From 2e5d9c857d4e6c9e7b7d8c8c86a68a7842d213d6 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Tue, 18 Mar 2008 17:00:14 -0700 Subject: 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 Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/x86/Kconfig') 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 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" -- cgit v1.2.3