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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 | /* $Id: r4k_switch.S,v 1.1 1999/12/04 03:59:00 ralf Exp $ * * 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, 1995, 1996, 1998, 1999 by Ralf Baechle * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com) * Copyright (C) 1994, 1995, 1996, by Andreas Busse * Copyright (C) 1999 Silicon Graphics, Inc. */ #include <linux/config.h> #include <asm/asm.h> #include <asm/bootinfo.h> #include <asm/cachectl.h> #include <asm/current.h> #include <asm/fpregdef.h> #include <asm/mipsregs.h> #include <asm/offset.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/processor.h> #include <asm/regdef.h> #include <asm/stackframe.h> #include <asm/asmmacro.h> .set mips3 /* * task_struct *resume(task_struct *prev, task_struct *next) */ .set noreorder .align 5 LEAF(resume) mfc0 t1, CP0_STATUS sd t1, THREAD_STATUS(a0) cpu_save_nonscratch a0 sd ra, THREAD_REG31(a0) /* * The order of restoring the registers takes care of the race * updating $28, $29 and kernelsp without disabling ints. */ move $28, a1 cpu_restore_nonscratch $28 #ifndef CONFIG_SMP daddiu t0, $28, KERNEL_STACK_SIZE-32 sd t0, kernelsp #else mtc0 a1, CP0_WATCHLO dsrl32 a1, a1, 0 mtc0 a1, CP0_WATCHHI #endif mfc0 t1, CP0_STATUS /* Do we really need this? */ li a3, 0xff00 and t1, a3 ld a2, THREAD_STATUS($28) nor a3, $0, a3 and a2, a3 or a2, t1 mtc0 a2, CP0_STATUS jr ra move v0, a0 END(resume) /* * Do lazy fpu context switch. Saves FPU context to the process in a0 * and loads the new context of the current process. */ #define ST_OFF (KERNEL_STACK_SIZE - 32 - PT_SIZE + PT_STATUS) LEAF(lazy_fpu_switch) mfc0 t0, CP0_STATUS # enable cp1 li t3, 0x20000000 or t0, t3 mtc0 t0, CP0_STATUS beqz a0, 2f # Save floating point state nor t3, zero, t3 ld t1, ST_OFF(a0) # last thread looses fpu and t1, t3 sd t1, ST_OFF(a0) sll t2, t1, 5 bgez t2, 1f sdc1 $f0, (THREAD_FPU + 0x00)(a0) fpu_save_16odd a0 1: fpu_save_16even a0 t1 # clobbers t1 2: beqz a1, 3f sll t0, t0, 5 # load new fp state bgez t0, 1f ldc1 $f0, (THREAD_FPU + 0x00)($28) fpu_restore_16odd $28 1: .set reorder fpu_restore_16even $28, t0 # clobbers t0 3: jr ra END(lazy_fpu_switch) /* * Save a thread's fp context. */ .set noreorder LEAF(save_fp) mfc0 t0, CP0_STATUS sll t1, t0, 5 bgez t1, 1f # 16 register mode? nop fpu_save_16odd a0 1: fpu_save_16even a0 t1 # clobbers t1 jr ra sdc1 $f0, (THREAD_FPU + 0x00)(a0) END(save_fp) /* * Load the FPU with signalling NANS. This bit pattern we're using has * the property that no matter whether considered as single or as double * precision represents signaling NANS. * * We initialize fcr31 to rounding to nearest, no exceptions. */ #define FPU_DEFAULT 0x00000000 LEAF(init_fpu) mfc0 t0, CP0_STATUS li t1, 0x20000000 or t0, t1 mtc0 t0, CP0_STATUS sll t0, t0, 5 li t1, FPU_DEFAULT ctc1 t1, fcr31 bgez t0, 1f # 16 / 32 register mode? li t0, -1 dmtc1 t0, $f1 dmtc1 t0, $f3 dmtc1 t0, $f5 dmtc1 t0, $f7 dmtc1 t0, $f9 dmtc1 t0, $f11 dmtc1 t0, $f13 dmtc1 t0, $f15 dmtc1 t0, $f17 dmtc1 t0, $f19 dmtc1 t0, $f21 dmtc1 t0, $f23 dmtc1 t0, $f25 dmtc1 t0, $f27 dmtc1 t0, $f29 dmtc1 t0, $f31 1: dmtc1 t0, $f0 dmtc1 t0, $f2 dmtc1 t0, $f4 dmtc1 t0, $f6 dmtc1 t0, $f8 dmtc1 t0, $f10 dmtc1 t0, $f12 dmtc1 t0, $f14 dmtc1 t0, $f16 dmtc1 t0, $f18 dmtc1 t0, $f20 dmtc1 t0, $f22 dmtc1 t0, $f24 dmtc1 t0, $f26 dmtc1 t0, $f28 jr ra dmtc1 t0, $f30 END(init_fpu) |