From: James Morse <james.morse@arm.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC30P1 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/commit/?h=mp... -------------------------------- When a CPU is brought online, only the MPAM1_EL1 sysreg is set. For completeness restore the MPAM0_EL1 register too. This isn't expected to cause a problem as cpuhp happens from the idle thread, which can't return to user-space. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- arch/arm64/kernel/cpufeature.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 3958738da32f..995c96ed4b94 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2378,6 +2378,11 @@ static void __maybe_unused cpu_enable_mpam(const struct arm64_cpu_capabilities *entry) { u64 idr = read_sanitised_ftr_reg(SYS_MPAMIDR_EL1); + int cpu = smp_processor_id(); + u64 regval = 0; + + if (IS_ENABLED(CONFIG_ARM64_MPAM)) + regval = READ_ONCE(per_cpu(arm64_mpam_current, cpu)); /* * Initialise MPAM EL2 registers and disable EL2 traps. @@ -2394,6 +2399,7 @@ cpu_enable_mpam(const struct arm64_cpu_capabilities *entry) * been throttled to release the lock. */ write_sysreg_s(0, SYS_MPAM1_EL1); + write_sysreg_s(regval, SYS_MPAM0_EL1); } static void mpam_extra_caps(void) -- 2.25.1