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authorAndreas Herrmann <andreas.herrmann3@amd.com>2008-01-30 13:32:41 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:32:41 +0100
commit9566e91d494ed0668edf88f852de7f251fe8fe9a (patch)
tree9dd4f7ab840e688a3927560349450f941a45ba0b /arch/x86/kernel/setup_64.c
parentddb25f9ac1c4b4f9ba0bdacd7850a921a0c6886c (diff)
x86: fix detection of CONSTANT_TSC bit for AMD CPUs
Commits - c52f61fcbdb2aa84f0e4d831ef07f375e6b99b2c (x86: allow TSC clock source on AMD Fam10h and some cleanup) - e30436f05d456efaff77611e4494f607b14c2782 (x86: move X86_FEATURE_CONSTANT_TSC into early cpu feature detection) are supposed to fix the detection of contant TSC for AMD CPUs. Unfortunately on x86_64 it does still not work with current x86/mm. For a Phenom I still get: ... TSC calibrated against PM_TIMER Marking TSC unstable due to TSCs unsynchronized time.c: Detected 2288.366 MHz processor. ... We have to set c->x86_power in early_identify_cpu to properly detect the CONSTANT_TSC bit in early_init_amd. Attached patch fixes this issue. Following the relevant boot messages when the fix is used: ... TSC calibrated against PM_TIMER time.c: Detected 2288.279 MHz processor. ... Initializing CPU#1 ... checking TSC synchronization [CPU#0 -> CPU#1]: passed. ... Initializing CPU#2 ... checking TSC synchronization [CPU#0 -> CPU#2]: passed. ... Booting processor 3/4 APIC 0x3 ... checking TSC synchronization [CPU#0 -> CPU#3]: passed. Brought up 4 CPUs ... Patch is against x86/mm (v2.6.24-rc8-672-ga9f7faa). Please apply. Set c->x86_power in early_identify_cpu. This ensures that X86_FEATURE_CONSTANT_TSC can properly be set in early_init_amd. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/setup_64.c')
-rw-r--r--arch/x86/kernel/setup_64.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 3cae326093c..1caf7458dc4 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -996,6 +996,10 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
c->x86_capability[2] = cpuid_edx(0x80860001);
}
+ c->extended_cpuid_level = cpuid_eax(0x80000000);
+ if (c->extended_cpuid_level >= 0x80000007)
+ c->x86_power = cpuid_edx(0x80000007);
+
switch (c->x86_vendor) {
case X86_VENDOR_AMD:
early_init_amd(c);
@@ -1066,11 +1070,6 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
numa_add_cpu(smp_processor_id());
#endif
- c->extended_cpuid_level = cpuid_eax(0x80000000);
-
- if (c->extended_cpuid_level >= 0x80000007)
- c->x86_power = cpuid_edx(0x80000007);
-
switch (c->x86_vendor) {
case X86_VENDOR_AMD:
early_init_amd(c);