[PATCH v4 03/26] arm64: cpufeature: Use alternatives for VHE cpu_enable
From: Julien Thierry <hidden>
Date: 2018-05-25 09:56:53
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
The cpu_enable callback for VHE feature requires all alternatives to have been applied. This prevents applying VHE alternative separately from the rest. Use an alternative depending on VHE feature to know whether VHE alternatives have already been applied. Signed-off-by: Julien Thierry <redacted> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Marc Zyngier <redacted> Cc: Christoffer Dall <redacted> --- arch/arm64/kernel/cpufeature.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index a177104..a3a5585d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -1013,6 +1013,8 @@ static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused) { + u64 tmp = 0; + /* * Copy register values that aren't redirected by hardware. *
@@ -1021,8 +1023,15 @@ static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused) * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to * do anything here. */ - if (!alternatives_applied) - write_sysreg(read_sysreg(tpidr_el1), tpidr_el2); + asm volatile(ALTERNATIVE( + "mrs %0, tpidr_el1\n" + "msr tpidr_el2, %0", + "nop\n" + "nop", + ARM64_HAS_VIRT_HOST_EXTN) + : "+r" (tmp) + : + : "memory"); } #endif
--
1.9.1