already allocated devres and record the original INTx along with the
devres_alloc() call.

Link: https://lore.kernel.org/r/20241031134300.10296-1-tiwai@suse.de
Fixes: 25216afc9db5 ("PCI: Add managed pcim_intx()")
Link: https://lore.kernel.org/87v7xk2ps5.wl-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Philipp Stanner 
Cc: stable@vger.kernel.org	# v6.11+

PCI: Remove devres from pci_intx()

2025-01-18T20:38:49+00:00

pci_intx() is a hybrid function which can sometimes be managed through
devres. This hybrid nature is undesirable.

Since all users of pci_intx() have by now been ported either to
always-managed pcim_intx() or never-managed pci_intx_unmanaged(), the
devres functionality can be removed from pci_intx().

Consequently, pci_intx_unmanaged() is now redundant, because pci_intx()
itself is now unmanaged.

Remove the devres functionality from pci_intx(). Have all users of
pci_intx_unmanaged() call pci_intx(). Remove pci_intx_unmanaged().

Link: https://lore.kernel.org/r/20241209130632.132074-13-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas 
Acked-by: Paolo Abeni

PCI: Export pci_intx_unmanaged() and pcim_intx()

2025-01-18T20:38:48+00:00

pci_intx() is a hybrid function which sometimes performs devres operations,
depending on whether pcim_enable_device() has been used to enable the
pci_dev. This sometimes-managed nature of the function is problematic.
Notably, it causes the function to allocate under some circumstances which
makes it unusable from interrupt context.

Export pcim_intx() (which is always managed) and rename __pcim_intx()
(which is never managed) to pci_intx_unmanaged() and export it as well.

Then all callers of pci_intx() can be ported to the version they need,
depending whether they use pci_enable_device() or pcim_enable_device().

Link: https://lore.kernel.org/r/20241209130632.132074-3-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Damien Le Moal

PCI: Encourage resource request API users to supply driver name

2024-12-05T17:29:52+00:00

PCI region request functions have a @name parameter (sometimes called
"res_name"). It is used in a log message to inform drivers about request
collisions, e.g., when another driver has requested that region already.

This message is only useful when it contains the actual owner of the
region, i.e., which driver requested it. So far, a great many drivers
misuse the @name parameter and just pass pci_name(), which doesn't result
in useful debug information.

Rename "res_name" to "name".

Detail @name's purpose in the docstrings.

Link: https://lore.kernel.org/r/20241203100023.31152-2-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
[bhelgaas: tweak comment wording to include "driver"]
Signed-off-by: Bjorn Helgaas

PCI: Deprecate pcim_iounmap_regions()

2024-11-07T13:10:02+00:00

pcim_ioumap_region() has recently been made a public function and does
not have the disadvantage of having to deal with the legacy iomap table,
as pcim_iounmap_regions() does.

Deprecate pcim_iounmap_regions().

Link: https://lore.kernel.org/r/20241016094911.24818-4-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas

PCI: Make pcim_iounmap_region() a public function

2024-10-30T21:12:47+00:00

The function pcim_iounmap_regions() is problematic because it uses a
bitmask mechanism to release / iounmap multiple BARs at once. It, thus,
prevents getting rid of the problematic iomap table mechanism which was
deprecated in commit e354bb84a4c1 ("PCI: Deprecate pcim_iomap_table(),
pcim_iomap_regions_request_all()").

pcim_iounmap_region() does not have that problem. Make it public as the
successor of pcim_iounmap_regions().

Link: https://lore.kernel.org/r/20241016094911.24818-3-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas

PCI: Remove pcim_iomap_regions_request_all()

2024-10-30T21:07:39+00:00

pcim_iomap_regions_request_all() have been deprecated in
commit e354bb84a4c1 ("PCI: Deprecate pcim_iomap_table(),
pcim_iomap_regions_request_all()").

All users of this function have been ported to other interfaces by now.

Remove pcim_iomap_regions_request_all().

Link: https://lore.kernel.org/r/20241030112743.104395-11-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Damien Le Moal

PCI: Make pcim_request_all_regions() a public function

2024-10-30T21:07:36+00:00

In order to remove the deprecated function
pcim_iomap_regions_request_all(), a few drivers need an interface to
request all BARs a PCI device offers.

Make pcim_request_all_regions() a public interface.

Link: https://lore.kernel.org/r/20241030112743.104395-2-pstanner@redhat.com
Signed-off-by: Philipp Stanner 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Damien Le Moal 
Reviewed-by: Ilpo Järvinen