[PATCHv3 02/17] arm64: add C wrappers for SET_PSTATE_*()

Mark Rutland
2020-10-26T13:34:20Z

To make callsites easier to read, add trivial C wrappers for the
SET_PSTATE_*() helpers, and convert trivial uses over to these. The new
wrappers will be used further in subsequent patches.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/sysreg.h | 4 ++++
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/proton-pack.c | 4 ++--
3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index d52c1b3ce5894..bfd5f724c7ff0 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -98,6 +98,10 @@
#define SET_PSTATE_SSBS(x) __emit_inst(0xd500401f | PSTATE_SSBS | ((!!x) << PSTATE_Imm_shift))
#define SET_PSTATE_TCO(x) __emit_inst(0xd500401f | PSTATE_TCO | ((!!x) << PSTATE_Imm_shift))

+#define set_pstate_pan(x) asm volatile(SET_PSTATE_PAN(x))
+#define set_pstate_uao(x) asm volatile(SET_PSTATE_UAO(x))
+#define set_pstate_ssbs(x) asm volatile(SET_PSTATE_SSBS(x))
+
#define __SYS_BARRIER_INSN(CRm, op2, Rt) \
__emit_inst(0xd5000000 | sys_insn(0, 3, 3, (CRm), (op2)) | ((Rt) & 0x1f))

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index dcc165b3fc046..4ff0369bd0b35 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1598,7 +1598,7 @@ static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
WARN_ON_ONCE(in_interrupt());

sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
- asm(SET_PSTATE_PAN(1));
+ set_pstate_pan(1);
}
#endif /* CONFIG_ARM64_PAN */

diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 25f3c80b5ffe4..d59f982fce3d1 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -539,12 +539,12 @@ static enum mitigation_state spectre_v4_enable_hw_mitigation(void)

if (spectre_v4_mitigations_off()) {
sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
- asm volatile(SET_PSTATE_SSBS(1));
+ set_pstate_ssbs(1);
return SPECTRE_VULNERABLE;
}

/* SCTLR_EL1.DSSBS was initialised to 0 during boot */
- asm volatile(SET_PSTATE_SSBS(0));
+ set_pstate_ssbs(0);
return SPECTRE_MITIGATED;
}