Erratum A-008139 can cause duplicate TLB entries if an indirect
entry is overwritten using tlbwe while the other thread is using it to
do a lookup. Work around this by using tlbilx to invalidate prior
to overwriting.
To avoid the need to save another register to hold MAS1 during the
workaround code, TID clearing has been moved from tlb_miss_kernel_e6500
until after the SMT section.
Signed-off-by: Scott Wood <scottw...@freescale.com>
---
arch/powerpc/mm/tlb_low_64e.S | 68 +++++++++++++++++++++++++++++++++++--------
1 file changed, 56 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S
index 57c4d66..89bf95b 100644
--- a/arch/powerpc/mm/tlb_low_64e.S
+++ b/arch/powerpc/mm/tlb_low_64e.S
@@ -299,7 +299,9 @@ itlb_miss_fault_bolted:
* r10 = crap (free to use)
*/
tlb_miss_common_e6500:
-BEGIN_FTR_SECTION
+ crmove cr2*4+2,cr0*4+2 /* cr2.eq != 0 if kernel address */
+
+BEGIN_FTR_SECTION /* CPU_FTR_SMT */
/*
* Search if we already have an indirect entry for that virtual
* address, and if we do, bail out.
@@ -324,17 +326,62 @@ BEGIN_FTR_SECTION
b 1b
.previous
+ /*
+ * Erratum A-008139 says that we can't use tlbwe to change
+ * an indirect entry in any way (including replacing or
+ * invalidating) if the other thread could be in the process
+ * of a lookup. The workaround is to invalidate the entry
+ * with tlbilx before overwriting.
+ */
+
+ lbz r15,TCD_ESEL_NEXT(r11)
+ rlwinm r10,r15,16,0xff0000
+ oris r10,r10,MAS0_TLBSEL(1)@h
+ mtspr SPRN_MAS0,r10
+ isync
+ tlbre
mfspr r15,SPRN_MAS1
- mfspr r10,SPRN_MAS2
+ andis. r15,r15,MAS1_VALID@h
+ beq 5f
+
+BEGIN_FTR_SECTION_NESTED(532)
+ mfspr r10,SPRN_MAS8
+ rlwinm r10,r10,0,0x80000fff /* tgs,tlpid -> sgs,slpid */
+ mtspr SPRN_MAS5,r10
+END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
- tlbsx 0,r16
- mtspr SPRN_MAS2,r10
mfspr r10,SPRN_MAS1
- mtspr SPRN_MAS1,r15
+ rlwinm r15,r10,0,0x3fff0000 /* tid -> spid */
+ rlwimi r15,r10,20,0x00000003 /* ind,ts -> sind,sas */
+ mfspr r10,SPRN_MAS6
+ mtspr SPRN_MAS6,r15
+
+ mfspr r15,SPRN_MAS2
+ isync
+ tlbilxva 0,r15
+ isync
+
+ mtspr SPRN_MAS6,r10
- andis. r10,r10,MAS1_VALID@h
+5:
+BEGIN_FTR_SECTION_NESTED(532)
+ li r10,0
+ mtspr SPRN_MAS8,r10
+ mtspr SPRN_MAS5,r10
+END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
+
+ tlbsx 0,r16
+ mfspr r10,SPRN_MAS1
+ andis. r15,r10,MAS1_VALID@h
bne tlb_miss_done_e6500
-END_FTR_SECTION_IFSET(CPU_FTR_SMT)
+FTR_SECTION_ELSE
+ mfspr r10,SPRN_MAS1
+ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT)
+
+ oris r10,r10,MAS1_VALID@h
+ beq cr2,4f
+ rlwinm r10,r10,0,16,1 /* Clear TID */
+4: mtspr SPRN_MAS1,r10
/* Now, we need to walk the page tables. First check if we are in
* range.
@@ -410,12 +457,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_SMT)
rfi
tlb_miss_kernel_e6500:
- mfspr r10,SPRN_MAS1
ld r14,PACA_KERNELPGD(r13)
- cmpldi cr0,r15,8 /* Check for vmalloc region */
- rlwinm r10,r10,0,16,1 /* Clear TID */
- mtspr SPRN_MAS1,r10
- beq+ tlb_miss_common_e6500
+ cmpldi cr1,r15,8 /* Check for vmalloc region */
+ beq+ cr1,tlb_miss_common_e6500
tlb_miss_fault_e6500:
tlb_unlock_e6500
--
1.9.1
--
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