This patchset adds support of Write-Through (WT) mapping on x86. The study below shows that using WT mapping may be useful for non-volatile memory. http://www.hpl.hp.com/techreports/2012/HPL-2012-236.pdf All new/modified interfaces have been tested. v8: - Rebased to 4.0-rc1 and resolved conflicts with 9d34cfdf4 in patch 5/7. v7: - Rebased to 3.19-rc3 as Juergen's patchset for the PAT management has been accepted. v6: - Dropped the patch moving [set|get]_page_memtype() to pat.c since the tip branch already has this change. - Fixed an issue when CONFIG_X86_PAT is not defined. v5: - Clarified comment of why using slot 7. (Andy Lutomirski, Thomas Gleixner) - Moved [set|get]_page_memtype() to pat.c. (Thomas Gleixner) - Removed BUG() from set_page_memtype(). (Thomas Gleixner) v4: - Added set_memory_wt() by adding WT support of regular memory. v3: - Dropped the set_memory_wt() patch. (Andy Lutomirski) - Refactored the !pat_enabled handling. (H. Peter Anvin, Andy Lutomirski) - Added the picture of PTE encoding. (Konrad Rzeszutek Wilk) v2: - Changed WT to use slot 7 of the PAT MSR. (H. Peter Anvin, Andy Lutomirski) - Changed to have conservative checks to exclude all Pentium 2, 3, M, and 4 families. (Ingo Molnar, Henrique de Moraes Holschuh, Andy Lutomirski) - Updated documentation to cover WT interfaces and usages. (Andy Lutomirski, Yigal Korman) --- Toshi Kani (7): 1/7 x86, mm, pat: Set WT to PA7 slot of PAT MSR 2/7 x86, mm, pat: Change reserve_memtype() to handle WT 3/7 x86, mm, asm-gen: Add ioremap_wt() for WT 4/7 x86, mm, pat: Add pgprot_writethrough() for WT 5/7 x86, mm, pat: Refactor !pat_enable handling 6/7 x86, mm, asm: Add WT support to set_page_memtype() 7/7 x86, mm: Add set_memory_wt() for WT --- Documentation/x86/pat.txt | 13 ++- arch/x86/include/asm/cacheflush.h | 6 +- arch/x86/include/asm/io.h | 2 + arch/x86/include/asm/pgtable_types.h | 3 + arch/x86/mm/init.c | 6 +- arch/x86/mm/iomap_32.c | 12 +-- arch/x86/mm/ioremap.c | 26 ++++- arch/x86/mm/pageattr.c | 61 +++++++++-- arch/x86/mm/pat.c | 194 ++++++++++++++++++++++++----------- include/asm-generic/io.h | 9 ++ include/asm-generic/iomap.h | 4 + include/asm-generic/pgtable.h | 4 + 12 files changed, 251 insertions(+), 89 deletions(-) -- 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>