[tip:x86/mm] x86/mm/pat: Add pgprot_writethrough()

tip-bot for Toshi Kani
2015-06-07T17:43:20Z

Commit-ID: d1b4bfbfac32da43bfc8425be1c4303548e20527
Gitweb: http://git.kernel.org/tip/d1b4bfbfac32da43bfc8425be1c4303548e20527
Author: Toshi Kani <toshi.kani@hp.com>
AuthorDate: Thu, 4 Jun 2015 18:55:18 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 7 Jun 2015 15:28:58 +0200

x86/mm/pat: Add pgprot_writethrough()

Add pgprot_writethrough() for setting page protection flags to
Write-Through mode.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-11-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/pgtable_types.h | 3 +++
arch/x86/mm/pat.c | 7 +++++++
include/asm-generic/pgtable.h | 4 ++++
3 files changed, 14 insertions(+)

diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 78f0c8c..13f310b 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -367,6 +367,9 @@ extern int nx_enabled;
#define pgprot_writecombine pgprot_writecombine
extern pgprot_t pgprot_writecombine(pgprot_t prot);

+#define pgprot_writethrough pgprot_writethrough
+extern pgprot_t pgprot_writethrough(pgprot_t prot);
+
/* Indicate that x86 has its own track and untrack pfn vma functions */
#define __HAVE_PFNMAP_TRACKING

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 6311193..076187c 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -1000,6 +1000,13 @@ pgprot_t pgprot_writecombine(pgprot_t prot)
}
EXPORT_SYMBOL_GPL(pgprot_writecombine);

+pgprot_t pgprot_writethrough(pgprot_t prot)
+{
+ return __pgprot(pgprot_val(prot) |
+ cachemode2protval(_PAGE_CACHE_MODE_WT));
+}
+EXPORT_SYMBOL_GPL(pgprot_writethrough);
+
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)

static struct memtype *memtype_get_idx(loff_t pos)
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 39f1d6a..bd910ce 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -262,6 +262,10 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
#define pgprot_writecombine pgprot_noncached
#endif

+#ifndef pgprot_writethrough
+#define pgprot_writethrough pgprot_noncached
+#endif
+
#ifndef pgprot_device
#define pgprot_device pgprot_noncached
#endif