summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
diff options
context:
space:
mode:
authorYazen Ghannam <yazen.ghannam@amd.com>2026-09-03 10:43:25 -0500
committerBorislav Petkov (AMD) <bp@alien8.de>2026-09-10 18:05:43 -0700
commit27600805e62f800bacf990354632eae4e487d34c (patch)
treee8aec0ddfaa0bc264d79af632e3de3f1b75ae4c8 /Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
downloadlinux-stable-27600805e62f800bacf990354632eae4e487d34c.tar.gz
linux-stable-27600805e62f800bacf990354632eae4e487d34c.zip
x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted
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 <sashiko-bot@kernel.org> Assisted-by: LLM Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Cc: <stable@kernel.org> Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com
Diffstat (limited to 'Documentation/ABI/testing/sysfs-firmware-efi-runtime-map')
-rw-r--r--Documentation/ABI/testing/sysfs-firmware-efi-runtime-map36
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
new file mode 100644
index 000000000..9c4d581be
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
@@ -0,0 +1,36 @@
+What: /sys/firmware/efi/runtime-map/
+Date: December 2013
+Contact: Dave Young <dyoung@redhat.com>
+Description: Switching efi runtime services to virtual mode requires
+ that all efi memory ranges which have the runtime attribute
+ bit set to be mapped to virtual addresses.
+
+ The efi runtime services can only be switched to virtual
+ mode once without rebooting. The kexec kernel must maintain
+ the same physical to virtual address mappings as the first
+ kernel. The mappings are exported to sysfs so userspace tools
+ can reassemble them and pass them into the kexec kernel.
+
+ /sys/firmware/efi/runtime-map/ is the directory the kernel
+ exports that information in.
+
+ subdirectories are named with the number of the memory range::
+
+ /sys/firmware/efi/runtime-map/0
+ /sys/firmware/efi/runtime-map/1
+ /sys/firmware/efi/runtime-map/2
+ /sys/firmware/efi/runtime-map/3
+ ...
+
+ Each subdirectory contains five files:
+
+ ========= =========================================
+ attribute The attributes of the memory range.
+ num_pages The size of the memory range in pages.
+ phys_addr The physical address of the memory range.
+ type The type of the memory range.
+ virt_addr The virtual address of the memory range.
+ ========= =========================================
+
+ Above values are all hexadecimal numbers with the '0x' prefix.
+Users: Kexec