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| author | Will Deacon <will.deacon@arm.com> | 2018-06-14 11:21:34 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-12-06 16:47:04 +0000 |
| commit | bd4fb6d270bc423a9a4098108784f7f9254c4e6d (patch) | |
| tree | b795cee624fd00a3274c5d6efd89df71288cf1ff /arch/arm64/include/asm/sysreg.h | |
| parent | 0b587c84e42151fc5a636c7cebf7b03b281dc672 (diff) | |
| download | linux-next-bd4fb6d270bc423a9a4098108784f7f9254c4e6d.tar.gz | |
arm64: Add support for SB barrier and patch in over DSB; ISB sequences
We currently use a DSB; ISB sequence to inhibit speculation in set_fs().
Whilst this works for current CPUs, future CPUs may implement a new SB
barrier instruction which acts as an architected speculation barrier.
On CPUs that support it, patch in an SB; NOP sequence over the DSB; ISB
sequence and advertise the presence of the new instruction to userspace.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/sysreg.h')
| -rw-r--r-- | arch/arm64/include/asm/sysreg.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 0c909c4a932f..78f15858535e 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -104,6 +104,11 @@ #define SET_PSTATE_UAO(x) __emit_inst(0xd500401f | PSTATE_UAO | ((!!x) << PSTATE_Imm_shift)) #define SET_PSTATE_SSBS(x) __emit_inst(0xd500401f | PSTATE_SSBS | ((!!x) << PSTATE_Imm_shift)) +#define __SYS_BARRIER_INSN(CRm, op2, Rt) \ + __emit_inst(0xd5000000 | sys_insn(0, 3, 3, (CRm), (op2)) | ((Rt) & 0x1f)) + +#define SB_BARRIER_INSN __SYS_BARRIER_INSN(0, 7, 31) + #define SYS_DC_ISW sys_insn(1, 0, 7, 6, 2) #define SYS_DC_CSW sys_insn(1, 0, 7, 10, 2) #define SYS_DC_CISW sys_insn(1, 0, 7, 14, 2) @@ -528,6 +533,7 @@ #define ID_AA64ISAR0_AES_SHIFT 4 /* id_aa64isar1 */ +#define ID_AA64ISAR1_SB_SHIFT 36 #define ID_AA64ISAR1_LRCPC_SHIFT 20 #define ID_AA64ISAR1_FCMA_SHIFT 16 #define ID_AA64ISAR1_JSCVT_SHIFT 12 |