[U-Boot] [PATCH v4 2/8] mips: implement to access the KSEG0/1 memory range in map_physmem

Marek Vasut
2015-12-26T07:25:32Z

On Friday, December 25, 2015 at 07:56:22 PM, Wills Wang wrote:
> U-boot just use the no MMU virtual address segment(KSEG0/1), this
> patch enable access the uncached memory range(KSEG1) by flag
> "MAP_NOCACHE", other flag for KSEG0 access.
>
> Signed-off-by: Wills Wang <wills.wang@live.com>
> ---
>
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
> arch/mips/include/asm/io.h | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
> index a7ab087..943053d 100644
> --- a/arch/mips/include/asm/io.h
> +++ b/arch/mips/include/asm/io.h
> @@ -485,7 +485,7 @@ static inline void sync(void)
> * that can be used to access the memory range with the caching
> * properties specified by "flags".
> */
> -#define MAP_NOCACHE (0)
> +#define MAP_NOCACHE (1)

I _think_ this is something someone familiar with mips has to review,
since I think this has a potential to break a lot of machines.

> #define MAP_WRCOMBINE (0)
> #define MAP_WRBACK (0)
> #define MAP_WRTHROUGH (0)
> @@ -493,7 +493,10 @@ static inline void sync(void)
> static inline void *
> map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
> {
> - return (void *)paddr;
> + if (flags)
> + return (void *)KSEG1ADDR(paddr);
> + else
> + return (void *)KSEG0ADDR(paddr);
> }
>
> /*

Best regards,
Marek Vasut