Commit-ID: d838270e2516db11084bed4e294017eb7b646a75 Gitweb: http://git.kernel.org/tip/d838270e2516db11084bed4e294017eb7b646a75 Author: Toshi Kani <toshi.kani@xxxxxx> AuthorDate: Thu, 4 Jun 2015 18:55:15 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Sun, 7 Jun 2015 15:28:56 +0200 x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings Add ioremap_wt() for creating Write-Through mappings on x86. It follows the same model as ioremap_wc() for multi-arch support. Define ARCH_HAS_IOREMAP_WT in the x86 version of io.h to indicate that ioremap_wt() is implemented on x86. Also update the PAT documentation file to cover ioremap_wt(). Signed-off-by: Toshi Kani <toshi.kani@xxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Elliott@xxxxxx Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Luis R. Rodriguez <mcgrof@xxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: arnd@xxxxxxxx Cc: hch@xxxxxx Cc: hmh@xxxxxxxxxx Cc: jgross@xxxxxxxx Cc: konrad.wilk@xxxxxxxxxx Cc: linux-mm <linux-mm@xxxxxxxxx> Cc: linux-nvdimm@xxxxxxxxxxxx Cc: stefan.bader@xxxxxxxxxxxxx Cc: yigal@xxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1433436928-31903-8-git-send-email-bp@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- Documentation/x86/pat.txt | 4 +++- arch/x86/include/asm/io.h | 2 ++ arch/x86/mm/ioremap.c | 21 +++++++++++++++++++++ include/asm-generic/io.h | 9 +++++++++ include/asm-generic/iomap.h | 4 ++++ 5 files changed, 39 insertions(+), 1 deletion(-) diff --git a/Documentation/x86/pat.txt b/Documentation/x86/pat.txt index 521bd8a..db0de6c 100644 --- a/Documentation/x86/pat.txt +++ b/Documentation/x86/pat.txt @@ -12,7 +12,7 @@ virtual addresses. PAT allows for different types of memory attributes. The most commonly used ones that will be supported at this time are Write-back, Uncached, -Write-combined and Uncached Minus. +Write-combined, Write-through and Uncached Minus. PAT APIs @@ -40,6 +40,8 @@ ioremap_nocache | -- | UC- | UC- | | | | | ioremap_wc | -- | -- | WC | | | | | +ioremap_wt | -- | -- | WT | + | | | | set_memory_uc | UC- | -- | -- | set_memory_wb | | | | | | | | diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index a944630..83ec9b1 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -35,6 +35,7 @@ */ #define ARCH_HAS_IOREMAP_WC +#define ARCH_HAS_IOREMAP_WT #include <linux/string.h> #include <linux/compiler.h> @@ -320,6 +321,7 @@ extern void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr); extern int ioremap_change_attr(unsigned long vaddr, unsigned long size, enum page_cache_mode pcm); extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size); +extern void __iomem *ioremap_wt(resource_size_t offset, unsigned long size); extern bool is_early_ioremap_ptep(pte_t *ptep); diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index cc0f17c..07cd46a 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -172,6 +172,10 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, prot = __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_WC)); break; + case _PAGE_CACHE_MODE_WT: + prot = __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_WT)); + break; case _PAGE_CACHE_MODE_WB: break; } @@ -297,6 +301,23 @@ void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size) } EXPORT_SYMBOL(ioremap_wc); +/** + * ioremap_wt - map memory into CPU space write through + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * This version of ioremap ensures that the memory is marked write through. + * Write through stores data into memory while keeping the cache up-to-date. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(ioremap_wt); + void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index 90ccba7..f56094c 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -785,8 +785,17 @@ static inline void __iomem *ioremap_wc(phys_addr_t offset, size_t size) } #endif +#ifndef ioremap_wt +#define ioremap_wt ioremap_wt +static inline void __iomem *ioremap_wt(phys_addr_t offset, size_t size) +{ + return ioremap_nocache(offset, size); +} +#endif + #ifndef iounmap #define iounmap iounmap + static inline void iounmap(void __iomem *addr) { } diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h index 1b41011..d8f8622 100644 --- a/include/asm-generic/iomap.h +++ b/include/asm-generic/iomap.h @@ -66,6 +66,10 @@ extern void ioport_unmap(void __iomem *); #define ioremap_wc ioremap_nocache #endif +#ifndef ARCH_HAS_IOREMAP_WT +#define ioremap_wt ioremap_nocache +#endif + #ifdef CONFIG_PCI /* Destroy a virtual mapping cookie for a PCI BAR (memory or IO) */ struct pci_dev; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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