x86: c_p_a clflush_cache_range fix

Because in i386 early boot stage, boot_cpu_data may be not available,
which makes clflush_cach_range() into infinite loop, which is called
by change_page_attr(). This patch fixes this by setting
boot_cpu_data.x86_clflush_size in early_cpu_detect().

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index db28aa9e2f69..d608c9ebbfe2 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -274,8 +274,10 @@ void __init cpu_detect(struct cpuinfo_x86 *c)
                 if (c->x86 >= 0x6)
                         c->x86_model += ((tfms >> 16) & 0xF) << 4;
                 c->x86_mask = tfms & 15;
-                if (cap0 & (1<<19))
+                if (cap0 & (1<<19)) {
                         c->x86_cache_alignment = ((misc >> 8) & 0xff) * 8;
+                        c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
+                }
         }
 }
 static void __cpuinit early_get_cap(struct cpuinfo_x86 *c)
@@ -317,6 +319,7 @@ static void __init early_cpu_detect(void)
         struct cpuinfo_x86 *c = &boot_cpu_data;
 
         c->x86_cache_alignment = 32;
+        c->x86_clflush_size = 32;
 
         if (!have_cpuid_p())
                 return;