diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-10-24 14:48:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-29 09:17:24 +0100 |
| commit | 8a235006cd422ad1c8ad1e3c2cfde1281ac52e48 (patch) | |
| tree | 9e8a697141506d2f6e4dbbe9c2a4944b4a0e28d7 /arch/arm64/include | |
| parent | 7ec258d023de4f118c942fe57647acbb89c8d863 (diff) | |
arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3
[ Upstream commit 8f04e8e6e29c93421a95b61cad62e3918425eac7 ]
On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD
state without needing to call into firmware.
This patch hooks into the existing SSBD infrastructure so that SSBS is
used on CPUs that support it, but it's all made horribly complicated by
the very real possibility of big/little systems that don't uniformly
provide the new capability.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ardb: add #include of asm/compat.h]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 7 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ptrace.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/sysreg.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/ptrace.h | 1 |
4 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 9b6ac522a71a..ec1725c6df21 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -153,6 +153,10 @@ static inline void start_thread(struct pt_regs *regs, unsigned long pc, { start_thread_common(regs, pc); regs->pstate = PSR_MODE_EL0t; + + if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE) + regs->pstate |= PSR_SSBS_BIT; + regs->sp = sp; } @@ -169,6 +173,9 @@ static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc, regs->pstate |= COMPAT_PSR_E_BIT; #endif + if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE) + regs->pstate |= PSR_AA32_SSBS_BIT; + regs->compat_sp = sp; } #endif diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index 1b2a253de6a1..b466d763a90d 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -50,6 +50,7 @@ #define PSR_AA32_I_BIT 0x00000080 #define PSR_AA32_A_BIT 0x00000100 #define PSR_AA32_E_BIT 0x00000200 +#define PSR_AA32_SSBS_BIT 0x00800000 #define PSR_AA32_DIT_BIT 0x01000000 #define PSR_AA32_Q_BIT 0x08000000 #define PSR_AA32_V_BIT 0x10000000 diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 4724909642e7..50a89bcf9072 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -86,11 +86,14 @@ #define REG_PSTATE_PAN_IMM sys_reg(0, 0, 4, 0, 4) #define REG_PSTATE_UAO_IMM sys_reg(0, 0, 4, 0, 3) +#define REG_PSTATE_SSBS_IMM sys_reg(0, 3, 4, 0, 1) #define SET_PSTATE_PAN(x) __emit_inst(0xd5000000 | REG_PSTATE_PAN_IMM | \ (!!x)<<8 | 0x1f) #define SET_PSTATE_UAO(x) __emit_inst(0xd5000000 | REG_PSTATE_UAO_IMM | \ (!!x)<<8 | 0x1f) +#define SET_PSTATE_SSBS(x) __emit_inst(0xd5000000 | REG_PSTATE_SSBS_IMM | \ + (!!x)<<8 | 0x1f) #define SYS_DC_ISW sys_insn(1, 0, 7, 6, 2) #define SYS_DC_CSW sys_insn(1, 0, 7, 10, 2) diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h index 67d4c33974e8..eea58f8ec355 100644 --- a/arch/arm64/include/uapi/asm/ptrace.h +++ b/arch/arm64/include/uapi/asm/ptrace.h @@ -45,6 +45,7 @@ #define PSR_I_BIT 0x00000080 #define PSR_A_BIT 0x00000100 #define PSR_D_BIT 0x00000200 +#define PSR_SSBS_BIT 0x00001000 #define PSR_PAN_BIT 0x00400000 #define PSR_UAO_BIT 0x00800000 #define PSR_Q_BIT 0x08000000 |