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author | Toshi Kani <toshi.kani@hp.com> | 2015-06-04 18:55:14 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2015-06-07 15:28:55 +0200 |
commit | ecb2febaaa3945e1578359adc30ca818e78540fb (patch) | |
tree | f1b054c418316f4ba65c36eeded90efbfcea0aad | |
parent | 0d69bdff451a10aa48f80509e8bf18fb24683c06 (diff) | |
download | linux-ecb2febaaa3945e1578359adc30ca818e78540fb.tar.gz linux-ecb2febaaa3945e1578359adc30ca818e78540fb.tar.bz2 linux-ecb2febaaa3945e1578359adc30ca818e78540fb.zip |
x86/mm: Teach is_new_memtype_allowed() about Write-Through type
__ioremap_caller() calls reserve_memtype() and the passed down
@new_pcm contains the actual page cache type it reserved in the
success case.
is_new_memtype_allowed() verifies if converting to the new page
cache type is allowed when @pcm (the requested type) is
different from @new_pcm.
When WT is requested, the caller expects that writes are ordered
and uncached. Therefore, enhance is_new_memtype_allowed() to
disallow the following cases:
- If the request is WT, mapping type cannot be WB
- If the request is WT, mapping type cannot be WC
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.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: 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/1433436928-31903-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r-- | arch/x86/include/asm/pgtable.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index fe57e7a98839..2562e303405b 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -398,11 +398,17 @@ static inline int is_new_memtype_allowed(u64 paddr, unsigned long size, * requested memtype: * - request is uncached, return cannot be write-back * - request is write-combine, return cannot be write-back + * - request is write-through, return cannot be write-back + * - request is write-through, return cannot be write-combine */ if ((pcm == _PAGE_CACHE_MODE_UC_MINUS && new_pcm == _PAGE_CACHE_MODE_WB) || (pcm == _PAGE_CACHE_MODE_WC && - new_pcm == _PAGE_CACHE_MODE_WB)) { + new_pcm == _PAGE_CACHE_MODE_WB) || + (pcm == _PAGE_CACHE_MODE_WT && + new_pcm == _PAGE_CACHE_MODE_WB) || + (pcm == _PAGE_CACHE_MODE_WT && + new_pcm == _PAGE_CACHE_MODE_WC)) { return 0; } |