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authorRalf Baechle2012-10-13 22:46:26 +0200
committerRalf Baechle2012-10-16 22:21:27 +0200
commit02a5417751c31cd64197652c000a5ab0d3261465 (patch)
tree8f0ad16efad10d42ed45016baf517583d928e4e2 /arch/mips/mm
parent5210edcd527773c227465ad18e416a894966324f (diff)
MIPS: tlbex: Deal with re-definition of label
The microassembler used in tlbex.c does not notice if a label is redefined resulting in relocations against such labels silently missrelocated. The issues exists since commit add6eb04776db4189ea89f596cbcde31b899be9d [Synthesize TLB exception handlers at runtime.] in 2.6.10 and went unnoticed for so long because the relocations for the affected branches got computed to do something *almost* sensible. The issue affects R4000, R4400, QED/IDT RM5230, RM5231, RM5260, RM5261, RM5270 and RM5271 processors. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm')
-rw-r--r--arch/mips/mm/tlbex.c41
1 files changed, 34 insertions, 7 deletions
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 658a520364ce..6ea152552e51 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -148,8 +148,8 @@ enum label_id {
label_leave,
label_vmalloc,
label_vmalloc_done,
- label_tlbw_hazard,
- label_split,
+ label_tlbw_hazard_0,
+ label_split = label_tlbw_hazard_0 + 8,
label_tlbl_goaround1,
label_tlbl_goaround2,
label_nopage_tlbl,
@@ -167,7 +167,7 @@ UASM_L_LA(_second_part)
UASM_L_LA(_leave)
UASM_L_LA(_vmalloc)
UASM_L_LA(_vmalloc_done)
-UASM_L_LA(_tlbw_hazard)
+/* _tlbw_hazard_x is handled differently. */
UASM_L_LA(_split)
UASM_L_LA(_tlbl_goaround1)
UASM_L_LA(_tlbl_goaround2)
@@ -181,6 +181,30 @@ UASM_L_LA(_large_segbits_fault)
UASM_L_LA(_tlb_huge_update)
#endif
+static int __cpuinitdata hazard_instance;
+
+static void uasm_bgezl_hazard(u32 **p, struct uasm_reloc **r, int instance)
+{
+ switch (instance) {
+ case 0 ... 7:
+ uasm_il_bgezl(p, r, 0, label_tlbw_hazard_0 + instance);
+ return;
+ default:
+ BUG();
+ }
+}
+
+static void uasm_bgezl_label(struct uasm_label **l, u32 **p, int instance)
+{
+ switch (instance) {
+ case 0 ... 7:
+ uasm_build_label(l, *p, label_tlbw_hazard_0 + instance);
+ break;
+ default:
+ BUG();
+ }
+}
+
/*
* For debug purposes.
*/
@@ -478,9 +502,10 @@ static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
* This branch uses up a mtc0 hazard nop slot and saves
* two nops after the tlbw instruction.
*/
- uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
+ uasm_bgezl_hazard(p, r, hazard_instance);
tlbw(p);
- uasm_l_tlbw_hazard(l, *p);
+ uasm_bgezl_label(l, p, hazard_instance);
+ hazard_instance++;
uasm_i_nop(p);
break;
@@ -528,13 +553,15 @@ static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
case CPU_NEVADA:
uasm_i_nop(p); /* QED specifies 2 nops hazard */
+ uasm_i_nop(p); /* QED specifies 2 nops hazard */
/*
* This branch uses up a mtc0 hazard nop slot and saves
* a nop after the tlbw instruction.
*/
- uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
+ uasm_bgezl_hazard(p, r, hazard_instance);
tlbw(p);
- uasm_l_tlbw_hazard(l, *p);
+ uasm_bgezl_label(l, p, hazard_instance);
+ hazard_instance++;
break;
case CPU_RM7000: