| 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // CtxSwitch-x86_64.S -- |
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| 8 | // |
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| 9 | // Author : Thierry Delisle |
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| 10 | // Created On : Mon Nov 28 12:27:26 2016 |
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| 11 | // Last Modified By : Peter A. Buhr |
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| 12 | // Last Modified On : Fri Jul 21 22:28:11 2017 |
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| 13 | // Update Count : 1 |
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| 14 | // |
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| 15 | // This library is free software; you can redistribute it and/or modify it |
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| 16 | // under the terms of the GNU Lesser General Public License as published by the |
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| 17 | // Free Software Foundation; either version 2.1 of the License, or (at your |
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| 18 | // option) any later version. |
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| 19 | // |
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| 20 | // This library is distributed in the hope that it will be useful, but WITHOUT |
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| 21 | // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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| 22 | // FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
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| 23 | // for more details. |
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| 24 | // |
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| 25 | // You should have received a copy of the GNU Lesser General Public License |
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| 26 | // along with this library. |
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| 27 | // |
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| 28 | |
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| 29 | // This context switch routine depends on the fact that the stack of a new |
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| 30 | // thread has been set up to look like the thread has saved its context in |
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| 31 | // the normal manner. |
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| 32 | // |
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| 33 | // void CtxSwitch( machine_context *from, machine_context *to ); |
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| 34 | |
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| 35 | // Offsets in the context structure. This needs to be synchronized with the |
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| 36 | // high level code a little better. |
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| 37 | |
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| 38 | #define PTR_BYTE 8 |
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| 39 | #define SP_OFFSET ( 0 * PTR_BYTE ) |
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| 40 | #define FP_OFFSET ( 1 * PTR_BYTE ) |
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| 41 | |
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| 42 | //----------------------------------------------------------------------------- |
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| 43 | // Regular context switch routine which enables switching from one context to anouther |
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| 44 | .text |
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| 45 | .align 2 |
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| 46 | .globl __cfactx_switch |
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| 47 | .type __cfactx_switch, @function |
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| 48 | __cfactx_switch: |
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| 49 | |
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| 50 | // Save volatile registers on the stack. |
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| 51 | |
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| 52 | pushq %r15 |
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| 53 | pushq %r14 |
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| 54 | pushq %r13 |
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| 55 | pushq %r12 |
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| 56 | pushq %rbx |
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| 57 | |
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| 58 | // Save old context in the "from" area. |
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| 59 | |
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| 60 | movq %rsp,SP_OFFSET(%rdi) |
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| 61 | movq %rbp,FP_OFFSET(%rdi) |
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| 62 | |
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| 63 | // Load new context from the "to" area. |
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| 64 | |
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| 65 | movq SP_OFFSET(%rsi),%rsp |
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| 66 | movq FP_OFFSET(%rsi),%rbp |
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| 67 | |
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| 68 | // Load volatile registers from the stack. |
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| 69 | |
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| 70 | popq %rbx |
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| 71 | popq %r12 |
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| 72 | popq %r13 |
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| 73 | popq %r14 |
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| 74 | popq %r15 |
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| 75 | |
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| 76 | // Return to thread. |
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| 77 | |
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| 78 | ret |
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| 79 | .size __cfactx_switch, .-__cfactx_switch |
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| 80 | |
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| 81 | //----------------------------------------------------------------------------- |
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| 82 | // Stub used to create new stacks which are ready to be context switched to |
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| 83 | .text |
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| 84 | .align 2 |
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| 85 | .globl __cfactx_invoke_stub |
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| 86 | .type __cfactx_invoke_stub, @function |
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| 87 | __cfactx_invoke_stub: |
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| 88 | movq %rbx, %rdi |
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| 89 | movq %r12, %rsi |
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| 90 | jmp *%r13 |
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| 91 | .size __cfactx_invoke_stub, .-__cfactx_invoke_stub |
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| 92 | |
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| 93 | // Local Variables: // |
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| 94 | // mode: c // |
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| 95 | // tab-width: 4 // |
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| 96 | // End: // |
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