diff options
Diffstat (limited to 'arch/i386/kernel/cpu/mtrr/centaur.c')
| -rw-r--r-- | arch/i386/kernel/cpu/mtrr/centaur.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/mtrr/centaur.c b/arch/i386/kernel/cpu/mtrr/centaur.c new file mode 100644 index 00000000000..33f00ac314e --- /dev/null +++ b/arch/i386/kernel/cpu/mtrr/centaur.c @@ -0,0 +1,223 @@ +#include <linux/init.h> +#include <linux/mm.h> +#include <asm/mtrr.h> +#include <asm/msr.h> +#include "mtrr.h" + +static struct { + unsigned long high; + unsigned long low; +} centaur_mcr[8]; + +static u8 centaur_mcr_reserved; +static u8 centaur_mcr_type; /* 0 for winchip, 1 for winchip2 */ + +/* + * Report boot time MCR setups + */ + +static int +centaur_get_free_region(unsigned long base, unsigned long size) +/* [SUMMARY] Get a free MTRR. + <base> The starting (base) address of the region. + <size> The size (in bytes) of the region. + [RETURNS] The index of the region on success, else -1 on error. +*/ +{ + int i, max; + mtrr_type ltype; + unsigned long lbase; + unsigned int lsize; + + max = num_var_ranges; + for (i = 0; i < max; ++i) { + if (centaur_mcr_reserved & (1 << i)) + continue; + mtrr_if->get(i, &lbase, &lsize, <ype); + if (lsize == 0) + return i; + } + return -ENOSPC; +} + +void +mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi) +{ + centaur_mcr[mcr].low = lo; + centaur_mcr[mcr].high = hi; +} + +static void +centaur_get_mcr(unsigned int reg, unsigned long *base, + unsigned int *size, mtrr_type * type) +{ + *base = centaur_mcr[reg].high >> PAGE_SHIFT; + *size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT; + *type = MTRR_TYPE_WRCOMB; /* If it is there, it is write-combining */ + if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2)) + *type = MTRR_TYPE_UNCACHABLE; + if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25) + *type = MTRR_TYPE_WRBACK; + if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31) + *type = MTRR_TYPE_WRBACK; + +} + +static void centaur_set_mcr(unsigned int reg, unsigned long base, + unsigned long size, mtrr_type type) +{ + unsigned long low, high; + + if (size == 0) { + /* Disable */ + high = low = 0; + } else { + high = base << PAGE_SHIFT; + if (centaur_mcr_type == 0) + low = -size << PAGE_SHIFT | 0x1f; /* only support write-combining... */ + else { + if (type == MTRR_TYPE_UNCACHABLE) + low = -size << PAGE_SHIFT | 0x02; /* NC */ + else + low = -size << PAGE_SHIFT | 0x09; /* WWO,WC */ + } + } + centaur_mcr[reg].high = high; + centaur_mcr[reg].low = low; + wrmsr(MSR_IDT_MCR0 + reg, low, high); +} + +#if 0 +/* + * Initialise the later (saner) Winchip MCR variant. In this version + * the BIOS can pass us the registers it has used (but not their values) + * and the control register is read/write + */ + +static void __init +centaur_mcr1_init(void) +{ + unsigned i; + u32 lo, hi; + + /* Unfortunately, MCR's are read-only, so there is no way to + * find out what the bios might have done. + */ + + rdmsr(MSR_IDT_MCR_CTRL, lo, hi); + if (((lo >> 17) & 7) == 1) { /* Type 1 Winchip2 MCR */ + lo &= ~0x1C0; /* clear key */ + lo |= 0x040; /* set key to 1 */ + wrmsr(MSR_IDT_MCR_CTRL, lo, hi); /* unlock MCR */ + } + + centaur_mcr_type = 1; + + /* + * Clear any unconfigured MCR's. + */ + + for (i = 0; i < 8; ++i) { + if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0) { + if (!(lo & (1 << (9 + i)))) + wrmsr(MSR_IDT_MCR0 + i, 0, 0); + else + /* + * If the BIOS set up an MCR we cannot see it + * but we don't wish to obliterate it + */ + centaur_mcr_reserved |= (1 << i); + } + } + /* + * Throw the main write-combining switch... + * However if OOSTORE is enabled then people have already done far + * cleverer things and we should behave. + */ + + lo |= 15; /* Write combine enables */ + wrmsr(MSR_IDT_MCR_CTRL, lo, hi); +} + +/* + * Initialise the original winchip with read only MCR registers + * no used bitmask for the BIOS to pass on and write only control + */ + +static void __init +centaur_mcr0_init(void) +{ + unsigned i; + + /* Unfortunately, MCR's are read-only, so there is no way to + * find out what the bios might have done. + */ + + /* Clear any unconfigured MCR's. + * This way we are sure that the centaur_mcr array contains the actual + * values. The disadvantage is that any BIOS tweaks are thus undone. + * + */ + for (i = 0; i < 8; ++i) { + if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0) + wrmsr(MSR_IDT_MCR0 + i, 0, 0); + } + + wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0); /* Write only */ +} + +/* + * Initialise Winchip series MCR registers + */ + +static void __init +centaur_mcr_init(void) +{ + struct set_mtrr_context ctxt; + + set_mtrr_prepare_save(&ctxt); + set_mtrr_cache_disable(&ctxt); + + if (boot_cpu_data.x86_model == 4) + centaur_mcr0_init(); + else if (boot_cpu_data.x86_model == 8 || boot_cpu_data.x86_model == 9) + centaur_mcr1_init(); + + set_mtrr_done(&ctxt); +} +#endif + +static int centaur_validate_add_page(unsigned long base, + unsigned long size, unsigned int type) +{ + /* + * FIXME: Winchip2 supports uncached + */ + if (type != MTRR_TYPE_WRCOMB && + (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) { + printk(KERN_WARNING + "mtrr: only write-combining%s supported\n", + centaur_mcr_type ? " and uncacheable are" + : " is"); + return -EINVAL; + } + return 0; +} + +static struct mtrr_ops centaur_mtrr_ops = { + .vendor = X86_VENDOR_CENTAUR, +// .init = centaur_mcr_init, + .set = centaur_set_mcr, + .get = centaur_get_mcr, + .get_free_region = centaur_get_free_region, + .validate_add_page = centaur_validate_add_page, + .have_wrcomb = positive_have_wrcomb, +}; + +int __init centaur_init_mtrr(void) +{ + set_mtrr_ops(¢aur_mtrr_ops); + return 0; +} + +//arch_initcall(centaur_init_mtrr); |