| 1 | /* |
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| 2 | * Copyright (c) 2011 Aeroflex Gaisler |
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| 3 | * |
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| 4 | * BSD license: |
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| 5 | * |
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| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
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| 7 | * of this software and associated documentation files (the "Software"), to deal |
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| 8 | * in the Software without restriction, including without limitation the rights |
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| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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| 10 | * copies of the Software, and to permit persons to whom the Software is |
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| 11 | * furnished to do so, subject to the following conditions: |
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| 12 | * |
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| 13 | * The above copyright notice and this permission notice shall be included in |
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| 14 | * all copies or substantial portions of the Software. |
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| 15 | * |
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| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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| 22 | * THE SOFTWARE. |
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| 23 | */ |
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| 24 | |
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| 25 | |
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| 26 | #include <asm-leon/leonstack.h> |
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| 27 | #include <asm-leon/winmacros.h> |
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| 28 | |
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| 29 | /* Registers to not touch at all. */ |
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| 30 | #define t_psr l0 |
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| 31 | #define t_pc l1 |
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| 32 | #define t_npc l2 |
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| 33 | #define t_wim l3 |
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| 34 | #define twin_tmp1 l4 |
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| 35 | #define glob_tmp g4 |
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| 36 | #define curptr g6 |
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| 37 | |
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| 38 | /* Number of register windows */ |
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| 39 | .global _nwindows_min1, _nwindows |
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| 40 | |
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| 41 | .text |
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| 42 | .align 4 |
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| 43 | .globl leonbare_trapreturn, schedule_callback |
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| 44 | |
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| 45 | leonbare_trapreturn: |
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| 46 | |
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| 47 | /* a optional scheduler can be called here */ |
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| 48 | set schedule_callback, %g2 |
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| 49 | ld [%g2], %g2 |
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| 50 | cmp %g2,%g0 |
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| 51 | beq 3f |
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| 52 | nop |
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| 53 | |
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| 54 | jmpl %g2,%o7 |
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| 55 | #ifndef _SOFT_FLOAT |
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| 56 | add %sp, FW_REGS_SZ + 8 + SF_REGS_SZ , %o1 ! pt_regs ptr |
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| 57 | #else |
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| 58 | add %sp, SF_REGS_SZ , %o1 ! pt_regs ptr |
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| 59 | #endif |
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| 60 | |
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| 61 | 3: |
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| 62 | |
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| 63 | #ifndef _SOFT_FLOAT |
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| 64 | ld [%sp + (SF_REGS_SZ + PT_REGS_SZ + FW_REGS_SZ - 4)],%g2 |
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| 65 | sethi %hi(fpustate_current), %g3 |
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| 66 | st %g2, [%g3+%lo(fpustate_current)] |
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| 67 | #endif |
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| 68 | |
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| 69 | wr %t_psr, 0x0, %psr ! enable nesting again, clear ET |
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| 70 | |
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| 71 | #ifndef _FLAT |
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| 72 | /* Will the rett land us in the invalid window? */ |
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| 73 | mov 2, %g1 |
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| 74 | sll %g1, %t_psr, %g1 |
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| 75 | |
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| 76 | sethi %hi(_nwindows), %g2 !NWINDOWS |
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| 77 | ld [%g2+%lo(_nwindows)], %g2 |
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| 78 | |
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| 79 | srl %g1, %g2, %g2 |
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| 80 | or %g1, %g2, %g1 |
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| 81 | rd %wim, %g2 |
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| 82 | andcc %g2, %g1, %g0 |
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| 83 | be 1f ! Nope, just return from the trap |
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| 84 | sll %g2, 0x1, %g1 |
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| 85 | |
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| 86 | /* We have to grab a window before returning. */ |
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| 87 | sethi %hi(_nwindows_min1), %g3 !NWINDOWS-1 |
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| 88 | ld [%g3+%lo(_nwindows_min1)], %g3 |
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| 89 | |
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| 90 | srl %g2, %g3, %g2 |
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| 91 | or %g1, %g2, %g1 |
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| 92 | and %g1, 0xff, %g1 |
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| 93 | |
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| 94 | wr %g1, 0x0, %wim |
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| 95 | |
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| 96 | /* Grrr, make sure we load from the right %sp... */ |
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| 97 | PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1) |
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| 98 | |
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| 99 | restore %g0, %g0, %g0 |
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| 100 | RW_LOAD(sp) |
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| 101 | b 2f |
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| 102 | save %g0, %g0, %g0 |
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| 103 | |
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| 104 | /* Reload the entire frame in case this is from a |
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| 105 | * kernel system call or whatever... |
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| 106 | */ |
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| 107 | 1: |
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| 108 | #endif |
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| 109 | PT_LOAD_ALL(sp, t_psr, t_pc, t_npc, g1) |
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| 110 | 2: |
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| 111 | |
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| 112 | #ifdef _FLAT |
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| 113 | restore |
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| 114 | RW_LOAD(sp) |
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| 115 | save |
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| 116 | #endif |
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| 117 | |
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| 118 | wr %t_psr, 0x0, %psr |
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| 119 | nop; nop; nop |
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| 120 | |
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| 121 | jmp %t_pc |
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| 122 | rett %t_npc |
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| 123 | |
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| 124 | |
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| 125 | |
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| 126 | |
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| 127 | |
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| 128 | #ifdef _FLAT |
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| 129 | #warning _FLAT not implemented |
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| 130 | #endif |
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| 131 | |
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| 132 | |
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