Linux-2.6.33.2/arch/x86/kernel/cpu/centaur.c
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/processor.h>
#include <asm/e820.h>
#include <asm/mtrr.h>
#include <asm/msr.h>
#include "cpu.h"
#ifdef CONFIG_X86_OOSTORE
static u32 __cpuinit power2(u32 x)
{
u32 s = 1;
while (s <= x)
s <<= 1;
return s >>= 1;
}
/*
* Set up an actual MCR
*/
static void __cpuinit centaur_mcr_insert(int reg, u32 base, u32 size, int key)
{
u32 lo, hi;
hi = base & ~0xFFF;
lo = ~(size-1); /* Size is a power of 2 so this makes a mask */
lo &= ~0xFFF; /* Remove the ctrl value bits */
lo |= key; /* Attribute we wish to set */
wrmsr(reg+MSR_IDT_MCR0, lo, hi);
mtrr_centaur_report_mcr(reg, lo, hi); /* Tell the mtrr driver */
}
/*
* Figure what we can cover with MCR's
*
* Shortcut: We know you can't put 4Gig of RAM on a winchip
*/
static u32 __cpuinit ramtop(void)
{
u32 clip = 0xFFFFFFFFUL;
u32 top = 0;
int i;
for (i = 0; i < e820.nr_map; i++) {
unsigned long start, end;
if (e820.map[i].addr > 0xFFFFFFFFUL)
continue;
/*
* Don't MCR over reserved space. Ignore the ISA hole
* we frob around that catastrophe already
*/
if (e820.map[i].type == E820_RESERVED) {
if (e820.map[i].addr >= 0x100000UL &&
e820.map[i].addr < clip)
clip = e820.map[i].addr;
continue;
}
start = e820.map[i].addr;
end = e820.map[i].addr + e820.map[i].size;
if (start >= end)
continue;
if (end > top)
top = end;
}
/*
* Everything below 'top' should be RAM except for the ISA hole.
* Because of the limited MCR's we want to map NV/ACPI into our
* MCR range for gunk in RAM
*
* Clip might cause us to MCR insufficient RAM but that is an
* acceptable failure mode and should only bite obscure boxes with
* a VESA hole at 15Mb
*
* The second case Clip sometimes kicks in is when the EBDA is marked
* as reserved. Again we fail safe with reasonable results
*/
if (top > clip)
top = clip;
return top;
}
/*
* Compute a set of MCR's to give maximum coverage
*/
static int __cpuinit centaur_mcr_compute(int nr, int key)
{
u32 mem = ramtop();
u32 root = power2(mem);
u32 base = root;
u32 top = root;
u32 floor = 0;
int ct = 0;
while (ct < nr) {
u32 fspace = 0;
u32 high;
u32 low;
/*
* Find the largest block we will fill going upwards
*/
high = power2(mem-top);
/*
* Find the largest block we will fill going downwards
*/
low = base/2;
/*
* Don't fill below 1Mb going downwards as there
* is an ISA hole in the way.
*/
if (base <= 1024*1024)
low = 0;
/*
* See how much space we could cover by filling below
* the ISA hole
*/
if (floor == 0)
fspace = 512*1024;
else if (floor == 512*1024)
fspace = 128*1024;
/* And forget ROM space */
/*
* Now install the largest coverage we get
*/
if (fspace > high && fspace > low) {
centaur_mcr_insert(ct, floor, fspace, key);
floor += fspace;
} else if (high > low) {
centaur_mcr_insert(ct, top, high, key);
top += high;
} else if (low > 0) {
base -= low;
centaur_mcr_insert(ct, base, low, key);
} else
break;
ct++;
}
/*
* We loaded ct values. We now need to set the mask. The caller
* must do this bit.
*/
return ct;
}
static void __cpuinit centaur_create_optimal_mcr(void)
{
int used;
int i;
/*
* Allocate up to 6 mcrs to mark as much of ram as possible
* as write combining and weak write ordered.
*
* To experiment with: Linux never uses stack operations for
* mmio spaces so we could globally enable stack operation wc
*
* Load the registers with type 31 - full write combining, all
* writes weakly ordered.
*/
used = centaur_mcr_compute(6, 31);
/*
* Wipe unused MCRs
*/
for (i = used; i < 8; i++)
wrmsr(MSR_IDT_MCR0+i, 0, 0);
}
static void __cpuinit winchip2_create_optimal_mcr(void)
{
u32 lo, hi;
int used;
int i;
/*
* Allocate up to 6 mcrs to mark as much of ram as possible
* as write combining, weak store ordered.
*
* Load the registers with type 25
* 8 - weak write ordering
* 16 - weak read ordering
* 1 - write combining
*/
used = centaur_mcr_compute(6, 25);
/*
* Mark the registers we are using.
*/
rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
for (i = 0; i < used; i++)
lo |= 1<<(9+i);
wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
/*
* Wipe unused MCRs
*/
for (i = used; i < 8; i++)
wrmsr(MSR_IDT_MCR0+i, 0, 0);
}
/*
* Handle the MCR key on the Winchip 2.
*/
static void __cpuinit winchip2_unprotect_mcr(void)
{
u32 lo, hi;
u32 key;
rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
lo &= ~0x1C0; /* blank bits 8-6 */
key = (lo>>17) & 7;
lo |= key<<6; /* replace with unlock key */
wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
}
static void __cpuinit winchip2_protect_mcr(void)
{
u32 lo, hi;
rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
lo &= ~0x1C0; /* blank bits 8-6 */
wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
}
#endif /* CONFIG_X86_OOSTORE */
#define ACE_PRESENT (1 << 6)
#define ACE_ENABLED (1 << 7)
#define ACE_FCR (1 << 28) /* MSR_VIA_FCR */
#define RNG_PRESENT (1 << 2)
#define RNG_ENABLED (1 << 3)
#define RNG_ENABLE (1 << 6) /* MSR_VIA_RNG */
static void __cpuinit init_c3(struct cpuinfo_x86 *c)
{
u32 lo, hi;
/* Test for Centaur Extended Feature Flags presence */
if (cpuid_eax(0xC0000000) >= 0xC0000001) {
u32 tmp = cpuid_edx(0xC0000001);
/* enable ACE unit, if present and disabled */
if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
rdmsr(MSR_VIA_FCR, lo, hi);
lo |= ACE_FCR; /* enable ACE unit */
wrmsr(MSR_VIA_FCR, lo, hi);
printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
}
/* enable RNG unit, if present and disabled */
if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
rdmsr(MSR_VIA_RNG, lo, hi);
lo |= RNG_ENABLE; /* enable RNG unit */
wrmsr(MSR_VIA_RNG, lo, hi);
printk(KERN_INFO "CPU: Enabled h/w RNG\n");
}
/* store Centaur Extended Feature Flags as
* word 5 of the CPU capability bit array
*/
c->x86_capability[5] = cpuid_edx(0xC0000001);
}
#ifdef CONFIG_X86_32
/* Cyrix III family needs CX8 & PGE explicitly enabled. */
if (c->x86_model >= 6 && c->x86_model <= 9) {
rdmsr(MSR_VIA_FCR, lo, hi);
lo |= (1<<1 | 1<<7);
wrmsr(MSR_VIA_FCR, lo, hi);
set_cpu_cap(c, X86_FEATURE_CX8);
}
/* Before Nehemiah, the C3's had 3dNOW! */
if (c->x86_model >= 6 && c->x86_model < 9)
set_cpu_cap(c, X86_FEATURE_3DNOW);
#endif
if (c->x86 == 0x6 && c->x86_model >= 0xf) {
c->x86_cache_alignment = c->x86_clflush_size * 2;
set_cpu_cap(c, X86_FEATURE_REP_GOOD);
}
cpu_detect_cache_sizes(c);
}
enum {
ECX8 = 1<<1,
EIERRINT = 1<<2,
DPM = 1<<3,
DMCE = 1<<4,
DSTPCLK = 1<<5,
ELINEAR = 1<<6,
DSMC = 1<<7,
DTLOCK = 1<<8,
EDCTLB = 1<<8,
EMMX = 1<<9,
DPDC = 1<<11,
EBRPRED = 1<<12,
DIC = 1<<13,
DDC = 1<<14,
DNA = 1<<15,
ERETSTK = 1<<16,
E2MMX = 1<<19,
EAMD3D = 1<<20,
};
static void __cpuinit early_init_centaur(struct cpuinfo_x86 *c)
{
switch (c->x86) {
#ifdef CONFIG_X86_32
case 5:
/* Emulate MTRRs using Centaur's MCR. */
set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
break;
#endif
case 6:
if (c->x86_model >= 0xf)
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
break;
}
#ifdef CONFIG_X86_64
set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#endif
}
static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_32
char *name;
u32 fcr_set = 0;
u32 fcr_clr = 0;
u32 lo, hi, newlo;
u32 aa, bb, cc, dd;
/*
* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
* 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
*/
clear_cpu_cap(c, 0*32+31);
#endif
early_init_centaur(c);
switch (c->x86) {
#ifdef CONFIG_X86_32
case 5:
switch (c->x86_model) {
case 4:
name = "C6";
fcr_set = ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
fcr_clr = DPDC;
printk(KERN_NOTICE "Disabling bugged TSC.\n");
clear_cpu_cap(c, X86_FEATURE_TSC);
#ifdef CONFIG_X86_OOSTORE
centaur_create_optimal_mcr();
/*
* Enable:
* write combining on non-stack, non-string
* write combining on string, all types
* weak write ordering
*
* The C6 original lacks weak read order
*
* Note 0x120 is write only on Winchip 1
*/
wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
#endif
break;
case 8:
switch (c->x86_mask) {
default:
name = "2";
break;
case 7 ... 9:
name = "2A";
break;
case 10 ... 15:
name = "2B";
break;
}
fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|
E2MMX|EAMD3D;
fcr_clr = DPDC;
#ifdef CONFIG_X86_OOSTORE
winchip2_unprotect_mcr();
winchip2_create_optimal_mcr();
rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
/*
* Enable:
* write combining on non-stack, non-string
* write combining on string, all types
* weak write ordering
*/
lo |= 31;
wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
winchip2_protect_mcr();
#endif
break;
case 9:
name = "3";
fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|
E2MMX|EAMD3D;
fcr_clr = DPDC;
#ifdef CONFIG_X86_OOSTORE
winchip2_unprotect_mcr();
winchip2_create_optimal_mcr();
rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
/*
* Enable:
* write combining on non-stack, non-string
* write combining on string, all types
* weak write ordering
*/
lo |= 31;
wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
winchip2_protect_mcr();
#endif
break;
default:
name = "??";
}
rdmsr(MSR_IDT_FCR1, lo, hi);
newlo = (lo|fcr_set) & (~fcr_clr);
if (newlo != lo) {
printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n",
lo, newlo);
wrmsr(MSR_IDT_FCR1, newlo, hi);
} else {
printk(KERN_INFO "Centaur FCR is 0x%X\n", lo);
}
/* Emulate MTRRs using Centaur's MCR. */
set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
/* Report CX8 */
set_cpu_cap(c, X86_FEATURE_CX8);
/* Set 3DNow! on Winchip 2 and above. */
if (c->x86_model >= 8)
set_cpu_cap(c, X86_FEATURE_3DNOW);
/* See if we can find out some more. */
if (cpuid_eax(0x80000000) >= 0x80000005) {
/* Yes, we can. */
cpuid(0x80000005, &aa, &bb, &cc, &dd);
/* Add L1 data and code cache sizes. */
c->x86_cache_size = (cc>>24)+(dd>>24);
}
sprintf(c->x86_model_id, "WinChip %s", name);
break;
#endif
case 6:
init_c3(c);
break;
}
#ifdef CONFIG_X86_64
set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
#endif
}
static unsigned int __cpuinit
centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
{
#ifdef CONFIG_X86_32
/* VIA C3 CPUs (670-68F) need further shifting. */
if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
size >>= 8;
/*
* There's also an erratum in Nehemiah stepping 1, which
* returns '65KB' instead of '64KB'
* - Note, it seems this may only be in engineering samples.
*/
if ((c->x86 == 6) && (c->x86_model == 9) &&
(c->x86_mask == 1) && (size == 65))
size -= 1;
#endif
return size;
}
static const struct cpu_dev __cpuinitconst centaur_cpu_dev = {
.c_vendor = "Centaur",
.c_ident = { "CentaurHauls" },
.c_early_init = early_init_centaur,
.c_init = init_centaur,
.c_size_cache = centaur_size_cache,
.c_x86_vendor = X86_VENDOR_CENTAUR,
};
cpu_dev_register(centaur_cpu_dev);