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authorMark Brown <broonie@kernel.org>2018-12-11 23:44:49 +0300
committerMark Brown <broonie@kernel.org>2018-12-11 23:44:49 +0300
commite6202e8249aa7115af65f2d80b43c132816224ef (patch)
tree8865dd722ad55bb5e6bd5d446057395336ed0169 /mm/gup.c
parent2b96edb570709d6ca2e06842941c4bdf04b55f47 (diff)
parentd407c81adae57041ba82577e604e351f36b8afce (diff)
downloadlinux-e6202e8249aa7115af65f2d80b43c132816224ef.tar.xz
Merge branch 'for-linus' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-4.21
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..8cb68a50dbdf 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()).
*/
@@ -696,12 +702,11 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
if (!vma || start >= vma->vm_end) {
vma = find_extend_vma(mm, start);
if (!vma && in_gate_area(mm, start)) {
- int ret;
ret = get_gate_page(mm, start & PAGE_MASK,
gup_flags, &vma,
pages ? &pages[i] : NULL);
if (ret)
- return i ? : ret;
+ goto out;
ctx.page_mask = 0;
goto next_page;
}