[PATCH v5 1/8] arm: use generic fixmap.h

Kees Cook
2014-09-03T21:59:12Z

From: Mark Salter <msalter@redhat.com>

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>
---
arch/arm/include/asm/fixmap.h | 27 +++++++++------------------
arch/arm/mm/init.c | 2 +-
2 files changed, 10 insertions(+), 19 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
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 659c75d808dc..ad82c05bfc3a 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -570,7 +570,7 @@ void __init mem_init(void)
MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
MLK(ITCM_OFFSET, (unsigned long) itcm_end),
#endif
- MLK(FIXADDR_START, FIXADDR_TOP),
+ MLK(FIXADDR_START, FIXADDR_END),
MLM(VMALLOC_START, VMALLOC_END),
MLM(PAGE_OFFSET, (unsigned long)high_memory),
#ifdef CONFIG_HIGHMEM
--
1.9.1