x86: move mtrr cpu cap setting early in early_init_xxxx

Krzysztof Helt found MTRR is not detected on k6-2

root cause:
	we moved mtrr_bp_init() early for mtrr trimming,
and in early_detect we only read the CPU capability from cpuid,
so some cpu doesn't have that bit in cpuid.

So we need to add early_init_xxxx to preset those bit before mtrr_bp_init
for those earlier cpus.

this patch is for v2.6.27

Reported-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 28 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
index ada50505a5c8..13f8fa16b815 100644
--- a/arch/x86/kernel/cpu/cyrix.c
+++ b/arch/x86/kernel/cpu/cyrix.c
@@ -15,13 +15,11 @@
 /*
  * Read NSC/Cyrix DEVID registers (DIR) to get more detailed info. about the CPU
  */
-static void __cpuinit do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
+static void __cpuinit __do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
 {
         unsigned char ccr2, ccr3;
-        unsigned long flags;
 
         /* we test for DEVID by checking whether CCR3 is writable */
-        local_irq_save(flags);
         ccr3 = getCx86(CX86_CCR3);
         setCx86(CX86_CCR3, ccr3 ^ 0x80);
         getCx86(0xc0);   /* dummy to change bus */
@@ -44,9 +42,16 @@ static void __cpuinit do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
                 *dir0 = getCx86(CX86_DIR0);
                 *dir1 = getCx86(CX86_DIR1);
         }
-        local_irq_restore(flags);
 }
 
+static void __cpuinit do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        __do_cyrix_devid(dir0, dir1);
+        local_irq_restore(flags);
+}
 /*
  * Cx86_dir0_msb is a HACK needed by check_cx686_cpuid/slop in bugs.h in
  * order to identify the Cyrix CPU model after we're out of setup.c
@@ -161,6 +166,24 @@ static void __cpuinit geode_configure(void)
         local_irq_restore(flags);
 }
 
+static void __cpuinit early_init_cyrix(struct cpuinfo_x86 *c)
+{
+        unsigned char dir0, dir0_msn, dir1 = 0;
+
+        __do_cyrix_devid(&dir0, &dir1);
+        dir0_msn = dir0 >> 4; /* identifies CPU "family"   */
+
+        switch (dir0_msn) {
+        case 3: /* 6x86/6x86L */
+                /* Emulate MTRRs using Cyrix's ARRs. */
+                set_cpu_cap(c, X86_FEATURE_CYRIX_ARR);
+                break;
+        case 5: /* 6x86MX/M II */
+                /* Emulate MTRRs using Cyrix's ARRs. */
+                set_cpu_cap(c, X86_FEATURE_CYRIX_ARR);
+                break;
+        }
+}
 
 static void __cpuinit init_cyrix(struct cpuinfo_x86 *c)
 {
@@ -416,6 +439,7 @@ static void __cpuinit cyrix_identify(struct cpuinfo_x86 *c)
 static struct cpu_dev cyrix_cpu_dev __cpuinitdata = {
         .c_vendor       = "Cyrix",
         .c_ident        = { "CyrixInstead" },
+        .c_early_init   = early_init_cyrix,
         .c_init         = init_cyrix,
         .c_identify     = cyrix_identify,
 };