diff options
Diffstat (limited to 'arch/x86/kernel/cpu/centaur.c')
| -rw-r--r-- | arch/x86/kernel/cpu/centaur.c | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c new file mode 100644 index 0000000..473eac8 --- /dev/null +++ b/arch/x86/kernel/cpu/centaur.c @@ -0,0 +1,471 @@ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/bitops.h> +#include <asm/processor.h> +#include <asm/msr.h> +#include <asm/e820.h> +#include <asm/mtrr.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) /* 16388 */ +{ + int i; + u32 top = 0; + u32 clip = 0xFFFFFFFFUL; + + 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 catastrophy 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; + + /* + * Find the largest block we will fill going upwards + */ + + u32 high = power2(mem-top); + + /* + * Find the largest block we will fill going downwards + */ + + u32 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 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. + */ + int 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 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 + */ + + int 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); + } + + /* Cyrix III family needs CX8 & PGE explicity 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_bit(X86_FEATURE_CX8, c->x86_capability); + } + + /* Before Nehemiah, the C3's had 3dNOW! */ + if (c->x86_model >=6 && c->x86_model <9) + set_bit(X86_FEATURE_3DNOW, c->x86_capability); + + get_model_name(c); + display_cacheinfo(c); +} + +static void __cpuinit init_centaur(struct cpuinfo_x86 *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, + }; + + 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_bit(0*32+31, c->x86_capability); + + switch (c->x86) { + + 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_bit(X86_FEATURE_TSC, c->x86_capability); +#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_bit(X86_FEATURE_CENTAUR_MCR, c->x86_capability); + /* Report CX8 */ + set_bit(X86_FEATURE_CX8, c->x86_capability); + /* Set 3DNow! on Winchip 2 and above. */ + if (c->x86_model >=8) + set_bit(X86_FEATURE_3DNOW, c->x86_capability); + /* 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; + + case 6: + init_c3(c); + break; + } +} + +static unsigned int __cpuinit centaur_size_cache(struct cpuinfo_x86 * c, unsigned int size) +{ + /* VIA C3 CPUs (670-68F) need further shifting. */ + if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8))) + size >>= 8; + + /* VIA also screwed up Nehemiah stepping 1, and made + it return '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; + + return size; +} + +static struct cpu_dev centaur_cpu_dev __cpuinitdata = { + .c_vendor = "Centaur", + .c_ident = { "CentaurHauls" }, + .c_init = init_centaur, + .c_size_cache = centaur_size_cache, +}; + +int __init centaur_init_cpu(void) +{ + cpu_devs[X86_VENDOR_CENTAUR] = ¢aur_cpu_dev; + return 0; +} |
