1 /* 2 * Copyright (c) 2015, Linaro Limited 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 * POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <arm.h> 29 #include <kernel/vfp.h> 30 #include "vfp_private.h" 31 #include <assert.h> 32 33 bool vfp_is_enabled(void) 34 { 35 return !!(vfp_read_fpexc() & FPEXC_EN); 36 } 37 38 static bool instr_match_cp10_cp11(uint32_t instr, uint32_t mask) 39 { 40 if ((instr & mask) == mask) { 41 uint32_t coprocessor = instr & 0xf0; 42 43 if (coprocessor == 10 || coprocessor == 11) 44 return true; 45 } 46 return false; 47 } 48 49 bool vfp_is_vpfinstr(uint32_t instr, uint32_t spsr) 50 { 51 52 53 if (spsr & CPSR_T) { 54 /* Thumb mode */ 55 return instr_match_cp10_cp11(instr, 0xec000000) || 56 ((instr & 0xef000000) == 0xef000000) || 57 ((instr & 0xff100000) == 0xf9000000); 58 } else { 59 /* ARM mode */ 60 return instr_match_cp10_cp11(instr, 0x0c000000) || 61 ((instr & 0xfe000000) == 0xf2000000) || 62 ((instr & 0xff100000) == 0xf4000000); 63 } 64 } 65 66 void vfp_enable(void) 67 { 68 vfp_write_fpexc(vfp_read_fpexc() | FPEXC_EN); 69 } 70 71 void vfp_disable(void) 72 { 73 vfp_write_fpexc(vfp_read_fpexc() & ~FPEXC_EN); 74 } 75 76 void vfp_lazy_save_state_init(struct vfp_state *state) 77 { 78 uint32_t fpexc = vfp_read_fpexc(); 79 80 state->fpexc = fpexc; 81 vfp_write_fpexc(fpexc & ~FPEXC_EN); 82 } 83 84 void vfp_lazy_save_state_final(struct vfp_state *state) 85 { 86 if (state->fpexc & FPEXC_EN) { 87 uint32_t fpexc = vfp_read_fpexc(); 88 89 assert(!(fpexc & FPEXC_EN)); 90 vfp_write_fpexc(fpexc | FPEXC_EN); 91 state->fpscr = vfp_read_fpscr(); 92 vfp_save_extension_regs(state->reg); 93 vfp_write_fpexc(fpexc); 94 } 95 } 96 97 void vfp_lazy_restore_state(struct vfp_state *state, bool full_state) 98 { 99 100 if (full_state) { 101 /* 102 * Only restore VFP registers if they been touched as they 103 * otherwise are intact. 104 */ 105 106 /* FPEXC is restored to what's in state->fpexc below */ 107 vfp_write_fpexc(vfp_read_fpexc() | FPEXC_EN); 108 109 vfp_write_fpscr(state->fpscr); 110 vfp_restore_extension_regs(state->reg); 111 } 112 vfp_write_fpexc(state->fpexc); 113 } 114