1 files changed, 40 insertions, 3 deletions

diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index ad2135385699..d7df54cc7e4d 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -82,6 +82,11 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
 #define __flush_tlb_single(addr) __native_flush_tlb_single(addr)
 #endif
 
+struct tlb_context {
+	u64 ctx_id;
+	u64 tlb_gen;
+};
+
 struct tlb_state {
 	/*
 	 * cpu_tlbstate.loaded_mm should match CR3 whenever interrupts
@@ -97,6 +102,21 @@ struct tlb_state {
 	 * disabling interrupts when modifying either one.
 	 */
 	unsigned long cr4;
+
+	/*
+	 * This is a list of all contexts that might exist in the TLB.
+	 * Since we don't yet use PCID, there is only one context.
+	 *
+	 * For each context, ctx_id indicates which mm the TLB's user
+	 * entries came from.  As an invariant, the TLB will never
+	 * contain entries that are out-of-date as when that mm reached
+	 * the tlb_gen in the list.
+	 *
+	 * To be clear, this means that it's legal for the TLB code to
+	 * flush the TLB without updating tlb_gen.  This can happen
+	 * (for now, at least) due to paravirt remote flushes.
+	 */
+	struct tlb_context ctxs[1];
 };
 DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate);
 
@@ -248,9 +268,26 @@ static inline void __flush_tlb_one(unsigned long addr)
  * and page-granular flushes are available only on i486 and up.
  */
 struct flush_tlb_info {
-	struct mm_struct *mm;
-	unsigned long start;
-	unsigned long end;
+	/*
+	 * We support several kinds of flushes.
+	 *
+	 * - Fully flush a single mm.  .mm will be set, .end will be
+	 *   TLB_FLUSH_ALL, and .new_tlb_gen will be the tlb_gen to
+	 *   which the IPI sender is trying to catch us up.
+	 *
+	 * - Partially flush a single mm.  .mm will be set, .start and
+	 *   .end will indicate the range, and .new_tlb_gen will be set
+	 *   such that the changes between generation .new_tlb_gen-1 and
+	 *   .new_tlb_gen are entirely contained in the indicated range.
+	 *
+	 * - Fully flush all mms whose tlb_gens have been updated.  .mm
+	 *   will be NULL, .end will be TLB_FLUSH_ALL, and .new_tlb_gen
+	 *   will be zero.
+	 */
+	struct mm_struct	*mm;
+	unsigned long		start;
+	unsigned long		end;
+	u64			new_tlb_gen;
 };
 
 #define local_flush_tlb() __flush_tlb()