| Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2008 Travis Geiselbrecht |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files |
| 6 | * (the "Software"), to deal in the Software without restriction, |
| 7 | * including without limitation the rights to use, copy, modify, merge, |
| 8 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 9 | * and to permit persons to whom the Software is furnished to do so, |
| 10 | * subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 19 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 20 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 21 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 22 | */ |
| 23 | #include <asm.h> |
| 24 | |
| 25 | |
| 26 | /* context switch frame is as follows: |
| 27 | * ulr |
| 28 | * usp |
| 29 | * lr |
| 30 | * r11 |
| 31 | * r10 |
| 32 | * r9 |
| 33 | * r8 |
| 34 | * r7 |
| 35 | * r6 |
| 36 | * r5 |
| 37 | * r4 |
| 38 | */ |
| 39 | /* arm_context_switch(addr_t *old_sp, addr_t new_sp) */ |
| 40 | FUNCTION(arm_context_switch) |
| 41 | /* save all the usual registers + user regs */ |
| 42 | /* the spsr is saved and restored in the iframe by exceptions.S */ |
| 43 | sub r3, sp, #(11*4) /* can't use sp in user mode stm */ |
| 44 | mov r12, lr |
| 45 | stmia r3, { r4-r11, r12, r13, r14 }^ |
| 46 | |
| 47 | /* save old sp */ |
| 48 | str r3, [r0] |
| 49 | |
| Travis Geiselbrecht | 8d529ef | 2008-09-13 15:13:21 -0700 | [diff] [blame] | 50 | /* clear any exlusive locks that the old thread holds */ |
| 51 | #if ARM_ISA_ARMV7 |
| 52 | /* can clear it directly */ |
| 53 | .word 0xf57ff01f // clrex |
| 54 | #elif ARM_ISA_ARMV6 |
| 55 | /* have to do a fake strex to clear it */ |
| 56 | ldr r0, =strex_spot |
| 57 | strex r3, r2, [r0] |
| 58 | #endif |
| 59 | |
| Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 60 | /* load new regs */ |
| 61 | ldmia r1, { r4-r11, r12, r13, r14 }^ |
| 62 | mov lr, r12 /* restore lr */ |
| 63 | add sp, r1, #(11*4) /* restore sp */ |
| 64 | bx lr |
| 65 | |
| Travis Geiselbrecht | 8d529ef | 2008-09-13 15:13:21 -0700 | [diff] [blame] | 66 | .ltorg |
| 67 | |
| Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 68 | FUNCTION(arm_save_mode_regs) |
| 69 | mrs r1, cpsr |
| 70 | |
| 71 | #if ARM_ISA_ARMv6 |
| 72 | cps #0x11 /* fiq */ |
| 73 | str r13, [r0], #4 |
| 74 | str r14, [r0], #4 |
| 75 | cps #0x12 /* irq */ |
| 76 | str r13, [r0], #4 |
| 77 | str r14, [r0], #4 |
| 78 | cps #0x13 /* svc */ |
| 79 | str r13, [r0], #4 |
| 80 | str r14, [r0], #4 |
| 81 | cps #0x17 /* abt */ |
| 82 | str r13, [r0], #4 |
| 83 | str r14, [r0], #4 |
| 84 | cps #0x1b /* und */ |
| 85 | str r13, [r0], #4 |
| 86 | str r14, [r0], #4 |
| 87 | cps #0x1f /* sys */ |
| 88 | str r13, [r0], #4 |
| 89 | str r14, [r0], #4 |
| 90 | #else |
| 91 | // XXX implement |
| 92 | b . |
| 93 | #endif |
| 94 | |
| Travis Geiselbrecht | 09eeebd | 2009-01-19 23:59:16 -0800 | [diff] [blame] | 95 | msr cpsr_c, r1 |
| Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 96 | |
| 97 | bx lr |
| 98 | |
| Travis Geiselbrecht | 8d529ef | 2008-09-13 15:13:21 -0700 | [diff] [blame] | 99 | .data |
| 100 | strex_spot: |
| 101 | .word 0 |
| Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 102 | |
| 103 | |