coreboot-kgpe-d16/payloads/libpayload/arch/x86/cache.c

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/*
*
* Copyright 2022 Google LLC
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <stdint.h>
#include <arch/cache.h>
#include <arch/cpuid.h>
unsigned int dcache_line_bytes(void)
{
/*
* The value returned in EBX[15:8] is in 8-byte increments.
* Cache line size is EBX[15:8] * 8
*/
return (cpuid_ebx(1) & 0xff00) >> 5;
}
static inline int cpu_supports_wbnoinvd(void)
{
return (cpuid_ebx(0x80000008) >> 9) & 1;
}
static inline int cpu_supports_clwb(void)
{
return (cpuid_ebx(7) >> 24) & 1;
}
static inline int cpu_supports_clflushopt(void)
{
return (cpuid_sub_leaf_ebx(7, 0) >> 23) & 1;
}
static inline int cpu_supports_clflush(void)
{
return (cpuid_ebx(1) >> 19) & 1;
}
inline void dcache_invalidate_all(void)
{
asm volatile("invd" ::: "memory");
}
inline void dcache_clean_invalidate_all(void)
{
asm volatile("wbinvd" ::: "memory");
}
inline void dcache_clean_all(void)
{
if (cpu_supports_wbnoinvd()) {
asm volatile(
"sfence\n\t"
"wbnoinvd\n\t"
::: "memory");
} else {
dcache_clean_invalidate_all();
}
}
void dcache_clean_by_mva(void const *addr, size_t len)
{
unsigned long line, linesize;
linesize = dcache_line_bytes();
line = (uintptr_t)addr & ~(linesize - 1);
if (cpu_supports_clwb()) {
asm volatile("sfence");
while (line < (uintptr_t)addr + len) {
asm volatile("clwb (%0)" : : "r"(line) : "memory");
line += linesize;
}
} else {
dcache_clean_invalidate_by_mva(addr, len);
}
}
void dcache_invalidate_by_mva(void const *addr, size_t len)
{
/*
* x86 doesn't have a "invalidate without clean" for a cache line, fall
* back to both.
*/
dcache_clean_invalidate_by_mva(addr, len);
}
void dcache_clean_invalidate_by_mva(void const *addr, size_t len)
{
unsigned long line, linesize;
linesize = dcache_line_bytes();
line = (uintptr_t)addr & ~(linesize - 1);
if (cpu_supports_clflushopt()) {
asm volatile("sfence");
while (line < (uintptr_t)addr + len) {
asm volatile("clflushopt (%0)" ::"r"(line) : "memory");
line += linesize;
}
} else if (cpu_supports_clflush()) {
asm volatile("sfence");
while (line < (uintptr_t)addr + len) {
asm volatile("clflush (%0)" : : "r"(line) : "memory");
line += linesize;
}
} else {
dcache_clean_invalidate_all();
}
}