[PATCH] Invert sense of SLB class bit
Currently, we set the class bit in kernel SLB entries, and clear it on
user SLB entries. On POWER5, ERAT entries created in real mode have
the class bit clear. So to avoid flushing kernel ERAT entries on each
context switch, this patch inverts our usage of the class bit, setting
it on user SLB entries and clearing it on kernel SLB entries.
Booted on POWER5 and G5.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc64/kernel/entry.S b/arch/ppc64/kernel/entry.S
index b61572e..bf99b4a 100644
--- a/arch/ppc64/kernel/entry.S
+++ b/arch/ppc64/kernel/entry.S
@@ -400,15 +400,14 @@
cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */
cror eq,4*cr1+eq,eq
beq 2f /* if yes, don't slbie it */
- oris r0,r6,0x0800 /* set C (class) bit */
/* Bolt in the new stack SLB entry */
ld r7,KSP_VSID(r4) /* Get new stack's VSID */
- oris r6,r6,(SLB_ESID_V)@h
- ori r6,r6,(SLB_NUM_BOLTED-1)@l
- slbie r0
- slbie r0 /* Workaround POWER5 < DD2.1 issue */
- slbmte r7,r6
+ oris r0,r6,(SLB_ESID_V)@h
+ ori r0,r0,(SLB_NUM_BOLTED-1)@l
+ slbie r6
+ slbie r6 /* Workaround POWER5 < DD2.1 issue */
+ slbmte r7,r0
isync
2:
diff --git a/arch/ppc64/mm/hugetlbpage.c b/arch/ppc64/mm/hugetlbpage.c
index e7833c8..338771e 100644
--- a/arch/ppc64/mm/hugetlbpage.c
+++ b/arch/ppc64/mm/hugetlbpage.c
@@ -144,7 +144,8 @@
for (i = 0; i < NUM_LOW_AREAS; i++) {
if (! (areas & (1U << i)))
continue;
- asm volatile("slbie %0" : : "r" (i << SID_SHIFT));
+ asm volatile("slbie %0"
+ : : "r" ((i << SID_SHIFT) | SLBIE_C));
}
asm volatile("isync" : : : "memory");
@@ -164,7 +165,8 @@
continue;
for (j = 0; j < (1UL << (HTLB_AREA_SHIFT-SID_SHIFT)); j++)
asm volatile("slbie %0"
- :: "r" ((i << HTLB_AREA_SHIFT) + (j << SID_SHIFT)));
+ :: "r" (((i << HTLB_AREA_SHIFT)
+ + (j << SID_SHIFT)) | SLBIE_C));
}
asm volatile("isync" : : : "memory");
diff --git a/arch/ppc64/mm/slb.c b/arch/ppc64/mm/slb.c
index 244150a..0473953 100644
--- a/arch/ppc64/mm/slb.c
+++ b/arch/ppc64/mm/slb.c
@@ -87,8 +87,8 @@
int i;
asm volatile("isync" : : : "memory");
for (i = 0; i < offset; i++) {
- esid_data = (unsigned long)get_paca()->slb_cache[i]
- << SID_SHIFT;
+ esid_data = ((unsigned long)get_paca()->slb_cache[i]
+ << SID_SHIFT) | SLBIE_C;
asm volatile("slbie %0" : : "r" (esid_data));
}
asm volatile("isync" : : : "memory");
diff --git a/include/asm-ppc64/mmu.h b/include/asm-ppc64/mmu.h
index ad36bb2..7bc42eb 100644
--- a/include/asm-ppc64/mmu.h
+++ b/include/asm-ppc64/mmu.h
@@ -54,8 +54,10 @@
#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
#define SLB_VSID_LS ASM_CONST(0x0000000000000070) /* size of largepage */
-#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
-#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
+#define SLB_VSID_KERNEL (SLB_VSID_KP)
+#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS|SLB_VSID_C)
+
+#define SLBIE_C (0x08000000)
/*
* Hash table