From e3a67519ffcf03c2a3c36ed7cc41580ddc69f35e Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Tue, 9 Oct 2018 14:47:05 +0100 Subject: [PATCH 008/145] arm64: cpufeature: ctr: Fix cpu capability check for late CPUs [ Upstream commit 8ab66cbe63aeaf9e5970fb4aaef1c660fca59321 ] The matches() routine for a capability must honor the "scope" passed to it and return the proper results. i.e, when passed with SCOPE_LOCAL_CPU, it should check the status of the capability on the current CPU. This is used by verify_local_cpu_capabilities() on a late secondary CPU to make sure that it's compliant with the established system features. However, ARM64_HAS_CACHE_{IDC/DIC} always checks the system wide registers and this could mean that a late secondary CPU could return "true" (since the CPU hasn't updated the system wide registers yet) and thus lead the system in an inconsistent state, where the system assumes it has IDC/DIC feature, while the new CPU doesn't. Fixes: commit 6ae4b6e0578886eb36 ("arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC") Cc: Philip Elcan Cc: Shanker Donthineni Cc: Mark Rutland Cc: Will Deacon Signed-off-by: Suzuki K Poulose Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin --- arch/arm64/kernel/cpufeature.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e238b7932096..93f69d82225d 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -848,15 +848,29 @@ static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unus } static bool has_cache_idc(const struct arm64_cpu_capabilities *entry, - int __unused) + int scope) { - return read_sanitised_ftr_reg(SYS_CTR_EL0) & BIT(CTR_IDC_SHIFT); + u64 ctr; + + if (scope == SCOPE_SYSTEM) + ctr = arm64_ftr_reg_ctrel0.sys_val; + else + ctr = read_cpuid_cachetype(); + + return ctr & BIT(CTR_IDC_SHIFT); } static bool has_cache_dic(const struct arm64_cpu_capabilities *entry, - int __unused) + int scope) { - return read_sanitised_ftr_reg(SYS_CTR_EL0) & BIT(CTR_DIC_SHIFT); + u64 ctr; + + if (scope == SCOPE_SYSTEM) + ctr = arm64_ftr_reg_ctrel0.sys_val; + else + ctr = read_cpuid_cachetype(); + + return ctr & BIT(CTR_DIC_SHIFT); } #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -- 2.19.1