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| author | venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com> | 2008-03-19 01:00:24 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-17 17:41:20 +0200 |
| commit | b310f381d220b2c6e3fab16e8c6e4ca13eea75b2 (patch) | |
| tree | dd25df964cd1280ee4f908002726b5ab921da807 /arch | |
| parent | x86: PAT add set_memory_wc() interface (diff) | |
| download | linux-b310f381d220b2c6e3fab16e8c6e4ca13eea75b2.tar.xz linux-b310f381d220b2c6e3fab16e8c6e4ca13eea75b2.zip | |
x86: PAT add ioremap_wc() interface
Introduce ioremap_wc for wc remap.
(generic wrapper is in a later patch)
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/mm/ioremap.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 0cdb7f11ce49..51cd3956c564 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -97,6 +97,9 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, default: err = _set_memory_uc(vaddr, nrpages); break; + case _PAGE_CACHE_WC: + err = _set_memory_wc(vaddr, nrpages); + break; case _PAGE_CACHE_WB: err = _set_memory_wb(vaddr, nrpages); break; @@ -166,8 +169,13 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, * Do not fallback to certain memory types with certain * requested type: * - request is uncached, return cannot be write-back + * - request is uncached, return cannot be write-combine + * - request is write-combine, return cannot be write-back */ if ((prot_val == _PAGE_CACHE_UC && + (new_prot_val == _PAGE_CACHE_WB || + new_prot_val == _PAGE_CACHE_WC)) || + (prot_val == _PAGE_CACHE_WC && new_prot_val == _PAGE_CACHE_WB)) { free_memtype(phys_addr, phys_addr + size); return NULL; @@ -180,6 +188,9 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, default: prot = PAGE_KERNEL_NOCACHE; break; + case _PAGE_CACHE_WC: + prot = PAGE_KERNEL_WC; + break; case _PAGE_CACHE_WB: prot = PAGE_KERNEL; break; @@ -235,6 +246,25 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size) } EXPORT_SYMBOL(ioremap_nocache); +/** + * ioremap_wc - map memory into CPU space write combined + * @offset: bus address of the memory + * @size: size of the resource to map + * + * This version of ioremap ensures that the memory is marked write combining. + * Write combining allows faster writes to some hardware devices. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_wc(unsigned long phys_addr, unsigned long size) +{ + if (pat_wc_enabled) + return __ioremap(phys_addr, size, _PAGE_CACHE_WC); + else + return ioremap_nocache(phys_addr, size); +} +EXPORT_SYMBOL(ioremap_wc); + void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) { return __ioremap(phys_addr, size, _PAGE_CACHE_WB); |