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authorLinus Torvalds <torvalds@linux-foundation.org>2009-04-13 11:32:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-13 11:32:09 -0700
commitb8256b45d1245ad16221e8f965241267bd26c79d (patch)
tree88a72ca74e658322496f398fa579d51d10c69055 /arch/x86/mm/gup.c
parent8255309b887fcac11f791913a2d1d0b966a40d32 (diff)
parenta30469e7921a6dd2067e9e836d7787cfa0105627 (diff)
Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: add linux kernel support for YMM state x86: fix wrong section of pat_disable & make it static x86: Fix section mismatches in mpparse x86: fix set_fixmap to use phys_addr_t x86: Document get_user_pages_fast() x86, intr-remap: fix eoi for interrupt remapping without x2apic
Diffstat (limited to 'arch/x86/mm/gup.c')
-rw-r--r--arch/x86/mm/gup.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index be54176e9eb..6340cef6798 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -219,6 +219,22 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
return 1;
}
+/**
+ * get_user_pages_fast() - pin user pages in memory
+ * @start: starting user address
+ * @nr_pages: number of pages from start to pin
+ * @write: whether pages will be written to
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_pages long.
+ *
+ * Attempt to pin user pages in memory without taking mm->mmap_sem.
+ * If not successful, it will fall back to taking the lock and
+ * calling get_user_pages().
+ *
+ * Returns number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno.
+ */
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages)
{