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-rw-r--r--mm/highmem.c30
1 files changed, 26 insertions, 4 deletions
diff --git a/mm/highmem.c b/mm/highmem.c
index 35d47733cde4..7da4a7b6af11 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -104,8 +104,9 @@ static void flush_all_zero_pkmaps(void)
flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
}
-/* Flush all unused kmap mappings in order to remove stray
- mappings. */
+/**
+ * kmap_flush_unused - flush all unused kmap mappings in order to remove stray mappings
+ */
void kmap_flush_unused(void)
{
spin_lock(&kmap_lock);
@@ -163,6 +164,14 @@ start:
return vaddr;
}
+/**
+ * kmap_high - map a highmem page into memory
+ * @page: &struct page to map
+ *
+ * Returns the page's virtual memory address.
+ *
+ * We cannot call this from interrupts, as it may block.
+ */
void *kmap_high(struct page *page)
{
unsigned long vaddr;
@@ -170,8 +179,6 @@ void *kmap_high(struct page *page)
/*
* For highmem pages, we can't trust "virtual" until
* after we have the lock.
- *
- * We cannot call this from interrupts, as it may block
*/
spin_lock(&kmap_lock);
vaddr = (unsigned long)page_address(page);
@@ -185,6 +192,10 @@ void *kmap_high(struct page *page)
EXPORT_SYMBOL(kmap_high);
+/**
+ * kunmap_high - map a highmem page into memory
+ * @page: &struct page to unmap
+ */
void kunmap_high(struct page *page)
{
unsigned long vaddr;
@@ -259,6 +270,12 @@ static struct page_address_slot *page_slot(struct page *page)
return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)];
}
+/**
+ * page_address - get the mapped virtual address of a page
+ * @page: &struct page to get the virtual address of
+ *
+ * Returns the page's virtual address.
+ */
void *page_address(struct page *page)
{
unsigned long flags;
@@ -288,6 +305,11 @@ done:
EXPORT_SYMBOL(page_address);
+/**
+ * set_page_address - set a page's virtual address
+ * @page: &struct page to set
+ * @virtual: virtual address to use
+ */
void set_page_address(struct page *page, void *virtual)
{
unsigned long flags;