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authorMike Rapoport <rppt@linux.ibm.com>2018-11-16 15:08:29 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-11-18 10:15:10 -0800
commit78179556e7605ba07fd3ddba6ab8891fa457b93e (patch)
treebea07f194f19030ff8e50fed78cfaefea0422080 /mm/gup.c
parent5040f8df56fb90c7919f1c9b0b6e54c843437456 (diff)
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mm/gup.c: fix follow_page_mask() kerneldoc comment
Commit df06b37ffe5a ("mm/gup: cache dev_pagemap while pinning pages") modified the signature of follow_page_mask() but left the parameter description behind. Update the description to make the code and comments agree again. While at it, update formatting of the return value description to match Documentation/doc-guide/kernel-doc.rst guidelines. Link: http://lkml.kernel.org/r/1541603316-27832-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..aa43620a3270 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -385,11 +385,17 @@ static struct page *follow_p4d_mask(struct vm_area_struct *vma,
* @vma: vm_area_struct mapping @address
* @address: virtual address to look up
* @flags: flags modifying lookup behaviour
- * @page_mask: on output, *page_mask is set according to the size of the page
+ * @ctx: contains dev_pagemap for %ZONE_DEVICE memory pinning and a
+ * pointer to output page_mask
*
* @flags can have FOLL_ flags set, defined in <linux/mm.h>
*
- * Returns the mapped (struct page *), %NULL if no mapping exists, or
+ * When getting pages from ZONE_DEVICE memory, the @ctx->pgmap caches
+ * the device's dev_pagemap metadata to avoid repeating expensive lookups.
+ *
+ * On output, the @ctx->page_mask is set according to the size of the page.
+ *
+ * Return: the mapped (struct page *), %NULL if no mapping exists, or
* an error pointer if there is a mapping to something not represented
* by a page descriptor (see also vm_normal_page()).
*/