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#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/processor.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");
static void __init init_amd(struct cpuinfo_x86 *c)
{
u32 l, h;
int mbytes = num_physpages >> (20-PAGE_SHIFT);
int r;
/*
* 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;
/* Knock these two lines out if it debugs out ok */
printk(KERN_INFO "AMD K6 stepping B detected - ");
/* -- cut here -- */
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;
}
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:
set_bit(X86_FEATURE_K8, c->x86_capability);
break;
case 6:
set_bit(X86_FEATURE_K7, c->x86_capability);
break;
}
display_cacheinfo(c);
if (cpuid_eax(0x80000000) >= 0x80000008) {
c->x86_num_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
if (c->x86_num_cores & (c->x86_num_cores - 1))
c->x86_num_cores = 1;
}
#ifdef CONFIG_X86_SMP
/*
* On a AMD dual core setup the lower bits of the APIC id
* distingush the cores. Assumes number of cores is a power
* of two.
*/
if (c->x86_num_cores > 1) {
int cpu = smp_processor_id();
/* Fix up the APIC ID following AMD specifications. */
cpu_core_id[cpu] >>= hweight32(c->x86_num_cores - 1);
printk(KERN_INFO "CPU %d(%d) -> Core %d\n",
cpu, c->x86_num_cores, cpu_core_id[cpu]);
}
#endif
}
static unsigned int 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 __initdata = {
.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_identify = generic_identify,
.c_size_cache = amd_size_cache,
};
int __init amd_init_cpu(void)
{
cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;
return 0;
}
//early_arch_initcall(amd_init_cpu);
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