---

yaml --- r: 67332 b: refs/heads/master c: 00efee7 h: refs/heads/master v: v3
git-mirror · Sep 19, 2007 · c7eecd7 · c7eecd7
1 parent 8272da7
commit c7eecd7
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Showing 3 changed files with 7 additions and 9 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 61a564fd2e7ab13ab11a6ce8305433baacf344ef
+refs/heads/master: 00efee7d5d0d7888aafbf0d2de76943ee8aca47a
diff --git a/trunk/arch/powerpc/kernel/entry_64.S b/trunk/arch/powerpc/kernel/entry_64.S
@@ -385,15 +385,15 @@ BEGIN_FTR_SECTION
 	oris	r0,r6,(SLB_ESID_V)@h
 	ori	r0,r0,(SLB_NUM_BOLTED-1)@l
 
-	/* Update the last bolted SLB */
+	/* Update the last bolted SLB.  No write barriers are needed
+	 * here, provided we only update the current CPU's SLB shadow
+	 * buffer.
+	 */
 	ld	r9,PACA_SLBSHADOWPTR(r13)
 	li	r12,0
 	std	r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */
-	eieio
 	std	r7,SLBSHADOW_STACKVSID(r9)  /* Save VSID */
-	eieio
 	std	r0,SLBSHADOW_STACKESID(r9)  /* Save ESID */
-	eieio
 
 	slbie	r6
 	slbie	r6		/* Workaround POWER5 < DD2.1 issue */

diff --git a/trunk/arch/powerpc/mm/slb.c b/trunk/arch/powerpc/mm/slb.c
@@ -59,14 +59,12 @@ static inline void slb_shadow_update(unsigned long ea,
 {
 	/*
 	 * Clear the ESID first so the entry is not valid while we are
-	 * updating it.
+	 * updating it.  No write barriers are needed here, provided
+	 * we only update the current CPU's SLB shadow buffer.
 	 */
 	get_slb_shadow()->save_area[entry].esid = 0;
-	smp_wmb();
 	get_slb_shadow()->save_area[entry].vsid = mk_vsid_data(ea, flags);
-	smp_wmb();
 	get_slb_shadow()->save_area[entry].esid = mk_esid_data(ea, entry);
-	smp_wmb();
 }
 
 static inline void slb_shadow_clear(unsigned long entry)