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/*
* cacheattr.c: MTRR and PAT initialisation.
*
* Copyright (c) 2008, Citrix Systems, Inc.
*
* Authors:
* Keir Fraser <keir@xen.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*/
#include "util.h"
#include "config.h"
#define MSR_MTRRphysBase(reg) (0x200 + 2 * (reg))
#define MSR_MTRRphysMask(reg) (0x200 + 2 * (reg) + 1)
#define MSR_MTRRcap 0x00fe
#define MSR_MTRRfix64K_00000 0x0250
#define MSR_MTRRfix16K_80000 0x0258
#define MSR_MTRRfix16K_A0000 0x0259
#define MSR_MTRRfix4K_C0000 0x0268
#define MSR_MTRRfix4K_C8000 0x0269
#define MSR_MTRRfix4K_D0000 0x026a
#define MSR_MTRRfix4K_D8000 0x026b
#define MSR_MTRRfix4K_E0000 0x026c
#define MSR_MTRRfix4K_E8000 0x026d
#define MSR_MTRRfix4K_F0000 0x026e
#define MSR_MTRRfix4K_F8000 0x026f
#define MSR_PAT 0x0277
#define MSR_MTRRdefType 0x02ff
void cacheattr_init(void)
{
uint32_t eax, ebx, ecx, edx;
uint64_t mtrr_cap, mtrr_def, content, addr_mask;
unsigned int i, nr_var_ranges, phys_bits = 36;
/* Does the CPU support architectural MTRRs? */
cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
if ( !(edx & (1u << 12)) )
return;
/* Find the physical address size for this CPU. */
cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
if ( eax >= 0x80000008 )
{
cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
phys_bits = (uint8_t)eax;
}
printf("%u-bit phys ... ", phys_bits);
addr_mask = ((1ull << phys_bits) - 1) & ~((1ull << 12) - 1);
mtrr_cap = rdmsr(MSR_MTRRcap);
mtrr_def = (1u << 11) | 6; /* E, default type WB */
/* Fixed-range MTRRs supported? */
if ( mtrr_cap & (1u << 8) )
{
/* 0x00000-0x9ffff: Write Back (WB) */
content = 0x0606060606060606ull;
wrmsr(MSR_MTRRfix64K_00000, content);
wrmsr(MSR_MTRRfix16K_80000, content);
/* 0xa0000-0xbffff: Write Combining (WC) */
if ( mtrr_cap & (1u << 10) ) /* WC supported? */
content = 0x0101010101010101ull;
wrmsr(MSR_MTRRfix16K_A0000, content);
/* 0xc0000-0xfffff: Write Back (WB) */
content = 0x0606060606060606ull;
for ( i = 0; i < 8; i++ )
wrmsr(MSR_MTRRfix4K_C0000 + i, content);
mtrr_def |= 1u << 10; /* FE */
printf("fixed MTRRs ... ");
}
/* Variable-range MTRRs supported? */
nr_var_ranges = (uint8_t)mtrr_cap;
if ( nr_var_ranges != 0 )
{
unsigned long base = pci_mem_start, size;
int i;
for ( i = 0; (base != pci_mem_end) && (i < nr_var_ranges); i++ )
{
size = PAGE_SIZE;
while ( !(base & size) )
size <<= 1;
while ( ((base + size) < base) || ((base + size) > pci_mem_end) )
size >>= 1;
wrmsr(MSR_MTRRphysBase(i), base);
wrmsr(MSR_MTRRphysMask(i),
(~(uint64_t)(size-1) & addr_mask) | (1u << 11));
base += size;
}
printf("var MTRRs [%d/%d] ... ", i, nr_var_ranges);
}
wrmsr(MSR_MTRRdefType, mtrr_def);
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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