diff options
Diffstat (limited to 'arch/x86/include/asm/nops.h')
| -rw-r--r-- | arch/x86/include/asm/nops.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/x86/include/asm/nops.h b/arch/x86/include/asm/nops.h new file mode 100644 index 000000000..12f12b5cf --- /dev/null +++ b/arch/x86/include/asm/nops.h @@ -0,0 +1,147 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_NOPS_H +#define _ASM_X86_NOPS_H + +/* + * Define nops for use with alternative() and for tracing. + * + * *_NOP5_ATOMIC must be a single instruction. + */ + +#define NOP_DS_PREFIX 0x3e + +/* generic versions from gas + 1: nop + the following instructions are NOT nops in 64-bit mode, + for 64-bit mode use K8 or P6 nops instead + 2: movl %esi,%esi + 3: leal 0x00(%esi),%esi + 4: leal 0x00(,%esi,1),%esi + 6: leal 0x00000000(%esi),%esi + 7: leal 0x00000000(,%esi,1),%esi +*/ +#define GENERIC_NOP1 0x90 +#define GENERIC_NOP2 0x89,0xf6 +#define GENERIC_NOP3 0x8d,0x76,0x00 +#define GENERIC_NOP4 0x8d,0x74,0x26,0x00 +#define GENERIC_NOP5 GENERIC_NOP1,GENERIC_NOP4 +#define GENERIC_NOP6 0x8d,0xb6,0x00,0x00,0x00,0x00 +#define GENERIC_NOP7 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00 +#define GENERIC_NOP8 GENERIC_NOP1,GENERIC_NOP7 +#define GENERIC_NOP5_ATOMIC NOP_DS_PREFIX,GENERIC_NOP4 + +/* Opteron 64bit nops + 1: nop + 2: osp nop + 3: osp osp nop + 4: osp osp osp nop +*/ +#define K8_NOP1 GENERIC_NOP1 +#define K8_NOP2 0x66,K8_NOP1 +#define K8_NOP3 0x66,K8_NOP2 +#define K8_NOP4 0x66,K8_NOP3 +#define K8_NOP5 K8_NOP3,K8_NOP2 +#define K8_NOP6 K8_NOP3,K8_NOP3 +#define K8_NOP7 K8_NOP4,K8_NOP3 +#define K8_NOP8 K8_NOP4,K8_NOP4 +#define K8_NOP5_ATOMIC 0x66,K8_NOP4 + +/* K7 nops + uses eax dependencies (arbitrary choice) + 1: nop + 2: movl %eax,%eax + 3: leal (,%eax,1),%eax + 4: leal 0x00(,%eax,1),%eax + 6: leal 0x00000000(%eax),%eax + 7: leal 0x00000000(,%eax,1),%eax +*/ +#define K7_NOP1 GENERIC_NOP1 +#define K7_NOP2 0x8b,0xc0 +#define K7_NOP3 0x8d,0x04,0x20 +#define K7_NOP4 0x8d,0x44,0x20,0x00 +#define K7_NOP5 K7_NOP4,K7_NOP1 +#define K7_NOP6 0x8d,0x80,0,0,0,0 +#define K7_NOP7 0x8D,0x04,0x05,0,0,0,0 +#define K7_NOP8 K7_NOP7,K7_NOP1 +#define K7_NOP5_ATOMIC NOP_DS_PREFIX,K7_NOP4 + +/* P6 nops + uses eax dependencies (Intel-recommended choice) + 1: nop + 2: osp nop + 3: nopl (%eax) + 4: nopl 0x00(%eax) + 5: nopl 0x00(%eax,%eax,1) + 6: osp nopl 0x00(%eax,%eax,1) + 7: nopl 0x00000000(%eax) + 8: nopl 0x00000000(%eax,%eax,1) + Note: All the above are assumed to be a single instruction. + There is kernel code that depends on this. +*/ +#define P6_NOP1 GENERIC_NOP1 +#define P6_NOP2 0x66,0x90 +#define P6_NOP3 0x0f,0x1f,0x00 +#define P6_NOP4 0x0f,0x1f,0x40,0 +#define P6_NOP5 0x0f,0x1f,0x44,0x00,0 +#define P6_NOP6 0x66,0x0f,0x1f,0x44,0x00,0 +#define P6_NOP7 0x0f,0x1f,0x80,0,0,0,0 +#define P6_NOP8 0x0f,0x1f,0x84,0x00,0,0,0,0 +#define P6_NOP5_ATOMIC P6_NOP5 + +#ifdef __ASSEMBLY__ +#define _ASM_MK_NOP(x) .byte x +#else +#define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n" +#endif + +#if defined(CONFIG_MK7) +#define ASM_NOP1 _ASM_MK_NOP(K7_NOP1) +#define ASM_NOP2 _ASM_MK_NOP(K7_NOP2) +#define ASM_NOP3 _ASM_MK_NOP(K7_NOP3) +#define ASM_NOP4 _ASM_MK_NOP(K7_NOP4) +#define ASM_NOP5 _ASM_MK_NOP(K7_NOP5) +#define ASM_NOP6 _ASM_MK_NOP(K7_NOP6) +#define ASM_NOP7 _ASM_MK_NOP(K7_NOP7) +#define ASM_NOP8 _ASM_MK_NOP(K7_NOP8) +#define ASM_NOP5_ATOMIC _ASM_MK_NOP(K7_NOP5_ATOMIC) +#elif defined(CONFIG_X86_P6_NOP) +#define ASM_NOP1 _ASM_MK_NOP(P6_NOP1) +#define ASM_NOP2 _ASM_MK_NOP(P6_NOP2) +#define ASM_NOP3 _ASM_MK_NOP(P6_NOP3) +#define ASM_NOP4 _ASM_MK_NOP(P6_NOP4) +#define ASM_NOP5 _ASM_MK_NOP(P6_NOP5) +#define ASM_NOP6 _ASM_MK_NOP(P6_NOP6) +#define ASM_NOP7 _ASM_MK_NOP(P6_NOP7) +#define ASM_NOP8 _ASM_MK_NOP(P6_NOP8) +#define ASM_NOP5_ATOMIC _ASM_MK_NOP(P6_NOP5_ATOMIC) +#elif defined(CONFIG_X86_64) +#define ASM_NOP1 _ASM_MK_NOP(K8_NOP1) +#define ASM_NOP2 _ASM_MK_NOP(K8_NOP2) +#define ASM_NOP3 _ASM_MK_NOP(K8_NOP3) +#define ASM_NOP4 _ASM_MK_NOP(K8_NOP4) +#define ASM_NOP5 _ASM_MK_NOP(K8_NOP5) +#define ASM_NOP6 _ASM_MK_NOP(K8_NOP6) +#define ASM_NOP7 _ASM_MK_NOP(K8_NOP7) +#define ASM_NOP8 _ASM_MK_NOP(K8_NOP8) +#define ASM_NOP5_ATOMIC _ASM_MK_NOP(K8_NOP5_ATOMIC) +#else +#define ASM_NOP1 _ASM_MK_NOP(GENERIC_NOP1) +#define ASM_NOP2 _ASM_MK_NOP(GENERIC_NOP2) +#define ASM_NOP3 _ASM_MK_NOP(GENERIC_NOP3) +#define ASM_NOP4 _ASM_MK_NOP(GENERIC_NOP4) +#define ASM_NOP5 _ASM_MK_NOP(GENERIC_NOP5) +#define ASM_NOP6 _ASM_MK_NOP(GENERIC_NOP6) +#define ASM_NOP7 _ASM_MK_NOP(GENERIC_NOP7) +#define ASM_NOP8 _ASM_MK_NOP(GENERIC_NOP8) +#define ASM_NOP5_ATOMIC _ASM_MK_NOP(GENERIC_NOP5_ATOMIC) +#endif + +#define ASM_NOP_MAX 8 +#define NOP_ATOMIC5 (ASM_NOP_MAX+1) /* Entry for the 5-byte atomic NOP */ + +#ifndef __ASSEMBLY__ +extern const unsigned char * const *ideal_nops; +extern void arch_init_ideal_nops(void); +#endif + +#endif /* _ASM_X86_NOPS_H */ |