David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle |
| 7 | * Copyright (C) 1996 by Paul M. Antoine |
| 8 | * Copyright (C) 1999 Silicon Graphics |
| 9 | * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com |
| 10 | * Copyright (C) 2000 MIPS Technologies, Inc. |
| 11 | */ |
| 12 | #ifndef _ASM_SWITCH_TO_H |
| 13 | #define _ASM_SWITCH_TO_H |
| 14 | |
| 15 | #include <asm/cpu-features.h> |
| 16 | #include <asm/watch.h> |
| 17 | #include <asm/dsp.h> |
Jayachandran C | 2c952e0 | 2013-06-10 06:30:00 +0000 | [diff] [blame] | 18 | #include <asm/cop2.h> |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 19 | #include <asm/msa.h> |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 20 | |
| 21 | struct task_struct; |
| 22 | |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 23 | enum { |
| 24 | FP_SAVE_NONE = 0, |
| 25 | FP_SAVE_VECTOR = -1, |
| 26 | FP_SAVE_SCALAR = 1, |
| 27 | }; |
| 28 | |
Paul Burton | 8c0f8ab | 2013-11-19 17:30:37 +0000 | [diff] [blame] | 29 | /** |
| 30 | * resume - resume execution of a task |
| 31 | * @prev: The task previously executed. |
| 32 | * @next: The task to begin executing. |
| 33 | * @next_ti: task_thread_info(next). |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 34 | * @fp_save: Which, if any, FP context to save for prev. |
Paul Burton | 8c0f8ab | 2013-11-19 17:30:37 +0000 | [diff] [blame] | 35 | * |
| 36 | * This function is used whilst scheduling to save the context of prev & load |
| 37 | * the context of next. Returns prev. |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 38 | */ |
Paul Burton | 8c0f8ab | 2013-11-19 17:30:37 +0000 | [diff] [blame] | 39 | extern asmlinkage struct task_struct *resume(struct task_struct *prev, |
| 40 | struct task_struct *next, struct thread_info *next_ti, |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 41 | s32 fp_save); |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 42 | |
| 43 | extern unsigned int ll_bit; |
| 44 | extern struct task_struct *ll_task; |
| 45 | |
| 46 | #ifdef CONFIG_MIPS_MT_FPAFF |
| 47 | |
| 48 | /* |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 49 | * Handle the scheduler resume end of FPU affinity management. We do this |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 50 | * inline to try to keep the overhead down. If we have been forced to run on |
| 51 | * a "CPU" with an FPU because of a previous high level of FP computation, |
| 52 | * but did not actually use the FPU during the most recent time-slice (CU1 |
| 53 | * isn't set), we undo the restriction on cpus_allowed. |
| 54 | * |
| 55 | * We're not calling set_cpus_allowed() here, because we have no need to |
| 56 | * force prompt migration - we're already switching the current CPU to a |
| 57 | * different thread. |
| 58 | */ |
| 59 | |
| 60 | #define __mips_mt_fpaff_switch_to(prev) \ |
| 61 | do { \ |
| 62 | struct thread_info *__prev_ti = task_thread_info(prev); \ |
| 63 | \ |
| 64 | if (cpu_has_fpu && \ |
| 65 | test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) && \ |
| 66 | (!(KSTK_STATUS(prev) & ST0_CU1))) { \ |
| 67 | clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND); \ |
| 68 | prev->cpus_allowed = prev->thread.user_cpus_allowed; \ |
| 69 | } \ |
| 70 | next->thread.emulated_fp = 0; \ |
| 71 | } while(0) |
| 72 | |
| 73 | #else |
| 74 | #define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0) |
| 75 | #endif |
| 76 | |
| 77 | #define __clear_software_ll_bit() \ |
Markos Chandras | 7c151d3 | 2014-12-03 12:37:32 +0000 | [diff] [blame] | 78 | do { if (cpu_has_rw_llb) { \ |
| 79 | write_c0_lladdr(0); \ |
| 80 | } else { \ |
| 81 | if (!__builtin_constant_p(cpu_has_llsc) || !cpu_has_llsc)\ |
| 82 | ll_bit = 0; \ |
| 83 | } \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 84 | } while (0) |
| 85 | |
Ralf Baechle | 6916ce3 | 2015-07-29 12:14:42 +0200 | [diff] [blame] | 86 | /* |
| 87 | * For newly created kernel threads switch_to() will return to |
| 88 | * ret_from_kernel_thread, newly created user threads to ret_from_fork. |
| 89 | * That is, everything following resume() will be skipped for new threads. |
| 90 | * So everything that matters to new threads should be placed before resume(). |
| 91 | */ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 92 | #define switch_to(prev, next, last) \ |
| 93 | do { \ |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 94 | s32 __fpsave = FP_SAVE_NONE; \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 95 | __mips_mt_fpaff_switch_to(prev); \ |
Ralf Baechle | 6916ce3 | 2015-07-29 12:14:42 +0200 | [diff] [blame] | 96 | if (cpu_has_dsp) { \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 97 | __save_dsp(prev); \ |
Ralf Baechle | 6916ce3 | 2015-07-29 12:14:42 +0200 | [diff] [blame] | 98 | __restore_dsp(next); \ |
| 99 | } \ |
| 100 | if (cop2_present) { \ |
| 101 | set_c0_status(ST0_CU2); \ |
| 102 | if ((KSTK_STATUS(prev) & ST0_CU2)) { \ |
| 103 | if (cop2_lazy_restore) \ |
| 104 | KSTK_STATUS(prev) &= ~ST0_CU2; \ |
| 105 | cop2_save(prev); \ |
| 106 | } \ |
| 107 | if (KSTK_STATUS(next) & ST0_CU2 && \ |
| 108 | !cop2_lazy_restore) { \ |
| 109 | cop2_restore(next); \ |
| 110 | } \ |
| 111 | clear_c0_status(ST0_CU2); \ |
Jayachandran C | 2c952e0 | 2013-06-10 06:30:00 +0000 | [diff] [blame] | 112 | } \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 113 | __clear_software_ll_bit(); \ |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 114 | if (test_and_clear_tsk_thread_flag(prev, TIF_USEDFPU)) \ |
| 115 | __fpsave = FP_SAVE_SCALAR; \ |
| 116 | if (test_and_clear_tsk_thread_flag(prev, TIF_USEDMSA)) \ |
| 117 | __fpsave = FP_SAVE_VECTOR; \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 118 | if (cpu_has_userlocal) \ |
Ralf Baechle | 6916ce3 | 2015-07-29 12:14:42 +0200 | [diff] [blame] | 119 | write_c0_userlocal(task_thread_info(next)->tp_value); \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 120 | __restore_watch(); \ |
Ralf Baechle | 9cc719a | 2015-05-23 01:20:19 +0200 | [diff] [blame] | 121 | disable_msa(); \ |
Ralf Baechle | 6916ce3 | 2015-07-29 12:14:42 +0200 | [diff] [blame] | 122 | (last) = resume(prev, next, task_thread_info(next), __fpsave); \ |
David Howells | b81947c | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 123 | } while (0) |
| 124 | |
| 125 | #endif /* _ASM_SWITCH_TO_H */ |