1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright 2021 Advanced Micro Devices, Inc. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a 6 * copy of this software and associated documentation files (the "Software"), 7 * to deal in the Software without restriction, including without limitation 8 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 9 * and/or sell copies of the Software, and to permit persons to whom the 10 * Software is furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be included in 13 * all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 21 * OTHER DEALINGS IN THE SOFTWARE. 22 * 23 * Authors: AMD 24 * 25 */ 26 27 #include "dc_trace.h" 28 29 #if defined(CONFIG_X86) 30 #include <asm/fpu/api.h> 31 #elif defined(CONFIG_PPC64) 32 #include <asm/switch_to.h> 33 #include <asm/cputable.h> 34 #elif defined(CONFIG_ARM64) 35 #include <asm/neon.h> 36 #elif defined(CONFIG_LOONGARCH) 37 #include <asm/fpu.h> 38 #endif 39 40 /** 41 * DOC: DC FPU manipulation overview 42 * 43 * DC core uses FPU operations in multiple parts of the code, which requires a 44 * more specialized way to manage these areas' entrance. To fulfill this 45 * requirement, we created some wrapper functions that encapsulate 46 * kernel_fpu_begin/end to better fit our need in the display component. In 47 * summary, in this file, you can find functions related to FPU operation 48 * management. 49 */ 50 51 #ifdef notyet 52 static DEFINE_PER_CPU(int, fpu_recursion_depth); 53 #else 54 static int fpu_recursion_depth; 55 56 #define get_cpu_ptr(x) (x) 57 #define put_cpu_ptr(x) do {} while(0) 58 #endif 59 60 /** 61 * dc_assert_fp_enabled - Check if FPU protection is enabled 62 * 63 * This function tells if the code is already under FPU protection or not. A 64 * function that works as an API for a set of FPU operations can use this 65 * function for checking if the caller invoked it after DC_FP_START(). For 66 * example, take a look at dcn20_fpu.c file. 67 */ 68 void dc_assert_fp_enabled(void) 69 { 70 int *pcpu, depth = 0; 71 72 pcpu = get_cpu_ptr(&fpu_recursion_depth); 73 depth = *pcpu; 74 put_cpu_ptr(&fpu_recursion_depth); 75 76 ASSERT(depth >= 1); 77 } 78 79 /** 80 * dc_fpu_begin - Enables FPU protection 81 * @function_name: A string containing the function name for debug purposes 82 * (usually __func__) 83 * 84 * @line: A line number where DC_FP_START was invoked for debug purpose 85 * (usually __LINE__) 86 * 87 * This function is responsible for managing the use of kernel_fpu_begin() with 88 * the advantage of providing an event trace for debugging. 89 * 90 * Note: Do not call this function directly; always use DC_FP_START(). 91 */ 92 void dc_fpu_begin(const char *function_name, const int line) 93 { 94 int *pcpu; 95 96 pcpu = get_cpu_ptr(&fpu_recursion_depth); 97 *pcpu += 1; 98 99 if (*pcpu == 1) { 100 #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH) 101 migrate_disable(); 102 kernel_fpu_begin(); 103 #elif defined(CONFIG_PPC64) 104 if (cpu_has_feature(CPU_FTR_VSX_COMP)) { 105 preempt_disable(); 106 enable_kernel_vsx(); 107 } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { 108 preempt_disable(); 109 enable_kernel_altivec(); 110 } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { 111 preempt_disable(); 112 enable_kernel_fp(); 113 } 114 #elif defined(CONFIG_ARM64) 115 kernel_neon_begin(); 116 #endif 117 } 118 119 TRACE_DCN_FPU(true, function_name, line, *pcpu); 120 put_cpu_ptr(&fpu_recursion_depth); 121 } 122 123 /** 124 * dc_fpu_end - Disable FPU protection 125 * @function_name: A string containing the function name for debug purposes 126 * @line: A-line number where DC_FP_END was invoked for debug purpose 127 * 128 * This function is responsible for managing the use of kernel_fpu_end() with 129 * the advantage of providing an event trace for debugging. 130 * 131 * Note: Do not call this function directly; always use DC_FP_END(). 132 */ 133 void dc_fpu_end(const char *function_name, const int line) 134 { 135 int *pcpu; 136 137 pcpu = get_cpu_ptr(&fpu_recursion_depth); 138 *pcpu -= 1; 139 if (*pcpu <= 0) { 140 #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH) 141 kernel_fpu_end(); 142 migrate_enable(); 143 #elif defined(CONFIG_PPC64) 144 if (cpu_has_feature(CPU_FTR_VSX_COMP)) { 145 disable_kernel_vsx(); 146 preempt_enable(); 147 } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { 148 disable_kernel_altivec(); 149 preempt_enable(); 150 } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { 151 disable_kernel_fp(); 152 preempt_enable(); 153 } 154 #elif defined(CONFIG_ARM64) 155 kernel_neon_end(); 156 #endif 157 } 158 159 TRACE_DCN_FPU(false, function_name, line, *pcpu); 160 put_cpu_ptr(&fpu_recursion_depth); 161 } 162