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authorwill schmidt <will_schmidt@vnet.ibm.com>2007-10-30 14:59:33 -0400
committerPaul Mackerras <paulus@samba.org>2007-11-07 22:15:31 -0500
commit465ccab9eb8209a2a402710b24a9bff127b25b94 (patch)
tree2cd2c3012b7cc5da8d582e9dc221b3ff60c1c806 /arch/powerpc/mm
parente7bda183d4e3f6027ae9181c176a459423d04748 (diff)
[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 'arch/powerpc/mm')
-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)
149 slb_flush_and_rebolt(); 149 slb_flush_and_rebolt();
150} 150}
151 151
152/* Helper function to compare esids. There are four cases to handle.
153 * 1. The system is not 1T segment size capable. Use the GET_ESID compare.
154 * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID compare.
155 * 3. The system is 1T capable, only one of the two addresses is > 1T. This is not a match.
156 * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T macro to compare.
157 */
158static inline int esids_match(unsigned long addr1, unsigned long addr2)
159{
160 int esid_1t_count;
161
162 /* System is not 1T segment size capable. */
163 if (!cpu_has_feature(CPU_FTR_1T_SEGMENT))
164 return (GET_ESID(addr1) == GET_ESID(addr2));
165
166 esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) +
167 ((addr2 >> SID_SHIFT_1T) != 0));
168
169 /* both addresses are < 1T */
170 if (esid_1t_count == 0)
171 return (GET_ESID(addr1) == GET_ESID(addr2));
172
173 /* One address < 1T, the other > 1T. Not a match */
174 if (esid_1t_count == 1)
175 return 0;
176
177 /* Both addresses are > 1T. */
178 return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2));
179}
180
152/* Flush all user entries from the segment table of the current processor. */ 181/* Flush all user entries from the segment table of the current processor. */
153void switch_slb(struct task_struct *tsk, struct mm_struct *mm) 182void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
154{ 183{
@@ -194,15 +223,14 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
194 return; 223 return;
195 slb_allocate(pc); 224 slb_allocate(pc);
196 225
197 if (GET_ESID(pc) == GET_ESID(stack)) 226 if (esids_match(pc,stack))
198 return; 227 return;
199 228
200 if (is_kernel_addr(stack)) 229 if (is_kernel_addr(stack))
201 return; 230 return;
202 slb_allocate(stack); 231 slb_allocate(stack);
203 232
204 if ((GET_ESID(pc) == GET_ESID(unmapped_base)) 233 if (esids_match(pc,unmapped_base) || esids_match(stack,unmapped_base))
205 || (GET_ESID(stack) == GET_ESID(unmapped_base)))
206 return; 234 return;
207 235
208 if (is_kernel_addr(unmapped_base)) 236 if (is_kernel_addr(unmapped_base))