diff options
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/suspend.c | 17 |
2 files changed, 21 insertions, 6 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index a0c41dae0d81..cdf1dca64133 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -19,7 +19,9 @@ #define pr_fmt(fmt) "CPU features: " fmt #include <linux/bsearch.h> +#include <linux/cpumask.h> #include <linux/sort.h> +#include <linux/stop_machine.h> #include <linux/types.h> #include <asm/cpu.h> #include <asm/cpufeature.h> @@ -824,7 +826,13 @@ enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps) for (i = 0; caps[i].matches; i++) if (caps[i].enable && cpus_have_cap(caps[i].capability)) - on_each_cpu(caps[i].enable, NULL, true); + /* + * Use stop_machine() as it schedules the work allowing + * us to modify PSTATE, instead of on_each_cpu() which + * uses an IPI, giving us a PSTATE that disappears when + * we return. + */ + stop_machine(caps[i].enable, NULL, cpu_online_mask); } #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index b616e365cee3..5a0b1088c17c 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -1,7 +1,9 @@ #include <linux/ftrace.h> #include <linux/percpu.h> #include <linux/slab.h> +#include <asm/alternative.h> #include <asm/cacheflush.h> +#include <asm/cpufeature.h> #include <asm/debug-monitors.h> #include <asm/pgtable.h> #include <asm/memory.h> @@ -88,11 +90,16 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) ret = fn(arg); /* - * Never gets here, unless the suspend finisher fails. - * Successful cpu_suspend() should return from cpu_resume(), - * returning through this code path is considered an error - * If the return value is set to 0 force ret = -EOPNOTSUPP - * to make sure a proper error condition is propagated + * PSTATE was not saved over suspend/resume, re-enable any + * detected features that might not have been set correctly. + */ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, + CONFIG_ARM64_PAN)); + + /* + * Restore HW breakpoint registers to sane values + * before debug exceptions are possibly reenabled + * through local_dbg_restore. */ if (!ret) ret = -EOPNOTSUPP; |