/* arch/sparc64/kernel/ktlb.S: Kernel mapping TLB miss handling. * * Copyright (C) 1995, 1997, 2005, 2008 David S. Miller <davem@davemloft.net> * Copyright (C) 1996 Eddie C. Dost (ecd@brainaid.de) * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx) * Copyright (C) 1996,98,99 Jakub Jelinek (jj@sunsite.mff.cuni.cz) */ #include <asm/head.h> #include <asm/asi.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/tsb.h> .text .align 32 kvmap_itlb: /* g6: TAG TARGET */ mov TLB_TAG_ACCESS, %g4 ldxa [%g4] ASI_IMMU, %g4 /* sun4v_itlb_miss branches here with the missing virtual * address already loaded into %g4 */ kvmap_itlb_4v: kvmap_itlb_nonlinear: /* Catch kernel NULL pointer calls. */ sethi %hi(PAGE_SIZE), %g5 cmp %g4, %g5 bleu,pn %xcc, kvmap_dtlb_longpath nop KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_itlb_load) kvmap_itlb_tsb_miss: sethi %hi(LOW_OBP_ADDRESS), %g5 cmp %g4, %g5 blu,pn %xcc, kvmap_itlb_vmalloc_addr mov 0x1, %g5 sllx %g5, 32, %g5 cmp %g4, %g5 blu,pn %xcc, kvmap_itlb_obp nop kvmap_itlb_vmalloc_addr: KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath) TSB_LOCK_TAG(%g1, %g2, %g7) /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 mov 1, %g7 sllx %g7, TSB_TAG_INVALID_BIT, %g7 brgez,a,pn %g5, kvmap_itlb_longpath TSB_STORE(%g1, %g7) TSB_WRITE(%g1, %g5, %g6) /* fallthrough to TLB load */ kvmap_itlb_load: 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: 661: rdpr %pstate, %g5 wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate .section .sun4v_2insn_patch, "ax" .word 661b SET_GL(1) nop .previous rdpr %tpc, %g5 ba,pt %xcc, sparc64_realfault_common mov FAULT_CODE_ITLB, %g4 kvmap_itlb_obp: OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath) TSB_LOCK_TAG(%g1, %g2, %g7) TSB_WRITE(%g1, %g5, %g6) ba,pt %xcc, kvmap_itlb_load nop kvmap_dtlb_obp: OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath) TSB_LOCK_TAG(%g1, %g2, %g7) TSB_WRITE(%g1, %g5, %g6) ba,pt %xcc, kvmap_dtlb_load nop .align 32 kvmap_dtlb_tsb4m_load: TSB_LOCK_TAG(%g1, %g2, %g7) TSB_WRITE(%g1, %g5, %g6) ba,pt %xcc, kvmap_dtlb_load nop kvmap_dtlb: /* %g6: TAG TARGET */ mov TLB_TAG_ACCESS, %g4 ldxa [%g4] ASI_DMMU, %g4 /* sun4v_dtlb_miss branches here with the missing virtual * address already loaded into %g4 */ kvmap_dtlb_4v: brgez,pn %g4, kvmap_dtlb_nonlinear nop #ifdef CONFIG_DEBUG_PAGEALLOC /* Index through the base page size TSB even for linear * mappings when using page allocation debugging. */ KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load) #else /* Correct TAG_TARGET is already in %g6, check 4mb TSB. */ KERN_TSB4M_LOOKUP_TL1(%g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load) #endif /* TSB entry address left in %g1, lookup linear PTE. * Must preserve %g1 and %g6 (TAG). */ kvmap_dtlb_tsb4m_miss: /* Clear the PAGE_OFFSET top virtual bits, shift * down to get PFN, and make sure PFN is in range. */ sllx %g4, 21, %g5 /* Check to see if we know about valid memory at the 4MB * chunk this physical address will reside within. */ srlx %g5, 21 + 41, %g2 brnz,pn %g2, kvmap_dtlb_longpath nop /* This unconditional branch and delay-slot nop gets patched * by the sethi sequence once the bitmap is properly setup. */ .globl valid_addr_bitmap_insn valid_addr_bitmap_insn: ba,pt %xcc, 2f nop .subsection 2 .globl valid_addr_bitmap_patch valid_addr_bitmap_patch: sethi %hi(sparc64_valid_addr_bitmap), %g7 or %g7, %lo(sparc64_valid_addr_bitmap), %g7 .previous srlx %g5, 21 + 22, %g2 srlx %g2, 6, %g5 and %g2, 63, %g2 sllx %g5, 3, %g5 ldx [%g7 + %g5], %g5 mov 1, %g7 sllx %g7, %g2, %g7 andcc %g5, %g7, %g0 be,pn %xcc, kvmap_dtlb_longpath 2: sethi %hi(kpte_linear_bitmap), %g2 /* Get the 256MB physical address index. */ sllx %g4, 21, %g5 or %g2, %lo(kpte_linear_bitmap), %g2 srlx %g5, 21 + 28, %g5 and %g5, (32 - 1), %g7 /* Divide by 32 to get the offset into the bitmask. */ srlx %g5, 5, %g5 add %g7, %g7, %g7 sllx %g5, 3, %g5 /* kern_linear_pte_xor[(mask >> shift) & 3)] */ ldx [%g2 + %g5], %g2 srlx %g2, %g7, %g7 sethi %hi(kern_linear_pte_xor), %g5 and %g7, 3, %g7 or %g5, %lo(kern_linear_pte_xor), %g5 sllx %g7, 3, %g7 ldx [%g5 + %g7], %g2 .globl kvmap_linear_patch kvmap_linear_patch: ba,pt %xcc, kvmap_dtlb_tsb4m_load xor %g2, %g4, %g5 kvmap_dtlb_vmalloc_addr: KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath) TSB_LOCK_TAG(%g1, %g2, %g7) /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 mov 1, %g7 sllx %g7, TSB_TAG_INVALID_BIT, %g7 brgez,a,pn %g5, kvmap_dtlb_longpath TSB_STORE(%g1, %g7) TSB_WRITE(%g1, %g5, %g6) /* fallthrough to TLB load */ kvmap_dtlb_load: 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 #ifdef CONFIG_SPARSEMEM_VMEMMAP kvmap_vmemmap: sub %g4, %g5, %g5 srlx %g5, 22, %g5 sethi %hi(vmemmap_table), %g1 sllx %g5, 3, %g5 or %g1, %lo(vmemmap_table), %g1 ba,pt %xcc, kvmap_dtlb_load ldx [%g1 + %g5], %g5 #endif kvmap_dtlb_nonlinear: /* Catch kernel NULL pointer derefs. */ sethi %hi(PAGE_SIZE), %g5 cmp %g4, %g5 bleu,pn %xcc, kvmap_dtlb_longpath nop #ifdef CONFIG_SPARSEMEM_VMEMMAP /* Do not use the TSB for vmemmap. */ mov (VMEMMAP_BASE >> 40), %g5 sllx %g5, 40, %g5 cmp %g4,%g5 bgeu,pn %xcc, kvmap_vmemmap nop #endif KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load) kvmap_dtlb_tsbmiss: sethi %hi(MODULES_VADDR), %g5 cmp %g4, %g5 blu,pn %xcc, kvmap_dtlb_longpath mov (VMALLOC_END >> 40), %g5 sllx %g5, 40, %g5 cmp %g4, %g5 bgeu,pn %xcc, kvmap_dtlb_longpath nop kvmap_check_obp: sethi %hi(LOW_OBP_ADDRESS), %g5 cmp %g4, %g5 blu,pn %xcc, kvmap_dtlb_vmalloc_addr mov 0x1, %g5 sllx %g5, 32, %g5 cmp %g4, %g5 blu,pn %xcc, kvmap_dtlb_obp nop ba,pt %xcc, kvmap_dtlb_vmalloc_addr nop kvmap_dtlb_longpath: 661: rdpr %pstate, %g5 wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate .section .sun4v_2insn_patch, "ax" .word 661b SET_GL(1) ldxa [%g0] ASI_SCRATCHPAD, %g5 .previous rdpr %tl, %g3 cmp %g3, 1 661: mov TLB_TAG_ACCESS, %g4 ldxa [%g4] ASI_DMMU, %g5 .section .sun4v_2insn_patch, "ax" .word 661b ldx [%g5 + HV_FAULT_D_ADDR_OFFSET], %g5 nop .previous be,pt %xcc, sparc64_realfault_common mov FAULT_CODE_DTLB, %g4 ba,pt %xcc, winfix_trampoline nop