x86: new API for modifying CPU feature flags
Use an API for setting/clearing CPU features, so the
process can be debugged.
Adds:
set_cpu_feature()
clear_cpu_feature()
clear_all_cpu_features()
Todo:
mask_boot_cpu_features()
set_cpu_feature_word()
more?
(Hardcoded printk for now, should be dprintk.)
Signed-off-by: Chuck Ebbert <[EMAIL PROTECTED]>
---
include/asm-i386/cpufeature.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
--- 2.6.21-rc7-d390.orig/include/asm-i386/cpufeature.h
+++ 2.6.21-rc7-d390/include/asm-i386/cpufeature.h
@@ -108,6 +108,23 @@
#define cpu_has(c, bit) test_bit(bit, (c)->x86_capability)
#define boot_cpu_has(bit) test_bit(bit, boot_cpu_data.x86_capability)
+#define alter_cpu_feature(fn, feat, c) \
+ do { typeof(c) __c = (c); \
+ printk("CPU: %s: %s feature %s for CPU %p", \
+ __func__, #fn, #feat, __c); \
+ fn ## _bit(X86_FEATURE_ ## feat, __c->x86_capability); \
+ } while (0)
+
+#define set_cpu_feature(f, c) alter_cpu_feature(set, f, c)
+#define clear_cpu_feature(f, c) alter_cpu_feature(clear, f, c)
+
+#define clear_all_cpu_features(c) \
+ do { typeof(c) __c = (c); \
+ printk("CPU: %s: clearing all capabilities for CPU %p",
\
+ __func__, __c); \
+ memset(&__c->x86_capability, 0, sizeof
__c->x86_capability); \
+ } while (0)
+
#define cpu_has_fpu boot_cpu_has(X86_FEATURE_FPU)
#define cpu_has_vme boot_cpu_has(X86_FEATURE_VME)
#define cpu_has_de boot_cpu_has(X86_FEATURE_DE)
