[PATCH] [Powerpc] fix switch_slb handling of 1T ESID values

[Will Schmidt]

[Powerpc] fix switch_slb handling of 1T ESID values

Now that we have 1TB segment size support, we need to be using the
GET_ESID_1T macro when comparing ESID values for pc,stack, and
unmapped_base within switch_slb() when we're on a CPU that supports it.

This also happens to fix a duplicate-slb-entry inspired machine-check
exception I was seeing when trying to run java on a power6 partition.

Tested on power6 and power5.

Signed-Off-By:  Will Schmidt <will_schmidt at vnet.ibm.com>

---

There is a similar bit of code in stab.c switch_stab().  Should this change also be made there?
---

 arch/powerpc/mm/slb.c |   19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)


diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index bbd2c51..0c527d7 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -193,16 +193,25 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 		return;
 	slb_allocate(pc);
 
-	if (GET_ESID(pc) == GET_ESID(stack))
-		return;
+	if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
+		if (GET_ESID_1T(pc) == GET_ESID_1T(stack))
+			return;
+	} else
+		if (GET_ESID(pc) == GET_ESID(stack))
+			return;
 
 	if (is_kernel_addr(stack))
 		return;
 	slb_allocate(stack);
 
-	if ((GET_ESID(pc) == GET_ESID(unmapped_base))
-	    || (GET_ESID(stack) == GET_ESID(unmapped_base)))
-		return;
+	if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
+		if ((GET_ESID_1T(pc) == GET_ESID_1T(unmapped_base))
+		    || (GET_ESID_1T(stack) == GET_ESID_1T(unmapped_base)))
+			return;
+	} else
+		if ((GET_ESID(pc) == GET_ESID(unmapped_base))
+		    || (GET_ESID(stack) == GET_ESID(unmapped_base)))
+			return;
 
 	if (is_kernel_addr(unmapped_base))
 		return;