diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 2 | ||||
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/suspend.c | 17 | ||||
| -rw-r--r-- | arch/arm64/mm/fault.c | 14 |
5 files changed, 36 insertions, 11 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 308d96eaeeae..1695f77d8bf2 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -81,7 +81,7 @@ struct arm64_cpu_capabilities { const char *desc; u16 capability; bool (*matches)(const struct arm64_cpu_capabilities *); - void (*enable)(void *); /* Called on all active CPUs */ + int (*enable)(void *); /* Called on all active CPUs */ union { struct { /* To be used for erratum handling only */ u32 midr_model; diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index cef1cf398356..4be934fde409 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -190,7 +190,7 @@ static inline void spin_lock_prefetch(const void *ptr) #endif -void cpu_enable_pan(void *__unused); -void cpu_enable_uao(void *__unused); +int cpu_enable_pan(void *__unused); +int cpu_enable_uao(void *__unused); #endif /* __ASM_PROCESSOR_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 24ecbeb733ed..eda7d5915fbb 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> @@ -823,7 +825,13 @@ 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; diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 6c16e4963b39..18e5a2c3d554 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -29,7 +29,9 @@ #include <linux/sched.h> #include <linux/highmem.h> #include <linux/perf_event.h> +#include <linux/preempt.h> +#include <asm/bug.h> #include <asm/cpufeature.h> #include <asm/exception.h> #include <asm/debug-monitors.h> @@ -641,9 +643,17 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, NOKPROBE_SYMBOL(do_debug_exception); #ifdef CONFIG_ARM64_PAN -void cpu_enable_pan(void *__unused) +int cpu_enable_pan(void *__unused) { + /* + * We modify PSTATE. This won't work from irq context as the PSTATE + * is discarded once we return from the exception. + */ + WARN_ON_ONCE(in_interrupt()); + config_sctlr_el1(SCTLR_EL1_SPAN, 0); + asm(SET_PSTATE_PAN(1)); + return 0; } #endif /* CONFIG_ARM64_PAN */ @@ -654,7 +664,7 @@ void cpu_enable_pan(void *__unused) * We need to enable the feature at runtime (instead of adding it to * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. */ -void cpu_enable_uao(void *__unused) +int cpu_enable_uao(void *__unused) { asm(SET_PSTATE_UAO(1)); } |