Documentation/ABI: mark old kexec sysfs deprecated

The previous commit ("kexec: move sysfs entries to /sys/kernel/kexec")
moved all existing kexec sysfs entries to a new location. The ABI
document is updated to include a note about the deprecation of the old
kexec sysfs entries.

The following kexec sysfs entries are deprecated:
- /sys/kernel/kexec_loaded
- /sys/kernel/kexec_crash_loaded
- /sys/kernel/kexec_crash_size
- /sys/kernel/crash_elfcorehdr_size
- /sys/kernel/kexec_crash_cma_ranges

Link: https://lkml.kernel.org/r/20251118114507.1769455-3-sourabhjain@linux.ibm.com
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Aditya Gupta <adityag@linux.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh J Salgaonkar <mahesh@linux.ibm.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/ABI/obsolete/sysfs-kernel-kexec-kdump b/Documentation/ABI/obsolete/sysfs-kernel-kexec-kdump
new file mode 100644 (file)
index 0000000..ba26a6a
--- /dev/null
+++ b/Documentation/ABI/obsolete/sysfs-kernel-kexec-kdump
@@ -0,0 +1,71 @@
+NOTE: all the ABIs listed in this file are deprecated and will be removed after 2028.
+
+Here are the alternative ABIs:
++------------------------------------+-----------------------------------------+
+| Deprecated                         | Alternative                             |
++------------------------------------+-----------------------------------------+
+| /sys/kernel/kexec_loaded           | /sys/kernel/kexec/loaded                |
++------------------------------------+-----------------------------------------+
+| /sys/kernel/kexec_crash_loaded     | /sys/kernel/kexec/crash_loaded          |
++------------------------------------+-----------------------------------------+
+| /sys/kernel/kexec_crash_size       | /sys/kernel/kexec/crash_size            |
++------------------------------------+-----------------------------------------+
+| /sys/kernel/crash_elfcorehdr_size  | /sys/kernel/kexec/crash_elfcorehdr_size |
++------------------------------------+-----------------------------------------+
+| /sys/kernel/kexec_crash_cma_ranges | /sys/kernel/kexec/crash_cma_ranges      |
++------------------------------------+-----------------------------------------+
+
+
+What:          /sys/kernel/kexec_loaded
+Date:          Jun 2006
+Contact:       kexec@lists.infradead.org
+Description:   read only
+               Indicates whether a new kernel image has been loaded
+               into memory using the kexec system call. It shows 1 if
+               a kexec image is present and ready to boot, or 0 if none
+               is loaded.
+User:          kexec tools, kdump service
+
+What:          /sys/kernel/kexec_crash_loaded
+Date:          Jun 2006
+Contact:       kexec@lists.infradead.org
+Description:   read only
+               Indicates whether a crash (kdump) kernel is currently
+               loaded into memory. It shows 1 if a crash kernel has been
+               successfully loaded for panic handling, or 0 if no crash
+               kernel is present.
+User:          Kexec tools, Kdump service
+
+What:          /sys/kernel/kexec_crash_size
+Date:          Dec 2009
+Contact:       kexec@lists.infradead.org
+Description:   read/write
+               Shows the amount of memory reserved for loading the crash
+               (kdump) kernel. It reports the size, in bytes, of the
+               crash kernel area defined by the crashkernel= parameter.
+               This interface also allows reducing the crashkernel
+               reservation by writing a smaller value, and the reclaimed
+               space is added back to the system RAM.
+User:          Kdump service
+
+What:          /sys/kernel/crash_elfcorehdr_size
+Date:          Aug 2023
+Contact:       kexec@lists.infradead.org
+Description:   read only
+               Indicates the preferred size of the memory buffer for the
+               ELF core header used by the crash (kdump) kernel. It defines
+               how much space is needed to hold metadata about the crashed
+               system, including CPU and memory information. This information
+               is used by the user space utility kexec to support updating the
+               in-kernel kdump image during hotplug operations.
+User:          Kexec tools
+
+What:          /sys/kernel/kexec_crash_cma_ranges
+Date:          Nov 2025
+Contact:       kexec@lists.infradead.org
+Description:   read only
+               Provides information about the memory ranges reserved from
+               the Contiguous Memory Allocator (CMA) area that are allocated
+               to the crash (kdump) kernel. It lists the start and end physical
+               addresses of CMA regions assigned for crashkernel use.
+User:          kdump service

diff --git a/Documentation/ABI/testing/sysfs-kernel-kexec-kdump b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
deleted file mode 100644 (file)
index f6089e3..0000000
--- a/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
+++ /dev/null
@@ -1,53 +0,0 @@
-What:          /sys/kernel/kexec_loaded
-Date:          Jun 2006
-Contact:       kexec@lists.infradead.org
-Description:   read only
-               Indicates whether a new kernel image has been loaded
-               into memory using the kexec system call. It shows 1 if
-               a kexec image is present and ready to boot, or 0 if none
-               is loaded.
-User:          kexec tools, kdump service
-
-What:          /sys/kernel/kexec_crash_loaded
-Date:          Jun 2006
-Contact:       kexec@lists.infradead.org
-Description:   read only
-               Indicates whether a crash (kdump) kernel is currently
-               loaded into memory. It shows 1 if a crash kernel has been
-               successfully loaded for panic handling, or 0 if no crash
-               kernel is present.
-User:          Kexec tools, Kdump service
-
-What:          /sys/kernel/kexec_crash_size
-Date:          Dec 2009
-Contact:       kexec@lists.infradead.org
-Description:   read/write
-               Shows the amount of memory reserved for loading the crash
-               (kdump) kernel. It reports the size, in bytes, of the
-               crash kernel area defined by the crashkernel= parameter.
-               This interface also allows reducing the crashkernel
-               reservation by writing a smaller value, and the reclaimed
-               space is added back to the system RAM.
-User:          Kdump service
-
-What:          /sys/kernel/crash_elfcorehdr_size
-Date:          Aug 2023
-Contact:       kexec@lists.infradead.org
-Description:   read only
-               Indicates the preferred size of the memory buffer for the
-               ELF core header used by the crash (kdump) kernel. It defines
-               how much space is needed to hold metadata about the crashed
-               system, including CPU and memory information. This information
-               is used by the user space utility kexec to support updating the
-               in-kernel kdump image during hotplug operations.
-User:          Kexec tools
-
-What:          /sys/kernel/kexec_crash_cma_ranges
-Date:          Nov 2025
-Contact:       kexec@lists.infradead.org
-Description:   read only
-               Provides information about the memory ranges reserved from
-               the Contiguous Memory Allocator (CMA) area that are allocated
-               to the crash (kdump) kernel. It lists the start and end physical
-               addresses of CMA regions assigned for crashkernel use.
-User:          kdump service