As the number of FADump sysfs files increases it is hard to manage all of
them inside /sys/kernel directory. It's better to have all the FADump
related sysfs files in a dedicated directory /sys/kernel/fadump. But to
maintain the backward compatibility all the /sys/kernel/fadump_* sysfs
files are replicated inside /sys/kernel/fadump/ and eventually get removed
in future.

Added ABI documentation for all the replicated FADump sysfs file in
Documentation/ABI/testing/sysfs-kernel-fadump.

Signed-off-by: Sourabh Jain <sourabhj...@linux.ibm.com>
---
 Documentation/ABI/testing/sysfs-kernel-fadump | 41 +++++++++++++++++++
 arch/powerpc/kernel/fadump.c                  | 29 +++++++++++++
 arch/powerpc/platforms/powernv/opal-core.c    |  7 ++++
 3 files changed, 77 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-fadump

diff --git a/Documentation/ABI/testing/sysfs-kernel-fadump 
b/Documentation/ABI/testing/sysfs-kernel-fadump
new file mode 100644
index 000000000000..ed8eec3d759c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-fadump
@@ -0,0 +1,41 @@
+What:          /sys/kernel/fadump/fadump_*
+Date:          Sep 2019
+Contact:       linuxppc-dev@lists.ozlabs.org
+Description:
+               The /sys/kernel/fadump/fadump_* is a collection of FADump
+               sysfs file provide information about the configuration status
+               of Firmware Assisted Dump (FADump).
+
+What:          /sys/kernel/fadump/enabled
+Date:          Sep 2019
+Contact:       linuxppc-dev@lists.ozlabs.org
+Description:   read only
+               Primarily used to identify whether the FADump is enabled in
+               the kernel or not.
+User:          Kdump service
+
+What:          /sys/kernel/fadump/registered
+Date:          Sep 2019
+Contact:       linuxppc-dev@lists.ozlabs.org
+Description:   read/write
+               Helps to control the dump collect feature from userspace.
+               Setting 1 to this file enables the system to collect the
+               dump and 0 to disable it.
+User:          Kdump service
+
+What:          /sys/kernel/fadump/release_mem
+Date:          Sep 2019
+Contact:       linuxppc-dev@lists.ozlabs.org
+Description:   write only
+               This is a special sysfs file and only available when
+               the system is booted to capture the vmcore using FADump.
+               It is used to release the memory reserved by FADump to
+               save the crash dump.
+
+What:          /sys/kernel/fadump/release_opalcore
+Date:          Sep 2019
+Contact:       linuxppc-dev@lists.ozlabs.org
+Description:   write only
+               The sysfs file is available when the system is booted to
+               collect the dump on OPAL based machine. It used to release
+               the memory used to collect the opalcore.
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index ed59855430b9..bb70fa208a86 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -1418,6 +1418,9 @@ static int fadump_region_show(struct seq_file *m, void 
*private)
        return 0;
 }
 
+struct kobject *fadump_kobj;
+EXPORT_SYMBOL_GPL(fadump_kobj);
+
 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
                                                0200, NULL,
                                                fadump_release_memory_store);
@@ -1435,6 +1438,11 @@ static void fadump_init_files(void)
        struct dentry *debugfs_file;
        int rc = 0;
 
+       fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
+       if (!fadump_kobj) {
+               pr_err("failed to create fadump kobject\n");
+               return;
+       }
        rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
        if (rc)
                printk(KERN_ERR "fadump: unable to create sysfs file"
@@ -1458,6 +1466,27 @@ static void fadump_init_files(void)
                        printk(KERN_ERR "fadump: unable to create sysfs file"
                                " fadump_release_mem (%d)\n", rc);
        }
+       /* Replicating the following sysfs attributes in a new directory
+        * named fadump.
+        *
+        *      - fadump_enabled
+        *      - fadump_registered
+        *      - fadump_release_mem
+        */
+       rc = sysfs_create_file(fadump_kobj, &fadump_attr.attr);
+       if (rc)
+               pr_err("unable to create fadump/fadump_enabled sysfs file 
(%d)\n",
+                      rc);
+       rc = sysfs_create_file(fadump_kobj, &fadump_register_attr.attr);
+       if (rc)
+               pr_err("unable to create fadump/fadump_registered sysfs file 
(%d)\n",
+                      rc);
+       if (fw_dump.dump_active) {
+               rc = sysfs_create_file(fadump_kobj, &fadump_release_attr.attr);
+               if (rc)
+                       pr_err("unable to create fadump/fadump_release_mem 
sysfs file (%d)\n",
+                              rc);
+       }
        return;
 }
 
diff --git a/arch/powerpc/platforms/powernv/opal-core.c 
b/arch/powerpc/platforms/powernv/opal-core.c
index ed895d82c048..8c31aefe8814 100644
--- a/arch/powerpc/platforms/powernv/opal-core.c
+++ b/arch/powerpc/platforms/powernv/opal-core.c
@@ -631,6 +631,13 @@ static int __init opalcore_init(void)
                        rc);
        }
 
+       /* Replicating the fadump_release_opalcore sysfs file */
+       rc = sysfs_create_file(fadump_kobj, &opalcore_rel_attr.attr);
+       if (rc) {
+               pr_warn("unable to create fadump/fadump_release_opalcore sysfs 
file (%d)\n",
+                       rc)
+       }
+
        return 0;
 }
 fs_initcall(opalcore_init);
-- 
2.17.2

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