#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, int replace_reg)
/* [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, lsize;
max = num_var_ranges;
if (replace_reg >= 0 && replace_reg < max)
return replace_reg;
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 long *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);
