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From: Borislav Petkov <bp@alien8.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 07/20] x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings
Date: Thu,  4 Jun 2015 18:55:15 +0200
Message-ID: <1433436928-31903-8-git-send-email-bp@alien8.de> (raw)
In-Reply-To: <1433436928-31903-1-git-send-email-bp@alien8.de>

From: Toshi Kani <toshi.kani@hp.com>

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@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: arnd@arndb.de
Cc: Elliott@hp.com
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: stefan.bader@canonical.com
Cc: x86-ml <x86@kernel.org>
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433187393-22688-5-git-send-email-toshi.kani@hp.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 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 521bd8adc3b8..db0de6cfc351 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 a2b97404922d..6c3a130de503 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>
@@ -321,6 +322,7 @@ 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 cc0f17c5ad9f..07cd46a8f30a 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 90ccba7f9f9a..f56094cfdeff 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 1b41011643a5..d8f8622fa044 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;
-- 
2.3.5


  parent reply index

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-04 16:55 [PATCH 00/20] tip queue 2015-06-04 Borislav Petkov
2015-06-04 16:55 ` [PATCH 01/20] x86/mm/pat: Untangle pat_init() Borislav Petkov
2015-06-07 17:39   ` [tip:x86/mm] " tip-bot for Borislav Petkov
2015-06-04 16:55 ` [PATCH 02/20] x86/mm/pat: Emulate PAT when it is disabled Borislav Petkov
2015-06-07 17:39   ` [tip:x86/mm] " tip-bot for Borislav Petkov
2015-06-04 16:55 ` [PATCH 03/20] x86/mm/pat: Remove pat_enabled() checks Borislav Petkov
2015-06-07 17:40   ` [tip:x86/mm] " tip-bot for Borislav Petkov
2015-06-04 16:55 ` [PATCH 04/20] x86/mm/pat: Use 7th PAT MSR slot for Write-Through PAT type Borislav Petkov
2015-06-04 16:55 ` [PATCH 05/20] x86/mm/pat: Change reserve_memtype() for Write-Through type Borislav Petkov
2015-06-07 17:40   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 06/20] x86/mm: Teach is_new_memtype_allowed() about " Borislav Petkov
2015-06-07 17:41   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` Borislav Petkov [this message]
2015-06-07 17:41   ` [tip:x86/mm] x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 08/20] arch/*/io.h: Add ioremap_wt() to all architectures Borislav Petkov
2015-06-07 17:41   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 09/20] video/fbdev, asm/io.h: Remove ioremap_writethrough() Borislav Petkov
2015-06-07 17:41   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 10/20] x86/mm/pat: Add pgprot_writethrough() Borislav Petkov
2015-06-07 17:42   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 11/20] x86/mm/pat: Extend set_page_memtype() to support Write-Through type Borislav Petkov
2015-06-07 17:42   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 12/20] x86/mm: Add set_memory_wt() for " Borislav Petkov
2015-06-07 17:42   ` [tip:x86/mm] x86/mm/pat: " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 13/20] drivers/block/pmem: Map NVDIMM in Write-Through mode Borislav Petkov
2015-06-07 17:43   ` [tip:x86/mm] " tip-bot for Toshi Kani
2015-06-04 16:55 ` [PATCH 14/20] x86/mce: Add Local MCE definitions Borislav Petkov
2015-06-07 17:43   ` [tip:x86/core] " tip-bot for Ashok Raj
2015-06-04 16:55 ` [PATCH 15/20] x86/mce: Add infrastructure to support Local MCE Borislav Petkov
2015-06-07 17:43   ` [tip:x86/core] " tip-bot for Ashok Raj
2015-06-04 16:55 ` [PATCH 16/20] x86/mce: Handle Local MCE events Borislav Petkov
2015-06-07 17:44   ` [tip:x86/core] " tip-bot for Ashok Raj
2015-06-04 16:55 ` [PATCH 17/20] x86: Kill CONFIG_X86_HT Borislav Petkov
2015-06-07 17:44   ` [tip:x86/core] " tip-bot for Borislav Petkov
2015-06-04 16:55 ` [PATCH 18/20] x86/uapi: Do not export <asm/msr-index.h> as part of the user API headers Borislav Petkov
2015-06-07 17:44   ` [tip:x86/core] " tip-bot for Borislav Petkov
2015-06-04 16:55 ` [PATCH 19/20] x86/microcode: Disable builtin microcode loading on 32-bit for now Borislav Petkov
2015-06-07 17:45   ` [tip:x86/microcode] " tip-bot for Borislav Petkov
2015-06-04 16:55 ` [PATCH 20/20] x86/microcode: Correct variables type Borislav Petkov
2015-06-07 17:45   ` [tip:x86/microcode] x86/microcode: Correct CPU family related variable types tip-bot for Andy Shevchenko

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