[PATCH]CPUID workaround for intel CPU - Re: [PROBLEM] mtrr's not set, 2.6.13

Shaohua Li
2005-09-29T00:55:38Z

Hi Andrew,
This is patch to fix the Jim McCloskey's MTRR issue.
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>
---

linux-2.6.14-rc2-root/arch/i386/kernel/cpu/mtrr/main.c | 8 ++++++++
linux-2.6.14-rc2-root/arch/x86_64/kernel/setup.c | 6 ++++++
2 files changed, 14 insertions(+)

diff -puN arch/i386/kernel/cpu/mtrr/main.c~cpuid_errta arch/i386/kernel/cpu/mtrr/main.c
--- linux-2.6.14-rc2/arch/i386/kernel/cpu/mtrr/main.c~cpuid_errta 2005-09-29 08:35:34.000000000 +0800
+++ linux-2.6.14-rc2-root/arch/i386/kernel/cpu/mtrr/main.c 2005-09-29 08:37:16.000000000 +0800
@@ -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 &&
diff -puN arch/x86_64/kernel/setup.c~cpuid_errta arch/x86_64/kernel/setup.c
--- linux-2.6.14-rc2/arch/x86_64/kernel/setup.c~cpuid_errta 2005-09-29 08:35:34.000000000 +0800
+++ linux-2.6.14-rc2-root/arch/x86_64/kernel/setup.c 2005-09-29 08:37:48.000000000 +0800
@@ -992,6 +992,12 @@ static void __cpuinit init_intel(struct
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 (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_data.x86 == 0xF &&
+ boot_cpu_data.x86_model == 0x3 &&
+ boot_cpu_data.x86_mask == 0x4)
+ c->x86_phys_bits = 36;
}

if (c->x86 == 15)
_