This patchset adds support of Write-Through (WT) mapping on x86.
The study below shows that using WT mapping may be useful for
The patchset consists of the following changes.
- Patch 1/12 to 6/12 add ioremap_wt()
- Patch 7/12 adds pgprot_writethrough()
- Patch 8/12 to 9/12 add set_memory_wt()
- Patch 10/12 to 11/12 refactor !pat_enable paths
- Patch 12/12 changes the pmem driver to call ioremap_wt()
All new/modified interfaces have been tested.
- Removed ioremap_writethrough(). (Thomas Gleixner)
- Clarified and cleaned up multiple comments and functions.
- Changed ioremap_change_attr() to accept the WT type.
- Changed to export the set_xxx_wt() interfaces with GPL.
- 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.
- Rebased to 4.0-rc1 and resolved conflicts with 9d34cfdf4 in
- Rebased to 3.19-rc3 as Juergen's patchset for the PAT management
has been accepted.
- 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.
- Clarified comment of why using slot 7. (Andy Lutomirski,
- Moved [set|get]_page_memtype() to pat.c. (Thomas Gleixner)
- Removed BUG() from set_page_memtype(). (Thomas Gleixner)
- Added set_memory_wt() by adding WT support of regular memory.
- Dropped the set_memory_wt() patch. (Andy Lutomirski)
- Refactored the !pat_enabled handling. (H. Peter Anvin,
- Added the picture of PTE encoding. (Konrad Rzeszutek Wilk)
- Changed WT to use slot 7 of the PAT MSR. (H. Peter Anvin,
- Changed to have conservative checks to exclude all Pentium 2, 3,
M, and 4 families. (Ingo Molnar, Henrique de Moraes Holschuh,
- Updated documentation to cover WT interfaces and usages.
(Andy Lutomirski, Yigal Korman)
Toshi Kani (12):
1/12 x86, mm, pat: Set WT to PA7 slot of PAT MSR
2/12 x86, mm, pat: Change reserve_memtype() for WT
3/12 x86, asm: Change is_new_memtype_allowed() for WT
4/12 x86, mm, asm-gen: Add ioremap_wt() for WT
5/12 arch/*/asm/io.h: Add ioremap_wt() to all architectures
6/12 video/fbdev, asm/io.h: Remove ioremap_writethrough()
7/12 x86, mm, pat: Add pgprot_writethrough() for WT
8/12 x86, mm, asm: Add WT support to set_page_memtype()
9/12 x86, mm: Add set_memory_wt() for WT
10/12 x86, mm, pat: Cleanup init flags in pat_init()
11/12 x86, mm, pat: Refactor !pat_enable handling
12/12 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 | 4 +-
arch/m32r/include/asm/io.h | 1 +
arch/m68k/include/asm/io_mm.h | 4 +-
arch/m68k/include/asm/io_no.h | 4 +-
arch/metag/include/asm/io.h | 3 +
arch/microblaze/include/asm/io.h | 2 +-
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 | 2 +-
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 | 29 ++++-
arch/x86/mm/pageattr.c | 65 +++++++---
arch/x86/mm/pat.c | 232 +++++++++++++++++++++++------------
arch/xtensa/include/asm/io.h | 1 +
drivers/block/pmem.c | 4 +-
drivers/video/fbdev/amifb.c | 4 +-
drivers/video/fbdev/atafb.c | 3 +-
drivers/video/fbdev/hpfb.c | 4 +-
include/asm-generic/io.h | 9 ++
include/asm-generic/iomap.h | 4 +
include/asm-generic/pgtable.h | 4 +
34 files changed, 311 insertions(+), 127 deletions(-)