Support Write-Through mapping on x86

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 from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/