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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc64/kernel/itlb_base.S
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sparc64/kernel/itlb_base.S')
-rw-r--r--arch/sparc64/kernel/itlb_base.S83
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diff --git a/arch/sparc64/kernel/itlb_base.S b/arch/sparc64/kernel/itlb_base.S
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1/* $Id: itlb_base.S,v 1.12 2002/02/09 19:49:30 davem Exp $
2 * itlb_base.S: Front end to ITLB miss replacement strategy.
3 * This is included directly into the trap table.
4 *
5 * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com)
6 * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz)
7 */
8
9#if PAGE_SHIFT == 13
10/*
11 * To compute vpte offset, we need to do ((addr >> 13) << 3),
12 * which can be optimized to (addr >> 10) if bits 10/11/12 can
13 * be guaranteed to be 0 ... mmu_context.h does guarantee this
14 * by only using 10 bits in the hwcontext value.
15 */
16#define CREATE_VPTE_OFFSET1(r1, r2) \
17 srax r1, 10, r2
18#define CREATE_VPTE_OFFSET2(r1, r2)
19#define CREATE_VPTE_NOP nop
20#else /* PAGE_SHIFT */
21#define CREATE_VPTE_OFFSET1(r1, r2) \
22 srax r1, PAGE_SHIFT, r2
23#define CREATE_VPTE_OFFSET2(r1, r2) \
24 sllx r2, 3, r2
25#define CREATE_VPTE_NOP
26#endif /* PAGE_SHIFT */
27
28
29/* Ways we can get here:
30 *
31 * 1) Nucleus instruction misses from module code.
32 * 2) All user instruction misses.
33 *
34 * All real page faults merge their code paths to the
35 * sparc64_realfault_common label below.
36 */
37
38/* ITLB ** ICACHE line 1: Quick user TLB misses */
39 ldxa [%g1 + %g1] ASI_IMMU, %g4 ! Get TAG_ACCESS
40 CREATE_VPTE_OFFSET1(%g4, %g6) ! Create VPTE offset
41 CREATE_VPTE_OFFSET2(%g4, %g6) ! Create VPTE offset
42 ldxa [%g3 + %g6] ASI_P, %g5 ! Load VPTE
431: brgez,pn %g5, 3f ! Not valid, branch out
44 sethi %hi(_PAGE_EXEC), %g4 ! Delay-slot
45 andcc %g5, %g4, %g0 ! Executable?
46 be,pn %xcc, 3f ! Nope, branch.
47 nop ! Delay-slot
482: stxa %g5, [%g0] ASI_ITLB_DATA_IN ! Load PTE into TLB
49 retry ! Trap return
503: rdpr %pstate, %g4 ! Move into alternate globals
51
52/* ITLB ** ICACHE line 2: Real faults */
53 wrpr %g4, PSTATE_AG|PSTATE_MG, %pstate
54 rdpr %tpc, %g5 ! And load faulting VA
55 mov FAULT_CODE_ITLB, %g4 ! It was read from ITLB
56sparc64_realfault_common: ! Called by TL0 dtlb_miss too
57 stb %g4, [%g6 + TI_FAULT_CODE]
58 stx %g5, [%g6 + TI_FAULT_ADDR]
59 ba,pt %xcc, etrap ! Save state
601: rd %pc, %g7 ! ...
61 nop
62
63/* ITLB ** ICACHE line 3: Finish faults + window fixups */
64 call do_sparc64_fault ! Call fault handler
65 add %sp, PTREGS_OFF, %o0! Compute pt_regs arg
66 ba,pt %xcc, rtrap_clr_l6 ! Restore cpu state
67 nop
68winfix_trampoline:
69 rdpr %tpc, %g3 ! Prepare winfixup TNPC
70 or %g3, 0x7c, %g3 ! Compute offset to branch
71 wrpr %g3, %tnpc ! Write it into TNPC
72 done ! Do it to it
73
74/* ITLB ** ICACHE line 4: Unused... */
75 nop
76 nop
77 nop
78 nop
79 CREATE_VPTE_NOP
80
81#undef CREATE_VPTE_OFFSET1
82#undef CREATE_VPTE_OFFSET2
83#undef CREATE_VPTE_NOP