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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2020 Val Packett <val@packett.cool>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <linux/compat.h>
#include <linux/sched.h>
#include <asm/fpu/api.h>
#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) || \
defined(__i386__) || defined(__powerpc64__)
#include <machine/fpu.h>
/*
* Technically the Linux API isn't supposed to allow nesting sections
* either, but currently used versions of GPU drivers rely on nesting
* working, so we only enter the section on the outermost level.
*/
void
lkpi_kernel_fpu_begin(void)
{
if ((current->fpu_ctx_level)++ == 0)
fpu_kern_enter(curthread, NULL, FPU_KERN_NOCTX);
}
void
lkpi_kernel_fpu_end(void)
{
if (--(current->fpu_ctx_level) == 0)
fpu_kern_leave(curthread, NULL);
}
void
lkpi_fpu_safe_exec(fpu_safe_exec_cb_t func, void *ctx)
{
unsigned int save_fpu_level;
save_fpu_level =
__current_unallocated(curthread) ? 0 : current->fpu_ctx_level;
if (__predict_false(save_fpu_level != 0)) {
current->fpu_ctx_level = 1;
kernel_fpu_end();
}
func(ctx);
if (__predict_false(save_fpu_level != 0)) {
kernel_fpu_begin();
current->fpu_ctx_level = save_fpu_level;
}
}
#else
void
lkpi_kernel_fpu_begin(void)
{
}
void
lkpi_kernel_fpu_end(void)
{
}
void
lkpi_fpu_safe_exec(fpu_safe_exec_cb_t func, void *ctx)
{
func(ctx);
}
#endif
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