kernel/drivers/gpu/drm/amd/display/amdgpu_dm/dc_fpu.c
2024-07-22 17:22:30 +08:00

145 lines
4.4 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright 2021 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: AMD
*
*/
#include "dc_trace.h"
#if defined(CONFIG_X86)
#include <asm/fpu/api.h>
#elif defined(CONFIG_PPC64)
#include <asm/switch_to.h>
#include <asm/cputable.h>
#endif
/**
* DOC: DC FPU manipulation overview
*
* DC core uses FPU operations in multiple parts of the code, which requires a
* more specialized way to manage these areas' entrance. To fulfill this
* requirement, we created some wrapper functions that encapsulate
* kernel_fpu_begin/end to better fit our need in the display component. In
* summary, in this file, you can find functions related to FPU operation
* management.
*/
static DEFINE_PER_CPU(int, fpu_recursion_depth);
/**
* dc_assert_fp_enabled - Check if FPU protection is enabled
*
* This function tells if the code is already under FPU protection or not. A
* function that works as an API for a set of FPU operations can use this
* function for checking if the caller invoked it after DC_FP_START(). For
* example, take a look at dcn20_fpu.c file.
*/
inline void dc_assert_fp_enabled(void)
{
int *pcpu, depth = 0;
pcpu = get_cpu_ptr(&fpu_recursion_depth);
depth = *pcpu;
put_cpu_ptr(&fpu_recursion_depth);
ASSERT(depth >= 1);
}
/**
* dc_fpu_begin - Enables FPU protection
* @function_name: A string containing the function name for debug purposes
* (usually __func__)
*
* @line: A line number where DC_FP_START was invoked for debug purpose
* (usually __LINE__)
*
* This function is responsible for managing the use of kernel_fpu_begin() with
* the advantage of providing an event trace for debugging.
*
* Note: Do not call this function directly; always use DC_FP_START().
*/
void dc_fpu_begin(const char *function_name, const int line)
{
int *pcpu;
pcpu = get_cpu_ptr(&fpu_recursion_depth);
*pcpu += 1;
if (*pcpu == 1) {
#if defined(CONFIG_X86)
kernel_fpu_begin();
#elif defined(CONFIG_PPC64)
if (cpu_has_feature(CPU_FTR_VSX_COMP)) {
preempt_disable();
enable_kernel_vsx();
} else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) {
preempt_disable();
enable_kernel_altivec();
} else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) {
preempt_disable();
enable_kernel_fp();
}
#endif
}
TRACE_DCN_FPU(true, function_name, line, *pcpu);
put_cpu_ptr(&fpu_recursion_depth);
}
/**
* dc_fpu_end - Disable FPU protection
* @function_name: A string containing the function name for debug purposes
* @line: A-line number where DC_FP_END was invoked for debug purpose
*
* This function is responsible for managing the use of kernel_fpu_end() with
* the advantage of providing an event trace for debugging.
*
* Note: Do not call this function directly; always use DC_FP_END().
*/
void dc_fpu_end(const char *function_name, const int line)
{
int *pcpu;
pcpu = get_cpu_ptr(&fpu_recursion_depth);
*pcpu -= 1;
if (*pcpu <= 0) {
#if defined(CONFIG_X86)
kernel_fpu_end();
#elif defined(CONFIG_PPC64)
if (cpu_has_feature(CPU_FTR_VSX_COMP)) {
disable_kernel_vsx();
preempt_enable();
} else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) {
disable_kernel_altivec();
preempt_enable();
} else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) {
disable_kernel_fp();
preempt_enable();
}
#endif
}
TRACE_DCN_FPU(false, function_name, line, *pcpu);
put_cpu_ptr(&fpu_recursion_depth);
}