freebsd-skq/sys/arm64/include/vm.h
andrew bf70d7ed98 Add the VM_MEMATTR_WRITE_THROUGH memory type to arm64 and use it to support
VM_MEMATTR_WRITE_COMBINING in the kernel. This fixes a bug where Xorg would
use write back cached memory for its graphics buffers. This would produce
artifacts on the screen as cachelines were written to memory.

MFC after:	1 week
Sponsored by:	DARPA, AFRL
2017-05-13 13:01:15 +00:00

46 lines
1.8 KiB
C

/*-
* Copyright (c) 2009 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef _MACHINE_VM_H_
#define _MACHINE_VM_H_
/* Memory attribute configuration. */
#define VM_MEMATTR_DEVICE 0
#define VM_MEMATTR_UNCACHEABLE 1
#define VM_MEMATTR_WRITE_BACK 2
#define VM_MEMATTR_WRITE_THROUGH 3
#ifdef _KERNEL
/* If defined vmstat will try to use both of these in a switch statement */
#define VM_MEMATTR_WRITE_COMBINING VM_MEMATTR_WRITE_THROUGH
#endif
#define VM_MEMATTR_DEFAULT VM_MEMATTR_WRITE_BACK
#endif /* !_MACHINE_VM_H_ */