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| author | venkatesh.pallipadi@intel.com | 2008-03-19 01:00:14 +0100 |
|---|---|---|
| committer | Ingo Molnar | 2008-04-17 17:41:19 +0200 |
| commit | 2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6 (patch) | |
| tree | 6c90c0f9f38ff85e2f42ddc0f4ef0291cdd47d38 /arch/x86/Kconfig | |
| parent | x86: PAT documentation (diff) | |
| download | kernel-qcow2-linux-2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6.tar.gz kernel-qcow2-linux-2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6.tar.xz kernel-qcow2-linux-2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6.zip | |
x86: PAT infrastructure patch
Sets up pat_init() infrastructure.
PAT MSR has following setting.
PAT
|PCD
||PWT
|||
000 WB _PAGE_CACHE_WB
001 WC _PAGE_CACHE_WC
010 UC- _PAGE_CACHE_UC_MINUS
011 UC _PAGE_CACHE_UC
We are effectively changing WT from boot time setting to WC.
UC_MINUS is used to provide backward compatibility to existing /dev/mem
users(X).
reserve_memtype and free_memtype are new interfaces for maintaining alias-free
mapping. It is currently implemented in a simple way with a linked list and
not optimized. reserve and free tracks the effective memory type, as a result
of PAT and MTRR setting rather than what is actually requested in PAT.
pat_init piggy backs on mtrr_init as the rules for setting both pat and mtrr
are same.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fd27048087b8..5b46756e4c7c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1009,6 +1009,21 @@ config MTRR See <file:Documentation/mtrr.txt> for more information. +config X86_PAT + def_bool y + prompt "x86 PAT support" + depends on MTRR && NONPROMISC_DEVMEM + help + Use PAT attributes to setup page level cache control. + ---help--- + PATs are the modern equivalents of MTRRs and are much more + flexible than MTRRs. + + Say N here if you see bootup problems (boot crash, boot hang, + spontaneous reboots) or a non-working Xorg. + + If unsure, say Y. + config EFI def_bool n prompt "EFI runtime service support" |