When drivers access P2SB device resources, it calls p2sb_bar(). Before
the commit 5913320eb0 ("platform/x86: p2sb: Allow p2sb_bar() calls
during PCI device probe"), p2sb_bar() obtained the resources and then
called pci_stop_and_remove_bus_device() for clean up. Then the P2SB
device disappeared. The commit 5913320eb0 introduced the P2SB device
resource cache feature in the boot process. During the resource cache,
pci_stop_and_remove_bus_device() is called for the P2SB device, then the
P2SB device disappears regardless of whether p2sb_bar() is called or
not. Such P2SB device disappearance caused a confusion [1]. To avoid the
confusion, avoid the pci_stop_and_remove_bus_device() call when the BIOS
does not hide the P2SB device.
For that purpose, cache the P2SB device resources only if the BIOS hides
the P2SB device. Call p2sb_scan_and_cache() only if p2sb_hidden_by_bios
is true. This allows removing two branches from p2sb_scan_and_cache().
When p2sb_bar() is called, get the resources from the cache if the P2SB
device is hidden. Otherwise, read the resources from the unhidden P2SB
device.
Reported-by: Daniel Walker (danielwa) <danielwa@cisco.com>
Closes: https://lore.kernel.org/lkml/ZzTI+biIUTvFT6NC@goliath/ [1]
Fixes: 5913320eb0 ("platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241128002836.373745-5-shinichiro.kawasaki@wdc.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
To prepare for the following fix, move the code to hide and unhide the
P2SB device from p2sb_cache_resources() to p2sb_scan_and_cache().
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241128002836.373745-4-shinichiro.kawasaki@wdc.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
To prepare for the following fix, introduce the global flag
p2sb_hidden_by_bios. Check if the BIOS hides the P2SB device and store
the result in the flag. This allows to refer to the check result across
functions.
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241128002836.373745-3-shinichiro.kawasaki@wdc.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
To prepare for the following fix, factor out the code to read the P2SB
resource from the cache to the new function p2sb_read_from_cache().
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241128002836.373745-2-shinichiro.kawasaki@wdc.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Gemini Lake (Goldmont Plus) is an Apollo Lake (Goldmont) derived design and
as such has the P2SB at device.function 13.0, rather then at the default
31.1, just like Apollo Lake.
At a mapping to P2SB_DEVFN_GOLDMONT to p2sb_cpu_ids[] for Goldmont Plus,
so that the correct PCI bar gets cached.
This fixes P2SB unhiding not working on these devices, which fixes
SPI support for the bootrom SPI controller not working.
Fixes: 2841631a03 ("platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe")
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241116154546.85761-1-hdegoede@redhat.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
New CPU #defines encode vendor and family as well as model.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240531203706.233365-5-tony.luck@intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
The P2SB could get an invalid BAR from the BIOS, and that won't be fixed
up until pcibios_assign_resources(), which is an fs_initcall().
- Move p2sb_fs_init() to an fs_initcall_sync(). This is still early
enough to avoid a race with any dependent drivers.
- Add a check for IORESOURCE_UNSET in p2sb_valid_resource() to catch
unset BARs going forward.
- Return error values from p2sb_fs_init() so that the 'initcall_debug'
cmdline arg provides useful data.
Signed-off-by: Ben Fradella <bfradell@netapp.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240509164905.41016-1-bcfradella@proton.me
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
p2sb_get_devfn() always succeeds, make it return void and
remove error checking from its callers.
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240305094500.23778-1-hdegoede@redhat.com
On Goldmont p2sb_bar() only ever gets called for 2 devices, the actual P2SB
devfn 13,0 and the SPI controller which is part of the P2SB, devfn 13,2.
But the current p2sb code tries to cache BAR0 info for all of
devfn 13,0 to 13,7 . This involves calling pci_scan_single_device()
for device 13 functions 0-7 and the hw does not seem to like
pci_scan_single_device() getting called for some of the other hidden
devices. E.g. on an ASUS VivoBook D540NV-GQ065T this leads to continuous
ACPI errors leading to high CPU usage.
Fix this by only caching BAR0 info and thus only calling
pci_scan_single_device() for the P2SB and the SPI controller.
Fixes: 5913320eb0 ("platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe")
Reported-by: Danil Rybakov <danilrybakov249@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218531
Tested-by: Danil Rybakov <danilrybakov249@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240304134356.305375-2-hdegoede@redhat.com
Accesses to resource[] member of struct pci_dev shall be wrapped with
pci_resource_n() for future compatibility. Call the helper function in
p2sb_read_bar0().
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240108062059.3583028-3-shinichiro.kawasaki@wdc.com
Tested-by Klara Modin <klarasmodin@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
p2sb_bar() unhides P2SB device to get resources from the device. It
guards the operation by locking pci_rescan_remove_lock so that parallel
rescans do not find the P2SB device. However, this lock causes deadlock
when PCI bus rescan is triggered by /sys/bus/pci/rescan. The rescan
locks pci_rescan_remove_lock and probes PCI devices. When PCI devices
call p2sb_bar() during probe, it locks pci_rescan_remove_lock again.
Hence the deadlock.
To avoid the deadlock, do not lock pci_rescan_remove_lock in p2sb_bar().
Instead, do the lock at fs_initcall. Introduce p2sb_cache_resources()
for fs_initcall which gets and caches the P2SB resources. At p2sb_bar(),
refer the cache and return to the caller.
Before operating the device at P2SB DEVFN for resource cache, check
that its device class is PCI_CLASS_MEMORY_OTHER 0x0580 that PCH
specifications define. This avoids unexpected operation to other devices
at the same DEVFN.
Link: https://lore.kernel.org/linux-pci/6xb24fjmptxxn5js2fjrrddjae6twex5bjaftwqsuawuqqqydx@7cl3uik5ef6j/
Fixes: 9745fb0747 ("platform/x86/intel: Add Primary to Sideband (P2SB) bridge support")
Cc: stable@vger.kernel.org
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240108062059.3583028-2-shinichiro.kawasaki@wdc.com
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by Klara Modin <klarasmodin@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
p2sb_bar() unhides P2SB device to get resources from the device. It
guards the operation by locking pci_rescan_remove_lock so that parallel
rescans do not find the P2SB device. However, this lock causes deadlock
when PCI bus rescan is triggered by /sys/bus/pci/rescan. The rescan
locks pci_rescan_remove_lock and probes PCI devices. When PCI devices
call p2sb_bar() during probe, it locks pci_rescan_remove_lock again.
Hence the deadlock.
To avoid the deadlock, do not lock pci_rescan_remove_lock in p2sb_bar().
Instead, do the lock at fs_initcall. Introduce p2sb_cache_resources()
for fs_initcall which gets and caches the P2SB resources. At p2sb_bar(),
refer the cache and return to the caller.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: 9745fb0747 ("platform/x86/intel: Add Primary to Sideband (P2SB) bridge support")
Cc: stable@vger.kernel.org
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/linux-pci/6xb24fjmptxxn5js2fjrrddjae6twex5bjaftwqsuawuqqqydx@7cl3uik5ef6j/
Link: https://lore.kernel.org/r/20231229063912.2517922-2-shinichiro.kawasaki@wdc.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
We have accessing P2SB from a very few places for quite known hardware.
When a new SoC appears in intel-family.h it's not obvious that it needs
to be added to p2sb.c as well. Instead, provide default BDF and refactor
p2sb_get_devfn() to always succeed. If in the future we would need to
exclude something, we may add a list of unsupported IDs.
Without this change the iTCO on Intel Comet Lake SoCs became unavailable:
i801_smbus 0000:00:1f.4: failed to create iTCO device
Fixes: 5c7b9167dd ("i2c: i801: convert to use common P2SB accessor")
Reported-and-tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221104154916.35231-1-andriy.shevchenko@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
We have to copy only selected fields from the original resource.
Because a PCI device will be removed immediately after getting
its resources, we may not use any allocated data, hence we may
not copy any pointers.
Consider the following scenario:
1/ a caller of p2sb_bar() gets the resource;
2/ the resource has been copied by platform_device_add_data()
in order to create a platform device;
3/ the platform device creation will call for the device driver's
->probe() as soon as a match found;
4/ the ->probe() takes given resources (see 2/) and tries to
access one of its field, i.e. 'name', in the
__devm_ioremap_resource() to create a pretty looking output;
5/ but the 'name' is a dangling pointer because p2sb_bar()
removed a PCI device, which 'name' had been copied to
the caller's memory.
6/ UAF (Use-After-Free) as a result.
Kudos to Mika for the initial analisys of the issue.
Fixes: 9745fb0747 ("platform/x86/intel: Add Primary to Sideband (P2SB) bridge support")
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/linux-i2c/YvPCbnKqDiL2XEKp@xsang-OptiPlex-9020/
Link: https://lore.kernel.org/linux-i2c/YtjAswDKfiuDfWYs@xsang-OptiPlex-9020/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220901113406.65876-1-andriy.shevchenko@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The P2SB library is used for various drivers, including server
platforms. That's why the dependency on X86_PLATFORM_DEVICES
seems superfluous.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220718145328.14374-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
