lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

x86: clean up and fix setup_clear/force_cpu_cap handling

Browse Source 
setup_force_cpu_cap() only have one user (Xen guest code),
but it should not reuse cleared_cpu_cpus, otherwise it
will have problems on SMP.

Need to have a separate cpu_cpus_set array too, for forced-on
flags, beyond the forced-off flags.

Also need to setup handling before all cpus caps are combined.

[ Impact: fix the forced-set CPU feature flag logic ]

Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Yinghai Lu
2009-05-09 23:47:42 -07:00
committed by Ingo Molnar
parent 3969c52d4d
commit 3e0c373749
3 changed files with 16 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
arch/x86/kernel/cpu/common.c
View File

@@ -292,7 +292,8 @@ static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
return NULL; /* Not found */
}
__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
__u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
__u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
void load_percpu_segment(int cpu)
{
@@ -806,6 +807,16 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
#endif
init_hypervisor(c);
/*
* Clear/Set all flags overriden by options, need do it
* before following smp all cpus cap AND.
*/
for (i = 0; i < NCAPINTS; i++) {
c->x86_capability[i] &= ~cpu_caps_cleared[i];
c->x86_capability[i] |= cpu_caps_set[i];
}
/*
* On SMP, boot_cpu_data holds the common feature set between
* all CPUs; so make sure that we indicate which features are
@@ -818,10 +829,6 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
}
/* Clear all flags overriden by options */
for (i = 0; i < NCAPINTS; i++)
c->x86_capability[i] &= ~cleared_cpu_caps[i];
#ifdef CONFIG_X86_MCE
/* Init Machine Check Exception if available. */
mcheck_init(c);