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 | static DEFINE_PER_CPU(int, fpu_recursion_depth); |
52 | |
53 | /** |
54 | * dc_assert_fp_enabled - Check if FPU protection is enabled |
55 | * |
56 | * This function tells if the code is already under FPU protection or not. A |
57 | * function that works as an API for a set of FPU operations can use this |
58 | * function for checking if the caller invoked it after DC_FP_START(). For |
59 | * example, take a look at dcn20_fpu.c file. |
60 | */ |
61 | inline void dc_assert_fp_enabled(void) |
62 | { |
63 | int depth; |
64 | |
65 | depth = __this_cpu_read(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 depth; |
86 | |
87 | WARN_ON_ONCE(!in_task()); |
88 | preempt_disable(); |
89 | depth = __this_cpu_inc_return(fpu_recursion_depth); |
90 | |
91 | if (depth == 1) { |
92 | #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH) |
93 | kernel_fpu_begin(); |
94 | #elif defined(CONFIG_PPC64) |
95 | if (cpu_has_feature(CPU_FTR_VSX_COMP)) |
96 | enable_kernel_vsx(); |
97 | else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) |
98 | enable_kernel_altivec(); |
99 | else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) |
100 | enable_kernel_fp(); |
101 | #elif defined(CONFIG_ARM64) |
102 | kernel_neon_begin(); |
103 | #endif |
104 | } |
105 | |
106 | TRACE_DCN_FPU(true, function_name, line, 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 depth; |
122 | |
123 | depth = __this_cpu_dec_return(fpu_recursion_depth); |
124 | if (depth == 0) { |
125 | #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH) |
126 | kernel_fpu_end(); |
127 | #elif defined(CONFIG_PPC64) |
128 | if (cpu_has_feature(CPU_FTR_VSX_COMP)) |
129 | disable_kernel_vsx(); |
130 | else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) |
131 | disable_kernel_altivec(); |
132 | else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) |
133 | disable_kernel_fp(); |
134 | #elif defined(CONFIG_ARM64) |
135 | kernel_neon_end(); |
136 | #endif |
137 | } else { |
138 | WARN_ON_ONCE(depth < 0); |
139 | } |
140 | |
141 | TRACE_DCN_FPU(false, function_name, line, depth); |
142 | preempt_enable(); |
143 | } |
144 | |