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Diffstat (limited to 'arch/x86/mm/mmap.c')
-rw-r--r--arch/x86/mm/mmap.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 62285fe77b0f..155ecbac9e28 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -33,6 +33,8 @@
#include <linux/compat.h>
#include <asm/elf.h>
+#include "physaddr.h"
+
struct va_alignment __read_mostly va_align = {
.flags = -1,
};
@@ -220,3 +222,17 @@ bool mmap_address_hint_valid(unsigned long addr, unsigned long len)
return (addr > DEFAULT_MAP_WINDOW) == (addr + len > DEFAULT_MAP_WINDOW);
}
+
+/* Can we access it for direct reading/writing? Must be RAM: */
+int valid_phys_addr_range(phys_addr_t addr, size_t count)
+{
+ return addr + count <= __pa(high_memory);
+}
+
+/* Can we access it through mmap? Must be a valid physical address: */
+int valid_mmap_phys_addr_range(unsigned long pfn, size_t count)
+{
+ phys_addr_t addr = (phys_addr_t)pfn << PAGE_SHIFT;
+
+ return phys_addr_valid(addr + count - 1);
+}