Commit-ID: ecb2febaaa3945e1578359adc30ca818e78540fb Gitweb: http://git.kernel.org/tip/ecb2febaaa3945e1578359adc30ca818e78540fb Author: Toshi Kani <toshi.kani@xxxxxx> AuthorDate: Thu, 4 Jun 2015 18:55:14 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Sun, 7 Jun 2015 15:28:55 +0200 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@xxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> 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: 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/1433436928-31903-7-git-send-email-bp@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/include/asm/pgtable.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index fe57e7a..2562e30 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; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>