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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-06 09:48:31 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-06 09:48:31 -0700
commitc87985a3ce723995fc7b25e598238d67154108a1 (patch)
treee60def1b77c25c1d74180f62e8a5603f9826f209 /mm/swap.c
parentd155255a344c417acad74156654295a2964e6b81 (diff)
parent0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff)
Merge tty-next into 3.6-rc1
This handles the merge issue in: arch/um/drivers/line.c arch/um/drivers/line.h And resolves the duplicate patches that were in both trees do to the tty-next branch not getting merged into 3.6-rc1. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 4e7e2ec6707..77825883298 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)