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-rw-r--r--arch/x86/include/asm/alternative-asm.h4
-rw-r--r--arch/x86/include/asm/alternative.h6
-rw-r--r--arch/x86/include/asm/mmu_context.h8
-rw-r--r--arch/x86/include/asm/mshyperv.h1
-rw-r--r--arch/x86/include/asm/tlbflush.h24
5 files changed, 32 insertions, 11 deletions
diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
index e7636bac7372..6c98821fef5e 100644
--- a/arch/x86/include/asm/alternative-asm.h
+++ b/arch/x86/include/asm/alternative-asm.h
@@ -62,8 +62,10 @@
#define new_len2 145f-144f
/*
- * max without conditionals. Idea adapted from:
+ * gas compatible max based on the idea from:
* http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ *
+ * The additional "-" is needed because gas uses a "true" value of -1.
*/
#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index c096624137ae..ccbe24e697c4 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -103,12 +103,12 @@ static inline int alternatives_text_reserved(void *start, void *end)
alt_end_marker ":\n"
/*
- * max without conditionals. Idea adapted from:
+ * gas compatible max based on the idea from:
* http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
*
- * The additional "-" is needed because gas works with s32s.
+ * The additional "-" is needed because gas uses a "true" value of -1.
*/
-#define alt_max_short(a, b) "((" a ") ^ (((" a ") ^ (" b ")) & -(-((" a ") - (" b ")))))"
+#define alt_max_short(a, b) "((" a ") ^ (((" a ") ^ (" b ")) & -(-((" a ") < (" b ")))))"
/*
* Pad the second replacement alternative with additional NOPs if it is
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index c120b5db178a..3c856a15b98e 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -126,13 +126,7 @@ static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
DEBUG_LOCKS_WARN_ON(preemptible());
}
-static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
-{
- int cpu = smp_processor_id();
-
- if (cpumask_test_cpu(cpu, mm_cpumask(mm)))
- cpumask_clear_cpu(cpu, mm_cpumask(mm));
-}
+void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk);
static inline int init_new_context(struct task_struct *tsk,
struct mm_struct *mm)
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 738503e1f80c..530f448fddaf 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -289,6 +289,7 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
* to this information.
*/
extern u32 *hv_vp_index;
+extern u32 hv_max_vp_index;
/**
* hv_cpu_number_to_vp_number() - Map CPU to VP.
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 4893abf7f74f..d362161d3291 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -83,6 +83,13 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
#endif
/*
+ * If tlb_use_lazy_mode is true, then we try to avoid switching CR3 to point
+ * to init_mm when we switch to a kernel thread (e.g. the idle thread). If
+ * it's false, then we immediately switch CR3 when entering a kernel thread.
+ */
+DECLARE_STATIC_KEY_TRUE(tlb_use_lazy_mode);
+
+/*
* 6 because 6 should be plenty and struct tlb_state will fit in
* two cache lines.
*/
@@ -105,6 +112,23 @@ struct tlb_state {
u16 next_asid;
/*
+ * We can be in one of several states:
+ *
+ * - Actively using an mm. Our CPU's bit will be set in
+ * mm_cpumask(loaded_mm) and is_lazy == false;
+ *
+ * - Not using a real mm. loaded_mm == &init_mm. Our CPU's bit
+ * will not be set in mm_cpumask(&init_mm) and is_lazy == false.
+ *
+ * - Lazily using a real mm. loaded_mm != &init_mm, our bit
+ * is set in mm_cpumask(loaded_mm), but is_lazy == true.
+ * We're heuristically guessing that the CR3 load we
+ * skipped more than makes up for the overhead added by
+ * lazy mode.
+ */
+ bool is_lazy;
+
+ /*
* Access to this CR4 shadow and to H/W CR4 is protected by
* disabling interrupts when modifying either one.
*/

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