diff mbox

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

Message ID 1407423713-4160-2-git-send-email-keescook@chromium.org (mailing list archive)
State New, archived
Headers show

Commit Message

Kees Cook Aug. 7, 2014, 3:01 p.m. UTC 
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>
[update for "ARM: 8031/2: change fixmap mapping region to support 32 CPUs"]
[flipped highmem order, thanks to Laura Abbott]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
---
 arch/arm/include/asm/fixmap.h | 27 +++++++++------------------
 arch/arm/mm/highmem.c         |  8 ++++++--
 arch/arm/mm/init.c            |  2 +-
 3 files changed, 16 insertions(+), 21 deletions(-)

Comments

Leif Lindholm Aug. 7, 2014, 5:38 p.m. UTC | #1 
On Thu, Aug 07, 2014 at 08:01:46AM -0700, Kees Cook wrote:
> 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>
> [update for "ARM: 8031/2: change fixmap mapping region to support 32 CPUs"]
> [flipped highmem order, thanks to Laura Abbott]
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Cc: Laura Abbott <lauraa@codeaurora.org>
> ---
>  arch/arm/include/asm/fixmap.h | 27 +++++++++------------------
>  arch/arm/mm/highmem.c         |  8 ++++++--
>  arch/arm/mm/init.c            |  2 +-
>  3 files changed, 16 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
> index 74124b0d0d79..190142d174ee 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 FIXADDR_SIZE		(FIXADDR_END - FIXADDR_START)
>  
>  #define FIX_KMAP_NR_PTES	(FIXADDR_SIZE >> PAGE_SHIFT)
>  
> -#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_NR_PTES - 1,
> +	__end_of_fixed_addresses
> +};
>  
> -extern void __this_fixmap_does_not_exist(void);
> -
> -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/highmem.c b/arch/arm/mm/highmem.c
> index 45aeaaca9052..a1241ee8425e 100644
> --- a/arch/arm/mm/highmem.c
> +++ b/arch/arm/mm/highmem.c
> @@ -23,14 +23,18 @@ 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);

idx is now "unused variable".

> -	return *(fixmap_page_table + idx);
> +	pte_t *ppte = pte_offset_kernel(pmd_off_k(FIXADDR_START), vaddr);
> +
> +	return *ppte;
>  }
>  
>  void *kmap(struct page *page)
> 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

Apart from that, verified with early_ioremap/UEFI patches on TC2.

Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Kees Cook Aug. 7, 2014, 5:47 p.m. UTC | #2 
On Thu, Aug 7, 2014 at 10:38 AM, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> On Thu, Aug 07, 2014 at 08:01:46AM -0700, Kees Cook wrote:
>> 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>
>> [update for "ARM: 8031/2: change fixmap mapping region to support 32 CPUs"]
>> [flipped highmem order, thanks to Laura Abbott]
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> Cc: Laura Abbott <lauraa@codeaurora.org>
>> ---
>>  arch/arm/include/asm/fixmap.h | 27 +++++++++------------------
>>  arch/arm/mm/highmem.c         |  8 ++++++--
>>  arch/arm/mm/init.c            |  2 +-
>>  3 files changed, 16 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
>> index 74124b0d0d79..190142d174ee 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 FIXADDR_SIZE         (FIXADDR_END - FIXADDR_START)
>>
>>  #define FIX_KMAP_NR_PTES     (FIXADDR_SIZE >> PAGE_SHIFT)
>>
>> -#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_NR_PTES - 1,
>> +     __end_of_fixed_addresses
>> +};
>>
>> -extern void __this_fixmap_does_not_exist(void);
>> -
>> -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/highmem.c b/arch/arm/mm/highmem.c
>> index 45aeaaca9052..a1241ee8425e 100644
>> --- a/arch/arm/mm/highmem.c
>> +++ b/arch/arm/mm/highmem.c
>> @@ -23,14 +23,18 @@ 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);
>
> idx is now "unused variable".

Ah! Yes, thanks. I'll add HIGHMEM to my build cycles.

>
>> -     return *(fixmap_page_table + idx);
>> +     pte_t *ppte = pte_offset_kernel(pmd_off_k(FIXADDR_START), vaddr);
>> +
>> +     return *ppte;
>>  }
>>
>>  void *kmap(struct page *page)
>> 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
>
> Apart from that, verified with early_ioremap/UEFI patches on TC2.
>
> Tested-by: Leif Lindholm <leif.lindholm@linaro.org>

Thanks! I've added this and fixed idx above for the future v3 of this series.

-Kees
diff mbox

Patch

diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index 74124b0d0d79..190142d174ee 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 FIXADDR_SIZE		(FIXADDR_END - FIXADDR_START)
 
 #define FIX_KMAP_NR_PTES	(FIXADDR_SIZE >> PAGE_SHIFT)
 
-#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_NR_PTES - 1,
+	__end_of_fixed_addresses
+};
 
-extern void __this_fixmap_does_not_exist(void);
-
-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/highmem.c b/arch/arm/mm/highmem.c
index 45aeaaca9052..a1241ee8425e 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -23,14 +23,18 @@  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)
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