From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- Documentation/ABI/testing/sysfs-bus-cdx | 121 ++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-cdx (limited to 'Documentation/ABI/testing/sysfs-bus-cdx') diff --git a/Documentation/ABI/testing/sysfs-bus-cdx b/Documentation/ABI/testing/sysfs-bus-cdx new file mode 100644 index 000000000..e84277531 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-cdx @@ -0,0 +1,121 @@ +What: /sys/bus/cdx/rescan +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Writing y/1/on to this file will cause rescan of the bus + and devices on the CDX bus. Any new devices are scanned and + added to the list of Linux devices and any devices removed are + also deleted from Linux. + + For example:: + + # echo 1 > /sys/bus/cdx/rescan + +What: /sys/bus/cdx/devices/.../vendor +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Vendor ID for this CDX device, in hexadecimal. Vendor ID is + 16 bit identifier which is specific to the device manufacturer. + Combination of Vendor ID and Device ID identifies a device. + +What: /sys/bus/cdx/devices/.../device +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Device ID for this CDX device, in hexadecimal. Device ID is + 16 bit identifier to identify a device type within the range + of a device manufacturer. + Combination of Vendor ID and Device ID identifies a device. + +What: /sys/bus/cdx/devices/.../subsystem_vendor +Date: July 2023 +Contact: puneet.gupta@amd.com +Description: + Subsystem Vendor ID for this CDX device, in hexadecimal. + Subsystem Vendor ID is 16 bit identifier specific to the + card manufacturer. + +What: /sys/bus/cdx/devices/.../subsystem_device +Date: July 2023 +Contact: puneet.gupta@amd.com +Description: + Subsystem Device ID for this CDX device, in hexadecimal + Subsystem Device ID is 16 bit identifier specific to the + card manufacturer. + +What: /sys/bus/cdx/devices/.../class +Date: July 2023 +Contact: puneet.gupta@amd.com +Description: + This file contains the class of the CDX device, in hexadecimal. + Class is 24 bit identifier specifies the functionality of the device. + +What: /sys/bus/cdx/devices/.../revision +Date: July 2023 +Contact: puneet.gupta@amd.com +Description: + This file contains the revision field of the CDX device, in hexadecimal. + Revision is 8 bit revision identifier of the device. + +What: /sys/bus/cdx/devices/.../enable +Date: October 2023 +Contact: abhijit.gangurde@amd.com +Description: + CDX bus should be disabled before updating the devices in FPGA. + Writing n/0/off will attempt to disable the CDX bus and. + writing y/1/on will attempt to enable the CDX bus. Reading this file + gives the current state of the bus, 1 for enabled and 0 for disabled. + + For example:: + + # echo 1 > /sys/bus/cdx/.../enable + +What: /sys/bus/cdx/devices/.../reset +Date: March 2023 +Contact: nipun.gupta@amd.com +Description: + Writing y/1/on to this file resets the CDX device or all devices + on the bus. On resetting the device, the corresponding driver is + notified twice, once before the device is being reset, and again + after the reset has been complete. + + For example:: + + # echo 1 > /sys/bus/cdx/.../reset + +What: /sys/bus/cdx/devices/.../remove +Date: March 2023 +Contact: tarak.reddy@amd.com +Description: + Writing y/1/on to this file removes the corresponding + device from the CDX bus. If the device is to be reconfigured + reconfigured in the Hardware, the device can be removed, so + that the device driver does not access the device while it is + being reconfigured. + + For example:: + + # echo 1 > /sys/bus/cdx/devices/.../remove + +What: /sys/bus/cdx/devices/.../resource +Date: July 2023 +Contact: puneet.gupta@amd.com +Description: + The resource binary file contains the content of the memory + regions. These files can be m'maped from userspace. + +What: /sys/bus/cdx/devices/.../modalias +Date: July 2023 +Contact: nipun.gupta@amd.com +Description: + This attribute indicates the CDX ID of the device. + That is in the format: + cdx:vXXXXdXXXXsvXXXXsdXXXXcXXXXXX, + where: + + - vXXXX contains the vendor ID; + - dXXXX contains the device ID; + - svXXXX contains the subsystem vendor ID; + - sdXXXX contains the subsystem device ID; + - cXXXXXX contains the device class. -- cgit v1.3.1