Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753293AbaJ0XNp (ORCPT ); Mon, 27 Oct 2014 19:13:45 -0400 Received: from g2t1383g.austin.hp.com ([15.217.136.92]:18759 "EHLO g2t1383g.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658AbaJ0XJu (ORCPT ); Mon, 27 Oct 2014 19:09:50 -0400 From: Toshi Kani To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, jgross@suse.com, stefan.bader@canonical.com, luto@amacapital.net, hmh@hmh.eng.br, yigal@plexistor.com, konrad.wilk@oracle.com, Toshi Kani Subject: [PATCH v4 3/7] x86, mm, asm-gen: Add ioremap_wt() for WT Date: Mon, 27 Oct 2014 16:55:41 -0600 Message-Id: <1414450545-14028-4-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1414450545-14028-1-git-send-email-toshi.kani@hp.com> References: <1414450545-14028-1-git-send-email-toshi.kani@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds ioremap_wt() for creating WT mapping on x86. It follows the same model as ioremap_wc() for multi-architecture support. ARCH_HAS_IOREMAP_WT is defined 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 Reviewed-by: Konrad Rzeszutek Wilk --- Documentation/x86/pat.txt | 4 +++- arch/x86/include/asm/io.h | 2 ++ arch/x86/mm/ioremap.c | 24 ++++++++++++++++++++++++ include/asm-generic/io.h | 4 ++++ include/asm-generic/iomap.h | 4 ++++ 5 files changed, 37 insertions(+), 1 deletion(-) diff --git a/Documentation/x86/pat.txt b/Documentation/x86/pat.txt index cf08c9f..be7b8c2 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 @@ -38,6 +38,8 @@ 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 71b9e65..c813c86 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 #include @@ -316,6 +317,7 @@ extern void unxlate_dev_mem_ptr(unsigned long 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 8832e51..b096988 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -167,6 +167,10 @@ 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; } @@ -261,6 +265,26 @@ 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 writes 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) +{ + if (pat_enabled) + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT, + __builtin_return_address(0)); + else + return ioremap_nocache(phys_addr, size); +} +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 b8fdc57..9dd07bf 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -322,6 +322,10 @@ static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) #define ioremap_wc ioremap_nocache #endif +#ifndef ioremap_wt +#define ioremap_wt ioremap_nocache +#endif + 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/