arm: use generic fixmap.h

ARM is different from other architectures in that fixmap pages are indexed
with a positive offset from FIXADDR_START.  Other architectures index with
a negative offset from FIXADDR_TOP.  In order to use the generic fixmap.h
definitions, this patch redefines FIXADDR_TOP to be inclusive of the
useable range.  That is, FIXADDR_TOP is the virtual address of the topmost
fixed page.  The newly defined FIXADDR_END is the first virtual address
past the fixed mappings.

Signed-off-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
[kees: update for a05e54c103b0 ("ARM: 8031/2: change fixmap ...")]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Rob Herring <robh@kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>

1 files changed, 9 insertions, 18 deletions

diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index 74124b0d0d79..a7add6f9315d 100644
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -2,27 +2,18 @@
 #define _ASM_FIXMAP_H
 
 #define FIXADDR_START           0xffc00000UL
-#define FIXADDR_TOP             0xffe00000UL
-#define FIXADDR_SIZE            (FIXADDR_TOP - FIXADDR_START)
+#define FIXADDR_END             0xffe00000UL
+#define FIXADDR_TOP             (FIXADDR_END - PAGE_SIZE)
 
-#define FIX_KMAP_NR_PTES        (FIXADDR_SIZE >> PAGE_SHIFT)
+#include <asm/kmap_types.h>
 
-#define __fix_to_virt(x)        (FIXADDR_START + ((x) << PAGE_SHIFT))
-#define __virt_to_fix(x)        (((x) - FIXADDR_START) >> PAGE_SHIFT)
+enum fixed_addresses {
+        FIX_KMAP_BEGIN,
+        FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
 
-extern void __this_fixmap_does_not_exist(void);
+        __end_of_fixed_addresses
+};
 
-static inline unsigned long fix_to_virt(const unsigned int idx)
-{
-        if (idx >= FIX_KMAP_NR_PTES)
-                __this_fixmap_does_not_exist();
-        return __fix_to_virt(idx);
-}
-
-static inline unsigned int virt_to_fix(const unsigned long vaddr)
-{
-        BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
-        return __virt_to_fix(vaddr);
-}
+#include <asm-generic/fixmap.h>
 
 #endif