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 The patchset consists of the following changes. - Patch 1/10 to 5/10 add ioremap_wt() - Patch 6/10 adds pgprot_writethrough() - Patch 7/10 to 8/10 add set_memory_wt() - Patch 9/10 refactors !pat_enable paths - Patch 10/10 changes the pmem driver to call ioremap_wt() All new/modified interfaces have been tested. --- v9: - Changed to export the set_xxx_wt() interfaces with GPL. (Ingo Molnar) - Changed is_new_memtype_allowed() to handle WT cases. - Changed arch-specific io.h to define ioremap_wt(). - Changed the pmem driver to use ioremap_wt(). - Rebased to 4.1-rc3 and resolved minor conflicts. 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 (10): 1/10 x86, mm, pat: Set WT to PA7 slot of PAT MSR 2/10 x86, mm, pat: Change reserve_memtype() for WT 3/10 x86, asm: Change is_new_memtype_allowed() for WT 4/10 x86, mm, asm-gen: Add ioremap_wt() for WT 5/10 arch/*/asm/io.h: Add ioremap_wt() to all architectures 6/10 x86, mm, pat: Add pgprot_writethrough() for WT 7/10 x86, mm, asm: Add WT support to set_page_memtype() 8/10 x86, mm: Add set_memory_wt() for WT 9/10 x86, mm, pat: Refactor !pat_enable handling 10/10 drivers/block/pmem: Map NVDIMM with ioremap_wt() --- Documentation/x86/pat.txt | 13 ++- arch/arc/include/asm/io.h | 1 + arch/arm/include/asm/io.h | 1 + arch/arm64/include/asm/io.h | 1 + arch/avr32/include/asm/io.h | 1 + arch/frv/include/asm/io.h | 7 ++ arch/m32r/include/asm/io.h | 1 + arch/m68k/include/asm/io_mm.h | 7 ++ arch/m68k/include/asm/io_no.h | 6 ++ arch/metag/include/asm/io.h | 3 + arch/microblaze/include/asm/io.h | 1 + arch/mn10300/include/asm/io.h | 1 + arch/nios2/include/asm/io.h | 1 + arch/s390/include/asm/io.h | 1 + arch/sparc/include/asm/io_32.h | 1 + arch/sparc/include/asm/io_64.h | 1 + arch/tile/include/asm/io.h | 1 + arch/x86/include/asm/cacheflush.h | 6 +- arch/x86/include/asm/io.h | 2 + arch/x86/include/asm/pgtable.h | 8 +- 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 ++++++++++++++++++++++++----------- arch/xtensa/include/asm/io.h | 1 + drivers/block/pmem.c | 4 +- include/asm-generic/io.h | 9 ++ include/asm-generic/iomap.h | 4 + include/asm-generic/pgtable.h | 4 + 31 files changed, 296 insertions(+), 92 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>