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path: root/drivers/platform/x86/p2sb.c
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* platform/x86: p2sb: Use pci_resource_n() in p2sb_read_bar0()Shin'ichiro Kawasaki2024-01-221-1/+1
| | | | | | | | | | | | | 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>
* platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probeShin'ichiro Kawasaki2024-01-221-41/+139
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Revert "platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe"Shin'ichiro Kawasaki2024-01-041-131/+41
| | | | | | | | | | | | | | | | | 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>
* platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probeShin'ichiro Kawasaki2023-12-291-41/+131
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* platform/x86: p2sb: Don't fail if unknown CPU is foundAndy Shevchenko2022-11-071-9/+6
| | | | | | | | | | | | | | | | | | | | 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>
* platform/x86: p2sb: Fix UAF when caller uses resource nameAndy Shevchenko2022-09-011-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* platform/x86: p2sb: Move out of X86_PLATFORM_DEVICES dependencyAndy Shevchenko2022-08-011-0/+133
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>