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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef CPU_X86_CACHE
#define CPU_X86_CACHE
#include <cpu/x86/cr.h>
#define CR0_CacheDisable (CR0_CD)
#define CR0_NoWriteThrough (CR0_NW)
#define CPUID_FEATURE_CLFLUSH_BIT 19
#define CPUID_FEATURE_SELF_SNOOP_BIT 27
#if !defined(__ASSEMBLER__)
#include <arch/cpuid.h>
#include <stdbool.h>
#include <stddef.h>
static inline void wbinvd(void)
{
asm volatile ("wbinvd" ::: "memory");
}
static inline void invd(void)
{
asm volatile("invd" ::: "memory");
}
static inline void clflush(void *addr)
{
asm volatile ("clflush (%0)"::"r" (addr));
}
bool clflush_supported(void);
void clflush_region(const uintptr_t start, const size_t size);
/* The following functions require the __always_inline due to AMD
* function STOP_CAR_AND_CPU that disables cache as
* RAM, the cache as RAM stack can no longer be used. Called
* functions must be inlined to avoid stack usage. Also, the
* compiler must keep local variables register based and not
* allocated them from the stack. With gcc 4.5.0, some functions
* declared as inline are not being inlined. This patch forces
* these functions to always be inlined by adding the qualifier
* __always_inline to their declaration.
*/
static __always_inline void enable_cache(void)
{
CRx_TYPE cr0;
cr0 = read_cr0();
cr0 &= ~(CR0_CD | CR0_NW);
write_cr0(cr0);
}
/*
* Cache flushing is the most time-consuming step when programming the MTRRs.
* However, if the processor supports cache self-snooping (ss), we can skip
* this step and save time.
*/
static __always_inline bool self_snooping_supported(void)
{
return (cpuid_edx(1) >> CPUID_FEATURE_SELF_SNOOP_BIT) & 1;
}
static __always_inline void disable_cache(void)
{
/* Disable and write back the cache */
CRx_TYPE cr0;
cr0 = read_cr0();
cr0 |= CR0_CD;
write_cr0(cr0);
if (!self_snooping_supported())
wbinvd();
}
#endif /* !__ASSEMBLER__ */
#endif /* CPU_X86_CACHE */
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