1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * FPU support code, moved here from head.S so that it can be used 4 * by chips which use other head-whatever.S files. 5 * 6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 7 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> 8 * Copyright (C) 1996 Paul Mackerras. 9 * Copyright (C) 1997 Dan Malek (dmalek@jlc.net). 10 */ 11 12 #include <linux/export.h> 13 #include <asm/reg.h> 14 #include <asm/page.h> 15 #include <asm/mmu.h> 16 #include <asm/cputable.h> 17 #include <asm/cache.h> 18 #include <asm/thread_info.h> 19 #include <asm/ppc_asm.h> 20 #include <asm/asm-offsets.h> 21 #include <asm/ptrace.h> 22 #include <asm/asm-compat.h> 23 #include <asm/feature-fixups.h> 24 25 #ifdef CONFIG_VSX 26 #define __REST_1FPVSR(n,c,base) \ 27 BEGIN_FTR_SECTION \ 28 b 2f; \ 29 END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ 30 REST_FPR(n,base); \ 31 b 3f; \ 32 2: REST_VSR(n,c,base); \ 33 3: 34 35 #define __REST_32FPVSRS(n,c,base) \ 36 BEGIN_FTR_SECTION \ 37 b 2f; \ 38 END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ 39 REST_32FPRS(n,base); \ 40 b 3f; \ 41 2: REST_32VSRS(n,c,base); \ 42 3: 43 44 #define __SAVE_32FPVSRS(n,c,base) \ 45 BEGIN_FTR_SECTION \ 46 b 2f; \ 47 END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ 48 SAVE_32FPRS(n,base); \ 49 b 3f; \ 50 2: SAVE_32VSRS(n,c,base); \ 51 3: 52 #else 53 #define __REST_1FPVSR(n,b,base) REST_FPR(n, base) 54 #define __REST_32FPVSRS(n,b,base) REST_32FPRS(n, base) 55 #define __SAVE_32FPVSRS(n,b,base) SAVE_32FPRS(n, base) 56 #endif 57 #define REST_1FPVSR(n,c,base) __REST_1FPVSR(n,__REG_##c,__REG_##base) 58 #define REST_32FPVSRS(n,c,base) __REST_32FPVSRS(n,__REG_##c,__REG_##base) 59 #define SAVE_32FPVSRS(n,c,base) __SAVE_32FPVSRS(n,__REG_##c,__REG_##base) 60 61 /* 62 * Load state from memory into FP registers including FPSCR. 63 * Assumes the caller has enabled FP in the MSR. 64 */ 65 _GLOBAL(load_fp_state) 66 lfd fr0,FPSTATE_FPSCR(r3) 67 MTFSF_L(fr0) 68 REST_32FPVSRS(0, R4, R3) 69 blr 70 EXPORT_SYMBOL(load_fp_state) 71 _ASM_NOKPROBE_SYMBOL(load_fp_state); /* used by restore_math */ 72 73 /* 74 * Store FP state into memory, including FPSCR 75 * Assumes the caller has enabled FP in the MSR. 76 */ 77 _GLOBAL(store_fp_state) 78 SAVE_32FPVSRS(0, R4, R3) 79 mffs fr0 80 stfd fr0,FPSTATE_FPSCR(r3) 81 REST_1FPVSR(0, R4, R3) 82 blr 83 EXPORT_SYMBOL(store_fp_state) 84 85 /* 86 * This task wants to use the FPU now. 87 * On UP, disable FP for the task which had the FPU previously, 88 * and save its floating-point registers in its thread_struct. 89 * Load up this task's FP registers from its thread_struct, 90 * enable the FPU for the current task and return to the task. 91 * Note that on 32-bit this can only use registers that will be 92 * restored by fast_exception_return, i.e. r3 - r6, r10 and r11. 93 */ 94 _GLOBAL(load_up_fpu) 95 mfmsr r5 96 #ifdef CONFIG_PPC_BOOK3S_64 97 /* interrupt doesn't set MSR[RI] and HPT can fault on current access */ 98 ori r5,r5,MSR_FP|MSR_RI 99 #else 100 ori r5,r5,MSR_FP 101 #endif 102 #ifdef CONFIG_VSX 103 BEGIN_FTR_SECTION 104 oris r5,r5,MSR_VSX@h 105 END_FTR_SECTION_IFSET(CPU_FTR_VSX) 106 #endif 107 MTMSRD(r5) /* enable use of fpu now */ 108 isync 109 /* enable use of FP after return */ 110 #ifdef CONFIG_PPC32 111 addi r5,r2,THREAD 112 lwz r4,THREAD_FPEXC_MODE(r5) 113 ori r9,r9,MSR_FP /* enable FP for current */ 114 or r9,r9,r4 115 #else 116 ld r4,PACACURRENT(r13) 117 addi r5,r4,THREAD /* Get THREAD */ 118 lwz r4,THREAD_FPEXC_MODE(r5) 119 ori r12,r12,MSR_FP 120 or r12,r12,r4 121 std r12,_MSR(r1) 122 #ifdef CONFIG_PPC_BOOK3S_64 123 li r4,0 124 stb r4,PACASRR_VALID(r13) 125 #endif 126 #endif 127 li r4,1 128 stb r4,THREAD_LOAD_FP(r5) 129 addi r10,r5,THREAD_FPSTATE 130 lfd fr0,FPSTATE_FPSCR(r10) 131 MTFSF_L(fr0) 132 REST_32FPVSRS(0, R4, R10) 133 /* restore registers and return */ 134 /* we haven't used ctr or xer or lr */ 135 blr 136 _ASM_NOKPROBE_SYMBOL(load_up_fpu) 137 138 /* 139 * save_fpu(tsk) 140 * Save the floating-point registers in its thread_struct. 141 * Enables the FPU for use in the kernel on return. 142 */ 143 _GLOBAL(save_fpu) 144 addi r3,r3,THREAD /* want THREAD of task */ 145 PPC_LL r6,THREAD_FPSAVEAREA(r3) 146 PPC_LL r5,PT_REGS(r3) 147 PPC_LCMPI 0,r6,0 148 bne 2f 149 addi r6,r3,THREAD_FPSTATE 150 2: SAVE_32FPVSRS(0, R4, R6) 151 mffs fr0 152 stfd fr0,FPSTATE_FPSCR(r6) 153 REST_1FPVSR(0, R4, R6) 154 blr
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