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 #endif 35 36 /** 37 * DOC: DC FPU manipulation overview 38 * 39 * DC core uses FPU operations in multiple parts of the code, which requires a 40 * more specialized way to manage these areas' entrance. To fulfill this 41 * requirement, we created some wrapper functions that encapsulate 42 * kernel_fpu_begin/end to better fit our need in the display component. In 43 * summary, in this file, you can find functions related to FPU operation 44 * management. 45 */ 46 47 static DEFINE_PER_CPU(int, fpu_recursion_depth); 48 49 /** 50 * dc_assert_fp_enabled - Check if FPU protection is enabled 51 * 52 * This function tells if the code is already under FPU protection or not. A 53 * function that works as an API for a set of FPU operations can use this 54 * function for checking if the caller invoked it after DC_FP_START(). For 55 * example, take a look at dcn20_fpu.c file. 56 */ 57 inline void dc_assert_fp_enabled(void) 58 { 59 int *pcpu, depth = 0; 60 61 pcpu = get_cpu_ptr(&fpu_recursion_depth); 62 depth = *pcpu; 63 put_cpu_ptr(&fpu_recursion_depth); 64 65 ASSERT(depth >= 1); 66 } 67 68 /** 69 * dc_fpu_begin - Enables FPU protection 70 * @function_name: A string containing the function name for debug purposes 71 * (usually __func__) 72 * 73 * @line: A line number where DC_FP_START was invoked for debug purpose 74 * (usually __LINE__) 75 * 76 * This function is responsible for managing the use of kernel_fpu_begin() with 77 * the advantage of providing an event trace for debugging. 78 * 79 * Note: Do not call this function directly; always use DC_FP_START(). 80 */ 81 void dc_fpu_begin(const char *function_name, const int line) 82 { 83 int *pcpu; 84 85 pcpu = get_cpu_ptr(&fpu_recursion_depth); 86 *pcpu += 1; 87 88 if (*pcpu == 1) { 89 #if defined(CONFIG_X86) 90 kernel_fpu_begin(); 91 #elif defined(CONFIG_PPC64) 92 if (cpu_has_feature(CPU_FTR_VSX_COMP)) { 93 preempt_disable(); 94 enable_kernel_vsx(); 95 } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { 96 preempt_disable(); 97 enable_kernel_altivec(); 98 } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { 99 preempt_disable(); 100 enable_kernel_fp(); 101 } 102 #endif 103 } 104 105 TRACE_DCN_FPU(true, function_name, line, *pcpu); 106 put_cpu_ptr(&fpu_recursion_depth); 107 } 108 109 /** 110 * dc_fpu_end - Disable FPU protection 111 * @function_name: A string containing the function name for debug purposes 112 * @line: A-line number where DC_FP_END was invoked for debug purpose 113 * 114 * This function is responsible for managing the use of kernel_fpu_end() with 115 * the advantage of providing an event trace for debugging. 116 * 117 * Note: Do not call this function directly; always use DC_FP_END(). 118 */ 119 void dc_fpu_end(const char *function_name, const int line) 120 { 121 int *pcpu; 122 123 pcpu = get_cpu_ptr(&fpu_recursion_depth); 124 *pcpu -= 1; 125 if (*pcpu <= 0) { 126 #if defined(CONFIG_X86) 127 kernel_fpu_end(); 128 #elif defined(CONFIG_PPC64) 129 if (cpu_has_feature(CPU_FTR_VSX_COMP)) { 130 disable_kernel_vsx(); 131 preempt_enable(); 132 } else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { 133 disable_kernel_altivec(); 134 preempt_enable(); 135 } else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { 136 disable_kernel_fp(); 137 preempt_enable(); 138 } 139 #endif 140 } 141 142 TRACE_DCN_FPU(false, function_name, line, *pcpu); 143 put_cpu_ptr(&fpu_recursion_depth); 144 } 145