mirror_zfs/include/os/linux/kernel/linux/simd_aarch64.h
Brian Behlendorf 10fa254539
Linux 4.14, 4.19, 5.0+ compat: SIMD save/restore
Contrary to initial testing we cannot rely on these kernels to
invalidate the per-cpu FPU state and restore the FPU registers.
Nor can we guarantee that the kernel won't modify the FPU state
which we saved in the task struck.

Therefore, the kfpu_begin() and kfpu_end() functions have been
updated to save and restore the FPU state using our own dedicated
per-cpu FPU state variables.

This has the additional advantage of allowing us to use the FPU
again in user threads.  So we remove the code which was added to
use task queues to ensure some functions ran in kernel threads.

Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #9346
Closes #9403
2019-10-24 10:17:33 -07:00

55 lines
1.4 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (C) 2016 Romain Dolbeau <romain@dolbeau.org>.
*/
/*
* USER API:
*
* Kernel fpu methods:
* kfpu_allowed()
* kfpu_begin()
* kfpu_end()
* kfpu_init()
* kfpu_fini()
*/
#ifndef _LINUX_SIMD_AARCH64_H
#define _LINUX_SIMD_AARCH64_H
#include <sys/isa_defs.h>
#if defined(__aarch64__)
#include <sys/types.h>
#include <asm/neon.h>
#define kfpu_allowed() 1
#define kfpu_begin() kernel_neon_begin()
#define kfpu_end() kernel_neon_end()
#define kfpu_init() 0
#define kfpu_fini() ((void) 0)
#endif /* __aarch64__ */
#endif /* _LINUX_SIMD_AARCH64_H */