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Diffstat (limited to 'arch/sparc64/kernel/dtlb_base.S')
| -rw-r--r-- | arch/sparc64/kernel/dtlb_base.S | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/arch/sparc64/kernel/dtlb_base.S b/arch/sparc64/kernel/dtlb_base.S deleted file mode 100644 index 6528786..0000000 --- a/arch/sparc64/kernel/dtlb_base.S +++ /dev/null @@ -1,109 +0,0 @@ -/* $Id: dtlb_base.S,v 1.17 2001/10/11 22:33:52 davem Exp $ - * dtlb_base.S: Front end to DTLB miss replacement strategy. - * This is included directly into the trap table. - * - * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com) - * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz) - */ - -#include <asm/pgtable.h> -#include <asm/mmu.h> - -/* %g1 TLB_SFSR (%g1 + %g1 == TLB_TAG_ACCESS) - * %g2 (KERN_HIGHBITS | KERN_LOWBITS) - * %g3 VPTE base (0xfffffffe00000000) Spitfire/Blackbird (44-bit VA space) - * (0xffe0000000000000) Cheetah (64-bit VA space) - * %g7 __pa(current->mm->pgd) - * - * The VPTE base value is completely magic, but note that - * few places in the kernel other than these TLB miss - * handlers know anything about the VPTE mechanism or - * how it works (see VPTE_SIZE, TASK_SIZE and PTRS_PER_PGD). - * Consider the 44-bit VADDR Ultra-I/II case as an example: - * - * VA[0 : (1<<43)] produce VPTE index [%g3 : 0] - * VA[0 : -(1<<43)] produce VPTE index [%g3-(1<<(43-PAGE_SHIFT+3)) : %g3] - * - * For Cheetah's 64-bit VADDR space this is: - * - * VA[0 : (1<<63)] produce VPTE index [%g3 : 0] - * VA[0 : -(1<<63)] produce VPTE index [%g3-(1<<(63-PAGE_SHIFT+3)) : %g3] - * - * If you're paying attention you'll notice that this means half of - * the VPTE table is above %g3 and half is below, low VA addresses - * map progressively upwards from %g3, and high VA addresses map - * progressively upwards towards %g3. This trick was needed to make - * the same 8 instruction handler work both for Spitfire/Blackbird's - * peculiar VA space hole configuration and the full 64-bit VA space - * one of Cheetah at the same time. - */ - -/* Ways we can get here: - * - * 1) Nucleus loads and stores to/from PA-->VA direct mappings. - * 2) Nucleus loads and stores to/from vmalloc() areas. - * 3) User loads and stores. - * 4) User space accesses by nucleus at tl0 - */ - -#if PAGE_SHIFT == 13 -/* - * To compute vpte offset, we need to do ((addr >> 13) << 3), - * which can be optimized to (addr >> 10) if bits 10/11/12 can - * be guaranteed to be 0 ... mmu_context.h does guarantee this - * by only using 10 bits in the hwcontext value. - */ -#define CREATE_VPTE_OFFSET1(r1, r2) nop -#define CREATE_VPTE_OFFSET2(r1, r2) \ - srax r1, 10, r2 -#else -#define CREATE_VPTE_OFFSET1(r1, r2) \ - srax r1, PAGE_SHIFT, r2 -#define CREATE_VPTE_OFFSET2(r1, r2) \ - sllx r2, 3, r2 -#endif - -/* DTLB ** ICACHE line 1: Quick user TLB misses */ - mov TLB_SFSR, %g1 - ldxa [%g1 + %g1] ASI_DMMU, %g4 ! Get TAG_ACCESS - andcc %g4, TAG_CONTEXT_BITS, %g0 ! From Nucleus? -from_tl1_trap: - rdpr %tl, %g5 ! For TL==3 test - CREATE_VPTE_OFFSET1(%g4, %g6) ! Create VPTE offset - be,pn %xcc, kvmap ! Yep, special processing - CREATE_VPTE_OFFSET2(%g4, %g6) ! Create VPTE offset - cmp %g5, 4 ! Last trap level? - -/* DTLB ** ICACHE line 2: User finish + quick kernel TLB misses */ - be,pn %xcc, longpath ! Yep, cannot risk VPTE miss - nop ! delay slot - ldxa [%g3 + %g6] ASI_S, %g5 ! Load VPTE -1: brgez,pn %g5, longpath ! Invalid, branch out - nop ! Delay-slot -9: stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB - retry ! Trap return - nop - -/* DTLB ** ICACHE line 3: winfixups+real_faults */ -longpath: - rdpr %pstate, %g5 ! Move into alternate globals - wrpr %g5, PSTATE_AG|PSTATE_MG, %pstate - rdpr %tl, %g4 ! See where we came from. - cmp %g4, 1 ! Is etrap/rtrap window fault? - mov TLB_TAG_ACCESS, %g4 ! Prepare for fault processing - ldxa [%g4] ASI_DMMU, %g5 ! Load faulting VA page - be,pt %xcc, sparc64_realfault_common ! Jump to normal fault handling - mov FAULT_CODE_DTLB, %g4 ! It was read from DTLB - -/* DTLB ** ICACHE line 4: Unused... */ - ba,a,pt %xcc, winfix_trampoline ! Call window fixup code - nop - nop - nop - nop - nop - nop - nop - -#undef CREATE_VPTE_OFFSET1 -#undef CREATE_VPTE_OFFSET2 |
