Add an helper to check if a virtual address is in the highmem region.
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
---
include/linux/highmem.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index bb3f329..13dff37 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -41,6 +41,14 @@ void kmap_flush_unused(void);
struct page *kmap_to_page(void *addr);
+static inline bool is_highmem_addr(const void *x)
+{
+ unsigned long vaddr = (unsigned long)x;
+
+ return vaddr >= PKMAP_BASE &&
+ vaddr < ((PKMAP_BASE + LAST_PKMAP) * PAGE_SIZE);
+}
+
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -50,6 +58,11 @@ static inline struct page *kmap_to_page(void *addr)
return virt_to_page(addr);
}
+static inline bool is_highmem_addr(const void *x)
+{
+ return false;
+}
+
#define totalhigh_pages 0UL
#ifndef ARCH_HAS_KMAP
--
2.5.0
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