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-rw-r--r--arch/x86/include/asm/mmu.h2
-rw-r--r--arch/x86/include/asm/mmu_context.h16
2 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 876e74e8eec7..09b9620a73b4 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -19,6 +19,8 @@ typedef struct {
struct mutex lock;
void __user *vdso;
+
+ atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
} mm_context_t;
#ifdef CONFIG_SMP
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 52c18359f1dc..89c1fece224e 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -18,6 +18,18 @@ static inline void paravirt_activate_mm(struct mm_struct *prev,
}
#endif /* !CONFIG_PARAVIRT */
+#ifdef CONFIG_PERF_EVENTS
+static inline void load_mm_cr4(struct mm_struct *mm)
+{
+ if (atomic_read(&mm->context.perf_rdpmc_allowed))
+ cr4_set_bits(X86_CR4_PCE);
+ else
+ cr4_clear_bits(X86_CR4_PCE);
+}
+#else
+static inline void load_mm_cr4(struct mm_struct *mm) {}
+#endif
+
/*
* Used for LDT copy/destruction.
*/
@@ -52,6 +64,9 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
/* Stop flush ipis for the previous mm */
cpumask_clear_cpu(cpu, mm_cpumask(prev));
+ /* Load per-mm CR4 state */
+ load_mm_cr4(next);
+
/*
* Load the LDT, if the LDT is different.
*
@@ -87,6 +102,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
*/
load_cr3(next->pgd);
trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
+ load_mm_cr4(next);
load_LDT_nolock(&next->context);
}
}
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