lkml.org 
[lkml]   [2012]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 03/22] ARM: LPAE: use phys_addr_t on virt <--> phys conversion
On Tue, Jul 31, 2012 at 07:04:39PM -0400, Cyril Chemparathy wrote:
> This patch fixes up the types used when converting back and forth between
> physical and virtual addresses.
>
> Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
> Signed-off-by: Cyril Chemparathy <cyril@ti.com>
> ---
> arch/arm/include/asm/memory.h | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
> index 01c710d..4a0108f 100644
> --- a/arch/arm/include/asm/memory.h
> +++ b/arch/arm/include/asm/memory.h
> @@ -157,22 +157,27 @@ extern unsigned long __pv_phys_offset;
>
> extern unsigned long __pv_offset;
>
> -static inline unsigned long __virt_to_phys(unsigned long x)
> +static inline phys_addr_t __virt_to_phys(unsigned long x)
> {
> unsigned long t;
> early_patch_imm8(x, t, "add", __pv_offset);
> return t;
> }
>
> -static inline unsigned long __phys_to_virt(unsigned long x)
> +static inline unsigned long __phys_to_virt(phys_addr_t x)
> {
> unsigned long t;
> early_patch_imm8(x, t, "sub", __pv_offset);
> return t;
> }
> #else
> -#define __virt_to_phys(x) ((x) - PAGE_OFFSET + PHYS_OFFSET)
> -#define __phys_to_virt(x) ((x) - PHYS_OFFSET + PAGE_OFFSET)
> +
> +#define __virt_to_phys(x) \
> + ((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET)
> +
> +#define __phys_to_virt(x) \
> + ((unsigned long)((phys_addr_t)(x) - PHYS_OFFSET + PAGE_OFFSET))
> +
> #endif
> #endif
>
> @@ -207,14 +212,14 @@ static inline phys_addr_t virt_to_phys(const volatile void *x)
>
> static inline void *phys_to_virt(phys_addr_t x)
> {
> - return (void *)(__phys_to_virt((unsigned long)(x)));
> + return (void *)__phys_to_virt(x);
> }
>
> /*
> * Drivers should NOT use these either.
> */
> #define __pa(x) __virt_to_phys((unsigned long)(x))
> -#define __va(x) ((void *)__phys_to_virt((unsigned long)(x)))
> +#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
> #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)

This as a whole does not fill me with a great amount of enthusiasm,
because it breaks some of the typechecking that we have here.

The whole point of __phys_to_virt() and __virt_to_phys() is that they work
on integer types, and warn if you dare to use them with pointers. Adding
a cast into them breaks that.

The whole point is that the typecasting is explicitly inside phys_to_virt()
and virt_to_phys() and not their macro counterparts.

Secondly, are you sure that this patch is correct on its own? You're
passing a u64 into assembly only expecting a 32-bit register. Have you
checked it does the right thing with a 64-bit phys_addr_t on both LE
and BE?


\
 
 \ /
  Last update: 2012-08-06 14:03    [W:0.330 / U:1.256 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site