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path: root/drivers/platform/x86/p2sb.c
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2024-12-10p2sb: Do not scan and remove the P2SB device when it is unhiddenShin'ichiro Kawasaki
When drivers access P2SB device resources, it calls p2sb_bar(). Before the commit 5913320eb0b3 ("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 5913320eb0b3 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: 5913320eb0b3 ("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>
2024-12-10p2sb: Move P2SB hide and unhide code to p2sb_scan_and_cache()Shin'ichiro Kawasaki
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>
2024-12-10p2sb: Introduce the global flag p2sb_hidden_by_biosShin'ichiro Kawasaki
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>
2024-12-10p2sb: Factor out p2sb_read_from_cache()Shin'ichiro Kawasaki
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>
2024-11-18platform/x86: p2sb: Cache correct PCI bar for P2SB on Gemini LakeHans de Goede
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: 2841631a0365 ("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>
2024-06-03platform/x86: p2sb: Switch to new Intel CPU model definesTony Luck
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>
2024-05-14platform/x86: p2sb: Don't init until unassigned resources have been assignedBen Fradella
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>
2024-03-25platform/x86: p2sb: Make p2sb_get_devfn() return voidHans de Goede
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
2024-03-05platform/x86: p2sb: On Goldmont only cache P2SB and SPI devfn BARHans de Goede
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: 5913320eb0b3 ("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
2024-01-22platform/x86: p2sb: Use pci_resource_n() in p2sb_read_bar0()Shin'ichiro Kawasaki
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>
2024-01-22platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probeShin'ichiro Kawasaki
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: 9745fb07474f ("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>
2024-01-04Revert "platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe"Shin'ichiro Kawasaki
This reverts commit b28ff7a7c3245d7f62acc20f15b4361292fe4117. The commit introduced P2SB device scan and resource cache during the boot process to avoid deadlock. But it caused detection failure of IDE controllers on old systems [1]. The IDE controllers on old systems and P2SB devices on newer systems have same PCI DEVFN. It is suspected the confusion between those two is the failure cause. Revert the change at this moment until the proper solution gets ready. Link: https://lore.kernel.org/platform-driver-x86/CABq1_vjfyp_B-f4LAL6pg394bP6nDFyvg110TOLHHb0x4aCPeg@mail.gmail.com/T/#m07b30468d9676fc5e3bb2122371121e4559bb383 [1] Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20240104114050.3142690-1-shinichiro.kawasaki@wdc.com Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2023-12-29platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probeShin'ichiro Kawasaki
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: 9745fb07474f ("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>
2022-11-07platform/x86: p2sb: Don't fail if unknown CPU is foundAndy Shevchenko
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: 5c7b9167ddf8 ("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>
2022-09-01platform/x86: p2sb: Fix UAF when caller uses resource nameAndy Shevchenko
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: 9745fb07474f ("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>
2022-08-01platform/x86: p2sb: Move out of X86_PLATFORM_DEVICES dependencyAndy Shevchenko
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>