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linux-2.6/arch/x86/kernel/cpu/amd.c
Andi Kleen 0c07ee38c9 x86: use the correct cpuid method to detect MWAIT support for C states
Previously there was a AMD specific quirk to handle the case of
AMD Fam10h MWAIT not supporting any C states. But it turns out
that CPUID already has ways to detectly detect that without
using special quirks.

The new code simply checks if MWAIT supports at least C1 and doesn't
use it if it doesn't. No more vendor specific code.

Note this is does not simply clear MWAIT because MWAIT can be still
useful even without C states.

Credit goes to Ben Serebrin for pointing out the (nearly) obvious.

Cc: "Andreas Herrmann" <andreas.herrmann3@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:16 +01:00

348 lines
8.8 KiB
C

#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/apic.h>
#include <asm/mach_apic.h>
#include "cpu.h"
/*
* B step AMD K6 before B 9730xxxx have hardware bugs that can cause
* misexecution of code under Linux. Owners of such processors should
* contact AMD for precise details and a CPU swap.
*
* See http://www.multimania.com/poulot/k6bug.html
* http://www.amd.com/K6/k6docs/revgd.html
*
* The following test is erm.. interesting. AMD neglected to up
* the chip setting when fixing the bug but they also tweaked some
* performance at the same time..
*/
extern void vide(void);
__asm__(".align 4\nvide: ret");
#ifdef CONFIG_X86_LOCAL_APIC
#define ENABLE_C1E_MASK 0x18000000
#define CPUID_PROCESSOR_SIGNATURE 1
#define CPUID_XFAM 0x0ff00000
#define CPUID_XFAM_K8 0x00000000
#define CPUID_XFAM_10H 0x00100000
#define CPUID_XFAM_11H 0x00200000
#define CPUID_XMOD 0x000f0000
#define CPUID_XMOD_REV_F 0x00040000
/* AMD systems with C1E don't have a working lAPIC timer. Check for that. */
static __cpuinit int amd_apic_timer_broken(void)
{
u32 lo, hi;
u32 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
switch (eax & CPUID_XFAM) {
case CPUID_XFAM_K8:
if ((eax & CPUID_XMOD) < CPUID_XMOD_REV_F)
break;
case CPUID_XFAM_10H:
case CPUID_XFAM_11H:
rdmsr(MSR_K8_ENABLE_C1E, lo, hi);
if (lo & ENABLE_C1E_MASK) {
if (smp_processor_id() != boot_cpu_physical_apicid)
printk(KERN_INFO "AMD C1E detected late. "
" Force timer broadcast.\n");
return 1;
}
break;
default:
/* err on the side of caution */
return 1;
}
return 0;
}
#endif
int force_mwait __cpuinitdata;
void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
{
if (cpuid_eax(0x80000000) >= 0x80000007) {
c->x86_power = cpuid_edx(0x80000007);
if (c->x86_power & (1<<8))
set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
}
}
static void __cpuinit init_amd(struct cpuinfo_x86 *c)
{
u32 l, h;
int mbytes = num_physpages >> (20-PAGE_SHIFT);
int r;
#ifdef CONFIG_SMP
unsigned long long value;
/* Disable TLB flush filter by setting HWCR.FFDIS on K8
* bit 6 of msr C001_0015
*
* Errata 63 for SH-B3 steppings
* Errata 122 for all steppings (F+ have it disabled by default)
*/
if (c->x86 == 15) {
rdmsrl(MSR_K7_HWCR, value);
value |= 1 << 6;
wrmsrl(MSR_K7_HWCR, value);
}
#endif
early_init_amd(c);
/*
* FIXME: We should handle the K5 here. Set up the write
* range and also turn on MSR 83 bits 4 and 31 (write alloc,
* no bus pipeline)
*/
/* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
clear_bit(0*32+31, c->x86_capability);
r = get_model_name(c);
switch(c->x86)
{
case 4:
/*
* General Systems BIOSen alias the cpu frequency registers
* of the Elan at 0x000df000. Unfortuantly, one of the Linux
* drivers subsequently pokes it, and changes the CPU speed.
* Workaround : Remove the unneeded alias.
*/
#define CBAR (0xfffc) /* Configuration Base Address (32-bit) */
#define CBAR_ENB (0x80000000)
#define CBAR_KEY (0X000000CB)
if (c->x86_model==9 || c->x86_model == 10) {
if (inl (CBAR) & CBAR_ENB)
outl (0 | CBAR_KEY, CBAR);
}
break;
case 5:
if( c->x86_model < 6 )
{
/* Based on AMD doc 20734R - June 2000 */
if ( c->x86_model == 0 ) {
clear_bit(X86_FEATURE_APIC, c->x86_capability);
set_bit(X86_FEATURE_PGE, c->x86_capability);
}
break;
}
if ( c->x86_model == 6 && c->x86_mask == 1 ) {
const int K6_BUG_LOOP = 1000000;
int n;
void (*f_vide)(void);
unsigned long d, d2;
printk(KERN_INFO "AMD K6 stepping B detected - ");
/*
* It looks like AMD fixed the 2.6.2 bug and improved indirect
* calls at the same time.
*/
n = K6_BUG_LOOP;
f_vide = vide;
rdtscl(d);
while (n--)
f_vide();
rdtscl(d2);
d = d2-d;
if (d > 20*K6_BUG_LOOP)
printk("system stability may be impaired when more than 32 MB are used.\n");
else
printk("probably OK (after B9730xxxx).\n");
printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
}
/* K6 with old style WHCR */
if (c->x86_model < 8 ||
(c->x86_model== 8 && c->x86_mask < 8)) {
/* We can only write allocate on the low 508Mb */
if(mbytes>508)
mbytes=508;
rdmsr(MSR_K6_WHCR, l, h);
if ((l&0x0000FFFF)==0) {
unsigned long flags;
l=(1<<0)|((mbytes/4)<<1);
local_irq_save(flags);
wbinvd();
wrmsr(MSR_K6_WHCR, l, h);
local_irq_restore(flags);
printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
mbytes);
}
break;
}
if ((c->x86_model == 8 && c->x86_mask >7) ||
c->x86_model == 9 || c->x86_model == 13) {
/* The more serious chips .. */
if(mbytes>4092)
mbytes=4092;
rdmsr(MSR_K6_WHCR, l, h);
if ((l&0xFFFF0000)==0) {
unsigned long flags;
l=((mbytes>>2)<<22)|(1<<16);
local_irq_save(flags);
wbinvd();
wrmsr(MSR_K6_WHCR, l, h);
local_irq_restore(flags);
printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
mbytes);
}
/* Set MTRR capability flag if appropriate */
if (c->x86_model == 13 || c->x86_model == 9 ||
(c->x86_model == 8 && c->x86_mask >= 8))
set_bit(X86_FEATURE_K6_MTRR, c->x86_capability);
break;
}
if (c->x86_model == 10) {
/* AMD Geode LX is model 10 */
/* placeholder for any needed mods */
break;
}
break;
case 6: /* An Athlon/Duron */
/* Bit 15 of Athlon specific MSR 15, needs to be 0
* to enable SSE on Palomino/Morgan/Barton CPU's.
* If the BIOS didn't enable it already, enable it here.
*/
if (c->x86_model >= 6 && c->x86_model <= 10) {
if (!cpu_has(c, X86_FEATURE_XMM)) {
printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
rdmsr(MSR_K7_HWCR, l, h);
l &= ~0x00008000;
wrmsr(MSR_K7_HWCR, l, h);
set_bit(X86_FEATURE_XMM, c->x86_capability);
}
}
/* It's been determined by AMD that Athlons since model 8 stepping 1
* are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
* As per AMD technical note 27212 0.2
*/
if ((c->x86_model == 8 && c->x86_mask>=1) || (c->x86_model > 8)) {
rdmsr(MSR_K7_CLK_CTL, l, h);
if ((l & 0xfff00000) != 0x20000000) {
printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
((l & 0x000fffff)|0x20000000));
wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
}
}
break;
}
switch (c->x86) {
case 15:
/* Use K8 tuning for Fam10h and Fam11h */
case 0x10:
case 0x11:
set_bit(X86_FEATURE_K8, c->x86_capability);
break;
case 6:
set_bit(X86_FEATURE_K7, c->x86_capability);
break;
}
if (c->x86 >= 6)
set_bit(X86_FEATURE_FXSAVE_LEAK, c->x86_capability);
display_cacheinfo(c);
if (cpuid_eax(0x80000000) >= 0x80000008) {
c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
}
#ifdef CONFIG_X86_HT
/*
* On a AMD multi core setup the lower bits of the APIC id
* distinguish the cores.
*/
if (c->x86_max_cores > 1) {
int cpu = smp_processor_id();
unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf;
if (bits == 0) {
while ((1 << bits) < c->x86_max_cores)
bits++;
}
c->cpu_core_id = c->phys_proc_id & ((1<<bits)-1);
c->phys_proc_id >>= bits;
printk(KERN_INFO "CPU %d(%d) -> Core %d\n",
cpu, c->x86_max_cores, c->cpu_core_id);
}
#endif
if (cpuid_eax(0x80000000) >= 0x80000006) {
if ((c->x86 == 0x10) && (cpuid_edx(0x80000006) & 0xf000))
num_cache_leaves = 4;
else
num_cache_leaves = 3;
}
#ifdef CONFIG_X86_LOCAL_APIC
if (amd_apic_timer_broken())
local_apic_timer_disabled = 1;
#endif
/* K6s reports MCEs but don't actually have all the MSRs */
if (c->x86 < 6)
clear_bit(X86_FEATURE_MCE, c->x86_capability);
if (cpu_has_xmm)
set_bit(X86_FEATURE_MFENCE_RDTSC, c->x86_capability);
}
static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)
{
/* AMD errata T13 (order #21922) */
if ((c->x86 == 6)) {
if (c->x86_model == 3 && c->x86_mask == 0) /* Duron Rev A0 */
size = 64;
if (c->x86_model == 4 &&
(c->x86_mask==0 || c->x86_mask==1)) /* Tbird rev A1/A2 */
size = 256;
}
return size;
}
static struct cpu_dev amd_cpu_dev __cpuinitdata = {
.c_vendor = "AMD",
.c_ident = { "AuthenticAMD" },
.c_models = {
{ .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
{
[3] = "486 DX/2",
[7] = "486 DX/2-WB",
[8] = "486 DX/4",
[9] = "486 DX/4-WB",
[14] = "Am5x86-WT",
[15] = "Am5x86-WB"
}
},
},
.c_init = init_amd,
.c_size_cache = amd_size_cache,
};
int __init amd_init_cpu(void)
{
cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;
return 0;
}