static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
{
unsigned long lo, hi;
#ifdef CONFIG_X86_F00F_BUG
/*
* All current models of Pentium and Pentium with MMX technology CPUs
* have the F0 0F bug, which lets nonprivileged users lock up the
* system.
* Note that the workaround only should be initialized once...
*/
c->f00f_bug = 0;
if (!paravirt_enabled() && c->x86 == 5) {
static int f00f_workaround_enabled;
c->f00f_bug = 1;
if (!f00f_workaround_enabled) {
trap_init_f00f_bug();
printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
f00f_workaround_enabled = 1;
}
}
#endif
/*
* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
* model 3 mask 3
*/
if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
clear_cpu_cap(c, X86_FEATURE_SEP);
/*
* P4 Xeon errata 037 workaround.
* Hardware prefetcher may cause stale data to be loaded into the cache.
*/
if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
}
}
/*
* See if we have a good local APIC by checking for buggy Pentia,
* i.e. all B steppings and the C2 stepping of P54C when using their
* integrated APIC (see 11AP erratum in "Pentium Processor
* Specification Update").
*/
if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
(c->x86_mask < 0x6 || c->x86_mask == 0xb))
set_cpu_cap(c, X86_FEATURE_11AP);
#ifdef CONFIG_X86_INTEL_USERCOPY
/*
* Set up the preferred alignment for movsl bulk memory moves
*/
switch (c->x86) {
case 4: /* 486: untested */
break;
case 5: /* Old Pentia: untested */
break;
case 6: /* PII/PIII only like movsl with 8-byte alignment */
movsl_mask.mask = 7;
break;
case 15: /* P4 is OK down to 8-byte alignment */
movsl_mask.mask = 7;
break;
}
#endif
#ifdef CONFIG_X86_NUMAQ
numaq_tsc_disable();
#endif
intel_smp_check(c);
}
static void intel_workarounds(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_F00F_BUG
/*
* All models of Pentium and Pentium with MMX technology CPUs
* have the F0 0F bug, which lets nonprivileged users lock up the
* system. Announce that the fault handler will be checking for it.
* The Quark is also family 5, but does not have the same bug.
*/
clear_cpu_bug(c, X86_BUG_F00F);
if (!paravirt_enabled() && c->x86 == 5 && c->x86_model < 9) {
static int f00f_workaround_enabled;
set_cpu_bug(c, X86_BUG_F00F);
if (!f00f_workaround_enabled) {
printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
f00f_workaround_enabled = 1;
}
}
#endif
/*
* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
* model 3 mask 3
*/
if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
clear_cpu_cap(c, X86_FEATURE_SEP);
/*
* PAE CPUID issue: many Pentium M report no PAE but may have a
* functionally usable PAE implementation.
* Forcefully enable PAE if kernel parameter "forcepae" is present.
*/
if (forcepae) {
printk(KERN_WARNING "PAE forced!\n");
set_cpu_cap(c, X86_FEATURE_PAE);
add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
}
/*
* P4 Xeon errata 037 workaround.
* Hardware prefetcher may cause stale data to be loaded into the cache.
*/
if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
if (msr_set_bit(MSR_IA32_MISC_ENABLE,
MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT)
> 0) {
pr_info("CPU: C0 stepping P4 Xeon detected.\n");
pr_info("CPU: Disabling hardware prefetching (Errata 037)\n");
}
}
/*
* See if we have a good local APIC by checking for buggy Pentia,
* i.e. all B steppings and the C2 stepping of P54C when using their
* integrated APIC (see 11AP erratum in "Pentium Processor
* Specification Update").
*/
if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
(c->x86_mask < 0x6 || c->x86_mask == 0xb))
set_cpu_bug(c, X86_BUG_11AP);
#ifdef CONFIG_X86_INTEL_USERCOPY
/*
* Set up the preferred alignment for movsl bulk memory moves
*/
switch (c->x86) {
case 4: /* 486: untested */
break;
case 5: /* Old Pentia: untested */
break;
case 6: /* PII/PIII only like movsl with 8-byte alignment */
movsl_mask.mask = 7;
break;
case 15: /* P4 is OK down to 8-byte alignment */
movsl_mask.mask = 7;
break;
}
#endif
intel_smp_check(c);
}