X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=arch%2Fpowerpc%2Fmm%2Fslb.c;h=224e960650a09ce3e1face7057fd8643d58a9e0d;hb=5faad620264290b17e80a8b0996b039ea0d5ac73;hp=de0c8842415cb98232b3569dc78ba8f7e4b8765e;hpb=a8c4c20dfa8b28a3c99e33c639d9c2ea5657741e;p=powerpc.git

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index de0c884241..224e960650 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -22,6 +22,9 @@
 #include <asm/paca.h>
 #include <asm/cputable.h>
 #include <asm/cacheflush.h>
+#include <asm/smp.h>
+#include <asm/firmware.h>
+#include <linux/compiler.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) udbg_printf(fmt)
@@ -50,9 +53,32 @@ static inline unsigned long mk_vsid_data(unsigned long ea, unsigned long flags)
 	return (get_kernel_vsid(ea) << SLB_VSID_SHIFT) | flags;
 }
 
-static inline void create_slbe(unsigned long ea, unsigned long flags,
-			       unsigned long entry)
+static inline void slb_shadow_update(unsigned long esid, unsigned long vsid,
+				     unsigned long entry)
 {
+	/*
+	 * Clear the ESID first so the entry is not valid while we are
+	 * updating it.
+	 */
+	get_slb_shadow()->save_area[entry].esid = 0;
+	barrier();
+	get_slb_shadow()->save_area[entry].vsid = vsid;
+	barrier();
+	get_slb_shadow()->save_area[entry].esid = esid;
+
+}
+
+static inline void create_shadowed_slbe(unsigned long ea, unsigned long flags,
+					unsigned long entry)
+{
+	/*
+	 * Updating the shadow buffer before writing the SLB ensures
+	 * we don't get a stale entry here if we get preempted by PHYP
+	 * between these two statements.
+	 */
+	slb_shadow_update(mk_esid_data(ea, entry), mk_vsid_data(ea, flags),
+			  entry);
+
 	asm volatile("slbmte  %0,%1" :
 		     : "r" (mk_vsid_data(ea, flags)),
 		       "r" (mk_esid_data(ea, entry))
@@ -77,6 +103,10 @@ void slb_flush_and_rebolt(void)
 	if ((ksp_esid_data & ESID_MASK) == PAGE_OFFSET)
 		ksp_esid_data &= ~SLB_ESID_V;
 
+	/* Only third entry (stack) may change here so only resave that */
+	slb_shadow_update(ksp_esid_data,
+			  mk_vsid_data(ksp_esid_data, lflags), 2);
+
 	/* We need to do this all in asm, so we're sure we don't touch
 	 * the stack between the slbia and rebolting it. */
 	asm volatile("isync\n"
@@ -164,6 +194,7 @@ static inline void patch_slb_encoding(unsigned int *insn_addr,
 void slb_initialize(void)
 {
 	unsigned long linear_llp, vmalloc_llp, io_llp;
+	unsigned long lflags, vflags;
 	static int slb_encoding_inited;
 	extern unsigned int *slb_miss_kernel_load_linear;
 	extern unsigned int *slb_miss_kernel_load_io;
@@ -196,11 +227,12 @@ void slb_initialize(void)
 #endif
 	}
 
+	get_paca()->stab_rr = SLB_NUM_BOLTED;
+
 	/* On iSeries the bolted entries have already been set up by
 	 * the hypervisor from the lparMap data in head.S */
-#ifndef CONFIG_PPC_ISERIES
- {
-	unsigned long lflags, vflags;
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		return;
 
 	lflags = SLB_VSID_KERNEL | linear_llp;
 	vflags = SLB_VSID_KERNEL | vmalloc_llp;
@@ -209,17 +241,13 @@ void slb_initialize(void)
 	asm volatile("isync":::"memory");
 	asm volatile("slbmte  %0,%0"::"r" (0) : "memory");
 	asm volatile("isync; slbia; isync":::"memory");
-	create_slbe(PAGE_OFFSET, lflags, 0);
+	create_shadowed_slbe(PAGE_OFFSET, lflags, 0);
 
-	create_slbe(VMALLOC_START, vflags, 1);
+	create_shadowed_slbe(VMALLOC_START, vflags, 1);
 
 	/* We don't bolt the stack for the time being - we're in boot,
 	 * so the stack is in the bolted segment.  By the time it goes
 	 * elsewhere, we'll call _switch() which will bolt in the new
 	 * one. */
 	asm volatile("isync":::"memory");
- }
-#endif /* CONFIG_PPC_ISERIES */
-
-	get_paca()->stab_rr = SLB_NUM_BOLTED;
 }