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d1acb4210a
We have to make sure to use base-pagesize TLB entries even during the early transition period where we need TLB miss handling but don't have the kernel page tables setup yet for the linear region. Also, it is necessary therefore to not use the 4MB TSB for these translations, and instead use the normal kernel TSB. This allows us to also get rid of the 4MB tsb for debug builds which shrinks the kernel a little bit. Signed-off-by: David S. Miller <davem@davemloft.net>
285 lines
6.0 KiB
ArmAsm
285 lines
6.0 KiB
ArmAsm
/* arch/sparc64/kernel/ktlb.S: Kernel mapping TLB miss handling.
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*
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* Copyright (C) 1995, 1997, 2005 David S. Miller <davem@davemloft.net>
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* Copyright (C) 1996 Eddie C. Dost (ecd@brainaid.de)
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* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
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* Copyright (C) 1996,98,99 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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#include <asm/head.h>
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#include <asm/asi.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/tsb.h>
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.text
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.align 32
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kvmap_itlb:
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/* g6: TAG TARGET */
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mov TLB_TAG_ACCESS, %g4
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ldxa [%g4] ASI_IMMU, %g4
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/* sun4v_itlb_miss branches here with the missing virtual
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* address already loaded into %g4
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*/
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kvmap_itlb_4v:
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kvmap_itlb_nonlinear:
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/* Catch kernel NULL pointer calls. */
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sethi %hi(PAGE_SIZE), %g5
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cmp %g4, %g5
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bleu,pn %xcc, kvmap_dtlb_longpath
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nop
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KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_itlb_load)
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kvmap_itlb_tsb_miss:
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sethi %hi(LOW_OBP_ADDRESS), %g5
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cmp %g4, %g5
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blu,pn %xcc, kvmap_itlb_vmalloc_addr
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mov 0x1, %g5
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sllx %g5, 32, %g5
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cmp %g4, %g5
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blu,pn %xcc, kvmap_itlb_obp
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nop
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kvmap_itlb_vmalloc_addr:
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KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath)
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KTSB_LOCK_TAG(%g1, %g2, %g7)
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/* Load and check PTE. */
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ldxa [%g5] ASI_PHYS_USE_EC, %g5
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mov 1, %g7
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sllx %g7, TSB_TAG_INVALID_BIT, %g7
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brgez,a,pn %g5, kvmap_itlb_longpath
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KTSB_STORE(%g1, %g7)
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KTSB_WRITE(%g1, %g5, %g6)
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/* fallthrough to TLB load */
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kvmap_itlb_load:
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661: stxa %g5, [%g0] ASI_ITLB_DATA_IN
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retry
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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nop
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nop
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.previous
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/* For sun4v the ASI_ITLB_DATA_IN store and the retry
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* instruction get nop'd out and we get here to branch
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* to the sun4v tlb load code. The registers are setup
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* as follows:
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*
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* %g4: vaddr
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* %g5: PTE
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* %g6: TAG
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*
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* The sun4v TLB load wants the PTE in %g3 so we fix that
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* up here.
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*/
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ba,pt %xcc, sun4v_itlb_load
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mov %g5, %g3
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kvmap_itlb_longpath:
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661: rdpr %pstate, %g5
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wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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SET_GL(1)
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nop
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.previous
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rdpr %tpc, %g5
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ba,pt %xcc, sparc64_realfault_common
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mov FAULT_CODE_ITLB, %g4
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kvmap_itlb_obp:
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OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath)
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KTSB_LOCK_TAG(%g1, %g2, %g7)
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KTSB_WRITE(%g1, %g5, %g6)
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ba,pt %xcc, kvmap_itlb_load
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nop
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kvmap_dtlb_obp:
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OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath)
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KTSB_LOCK_TAG(%g1, %g2, %g7)
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KTSB_WRITE(%g1, %g5, %g6)
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ba,pt %xcc, kvmap_dtlb_load
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nop
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.align 32
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kvmap_dtlb_tsb4m_load:
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KTSB_LOCK_TAG(%g1, %g2, %g7)
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KTSB_WRITE(%g1, %g5, %g6)
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ba,pt %xcc, kvmap_dtlb_load
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nop
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kvmap_dtlb:
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/* %g6: TAG TARGET */
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mov TLB_TAG_ACCESS, %g4
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ldxa [%g4] ASI_DMMU, %g4
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/* sun4v_dtlb_miss branches here with the missing virtual
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* address already loaded into %g4
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*/
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kvmap_dtlb_4v:
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brgez,pn %g4, kvmap_dtlb_nonlinear
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nop
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#ifdef CONFIG_DEBUG_PAGEALLOC
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/* Index through the base page size TSB even for linear
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* mappings when using page allocation debugging.
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*/
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KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
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#else
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/* Correct TAG_TARGET is already in %g6, check 4mb TSB. */
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KERN_TSB4M_LOOKUP_TL1(%g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
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#endif
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/* TSB entry address left in %g1, lookup linear PTE.
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* Must preserve %g1 and %g6 (TAG).
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*/
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kvmap_dtlb_tsb4m_miss:
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sethi %hi(kpte_linear_bitmap), %g2
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or %g2, %lo(kpte_linear_bitmap), %g2
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/* Clear the PAGE_OFFSET top virtual bits, then shift
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* down to get a 256MB physical address index.
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*/
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sllx %g4, 21, %g5
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mov 1, %g7
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srlx %g5, 21 + 28, %g5
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/* Don't try this at home kids... this depends upon srlx
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* only taking the low 6 bits of the shift count in %g5.
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*/
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sllx %g7, %g5, %g7
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/* Divide by 64 to get the offset into the bitmask. */
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srlx %g5, 6, %g5
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sllx %g5, 3, %g5
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/* kern_linear_pte_xor[((mask & bit) ? 1 : 0)] */
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ldx [%g2 + %g5], %g2
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andcc %g2, %g7, %g0
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sethi %hi(kern_linear_pte_xor), %g5
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or %g5, %lo(kern_linear_pte_xor), %g5
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bne,a,pt %xcc, 1f
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add %g5, 8, %g5
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1: ldx [%g5], %g2
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.globl kvmap_linear_patch
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kvmap_linear_patch:
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ba,pt %xcc, kvmap_dtlb_tsb4m_load
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xor %g2, %g4, %g5
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kvmap_dtlb_vmalloc_addr:
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KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath)
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KTSB_LOCK_TAG(%g1, %g2, %g7)
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/* Load and check PTE. */
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ldxa [%g5] ASI_PHYS_USE_EC, %g5
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mov 1, %g7
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sllx %g7, TSB_TAG_INVALID_BIT, %g7
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brgez,a,pn %g5, kvmap_dtlb_longpath
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KTSB_STORE(%g1, %g7)
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KTSB_WRITE(%g1, %g5, %g6)
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/* fallthrough to TLB load */
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kvmap_dtlb_load:
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661: stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB
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retry
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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nop
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nop
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.previous
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/* For sun4v the ASI_DTLB_DATA_IN store and the retry
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* instruction get nop'd out and we get here to branch
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* to the sun4v tlb load code. The registers are setup
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* as follows:
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*
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* %g4: vaddr
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* %g5: PTE
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* %g6: TAG
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*
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* The sun4v TLB load wants the PTE in %g3 so we fix that
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* up here.
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*/
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ba,pt %xcc, sun4v_dtlb_load
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mov %g5, %g3
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kvmap_dtlb_nonlinear:
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/* Catch kernel NULL pointer derefs. */
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sethi %hi(PAGE_SIZE), %g5
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cmp %g4, %g5
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bleu,pn %xcc, kvmap_dtlb_longpath
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nop
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KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
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kvmap_dtlb_tsbmiss:
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sethi %hi(MODULES_VADDR), %g5
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cmp %g4, %g5
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blu,pn %xcc, kvmap_dtlb_longpath
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mov (VMALLOC_END >> 24), %g5
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sllx %g5, 24, %g5
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cmp %g4, %g5
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bgeu,pn %xcc, kvmap_dtlb_longpath
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nop
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kvmap_check_obp:
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sethi %hi(LOW_OBP_ADDRESS), %g5
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cmp %g4, %g5
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blu,pn %xcc, kvmap_dtlb_vmalloc_addr
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mov 0x1, %g5
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sllx %g5, 32, %g5
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cmp %g4, %g5
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blu,pn %xcc, kvmap_dtlb_obp
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nop
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ba,pt %xcc, kvmap_dtlb_vmalloc_addr
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nop
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kvmap_dtlb_longpath:
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661: rdpr %pstate, %g5
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wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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SET_GL(1)
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ldxa [%g0] ASI_SCRATCHPAD, %g5
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.previous
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rdpr %tl, %g3
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cmp %g3, 1
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661: mov TLB_TAG_ACCESS, %g4
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ldxa [%g4] ASI_DMMU, %g5
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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ldx [%g5 + HV_FAULT_D_ADDR_OFFSET], %g5
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nop
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.previous
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be,pt %xcc, sparc64_realfault_common
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mov FAULT_CODE_DTLB, %g4
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ba,pt %xcc, winfix_trampoline
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nop
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