From: Feng Tang Date: Mon, 13 Sep 2010 07:08:54 +0000 (+0800) Subject: x86: Add two helper macros for fixed address mapping X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5a47c7dae861c3ca3edf178546641909851bf715;p=linux-beck.git x86: Add two helper macros for fixed address mapping Sometimes fixmap will be used to map an physical address which is not PAGE align, so to use it we need first map it and then add the address offset to the mapped fixed address. These 2 new helpers are suggested by Ingo Molnar to make the process simpler. For a physicall address like "phys", a directly usable virtual address can be get by virt = (void *)set_fixmap_offset(fixed_idx, phys); or virt = (void *)set_fixmap_offset_nocache(fixed_idx, phys); (depends on whether the physical address is cachable or not). Signed-off-by: Feng Tang Cc: alan@linux.intel.com Cc: greg@kroah.com Cc: x86@kernel.org LKML-Reference: <1284361736-23011-3-git-send-email-feng.tang@intel.com> Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index d07b44f7d1dc..4d293dced62f 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -214,5 +214,20 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr) BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); return __virt_to_fix(vaddr); } + +/* Return an pointer with offset calculated */ +static inline unsigned long __set_fixmap_offset(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + __set_fixmap(idx, phys, flags); + return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1)); +} + +#define set_fixmap_offset(idx, phys) \ + __set_fixmap_offset(idx, phys, PAGE_KERNEL) + +#define set_fixmap_offset_nocache(idx, phys) \ + __set_fixmap_offset(idx, phys, PAGE_KERNEL_NOCACHE) + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_FIXMAP_H */