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Diffstat (limited to 'arch/mips/include/asm/switch_to.h')
| -rw-r--r-- | arch/mips/include/asm/switch_to.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h new file mode 100644 index 000000000000..5d33621b5658 --- /dev/null +++ b/arch/mips/include/asm/switch_to.h @@ -0,0 +1,85 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle + * Copyright (C) 1996 by Paul M. Antoine + * Copyright (C) 1999 Silicon Graphics + * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com + * Copyright (C) 2000 MIPS Technologies, Inc. + */ +#ifndef _ASM_SWITCH_TO_H +#define _ASM_SWITCH_TO_H + +#include <asm/cpu-features.h> +#include <asm/watch.h> +#include <asm/dsp.h> + +struct task_struct; + +/* + * switch_to(n) should switch tasks to task nr n, first + * checking that n isn't the current task, in which case it does nothing. + */ +extern asmlinkage void *resume(void *last, void *next, void *next_ti); + +extern unsigned int ll_bit; +extern struct task_struct *ll_task; + +#ifdef CONFIG_MIPS_MT_FPAFF + +/* + * Handle the scheduler resume end of FPU affinity management. We do this + * inline to try to keep the overhead down. If we have been forced to run on + * a "CPU" with an FPU because of a previous high level of FP computation, + * but did not actually use the FPU during the most recent time-slice (CU1 + * isn't set), we undo the restriction on cpus_allowed. + * + * We're not calling set_cpus_allowed() here, because we have no need to + * force prompt migration - we're already switching the current CPU to a + * different thread. + */ + +#define __mips_mt_fpaff_switch_to(prev) \ +do { \ + struct thread_info *__prev_ti = task_thread_info(prev); \ + \ + if (cpu_has_fpu && \ + test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) && \ + (!(KSTK_STATUS(prev) & ST0_CU1))) { \ + clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND); \ + prev->cpus_allowed = prev->thread.user_cpus_allowed; \ + } \ + next->thread.emulated_fp = 0; \ +} while(0) + +#else +#define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0) +#endif + +#define __clear_software_ll_bit() \ +do { \ + if (!__builtin_constant_p(cpu_has_llsc) || !cpu_has_llsc) \ + ll_bit = 0; \ +} while (0) + +#define switch_to(prev, next, last) \ +do { \ + __mips_mt_fpaff_switch_to(prev); \ + if (cpu_has_dsp) \ + __save_dsp(prev); \ + __clear_software_ll_bit(); \ + (last) = resume(prev, next, task_thread_info(next)); \ +} while (0) + +#define finish_arch_switch(prev) \ +do { \ + if (cpu_has_dsp) \ + __restore_dsp(current); \ + if (cpu_has_userlocal) \ + write_c0_userlocal(current_thread_info()->tp_value); \ + __restore_watch(); \ +} while (0) + +#endif /* _ASM_SWITCH_TO_H */ |