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x86: clean up and fix setup_clear/force_cpu_cap handling

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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
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4
arch/x86/include/asm/cpufeature.h
View File

@ -192,11 +192,11 @@ extern const char * const x86_power_flags[32];
#define clear_cpu_cap(c, bit) clear_bit(bit, (unsigned long *)((c)->x86_capability))
#define setup_clear_cpu_cap(bit) do { \
clear_cpu_cap(&boot_cpu_data, bit); \
set_bit(bit, (unsigned long *)cleared_cpu_caps); \
set_bit(bit, (unsigned long *)cpu_caps_cleared); \
} while (0)
#define setup_force_cpu_cap(bit) do { \
set_cpu_cap(&boot_cpu_data, bit); \
clear_bit(bit, (unsigned long *)cleared_cpu_caps); \
set_bit(bit, (unsigned long *)cpu_caps_set); \
} while (0)
#define cpu_has_fpu boot_cpu_has(X86_FEATURE_FPU)

3
arch/x86/include/asm/processor.h
View File

@ -135,7 +135,8 @@ extern struct cpuinfo_x86 boot_cpu_data;
extern struct cpuinfo_x86 new_cpu_data;
extern struct tss_struct doublefault_tss;
extern __u32 cleared_cpu_caps[NCAPINTS];
extern __u32 cpu_caps_cleared[NCAPINTS];
extern __u32 cpu_caps_set[NCAPINTS];
#ifdef CONFIG_SMP
DECLARE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);

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);