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 #endif 37 38 /** 39 * DOC: DC FPU manipulation overview 40 * 41 * DC core uses FPU operations in multiple parts of the code, which requires a 42 * more specialized way to manage these areas' entrance. To fulfill this 43 * requirement, we created some wrapper functions that encapsulate 44 * kernel_fpu_begin/end to better fit our need in the display component. In 45 * summary, in this file, you can find functions related to FPU operation 46 * management. 47 */ 48 49 static DEFINE_PER_CPU(int, fpu_recursion_depth); 50 51 /** 52 * dc_assert_fp_enabled - Check if FPU protection is enabled 53 * 54 * This function tells if the code is already under FPU protection or not. A 55 * function that works as an API for a set of FPU operations can use this 56 * function for checking if the caller invoked it after DC_FP_START(). For 57 * example, take a look at dcn20_fpu.c file. 58 */ 59 inline void dc_assert_fp_enabled(void) 60 { 61 int *pcpu, depth = 0; 62 63 pcpu = get_cpu_ptr(&fpu_recursion_depth); 64 depth = *pcpu; 65 put_cpu_ptr(&fpu_recursion_depth); 66 67 ASSERT(depth >= 1); 68 } 69 70 /** 71 * dc_fpu_begin - Enables FPU protection 72 * @function_name: A string containing the function name for debug purposes 73 * (usually __func__) 74 * 75 * @line: A line number where DC_FP_START was invoked for debug purpose 76 * (usually __LINE__) 77 * 78 * This function is responsible for managing the use of kernel_fpu_begin() with 79 * the advantage of providing an event trace for debugging. 80 * 81 * Note: Do not call this function directly; always use DC_FP_START(). 82 */ 83 void dc_fpu_begin(const char *function_name, const int line) 84 { 85 int *pcpu; 86 87 pcpu = get_cpu_ptr(&fpu_recursion_depth); 88 *pcpu += 1; 89 90 if (*pcpu == 1) { 91 #if defined(CONFIG_X86) 92 migrate_disable(); 93 kernel_fpu_begin(); 94 #elif defined(CONFIG_PPC64) 95 if (cpu_has_feature(CPU_FTR_VSX_COMP)) { 96 preempt_disable(); 97 enable_kernel_vsx(); 98 } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { 99 preempt_disable(); 100 enable_kernel_altivec(); 101 } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { 102 preempt_disable(); 103 enable_kernel_fp(); 104 } 105 #elif defined(CONFIG_ARM64) 106 kernel_neon_begin(); 107 #endif 108 } 109 110 TRACE_DCN_FPU(true, function_name, line, *pcpu); 111 put_cpu_ptr(&fpu_recursion_depth); 112 } 113 114 /** 115 * dc_fpu_end - Disable FPU protection 116 * @function_name: A string containing the function name for debug purposes 117 * @line: A-line number where DC_FP_END was invoked for debug purpose 118 * 119 * This function is responsible for managing the use of kernel_fpu_end() with 120 * the advantage of providing an event trace for debugging. 121 * 122 * Note: Do not call this function directly; always use DC_FP_END(). 123 */ 124 void dc_fpu_end(const char *function_name, const int line) 125 { 126 int *pcpu; 127 128 pcpu = get_cpu_ptr(&fpu_recursion_depth); 129 *pcpu -= 1; 130 if (*pcpu <= 0) { 131 #if defined(CONFIG_X86) 132 kernel_fpu_end(); 133 migrate_enable(); 134 #elif defined(CONFIG_PPC64) 135 if (cpu_has_feature(CPU_FTR_VSX_COMP)) { 136 disable_kernel_vsx(); 137 preempt_enable(); 138 } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { 139 disable_kernel_altivec(); 140 preempt_enable(); 141 } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { 142 disable_kernel_fp(); 143 preempt_enable(); 144 } 145 #elif defined(CONFIG_ARM64) 146 kernel_neon_end(); 147 #endif 148 } 149 150 TRACE_DCN_FPU(false, function_name, line, *pcpu); 151 put_cpu_ptr(&fpu_recursion_depth); 152 } 153