projects / mirror_ubuntu-hirsute-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| bf90e1ea VG |
1 | /* |
| 2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or modify | |
| 5 | * it under the terms of the GNU General Public License version 2 as | |
| 6 | * published by the Free Software Foundation. | |
| 7 | * | |
| 8 | * Vineetg: Aug 2009 | |
| 9 | * -Moved core context switch macro out of entry.S into this file. | |
| 10 | * -This is the more "natural" hand written assembler | |
| 11 | */ | |
| 12 | ||
| 13 | #include <asm/entry.h> /* For the SAVE_* macros */ | |
| 14 | #include <asm/asm-offsets.h> | |
| 15 | #include <asm/linkage.h> | |
| 16 | ||
| 17 | ;################### Low Level Context Switch ########################## | |
| 18 | ||
| 19 | .section .sched.text,"ax",@progbits | |
| 20 | .align 4 | |
| 21 | .global __switch_to | |
| 22 | .type __switch_to, @function | |
| 23 | __switch_to: | |
| 24 | ||
| 25 | /* Save regs on kernel mode stack of task */ | |
| 26 | st.a blink, [sp, -4] | |
| 27 | st.a fp, [sp, -4] | |
| 28 | SAVE_CALLEE_SAVED_KERNEL | |
| 29 | ||
| 30 | /* Save the now KSP in task->thread.ksp */ | |
| 31 | st.as sp, [r0, (TASK_THREAD + THREAD_KSP)/4] | |
| 32 | ||
| 33 | /* | |
| 34 | * Return last task in r0 (return reg) | |
| 35 | * On ARC, Return reg = First Arg reg = r0. | |
| 36 | * Since we already have last task in r0, | |
| 37 | * don't need to do anything special to return it | |
| 38 | */ | |
| 39 | ||
| 40 | /* hardware memory barrier */ | |
| 41 | sync | |
| 42 | ||
| 43 | /* | |
| 44 | * switch to new task, contained in r1 | |
| 45 | * Temp reg r3 is required to get the ptr to store val | |
| 46 | */ | |
| 47 | SET_CURR_TASK_ON_CPU r1, r3 | |
| 48 | ||
| 49 | /* reload SP with kernel mode stack pointer in task->thread.ksp */ | |
| 50 | ld.as sp, [r1, (TASK_THREAD + THREAD_KSP)/4] | |
| 51 | ||
| 52 | /* restore the registers */ | |
| 53 | RESTORE_CALLEE_SAVED_KERNEL | |
| 54 | ld.ab fp, [sp, 4] | |
| 55 | ld.ab blink, [sp, 4] | |
| 56 | j [blink] | |
| 57 | ||
| 58 | ARC_EXIT __switch_to |