[PATCH v2 5/5] mm: memory-failure: move return value documentation to function declaration

[Shuai Xue <xueshuai@linux.alibaba.com>]

Part of return value comments for memory_failure() were originally
documented at the call site. Move those comments to the function
declaration to improve code readability and to provide developers with
immediate access to function usage and return information.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
---
 arch/x86/kernel/cpu/mce/core.c |  7 -------
 mm/memory-failure.c            | 10 +++++++---
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index c1b945dbccdf..c81695f320bc 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1403,13 +1403,6 @@ static void kill_me_maybe(struct callback_head *cb)
 		return;
 	}
 
-	/*
-	 * -EHWPOISON from memory_failure() means that it already sent SIGBUS
-	 * to the current process with the proper error info,
-	 * -EOPNOTSUPP means hwpoison_filter() filtered the error event,
-	 *
-	 * In both cases, no further processing is required.
-	 */
 	if (ret == -EHWPOISON || ret == -EOPNOTSUPP)
 		return;
 
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index b037952565be..8649849bcdb4 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2216,9 +2216,13 @@ static void kill_procs_now(struct page *p, unsigned long pfn, int flags,
  * Must run in process context (e.g. a work queue) with interrupts
  * enabled and no spinlocks held.
  *
- * Return: 0 for successfully handled the memory error,
- *         -EOPNOTSUPP for hwpoison_filter() filtered the error event,
- *         < 0(except -EOPNOTSUPP) on failure.
+ * Return:
+ *   0             - success,
+ *   -ENXIO        - memory not managed by the kernel
+ *   -EOPNOTSUPP   - hwpoison_filter() filtered the error event,
+ *   -EHWPOISON    - the page was already poisoned, potentially
+ *                   kill process,
+ *   other negative values - failure.
  */
 int memory_failure(unsigned long pfn, int flags)
 {
-- 
2.39.3