Re: [PATCH v2 03/11] arm: use generic fixmap.h

Mark Salter
2013-12-11T23:15:54Z

On Mon, 2013-11-25 at 11:13 -0500, Mark Salter wrote:
> 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>
> CC: Russell King <linux@arm.linux.org.uk>
> CC: linux-arm-kernel@lists.infradead.org
> ---

Ping. Any concerns about this?

> arch/arm/include/asm/fixmap.h | 29 ++++++++---------------------
> arch/arm/mm/init.c | 2 +-
> 2 files changed, 9 insertions(+), 22 deletions(-)
>
> diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
> index bbae919..68ea615 100644
> --- a/arch/arm/include/asm/fixmap.h
> +++ b/arch/arm/include/asm/fixmap.h
> @@ -14,28 +14,15 @@
> */
>
> #define FIXADDR_START 0xfff00000UL
> -#define FIXADDR_TOP 0xfffe0000UL
> -#define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START)
> +#define FIXADDR_END 0xfffe0000UL
> +#define FIXADDR_TOP (FIXADDR_END - PAGE_SIZE)
>
> -#define FIX_KMAP_BEGIN 0
> -#define FIX_KMAP_END (FIXADDR_SIZE >> PAGE_SHIFT)
> +enum fixed_addresses {
> + FIX_KMAP_BEGIN,
> + FIX_KMAP_END = (FIXADDR_TOP - FIXADDR_START) >> PAGE_SHIFT,
> + __end_of_fixed_addresses
> +};
>
> -#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT))
> -#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT)
> -
> -extern void __this_fixmap_does_not_exist(void);
> -
> -static inline unsigned long fix_to_virt(const unsigned int idx)
> -{
> - if (idx >= FIX_KMAP_END)
> - __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 ca907f8..fb61c29 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -632,7 +632,7 @@ 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