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-rw-r--r--arch/arm64/include/asm/cpufeature.h2
-rw-r--r--arch/arm64/include/asm/processor.h2
-rw-r--r--arch/arm64/kernel/cpufeature.c10
-rw-r--r--arch/arm64/mm/fault.c3
4 files changed, 13 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 8136afc9df0d..8884b5d5f48c 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -77,7 +77,7 @@ 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 4acb7ca94fcd..d08559528927 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -186,6 +186,6 @@ static inline void spin_lock_prefetch(const void *x)
#endif
-void cpu_enable_pan(void *__unused);
+int cpu_enable_pan(void *__unused);
#endif /* __ASM_PROCESSOR_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 0669c63281ea..2735bf814592 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>
@@ -764,7 +766,13 @@ static void enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
for (i = 0; caps[i].desc; 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/mm/fault.c b/arch/arm64/mm/fault.c
index 4c1a118c1d09..d4634e6942ca 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -606,8 +606,9 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
}
#ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(void *__unused)
+int cpu_enable_pan(void *__unused)
{
config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+ return 0;
}
#endif /* CONFIG_ARM64_PAN */