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>
diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
index ada5050..13f8fa1 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 @@
*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 @@
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 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,
};