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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-08-13 15:39:10 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-08-13 15:39:10 -0400
commit0980bd9cd32de2fef7eaa2858345c49d14498625 (patch)
tree41f5f823d0569a81b22037e79c22d823933a63f1 /mm/swap.c
parent78821b2c0299ab807d483802f09897728b93bce0 (diff)
parent0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff)
Merge commit 'v3.6-rc1' into linux-next
* commit 'v3.6-rc1': (9532 commits) Linux 3.6-rc1 mm: remove node_start_pfn checking in new WARN_ON for now ARM: mmp: add missing irqs.h arm: mvebu: fix typo in .dtsi comment for Armada XP SoCs ARM: PRIMA2: delete redundant codes to restore LATCHED when timer resumes libceph: fix crypto key null deref, memory leak ceph: simplify+fix atomic_open sh: explicitly include sh_dma.h in setup-sh7722.c um: Add arch/x86/um to MAINTAINERS um: pass siginfo to guest process um: fix ubd_file_size for read-only files md/dm-raid: DM_RAID should select MD_RAID10 md/raid1: submit IO from originating thread instead of md thread. raid5: raid5d handle stripe in batch way raid5: make_request use batch stripe release um: pull interrupt_end() into userspace() um: split syscall_trace(), pass pt_regs to it um: switch UPT_SET_RETURN_VALUE and regs_return_value to pt_regs MIPS: Loongson 2: Sort out clock managment. locks: remove unused lm_release_private ...
Diffstat (limited to 'mm/swap.c')
-rw-r--r--mm/swap.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/mm/swap.c b/mm/swap.c
index 4e7e2ec67078..77825883298f 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -236,6 +236,58 @@ void put_pages_list(struct list_head *pages)
}
EXPORT_SYMBOL(put_pages_list);
+/*
+ * get_kernel_pages() - pin kernel pages in memory
+ * @kiov: An array of struct kvec structures
+ * @nr_segs: number of segments to pin
+ * @write: pinning for read/write, currently ignored
+ * @pages: array that receives pointers to the pages pinned.
+ * Should be at least nr_segs long.
+ *
+ * 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. Each page returned must be released
+ * with a put_page() call when it is finished with.
+ */
+int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write,
+ struct page **pages)
+{
+ int seg;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE))
+ return seg;
+
+ pages[seg] = kmap_to_page(kiov[seg].iov_base);
+ page_cache_get(pages[seg]);
+ }
+
+ return seg;
+}
+EXPORT_SYMBOL_GPL(get_kernel_pages);
+
+/*
+ * get_kernel_page() - pin a kernel page in memory
+ * @start: starting kernel address
+ * @write: pinning for read/write, currently ignored
+ * @pages: array that receives pointer to the page pinned.
+ * Must be at least nr_segs long.
+ *
+ * Returns 1 if page is pinned. If the page was not pinned, returns
+ * -errno. The page returned must be released with a put_page() call
+ * when it is finished with.
+ */
+int get_kernel_page(unsigned long start, int write, struct page **pages)
+{
+ const struct kvec kiov = {
+ .iov_base = (void *)start,
+ .iov_len = PAGE_SIZE
+ };
+
+ return get_kernel_pages(&kiov, 1, write, pages);
+}
+EXPORT_SYMBOL_GPL(get_kernel_page);
+
static void pagevec_lru_move_fn(struct pagevec *pvec,
void (*move_fn)(struct page *page, struct lruvec *lruvec, void *arg),
void *arg)