Commit 465ccab9 authored by will schmidt's avatar will schmidt Committed by Paul Mackerras

[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: default avatarWill Schmidt <will_schmidt@vnet.ibm.com>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent e7bda183
...@@ -149,6 +149,35 @@ void slb_vmalloc_update(void) ...@@ -149,6 +149,35 @@ void slb_vmalloc_update(void)
slb_flush_and_rebolt(); 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. */ /* Flush all user entries from the segment table of the current processor. */
void switch_slb(struct task_struct *tsk, struct mm_struct *mm) 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) ...@@ -194,15 +223,14 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
return; return;
slb_allocate(pc); slb_allocate(pc);
if (GET_ESID(pc) == GET_ESID(stack)) if (esids_match(pc,stack))
return; return;
if (is_kernel_addr(stack)) if (is_kernel_addr(stack))
return; return;
slb_allocate(stack); slb_allocate(stack);
if ((GET_ESID(pc) == GET_ESID(unmapped_base)) if (esids_match(pc,unmapped_base) || esids_match(stack,unmapped_base))
|| (GET_ESID(stack) == GET_ESID(unmapped_base)))
return; return;
if (is_kernel_addr(unmapped_base)) if (is_kernel_addr(unmapped_base))
......
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