1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2020 Val Packett <val@packett.cool> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 16 * 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 AUTHORS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/types.h> 29 #include <sys/param.h> 30 #include <sys/proc.h> 31 #include <sys/kernel.h> 32 33 #include <linux/compat.h> 34 #include <linux/sched.h> 35 36 #include <asm/fpu/api.h> 37 38 #ifdef LKPI_HAVE_FPU_CTX 39 40 #include <machine/fpu.h> 41 42 /* 43 * Technically the Linux API isn't supposed to allow nesting sections 44 * either, but currently used versions of GPU drivers rely on nesting 45 * working, so we only enter the section on the outermost level. 46 */ 47 48 void 49 lkpi_kernel_fpu_begin(void) 50 { 51 int err; 52 53 if ((current->fpu_ctx_level)++ == 0) { 54 err = linux_set_fpu_ctx(current); 55 fpu_kern_enter(curthread, current->fpu_ctx, 56 err == 0 ? FPU_KERN_KTHR : FPU_KERN_NOCTX); 57 } 58 } 59 60 void 61 lkpi_kernel_fpu_end(void) 62 { 63 if (--(current->fpu_ctx_level) == 0) 64 fpu_kern_leave(curthread, current->fpu_ctx); 65 } 66 67 #else 68 69 void 70 lkpi_kernel_fpu_begin(void) 71 { 72 } 73 74 void 75 lkpi_kernel_fpu_end(void) 76 { 77 } 78 79 #endif 80