| 1 | /* |
| 2 | * ========== Copyright Header Begin ========================================== |
| 3 | * |
| 4 | * OpenSPARC T2 Processor File: barrier_subr_v8.s |
| 5 | * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. |
| 6 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES. |
| 7 | * |
| 8 | * The above named program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public |
| 10 | * License version 2 as published by the Free Software Foundation. |
| 11 | * |
| 12 | * The above named program is distributed in the hope that it will be |
| 13 | * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public |
| 18 | * License along with this work; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. |
| 20 | * |
| 21 | * ========== Copyright Header End ============================================ |
| 22 | */ |
| 23 | #pragma ident "@(#)1.2 02/05/23 barrier_subr_v8.s" |
| 24 | |
| 25 | #include <sys/asm_linkage.h> |
| 26 | |
| 27 | #if 0 |
| 28 | |
| 29 | ENTRY(barrier) |
| 30 | ld [%o0 + 20], %o1 ! load bp->sbp into %o1 |
| 31 | ! atomic decrement of running count |
| 32 | add %o1, 4, %o2 |
| 33 | retry: ld [%o2], %o3 |
| 34 | add %o3, -1, %o4 |
| 35 | cas [%o2], %o3, %o4 |
| 36 | cmp %o3, %o4 |
| 37 | bne retry |
| 38 | nop |
| 39 | |
| 40 | ! check if this is the last one |
| 41 | cmp %o3, 1 |
| 42 | bne wait |
| 43 | nop |
| 44 | |
| 45 | ! YES, switch sub-barriers, reset count and CV |
| 46 | add %o0, 4, %o2 ! %o2 = &bp->sb[0] |
| 47 | cmp %o1, %o2 |
| 48 | bne 1f |
| 49 | nop |
| 50 | add %o0, 12, %o2 ! %o2 = &bp->sb[1] |
| 51 | 1: st %o2, [%o0 + 20] ! store %o2 into bp->sbp |
| 52 | set 1, %o4 |
| 53 | st %o4, [%o2] |
| 54 | ld [%o0], %o3 |
| 55 | st %o3, [%o2 + 4] |
| 56 | |
| 57 | ! release the CV busy-waiters |
| 58 | retl |
| 59 | clr [%o1] |
| 60 | |
| 61 | ! NO, busy-wait on CV |
| 62 | wait: ld [%o1], %o2 |
| 63 | tst %o2 |
| 64 | bne wait |
| 65 | nop |
| 66 | retl |
| 67 | nop |
| 68 | SET_SIZE(barrier) |
| 69 | |
| 70 | #else |
| 71 | |
| 72 | .global cpu_barrier |
| 73 | ENTRY(barrier) |
| 74 | or %o0, 0, %o5 ! loopticks |
| 75 | set cpu_barrier, %o0 |
| 76 | ld [%o0 + 20], %o1 ! load bp->sbp into %o1 |
| 77 | ld [%o0 + 24], %o0 !!!!!! global tick pointer |
| 78 | |
| 79 | ! atomic decrement of running count |
| 80 | add %o1, 4, %o2 |
| 81 | retry: ld [%o2], %o3 |
| 82 | add %o3, -1, %o4 |
| 83 | cas [%o2], %o3, %o4 |
| 84 | cmp %o3, %o4 |
| 85 | bne retry |
| 86 | nop |
| 87 | |
| 88 | retry1: ldx [%o0], %o2 !! |
| 89 | add %o2, %o5, %o4 !! |
| 90 | casx [%o0], %o2, %o4 !! |
| 91 | cmp %o2, %o4 !! |
| 92 | bne,pn %xcc, retry1 |
| 93 | nop !! |
| 94 | |
| 95 | ! check if this is the last one |
| 96 | cmp %o3, 1 |
| 97 | bne wait |
| 98 | nop |
| 99 | |
| 100 | ! YES, switch sub-barriers, reset count and CV |
| 101 | set cpu_barrier, %o0 |
| 102 | add %o0, 4, %o2 ! %o2 = &bp->sb[0] |
| 103 | cmp %o1, %o2 |
| 104 | bne 1f |
| 105 | nop |
| 106 | add %o0, 12, %o2 ! %o2 = &bp->sb[1] |
| 107 | 1: st %o2, [%o0 + 20] ! store %o2 into bp->sbp |
| 108 | set 1, %o4 |
| 109 | st %o4, [%o2] |
| 110 | ld [%o0], %o3 |
| 111 | st %o3, [%o2 + 4] |
| 112 | |
| 113 | ! release the CV busy-waiters |
| 114 | retl |
| 115 | clr [%o1] |
| 116 | |
| 117 | ! NO, busy-wait on CV |
| 118 | wait: ld [%o1], %o2 |
| 119 | tst %o2 |
| 120 | bne wait |
| 121 | nop |
| 122 | retl |
| 123 | nop |
| 124 | SET_SIZE(barrier) |
| 125 | |
| 126 | |
| 127 | |
| 128 | #endif |