• T
    x86/mm: Teach is_new_memtype_allowed() about Write-Through type · ecb2feba
    Toshi Kani 提交于
    __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: NToshi Kani <toshi.kani@hp.com>
    Signed-off-by: NBorislav Petkov <bp@suse.de>
    Reviewed-by: NThomas 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.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
    ecb2feba
pgtable.h 21.4 KB