[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(). A new helper function called
esids_match() contains the logic for deciding when to call GET_ESID
and GET_ESID_1T.
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 <[EMAIL PROTECTED]>
---
Just a bit of whitespace cosmetic touchup in this version, as suggested
by Stephen Rothwell.
---
arch/powerpc/mm/slb.c | 34 +++++++++++++++++++++++++++++++---
1 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index bbd2c51..8cbbfab 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -148,6 +148,35 @@ void slb_vmalloc_update(void)
slb_flush_and_rebolt();
}
+/* Helper function to compare esids. There are four cases to handle.
+ * 1. The system is not 1T segment size capable. Use the GET_ESID compare.
+ * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID
compare.
+ * 3. The system is 1T capable, only one of the two addresses is > 1T. This
is not a match.
+ * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T
macro to compare.
+ */
+static inline int esids_match(unsigned long addr1, unsigned long addr2)
+{
+ int esid_1t_count;
+
+ /* System is not 1T segment size capable. */
+ if (!cpu_has_feature(CPU_FTR_1T_SEGMENT))
+ return (GET_ESID(addr1) == GET_ESID(addr2));
+
+ esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) +
+ ((addr2 >> SID_SHIFT_1T) != 0));
+
+ /* both addresses are < 1T */
+ if (esid_1t_count == 0)
+ return (GET_ESID(addr1) == GET_ESID(addr2));
+
+ /* One address < 1T, the other > 1T. Not a match */
+ if (esid_1t_count == 1)
+ return 0;
+
+ /* Both addresses are > 1T. */
+ return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2));
+}
+
/* Flush all user entries from the segment table of the current processor. */
void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
{
@@ -193,15 +222,14 @@ void switch_slb(struct task_struct *tsk, struct mm_struct
*mm)
return;
slb_allocate(pc);
- if (GET_ESID(pc) == GET_ESID(stack))
+ if (esids_match(pc,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)))
+ if (esids_match(pc,unmapped_base) || esids_match(stack,unmapped_base))
return;
if (is_kernel_addr(unmapped_base))
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
