linux/arch/arm64/include/asm/cache.h
Jungseok Lee e4f88d833b arm64: Implement support for read-mostly sections
As putting data which is read mostly together, we can avoid
unnecessary cache line bouncing.

Other architectures, such as ARM and x86, adopted the same idea.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-12-03 10:19:35 +00:00

46 lines
1.3 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_CACHE_H
#define __ASM_CACHE_H
#include <asm/cachetype.h>
#define L1_CACHE_SHIFT 6
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
/*
* Memory returned by kmalloc() may be used for DMA, so we must make
* sure that all such allocations are cache aligned. Otherwise,
* unrelated code may cause parts of the buffer to be read into the
* cache before the transfer is done, causing old data to be seen by
* the CPU.
*/
#define ARCH_DMA_MINALIGN L1_CACHE_BYTES
#ifndef __ASSEMBLY__
#define __read_mostly __attribute__((__section__(".data..read_mostly")))
static inline int cache_line_size(void)
{
u32 cwg = cache_type_cwg();
return cwg ? 4 << cwg : L1_CACHE_BYTES;
}
#endif /* __ASSEMBLY__ */
#endif