[PATCH] x86_64/i386: Compute correct MTRR mask on early Noconas

Force correct address space size for MTRR on some 64bit Intel Xeons

They report 40bit, but only have 36bits of physical address space.
This caused problems with setting up the correct masks for MTRR,
resulting in incorrect MTRRs.

CPUID workaround for steppings 0F33h(supporting x86) and 0F34h(supporting x86
and EM64T). Detail info can be found at:
http://download.intel.com/design/Xeon/specupdt/30240216.pdf
http://download.intel.com/design/Pentium4/specupdt/30235221.pdf

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Andi Kleen 2005-10-30 01:49:38 -05:00 committed by Chris Wright
parent 4b490b0c8d
commit 067d66baa9
2 changed files with 13 additions and 0 deletions

View file

@ -626,6 +626,14 @@ void __init mtrr_bp_init(void)
if (cpuid_eax(0x80000000) >= 0x80000008) {
u32 phys_addr;
phys_addr = cpuid_eax(0x80000008) & 0xff;
/* CPUID workaround for Intel 0F33/0F34 CPU */
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
boot_cpu_data.x86 == 0xF &&
boot_cpu_data.x86_model == 0x3 &&
(boot_cpu_data.x86_mask == 0x3 ||
boot_cpu_data.x86_mask == 0x4))
phys_addr = 36;
size_or_mask = ~((1 << (phys_addr - PAGE_SHIFT)) - 1);
size_and_mask = ~size_or_mask & 0xfff00000;
} else if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR &&

View file

@ -993,6 +993,11 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
unsigned eax = cpuid_eax(0x80000008);
c->x86_virt_bits = (eax >> 8) & 0xff;
c->x86_phys_bits = eax & 0xff;
/* CPUID workaround for Intel 0F34 CPU */
if (c->x86_vendor == X86_VENDOR_INTEL &&
c->x86 == 0xF && c->x86_model == 0x3 &&
c->x86_mask == 0x4)
c->x86_phys_bits = 36;
}
if (c->x86 == 15)