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 void vfp_enable(void) 39 { 40 vfp_write_fpexc(vfp_read_fpexc() | FPEXC_EN); 41 } 42 43 void vfp_disable(void) 44 { 45 vfp_write_fpexc(vfp_read_fpexc() & ~FPEXC_EN); 46 } 47 48 void vfp_lazy_save_state_init(struct vfp_state *state) 49 { 50 uint32_t fpexc = vfp_read_fpexc(); 51 52 state->fpexc = fpexc; 53 vfp_write_fpexc(fpexc & ~FPEXC_EN); 54 } 55 56 void vfp_lazy_save_state_final(struct vfp_state *state) 57 { 58 if (state->fpexc & FPEXC_EN) { 59 uint32_t fpexc = vfp_read_fpexc(); 60 61 assert(!(fpexc & FPEXC_EN)); 62 vfp_write_fpexc(fpexc | FPEXC_EN); 63 state->fpscr = vfp_read_fpscr(); 64 vfp_save_extension_regs(state->reg); 65 vfp_write_fpexc(fpexc); 66 } 67 } 68 69 void vfp_lazy_restore_state(struct vfp_state *state, bool full_state) 70 { 71 72 if (full_state) { 73 /* 74 * Only restore VFP registers if they been touched as they 75 * otherwise are intact. 76 */ 77 78 /* FPEXC is restored to what's in state->fpexc below */ 79 vfp_write_fpexc(vfp_read_fpexc() | FPEXC_EN); 80 81 vfp_write_fpscr(state->fpscr); 82 vfp_restore_extension_regs(state->reg); 83 } 84 vfp_write_fpexc(state->fpexc); 85 } 86