// 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"
#include <linux/fpu.h>
/**
* 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 depth;
depth = __this_cpu_read(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 depth;
WARN_ON_ONCE(!in_task());
preempt_disable();
depth = __this_cpu_inc_return(fpu_recursion_depth);
if (depth == 1) {
BUG_ON(!kernel_fpu_available());
kernel_fpu_begin();
}
TRACE_DCN_FPU(true, function_name, line, 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 depth;
depth = __this_cpu_dec_return(fpu_recursion_depth);
if (depth == 0) {
kernel_fpu_end();
} else {
WARN_ON_ONCE(depth < 0);
}
TRACE_DCN_FPU(false, function_name, line, depth);
preempt_enable();
}
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