3 files changed, 29 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ac0631958b20..2ef7ea860379 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -135,11 +135,13 @@ int main(void)
         DEFINE(PACA_STARTPURR, offsetof(struct paca_struct, startpurr));
         DEFINE(PACA_USER_TIME, offsetof(struct paca_struct, user_time));
         DEFINE(PACA_SYSTEM_TIME, offsetof(struct paca_struct, system_time));
+        DEFINE(PACA_SLBSHADOWPTR, offsetof(struct paca_struct, slb_shadow_ptr));
 
         DEFINE(LPPACASRR0, offsetof(struct lppaca, saved_srr0));
         DEFINE(LPPACASRR1, offsetof(struct lppaca, saved_srr1));
         DEFINE(LPPACAANYINT, offsetof(struct lppaca, int_dword.any_int));
         DEFINE(LPPACADECRINT, offsetof(struct lppaca, int_dword.fields.decr_int));
+        DEFINE(SLBSHADOW_SAVEAREA, offsetof(struct slb_shadow, save_area));
 #endif /* CONFIG_PPC64 */
 
         /* RTAS */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 54d9f5cdaab4..5baea498ea64 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -323,6 +323,11 @@ _GLOBAL(ret_from_fork)
  * The code which creates the new task context is in 'copy_thread'
  * in arch/powerpc/kernel/process.c 
  */
+#define SHADOW_SLB_BOLTED_STACK_ESID \
+                (SLBSHADOW_SAVEAREA + 0x10*(SLB_NUM_BOLTED-1))
+#define SHADOW_SLB_BOLTED_STACK_VSID \
+                (SLBSHADOW_SAVEAREA + 0x10*(SLB_NUM_BOLTED-1) + 8)
+
         .align  7
 _GLOBAL(_switch)
         mflr    r0
@@ -375,6 +380,14 @@ BEGIN_FTR_SECTION
         ld      r7,KSP_VSID(r4) /* Get new stack's VSID */
         oris    r0,r6,(SLB_ESID_V)@h
         ori     r0,r0,(SLB_NUM_BOLTED-1)@l
+
+        /* Update the last bolted SLB */
+        ld      r9,PACA_SLBSHADOWPTR(r13)
+        li      r12,0
+        std     r12,SHADOW_SLB_BOLTED_STACK_ESID(r9) /* Clear ESID */
+        std     r7,SHADOW_SLB_BOLTED_STACK_VSID(r9)  /* Save VSID */
+        std     r0,SHADOW_SLB_BOLTED_STACK_ESID(r9)  /* Save ESID */
+
         slbie   r6
         slbie   r6              /* Workaround POWER5 < DD2.1 issue */
         slbmte  r7,r0
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index c68741fed14b..55f1a25085cd 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -17,6 +17,7 @@
 #include <asm/lppaca.h>
 #include <asm/iseries/it_lp_reg_save.h>
 #include <asm/paca.h>
+#include <asm/mmu.h>
 
 
 /* This symbol is provided by the linker - let it fill in the paca
@@ -45,6 +46,17 @@ struct lppaca lppaca[] = {
         },
 };
 
+/*
+ * 3 persistent SLBs are registered here.  The buffer will be zero
+ * initially, hence will all be invaild until we actually write them.
+ */
+struct slb_shadow slb_shadow[] __cacheline_aligned = {
+        [0 ... (NR_CPUS-1)] = {
+                .persistent = SLB_NUM_BOLTED,
+                .buffer_length = sizeof(struct slb_shadow),
+        },
+};
+
 /* The Paca is an array with one entry per processor.  Each contains an
  * lppaca, which contains the information shared between the
  * hypervisor and Linux.
@@ -59,7 +71,8 @@ struct lppaca lppaca[] = {
         .lock_token = 0x8000,                                               \
         .paca_index = (number),         /* Paca Index */                    \
         .kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL,             \
-        .hw_cpu_id = 0xffff,
+        .hw_cpu_id = 0xffff,                                                \
+        .slb_shadow_ptr = &slb_shadow[number],
 
 #ifdef CONFIG_PPC_ISERIES
 #define PACA_INIT_ISERIES(number)                                           \