From 459b6e621e0e15315c25bac47fa7113e5818d45d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sat, 11 Feb 2006 12:21:20 -0800 Subject: [PATCH] [SPARC64]: Fix some SUN4V TLB miss bugs. Code patching did not sign extend negative branch offsets correctly. Kernel TLB miss path needs patching and %g4 register preservation in order to handle SUN4V correctly. Signed-off-by: David S. Miller --- arch/sparc64/kernel/ktlb.S | 67 +++++++++++++++++++++++++++++++----- arch/sparc64/kernel/sun4v_tlb_miss.S | 14 +++++--- include/asm-sparc64/ttable.h | 10 +++--- 3 files changed, 73 insertions(+), 18 deletions(-) diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S index f6bb2e0..2d333ab 100644 --- a/arch/sparc64/kernel/ktlb.S +++ b/arch/sparc64/kernel/ktlb.S @@ -48,7 +48,7 @@ kvmap_itlb_tsb_miss: kvmap_itlb_vmalloc_addr: KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath) - KTSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g7) /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 @@ -60,8 +60,29 @@ kvmap_itlb_vmalloc_addr: /* fallthrough to TLB load */ kvmap_itlb_load: - stxa %g5, [%g0] ASI_ITLB_DATA_IN ! Reload TLB + +661: stxa %g5, [%g0] ASI_ITLB_DATA_IN retry + .section .sun4v_2insn_patch, "ax" + .word 661b + nop + nop + .previous + + /* For sun4v the ASI_ITLB_DATA_IN store and the retry + * instruction get nop'd out and we get here to branch + * to the sun4v tlb load code. The registers are setup + * as follows: + * + * %g4: vaddr + * %g5: PTE + * %g6: TAG + * + * The sun4v TLB load wants the PTE in %g3 so we fix that + * up here. + */ + ba,pt %xcc, sun4v_itlb_load + mov %g5, %g3 kvmap_itlb_longpath: @@ -80,7 +101,7 @@ kvmap_itlb_longpath: kvmap_itlb_obp: OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath) - KTSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g7) KTSB_WRITE(%g1, %g5, %g6) @@ -90,7 +111,7 @@ kvmap_itlb_obp: kvmap_dtlb_obp: OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath) - KTSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g7) KTSB_WRITE(%g1, %g5, %g6) @@ -129,7 +150,7 @@ kvmap_linear_patch: kvmap_dtlb_vmalloc_addr: KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath) - KTSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g7) /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 @@ -141,8 +162,29 @@ kvmap_dtlb_vmalloc_addr: /* fallthrough to TLB load */ kvmap_dtlb_load: - stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB + +661: stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB retry + .section .sun4v_2insn_patch, "ax" + .word 661b + nop + nop + .previous + + /* For sun4v the ASI_DTLB_DATA_IN store and the retry + * instruction get nop'd out and we get here to branch + * to the sun4v tlb load code. The registers are setup + * as follows: + * + * %g4: vaddr + * %g5: PTE + * %g6: TAG + * + * The sun4v TLB load wants the PTE in %g3 so we fix that + * up here. + */ + ba,pt %xcc, sun4v_dtlb_load + mov %g5, %g3 kvmap_dtlb_nonlinear: /* Catch kernel NULL pointer derefs. */ @@ -185,10 +227,17 @@ kvmap_dtlb_longpath: nop .previous - rdpr %tl, %g4 - cmp %g4, 1 - mov TLB_TAG_ACCESS, %g4 + rdpr %tl, %g3 + cmp %g3, 1 + +661: mov TLB_TAG_ACCESS, %g4 ldxa [%g4] ASI_DMMU, %g5 + .section .sun4v_2insn_patch, "ax" + .word 661b + mov %g4, %g5 + nop + .previous + be,pt %xcc, sparc64_realfault_common mov FAULT_CODE_DTLB, %g4 ba,pt %xcc, winfix_trampoline diff --git a/arch/sparc64/kernel/sun4v_tlb_miss.S b/arch/sparc64/kernel/sun4v_tlb_miss.S index f712913..597359c 100644 --- a/arch/sparc64/kernel/sun4v_tlb_miss.S +++ b/arch/sparc64/kernel/sun4v_tlb_miss.S @@ -96,7 +96,7 @@ sun4v_dtlb_miss: /* Load UTSB reg into %g1. */ mov SCRATCHPAD_UTSBREG1, %g1 - ldxa [%g1 + %g1] ASI_SCRATCHPAD, %g1 + ldxa [%g1] ASI_SCRATCHPAD, %g1 LOAD_DTLB_INFO(%g2, %g4, %g5) COMPUTE_TAG_TARGET(%g6, %g4, %g5, %g3, kvmap_dtlb_4v) @@ -149,14 +149,19 @@ sun4v_dtlb_prot: * SCRATCHPAD_MMU_MISS contents in %g2. */ sun4v_itsb_miss: - ba,pt %xcc, sun4v_tsb_miss_common + mov SCRATCHPAD_UTSBREG1, %g1 + ldxa [%g1] ASI_SCRATCHPAD, %g1 + brz,pn %g5, kvmap_itlb_4v mov FAULT_CODE_ITLB, %g3 /* Called from trap table with TAG TARGET placed into * %g6 and SCRATCHPAD_UTSBREG1 contents in %g1. */ sun4v_dtsb_miss: - mov FAULT_CODE_DTLB, %g3 + mov SCRATCHPAD_UTSBREG1, %g1 + ldxa [%g1] ASI_SCRATCHPAD, %g1 + brz,pn %g5, kvmap_dtlb_4v + mov FAULT_CODE_DTLB, %g3 /* Create TSB pointer into %g1. This is something like: * @@ -312,7 +317,8 @@ sun4v_stdfmna: or %g2, %lo(OLD), %g2; \ sub %g1, %g2, %g1; \ sethi %hi(BRANCH_ALWAYS), %g3; \ - srl %g1, 2, %g1; \ + sll %g1, 11, %g1; \ + srl %g1, 11 + 2, %g1; \ or %g3, %lo(BRANCH_ALWAYS), %g3; \ or %g3, %g1, %g3; \ stw %g3, [%g2]; \ diff --git a/include/asm-sparc64/ttable.h b/include/asm-sparc64/ttable.h index 6bb86a7..9e28b24 100644 --- a/include/asm-sparc64/ttable.h +++ b/include/asm-sparc64/ttable.h @@ -186,19 +186,19 @@ ldx [%g2 + HV_FAULT_I_CTX_OFFSET], %g5; \ srlx %g4, 22, %g7; \ sllx %g5, 48, %g6; \ - brz,pn %g5, kvmap_itlb_4v; \ + ba,pt %xcc, sun4v_itsb_miss; \ or %g6, %g7, %g6; \ - ba,a,pt %xcc, sun4v_itsb_miss; + nop; -#define SUN4V_DTSB_MISS \ +#define SUN4V_DTSB_MISS \ ldxa [%g0] ASI_SCRATCHPAD, %g2; \ ldx [%g2 + HV_FAULT_D_ADDR_OFFSET], %g4; \ ldx [%g2 + HV_FAULT_D_CTX_OFFSET], %g5; \ srlx %g4, 22, %g7; \ sllx %g5, 48, %g6; \ - brz,pn %g5, kvmap_dtlb_4v; \ + ba,pt %xcc, sun4v_dtsb_miss; \ or %g6, %g7, %g6; \ - ba,a,pt %xcc, sun4v_dtsb_miss; + nop; /* Before touching these macros, you owe it to yourself to go and * see how arch/sparc64/kernel/winfixup.S works... -DaveM -- 2.7.4