<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux/pci.h, branch v6.6.71</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>PCI: Detect and trust built-in Thunderbolt chips</title>
<updated>2024-12-14T19:00:14+00:00</updated>
<author>
<name>Esther Shimanovich</name>
<email>eshimanovich@chromium.org</email>
</author>
<published>2024-09-10T17:57:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b824ea2af6e035eff8aefdb5f3f721fd38afe32b'/>
<id>b824ea2af6e035eff8aefdb5f3f721fd38afe32b</id>
<content type='text'>
[ Upstream commit 3b96b895127b7c0aed63d82c974b46340e8466c1 ]

Some computers with CPUs that lack Thunderbolt features use discrete
Thunderbolt chips to add Thunderbolt functionality. These Thunderbolt
chips are located within the chassis; between the Root Port labeled
ExternalFacingPort and the USB-C port.

These Thunderbolt PCIe devices should be labeled as fixed and trusted, as
they are built into the computer. Otherwise, security policies that rely on
those flags may have unintended results, such as preventing USB-C ports
from enumerating.

Detect the above scenario through the process of elimination.

  1) Integrated Thunderbolt host controllers already have Thunderbolt
     implemented, so anything outside their external facing Root Port is
     removable and untrusted.

     Detect them using the following properties:

       - Most integrated host controllers have the "usb4-host-interface"
         ACPI property, as described here:

         https://learn.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#mapping-native-protocols-pcie-displayport-tunneled-through-usb4-to-usb4-host-routers

       - Integrated Thunderbolt PCIe Root Ports before Alder Lake do not
         have the "usb4-host-interface" ACPI property. Identify those by
         their PCI IDs instead.

  2) If a Root Port does not have integrated Thunderbolt capabilities, but
     has the "ExternalFacingPort" ACPI property, that means the
     manufacturer has opted to use a discrete Thunderbolt host controller
     that is built into the computer.

     This host controller can be identified by virtue of being located
     directly below an external-facing Root Port that lacks integrated
     Thunderbolt. Label it as trusted and fixed.

     Everything downstream from it is untrusted and removable.

The "ExternalFacingPort" ACPI property is described here:
https://learn.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-externally-exposed-pcie-root-ports

Link: https://lore.kernel.org/r/20240910-trust-tbt-fix-v5-1-7a7a42a5f496@chromium.org
Suggested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Esther Shimanovich &lt;eshimanovich@chromium.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Tested-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3b96b895127b7c0aed63d82c974b46340e8466c1 ]

Some computers with CPUs that lack Thunderbolt features use discrete
Thunderbolt chips to add Thunderbolt functionality. These Thunderbolt
chips are located within the chassis; between the Root Port labeled
ExternalFacingPort and the USB-C port.

These Thunderbolt PCIe devices should be labeled as fixed and trusted, as
they are built into the computer. Otherwise, security policies that rely on
those flags may have unintended results, such as preventing USB-C ports
from enumerating.

Detect the above scenario through the process of elimination.

  1) Integrated Thunderbolt host controllers already have Thunderbolt
     implemented, so anything outside their external facing Root Port is
     removable and untrusted.

     Detect them using the following properties:

       - Most integrated host controllers have the "usb4-host-interface"
         ACPI property, as described here:

         https://learn.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#mapping-native-protocols-pcie-displayport-tunneled-through-usb4-to-usb4-host-routers

       - Integrated Thunderbolt PCIe Root Ports before Alder Lake do not
         have the "usb4-host-interface" ACPI property. Identify those by
         their PCI IDs instead.

  2) If a Root Port does not have integrated Thunderbolt capabilities, but
     has the "ExternalFacingPort" ACPI property, that means the
     manufacturer has opted to use a discrete Thunderbolt host controller
     that is built into the computer.

     This host controller can be identified by virtue of being located
     directly below an external-facing Root Port that lacks integrated
     Thunderbolt. Label it as trusted and fixed.

     Everything downstream from it is untrusted and removable.

The "ExternalFacingPort" ACPI property is described here:
https://learn.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-externally-exposed-pcie-root-ports

Link: https://lore.kernel.org/r/20240910-trust-tbt-fix-v5-1-7a7a42a5f496@chromium.org
Suggested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Esther Shimanovich &lt;eshimanovich@chromium.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Tested-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "PCI/MSI: Provide stubs for IMS functions"</title>
<updated>2024-10-17T13:24:07+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2024-04-10T22:13:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9790a7acc3527f5cd2dd3b273f6df8e02e432793'/>
<id>9790a7acc3527f5cd2dd3b273f6df8e02e432793</id>
<content type='text'>
[ Upstream commit 372c669271bff736c5bc275c982d8d1b4f1f147c ]

This reverts commit 41efa431244f6498833ff8ee8dde28c4924c5479.

IMS (Interrupt Message Store) support appeared in v6.2, but there are no
users yet.

Remove it for now.  We can add it back when a user comes along.  If this is
re-added later, this could be squashed with these commits:

  0194425af0c8 ("PCI/MSI: Provide IMS (Interrupt Message Store) support")
  c9e5bea27383 ("PCI/MSI: Provide pci_ims_alloc/free_irq()")

which added the non-stub implementations.

Link: https://lore.kernel.org/r/20240410221307.2162676-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 372c669271bff736c5bc275c982d8d1b4f1f147c ]

This reverts commit 41efa431244f6498833ff8ee8dde28c4924c5479.

IMS (Interrupt Message Store) support appeared in v6.2, but there are no
users yet.

Remove it for now.  We can add it back when a user comes along.  If this is
re-added later, this could be squashed with these commits:

  0194425af0c8 ("PCI/MSI: Provide IMS (Interrupt Message Store) support")
  c9e5bea27383 ("PCI/MSI: Provide pci_ims_alloc/free_irq()")

which added the non-stub implementations.

Link: https://lore.kernel.org/r/20240410221307.2162676-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Add pci_get_base_class() helper</title>
<updated>2024-08-11T10:47:15+00:00</updated>
<author>
<name>Sui Jingfeng</name>
<email>suijingfeng@loongson.cn</email>
</author>
<published>2023-08-25T06:27:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ccab04dc573e874899a44fd25a4c882d5e3c6de0'/>
<id>ccab04dc573e874899a44fd25a4c882d5e3c6de0</id>
<content type='text'>
[ Upstream commit d427da2323b093a65d8317783e76ab8fad2e2ef0 ]

There is no function to get all PCI devices in a system by matching
against the base class code only, ignoring the sub-class code and
the programming interface.  Add pci_get_base_class() to suit the
need.

For example, if a driver wants to process all PCI display devices in
a system, it can do so like this:

  pdev = NULL;
  while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
    do_something_for_pci_display_device(pdev);
  }

Link: https://lore.kernel.org/r/20230825062714.6325-2-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng &lt;suijingfeng@loongson.cn&gt;
[bhelgaas: reword commit log]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Stable-dep-of: c2bc958b2b03 ("fbdev: vesafb: Detect VGA compatibility from screen info's VESA attributes")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d427da2323b093a65d8317783e76ab8fad2e2ef0 ]

There is no function to get all PCI devices in a system by matching
against the base class code only, ignoring the sub-class code and
the programming interface.  Add pci_get_base_class() to suit the
need.

For example, if a driver wants to process all PCI display devices in
a system, it can do so like this:

  pdev = NULL;
  while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
    do_something_for_pci_display_device(pdev);
  }

Link: https://lore.kernel.org/r/20230825062714.6325-2-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng &lt;suijingfeng@loongson.cn&gt;
[bhelgaas: reword commit log]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Stable-dep-of: c2bc958b2b03 ("fbdev: vesafb: Detect VGA compatibility from screen info's VESA attributes")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Introduce cleanup helpers for device reference counts and locks</title>
<updated>2024-08-03T06:54:33+00:00</updated>
<author>
<name>Ira Weiny</name>
<email>ira.weiny@intel.com</email>
</author>
<published>2023-12-21T00:17:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9b6742dcdc597bb811688cb3b25737b0a3780dc1'/>
<id>9b6742dcdc597bb811688cb3b25737b0a3780dc1</id>
<content type='text'>
commit ced085ef369af7a2b6da962ec2fbd01339f60693 upstream.

The "goto error" pattern is notorious for introducing subtle resource
leaks. Use the new cleanup.h helpers for PCI device reference counts and
locks.

Similar to the new put_device() and device_lock() cleanup helpers,
__free(put_device) and guard(device), define the same for PCI devices,
__free(pci_dev_put) and guard(pci_dev).  These helpers eliminate the
need for "goto free;" and "goto unlock;" patterns. For example, A
'struct pci_dev *' instance declared as:

    struct pci_dev *pdev __free(pci_dev_put) = NULL;

...will automatically call pci_dev_put() if @pdev is non-NULL when @pdev
goes out of scope (automatic variable scope). If a function wants to
invoke pci_dev_put() on error, but return @pdev on success, it can do:

    return no_free_ptr(pdev);

...or:

    return_ptr(pdev);

For potential cleanup opportunity there are 587 open-coded calls to
pci_dev_put() in the kernel with 65 instances within 10 lines of a goto
statement with the CXL driver threatening to add another one.

The guard() helper holds the associated lock for the remainder of the
current scope in which it was invoked. So, for example:

    func(...)
    {
        if (...) {
            ...
            guard(pci_dev); /* pci_dev_lock() invoked here */
            ...
        } /* &lt;- implied pci_dev_unlock() triggered here */
    }

There are 15 invocations of pci_dev_unlock() in the kernel with 5
instances within 10 lines of a goto statement. Again, the CXL driver is
threatening to add another.

Introduce these helpers to preclude the addition of new more error prone
goto put; / goto unlock; sequences. For now, these helpers are used in
drivers/cxl/pci.c to allow ACPI error reports to be fed back into the
CXL driver associated with the PCI device identified in the report.

Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-8-1bb8a4ca2c7a@intel.com
[djbw: rewrite changelog]
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ced085ef369af7a2b6da962ec2fbd01339f60693 upstream.

The "goto error" pattern is notorious for introducing subtle resource
leaks. Use the new cleanup.h helpers for PCI device reference counts and
locks.

Similar to the new put_device() and device_lock() cleanup helpers,
__free(put_device) and guard(device), define the same for PCI devices,
__free(pci_dev_put) and guard(pci_dev).  These helpers eliminate the
need for "goto free;" and "goto unlock;" patterns. For example, A
'struct pci_dev *' instance declared as:

    struct pci_dev *pdev __free(pci_dev_put) = NULL;

...will automatically call pci_dev_put() if @pdev is non-NULL when @pdev
goes out of scope (automatic variable scope). If a function wants to
invoke pci_dev_put() on error, but return @pdev on success, it can do:

    return no_free_ptr(pdev);

...or:

    return_ptr(pdev);

For potential cleanup opportunity there are 587 open-coded calls to
pci_dev_put() in the kernel with 65 instances within 10 lines of a goto
statement with the CXL driver threatening to add another one.

The guard() helper holds the associated lock for the remainder of the
current scope in which it was invoked. So, for example:

    func(...)
    {
        if (...) {
            ...
            guard(pci_dev); /* pci_dev_lock() invoked here */
            ...
        } /* &lt;- implied pci_dev_unlock() triggered here */
    }

There are 15 invocations of pci_dev_unlock() in the kernel with 5
instances within 10 lines of a goto statement. Again, the CXL driver is
threatening to add another.

Introduce these helpers to preclude the addition of new more error prone
goto put; / goto unlock; sequences. For now, these helpers are used in
drivers/cxl/pci.c to allow ACPI error reports to be fed back into the
CXL driver associated with the PCI device identified in the report.

Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Link: https://lore.kernel.org/r/20231220-cxl-cper-v5-8-1bb8a4ca2c7a@intel.com
[djbw: rewrite changelog]
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Do not wait for disconnected devices when resuming</title>
<updated>2024-06-27T11:49:05+00:00</updated>
<author>
<name>Ilpo Järvinen</name>
<email>ilpo.jarvinen@linux.intel.com</email>
</author>
<published>2024-02-08T13:23:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fae0e055d01d245088c497826c2be141b0df9f09'/>
<id>fae0e055d01d245088c497826c2be141b0df9f09</id>
<content type='text'>
[ Upstream commit 6613443ffc49d03e27f0404978f685c4eac43fba ]

On runtime resume, pci_dev_wait() is called:

  pci_pm_runtime_resume()
    pci_pm_bridge_power_up_actions()
      pci_bridge_wait_for_secondary_bus()
        pci_dev_wait()

While a device is runtime suspended along with its PCI hierarchy, the
device could get disconnected. In such case, the link will not come up no
matter how long pci_dev_wait() waits for it.

Besides the above mentioned case, there could be other ways to get the
device disconnected while pci_dev_wait() is waiting for the link to come
up.

Make pci_dev_wait() exit if the device is already disconnected to avoid
unnecessary delay.

The use cases of pci_dev_wait() boil down to two:

  1. Waiting for the device after reset
  2. pci_bridge_wait_for_secondary_bus()

The callers in both cases seem to benefit from propagating the
disconnection as error even if device disconnection would be more
analoguous to the case where there is no device in the first place which
return 0 from pci_dev_wait(). In the case 2, it results in unnecessary
marking of the devices disconnected again but that is just harmless extra
work.

Also make sure compiler does not become too clever with dev-&gt;error_state
and use READ_ONCE() to force a fetch for the up-to-date value.

Link: https://lore.kernel.org/r/20240208132322.4811-1-ilpo.jarvinen@linux.intel.com
Reported-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6613443ffc49d03e27f0404978f685c4eac43fba ]

On runtime resume, pci_dev_wait() is called:

  pci_pm_runtime_resume()
    pci_pm_bridge_power_up_actions()
      pci_bridge_wait_for_secondary_bus()
        pci_dev_wait()

While a device is runtime suspended along with its PCI hierarchy, the
device could get disconnected. In such case, the link will not come up no
matter how long pci_dev_wait() waits for it.

Besides the above mentioned case, there could be other ways to get the
device disconnected while pci_dev_wait() is waiting for the link to come
up.

Make pci_dev_wait() exit if the device is already disconnected to avoid
unnecessary delay.

The use cases of pci_dev_wait() boil down to two:

  1. Waiting for the device after reset
  2. pci_bridge_wait_for_secondary_bus()

The callers in both cases seem to benefit from propagating the
disconnection as error even if device disconnection would be more
analoguous to the case where there is no device in the first place which
return 0 from pci_dev_wait(). In the case 2, it results in unnecessary
marking of the devices disconnected again but that is just harmless extra
work.

Also make sure compiler does not become too clever with dev-&gt;error_state
and use READ_ONCE() to force a fetch for the up-to-date value.

Link: https://lore.kernel.org/r/20240208132322.4811-1-ilpo.jarvinen@linux.intel.com
Reported-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Tested-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/ASPM: Fix deadlock when enabling ASPM</title>
<updated>2024-04-27T15:11:44+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2024-01-30T10:02:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b0f4478838be1f1d330061201898fef65bf8fd7c'/>
<id>b0f4478838be1f1d330061201898fef65bf8fd7c</id>
<content type='text'>
commit 1e560864159d002b453da42bd2c13a1805515a20 upstream.

A last minute revert in 6.7-final introduced a potential deadlock when
enabling ASPM during probe of Qualcomm PCIe controllers as reported by
lockdep:

  ============================================
  WARNING: possible recursive locking detected
  6.7.0 #40 Not tainted
  --------------------------------------------
  kworker/u16:5/90 is trying to acquire lock:
  ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pcie_aspm_pm_state_change+0x58/0xdc

              but task is already holding lock:
  ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc

              other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(pci_bus_sem);
    lock(pci_bus_sem);

               *** DEADLOCK ***

  Call trace:
   print_deadlock_bug+0x25c/0x348
   __lock_acquire+0x10a4/0x2064
   lock_acquire+0x1e8/0x318
   down_read+0x60/0x184
   pcie_aspm_pm_state_change+0x58/0xdc
   pci_set_full_power_state+0xa8/0x114
   pci_set_power_state+0xc4/0x120
   qcom_pcie_enable_aspm+0x1c/0x3c [pcie_qcom]
   pci_walk_bus+0x64/0xbc
   qcom_pcie_host_post_init_2_7_0+0x28/0x34 [pcie_qcom]

The deadlock can easily be reproduced on machines like the Lenovo ThinkPad
X13s by adding a delay to increase the race window during asynchronous
probe where another thread can take a write lock.

Add a new pci_set_power_state_locked() and associated helper functions that
can be called with the PCI bus semaphore held to avoid taking the read lock
twice.

Link: https://lore.kernel.org/r/ZZu0qx2cmn7IwTyQ@hovoldconsulting.com
Link: https://lore.kernel.org/r/20240130100243.11011-1-johan+linaro@kernel.org
Fixes: f93e71aea6c6 ("Revert "PCI/ASPM: Remove pcie_aspm_pm_state_change()"")
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	# 6.7
[bhelgaas: backported to v6.6.y, which contains 8cc22ba3f77c ("Revert
 "PCI/ASPM: Remove pcie_aspm_pm_state_change()""), a backport of
 f93e71aea6c6.  This omits the drivers/pci/controller/dwc/pcie-qcom.c hunk
 that updates qcom_pcie_enable_aspm(), which was added by 9f4f3dfad8cf
 ("PCI: qcom: Enable ASPM for platforms supporting 1.9.0 ops"), which is not
 present in v6.6.28.]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1e560864159d002b453da42bd2c13a1805515a20 upstream.

A last minute revert in 6.7-final introduced a potential deadlock when
enabling ASPM during probe of Qualcomm PCIe controllers as reported by
lockdep:

  ============================================
  WARNING: possible recursive locking detected
  6.7.0 #40 Not tainted
  --------------------------------------------
  kworker/u16:5/90 is trying to acquire lock:
  ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pcie_aspm_pm_state_change+0x58/0xdc

              but task is already holding lock:
  ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc

              other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(pci_bus_sem);
    lock(pci_bus_sem);

               *** DEADLOCK ***

  Call trace:
   print_deadlock_bug+0x25c/0x348
   __lock_acquire+0x10a4/0x2064
   lock_acquire+0x1e8/0x318
   down_read+0x60/0x184
   pcie_aspm_pm_state_change+0x58/0xdc
   pci_set_full_power_state+0xa8/0x114
   pci_set_power_state+0xc4/0x120
   qcom_pcie_enable_aspm+0x1c/0x3c [pcie_qcom]
   pci_walk_bus+0x64/0xbc
   qcom_pcie_host_post_init_2_7_0+0x28/0x34 [pcie_qcom]

The deadlock can easily be reproduced on machines like the Lenovo ThinkPad
X13s by adding a delay to increase the race window during asynchronous
probe where another thread can take a write lock.

Add a new pci_set_power_state_locked() and associated helper functions that
can be called with the PCI bus semaphore held to avoid taking the read lock
twice.

Link: https://lore.kernel.org/r/ZZu0qx2cmn7IwTyQ@hovoldconsulting.com
Link: https://lore.kernel.org/r/20240130100243.11011-1-johan+linaro@kernel.org
Fixes: f93e71aea6c6 ("Revert "PCI/ASPM: Remove pcie_aspm_pm_state_change()"")
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	# 6.7
[bhelgaas: backported to v6.6.y, which contains 8cc22ba3f77c ("Revert
 "PCI/ASPM: Remove pcie_aspm_pm_state_change()""), a backport of
 f93e71aea6c6.  This omits the drivers/pci/controller/dwc/pcie-qcom.c hunk
 that updates qcom_pcie_enable_aspm(), which was added by 9f4f3dfad8cf
 ("PCI: qcom: Enable ASPM for platforms supporting 1.9.0 ops"), which is not
 present in v6.6.28.]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Make pci_dev_is_disconnected() helper public for other drivers</title>
<updated>2024-03-26T22:19:36+00:00</updated>
<author>
<name>Ethan Zhao</name>
<email>haifeng.zhao@linux.intel.com</email>
</author>
<published>2024-03-05T12:21:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e33ee8d5e6fcb54d0e04269e4303d30d54922303'/>
<id>e33ee8d5e6fcb54d0e04269e4303d30d54922303</id>
<content type='text'>
[ Upstream commit 39714fd73c6b60a8d27bcc5b431afb0828bf4434 ]

Make pci_dev_is_disconnected() public so that it can be called from
Intel VT-d driver to quickly fix/workaround the surprise removal
unplug hang issue for those ATS capable devices on PCIe switch downstream
hotplug capable ports.

Beside pci_device_is_present() function, this one has no config space
space access, so is light enough to optimize the normal pure surprise
removal and safe removal flow.

Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Tested-by: Haorong Ye &lt;yehaorong@bytedance.com&gt;
Signed-off-by: Ethan Zhao &lt;haifeng.zhao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240301080727.3529832-2-haifeng.zhao@linux.intel.com
Signed-off-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Stable-dep-of: 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 39714fd73c6b60a8d27bcc5b431afb0828bf4434 ]

Make pci_dev_is_disconnected() public so that it can be called from
Intel VT-d driver to quickly fix/workaround the surprise removal
unplug hang issue for those ATS capable devices on PCIe switch downstream
hotplug capable ports.

Beside pci_device_is_present() function, this one has no config space
space access, so is light enough to optimize the normal pure surprise
removal and safe removal flow.

Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Tested-by: Haorong Ye &lt;yehaorong@bytedance.com&gt;
Signed-off-by: Ethan Zhao &lt;haifeng.zhao@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240301080727.3529832-2-haifeng.zhao@linux.intel.com
Signed-off-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Stable-dep-of: 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Avoid potential out-of-bounds read in pci_dev_for_each_resource()</title>
<updated>2024-01-25T23:35:50+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2023-10-30T11:42:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5b3e25efe16e06779a9a7c7610217c1b921ec179'/>
<id>5b3e25efe16e06779a9a7c7610217c1b921ec179</id>
<content type='text'>
[ Upstream commit 3171e46d677a668eed3086da78671f1e4f5b8405 ]

Coverity complains that pointer in the pci_dev_for_each_resource() may be
wrong, i.e., might be used for the out-of-bounds read.

There is no actual issue right now because we have another check afterwards
and the out-of-bounds read is not being performed. In any case it's better
code with this fixed, hence the proposed change.

As Jonas pointed out "It probably makes the code slightly less performant
as res will now be checked for being not NULL (which will always be true),
but I doubt it will be significant (or in any hot paths)."

Fixes: 09cc90063240 ("PCI: Introduce pci_dev_for_each_resource()")
Reported-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Closes: https://lore.kernel.org/r/20230509182122.GA1259567@bhelgaas
Suggested-by: Jonas Gorski &lt;jonas.gorski@gmail.com&gt;
Link: https://lore.kernel.org/r/20231030114218.2752236-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3171e46d677a668eed3086da78671f1e4f5b8405 ]

Coverity complains that pointer in the pci_dev_for_each_resource() may be
wrong, i.e., might be used for the out-of-bounds read.

There is no actual issue right now because we have another check afterwards
and the out-of-bounds read is not being performed. In any case it's better
code with this fixed, hence the proposed change.

As Jonas pointed out "It probably makes the code slightly less performant
as res will now be checked for being not NULL (which will always be true),
but I doubt it will be significant (or in any hot paths)."

Fixes: 09cc90063240 ("PCI: Introduce pci_dev_for_each_resource()")
Reported-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Closes: https://lore.kernel.org/r/20230509182122.GA1259567@bhelgaas
Suggested-by: Jonas Gorski &lt;jonas.gorski@gmail.com&gt;
Link: https://lore.kernel.org/r/20231030114218.2752236-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/ASPM: Add pci_enable_link_state_locked()</title>
<updated>2023-12-20T16:01:53+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-11-28T08:15:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1e1f461ea574b1a9aba7ffcc15d8721c087c5cda'/>
<id>1e1f461ea574b1a9aba7ffcc15d8721c087c5cda</id>
<content type='text'>
commit 718ab8226636a1a3a7d281f5d6a7ad7c925efe5a upstream.

Add pci_enable_link_state_locked() for enabling link states that can be
used in contexts where a pci_bus_sem read lock is already held (e.g. from
pci_walk_bus()).

This helper will be used to fix a couple of potential deadlocks where
the current helper is called with the lock already held, hence the CC
stable tag.

Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Link: https://lore.kernel.org/r/20231128081512.19387-2-johan+linaro@kernel.org
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
[bhelgaas: include helper name in subject, commit log]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;	# 6.3
Cc: Michael Bottini &lt;michael.a.bottini@linux.intel.com&gt;
Cc: David E. Box &lt;david.e.box@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 718ab8226636a1a3a7d281f5d6a7ad7c925efe5a upstream.

Add pci_enable_link_state_locked() for enabling link states that can be
used in contexts where a pci_bus_sem read lock is already held (e.g. from
pci_walk_bus()).

This helper will be used to fix a couple of potential deadlocks where
the current helper is called with the lock already held, hence the CC
stable tag.

Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Link: https://lore.kernel.org/r/20231128081512.19387-2-johan+linaro@kernel.org
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
[bhelgaas: include helper name in subject, commit log]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;	# 6.3
Cc: Michael Bottini &lt;michael.a.bottini@linux.intel.com&gt;
Cc: David E. Box &lt;david.e.box@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/MSI: Provide stubs for IMS functions</title>
<updated>2023-11-20T10:58:54+00:00</updated>
<author>
<name>Reinette Chatre</name>
<email>reinette.chatre@intel.com</email>
</author>
<published>2023-10-17T17:56:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27a4b416a08467845c8fb0049c334b517cd8ea7e'/>
<id>27a4b416a08467845c8fb0049c334b517cd8ea7e</id>
<content type='text'>
[ Upstream commit 41efa431244f6498833ff8ee8dde28c4924c5479 ]

The IMS related functions (pci_create_ims_domain(), pci_ims_alloc_irq(),
and pci_ims_free_irq()) are not declared when CONFIG_PCI_MSI is disabled.

Provide definitions of these functions for use when callers are compiled
with CONFIG_PCI_MSI disabled.

Fixes: 0194425af0c8 ("PCI/MSI: Provide IMS (Interrupt Message Store) support")
Fixes: c9e5bea27383 ("PCI/MSI: Provide pci_ims_alloc/free_irq()")
Signed-off-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/14ff656899a3757453f8584c1109d7a9b98fa258.1697564731.git.reinette.chatre@intel.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 41efa431244f6498833ff8ee8dde28c4924c5479 ]

The IMS related functions (pci_create_ims_domain(), pci_ims_alloc_irq(),
and pci_ims_free_irq()) are not declared when CONFIG_PCI_MSI is disabled.

Provide definitions of these functions for use when callers are compiled
with CONFIG_PCI_MSI disabled.

Fixes: 0194425af0c8 ("PCI/MSI: Provide IMS (Interrupt Message Store) support")
Fixes: c9e5bea27383 ("PCI/MSI: Provide pci_ims_alloc/free_irq()")
Signed-off-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/14ff656899a3757453f8584c1109d7a9b98fa258.1697564731.git.reinette.chatre@intel.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
