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Diffstat (limited to 'arch/powerpc/mm/slb.c')
-rw-r--r--arch/powerpc/mm/slb.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 5b7038f248b6..a685652effeb 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -92,15 +92,13 @@ static inline void create_shadowed_slbe(unsigned long ea, int ssize,
: "memory" );
}
-void slb_flush_and_rebolt(void)
+static void __slb_flush_and_rebolt(void)
{
/* If you change this make sure you change SLB_NUM_BOLTED
* appropriately too. */
unsigned long linear_llp, vmalloc_llp, lflags, vflags;
unsigned long ksp_esid_data, ksp_vsid_data;
- WARN_ON(!irqs_disabled());
-
linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
lflags = SLB_VSID_KERNEL | linear_llp;
@@ -117,12 +115,6 @@ void slb_flush_and_rebolt(void)
ksp_vsid_data = get_slb_shadow()->save_area[2].vsid;
}
- /*
- * We can't take a PMU exception in the following code, so hard
- * disable interrupts.
- */
- hard_irq_disable();
-
/* 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"
@@ -139,6 +131,21 @@ void slb_flush_and_rebolt(void)
: "memory");
}
+void slb_flush_and_rebolt(void)
+{
+
+ WARN_ON(!irqs_disabled());
+
+ /*
+ * We can't take a PMU exception in the following code, so hard
+ * disable interrupts.
+ */
+ hard_irq_disable();
+
+ __slb_flush_and_rebolt();
+ get_paca()->slb_cache_ptr = 0;
+}
+
void slb_vmalloc_update(void)
{
unsigned long vflags;
@@ -180,12 +187,20 @@ static inline int esids_match(unsigned long addr1, unsigned long addr2)
/* Flush all user entries from the segment table of the current processor. */
void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
{
- unsigned long offset = get_paca()->slb_cache_ptr;
+ unsigned long offset;
unsigned long slbie_data = 0;
unsigned long pc = KSTK_EIP(tsk);
unsigned long stack = KSTK_ESP(tsk);
unsigned long unmapped_base;
+ /*
+ * We need interrupts hard-disabled here, not just soft-disabled,
+ * so that a PMU interrupt can't occur, which might try to access
+ * user memory (to get a stack trace) and possible cause an SLB miss
+ * which would update the slb_cache/slb_cache_ptr fields in the PACA.
+ */
+ hard_irq_disable();
+ offset = get_paca()->slb_cache_ptr;
if (!cpu_has_feature(CPU_FTR_NO_SLBIE_B) &&
offset <= SLB_CACHE_ENTRIES) {
int i;
@@ -200,7 +215,7 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
}
asm volatile("isync" : : : "memory");
} else {
- slb_flush_and_rebolt();
+ __slb_flush_and_rebolt();
}
/* Workaround POWER5 < DD2.1 issue */