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authorwill schmidt <will_schmidt@vnet.ibm.com>2007-10-31 05:59:33 +1100
committerPaul Mackerras <paulus@samba.org>2007-11-08 14:15:31 +1100
commit465ccab9eb8209a2a402710b24a9bff127b25b94 (patch)
tree2cd2c3012b7cc5da8d582e9dc221b3ff60c1c806
parent[POWERPC] Fix build failure when CONFIG_VIRT_CPU_ACCOUNTING is not defined (diff)
downloadlinux-dev-465ccab9eb8209a2a402710b24a9bff127b25b94.tar.xz
linux-dev-465ccab9eb8209a2a402710b24a9bff127b25b94.zip
[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 fixes 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@vnet.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to '')
-rw-r--r--arch/powerpc/mm/slb.c34
1 files changed, 31 insertions, 3 deletions
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 637afb2386b7..27922dff8b94 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -149,6 +149,35 @@ 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)
{
@@ -194,15 +223,14 @@ 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))