[PATCH v3 1/7] arm: use generic fixmap.h
From: Kees Cook
Date: Tue Aug 12 2014 - 14:27:50 EST
From: Mark Salter <msalter@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx>
[kees: update for a05e54c103b0b8 "ARM: 8031/2: change fixmap ..."]
[kees: fixed highmem usage, thanks to Laura Abbott and Rob Herring]
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Laura Abbott <lauraa@xxxxxxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
---
arch/arm/include/asm/fixmap.h | 27 +++++++++------------------
arch/arm/include/asm/highmem.h | 1 -
arch/arm/mm/highmem.c | 15 ++++++++-------
arch/arm/mm/init.c | 2 +-
arch/arm/mm/mmu.c | 6 +++---
5 files changed, 21 insertions(+), 30 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/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 535579511ed0..91b99abe7a95 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -18,7 +18,6 @@
} while (0)
extern pte_t *pkmap_page_table;
-extern pte_t *fixmap_page_table;
extern void *kmap_high(struct page *page);
extern void kunmap_high(struct page *page);
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 45aeaaca9052..f87e0b89b738 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -18,19 +18,20 @@
#include <asm/tlbflush.h>
#include "mm.h"
-pte_t *fixmap_page_table;
-
static inline void set_fixmap_pte(int idx, pte_t pte)
{
unsigned long vaddr = __fix_to_virt(idx);
- set_pte_ext(fixmap_page_table + idx, pte, 0);
+ pte_t *ppte = pte_offset_kernel(pmd_off_k(FIXADDR_START), vaddr);
+
+ set_pte_ext(ppte, pte, 0);
local_flush_tlb_kernel_page(vaddr);
}
static inline pte_t get_fixmap_pte(unsigned long vaddr)
{
- unsigned long idx = __virt_to_fix(vaddr);
- return *(fixmap_page_table + idx);
+ pte_t *ppte = pte_offset_kernel(pmd_off_k(FIXADDR_START), vaddr);
+
+ return *ppte;
}
void *kmap(struct page *page)
@@ -84,7 +85,7 @@ void *kmap_atomic(struct page *page)
* With debugging enabled, kunmap_atomic forces that entry to 0.
* Make sure it was indeed properly unmapped.
*/
- BUG_ON(!pte_none(*(fixmap_page_table + idx)));
+ BUG_ON(!pte_none(*get_fixmap_pte(vaddr)));
#endif
/*
* When debugging is off, kunmap_atomic leaves the previous mapping
@@ -134,7 +135,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(idx);
#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(fixmap_page_table + idx)));
+ BUG_ON(!pte_none(*get_fixmap_pte(vaddr)));
#endif
set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
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
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 8348ed6b2efe..7fa0966cd15f 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1326,10 +1326,10 @@ static void __init kmap_init(void)
#ifdef CONFIG_HIGHMEM
pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),
PKMAP_BASE, _PAGE_KERNEL_TABLE);
-
- fixmap_page_table = early_pte_alloc(pmd_off_k(FIXADDR_START),
- FIXADDR_START, _PAGE_KERNEL_TABLE);
#endif
+
+ early_pte_alloc(pmd_off_k(FIXADDR_START), FIXADDR_START,
+ _PAGE_KERNEL_TABLE);
}
static void __init map_lowmem(void)
--
1.9.1
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