diff options
Diffstat (limited to 'arch/arc/kernel/ctx_sw.c')
| -rw-r--r-- | arch/arc/kernel/ctx_sw.c | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/arch/arc/kernel/ctx_sw.c b/arch/arc/kernel/ctx_sw.c deleted file mode 100644 index 1a76f2d6f694..000000000000 --- a/arch/arc/kernel/ctx_sw.c +++ /dev/null @@ -1,112 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) - * - * Vineetg: Aug 2009 - * -"C" version of lowest level context switch asm macro called by schedular - * gcc doesn't generate the dward CFI info for hand written asm, hence can't - * backtrace out of it (e.g. tasks sleeping in kernel). - * So we cheat a bit by writing almost similar code in inline-asm. - * -This is a hacky way of doing things, but there is no other simple way. - * I don't want/intend to extend unwinding code to understand raw asm - */ - -#include <asm/asm-offsets.h> -#include <linux/sched.h> -#include <linux/sched/debug.h> - -#define KSP_WORD_OFF ((TASK_THREAD + THREAD_KSP) / 4) - -struct task_struct *__sched -__switch_to(struct task_struct *prev_task, struct task_struct *next_task) -{ - unsigned int tmp; - unsigned int prev = (unsigned int)prev_task; - unsigned int next = (unsigned int)next_task; - - __asm__ __volatile__( - /* FP/BLINK save generated by gcc (standard function prologue */ - "st.a r13, [sp, -4] \n\t" - "st.a r14, [sp, -4] \n\t" - "st.a r15, [sp, -4] \n\t" - "st.a r16, [sp, -4] \n\t" - "st.a r17, [sp, -4] \n\t" - "st.a r18, [sp, -4] \n\t" - "st.a r19, [sp, -4] \n\t" - "st.a r20, [sp, -4] \n\t" - "st.a r21, [sp, -4] \n\t" - "st.a r22, [sp, -4] \n\t" - "st.a r23, [sp, -4] \n\t" - "st.a r24, [sp, -4] \n\t" -#ifndef CONFIG_ARC_CURR_IN_REG - "st.a r25, [sp, -4] \n\t" -#else - "sub sp, sp, 4 \n\t" /* usual r25 placeholder */ -#endif - - /* set ksp of outgoing task in tsk->thread.ksp */ -#if KSP_WORD_OFF <= 255 - "st.as sp, [%3, %1] \n\t" -#else - /* - * Workaround for NR_CPUS=4k - * %1 is bigger than 255 (S9 offset for st.as) - */ - "add2 r24, %3, %1 \n\t" - "st sp, [r24] \n\t" -#endif - - /* - * setup _current_task with incoming tsk. - * optionally, set r25 to that as well - * For SMP extra work to get to &_current_task[cpu] - * (open coded SET_CURR_TASK_ON_CPU) - */ -#ifndef CONFIG_SMP - "st %2, [@_current_task] \n\t" -#else - "lr r24, [identity] \n\t" - "lsr r24, r24, 8 \n\t" - "bmsk r24, r24, 7 \n\t" - "add2 r24, @_current_task, r24 \n\t" - "st %2, [r24] \n\t" -#endif -#ifdef CONFIG_ARC_CURR_IN_REG - "mov r25, %2 \n\t" -#endif - - /* get ksp of incoming task from tsk->thread.ksp */ - "ld.as sp, [%2, %1] \n\t" - - /* start loading it's CALLEE reg file */ - -#ifndef CONFIG_ARC_CURR_IN_REG - "ld.ab r25, [sp, 4] \n\t" -#else - "add sp, sp, 4 \n\t" -#endif - "ld.ab r24, [sp, 4] \n\t" - "ld.ab r23, [sp, 4] \n\t" - "ld.ab r22, [sp, 4] \n\t" - "ld.ab r21, [sp, 4] \n\t" - "ld.ab r20, [sp, 4] \n\t" - "ld.ab r19, [sp, 4] \n\t" - "ld.ab r18, [sp, 4] \n\t" - "ld.ab r17, [sp, 4] \n\t" - "ld.ab r16, [sp, 4] \n\t" - "ld.ab r15, [sp, 4] \n\t" - "ld.ab r14, [sp, 4] \n\t" - "ld.ab r13, [sp, 4] \n\t" - - /* last (ret value) = prev : although for ARC it mov r0, r0 */ - "mov %0, %3 \n\t" - - /* FP/BLINK restore generated by gcc (standard func epilogue */ - - : "=r"(tmp) - : "n"(KSP_WORD_OFF), "r"(next), "r"(prev) - : "blink" - ); - - return (struct task_struct *)tmp; -} |