u-boot/arch/arm/lib/cache.c
Aneesh V cba4b1809f arm: do not force d-cache enable on all boards
c2dd0d4554 added dcache_enable()
to board_init_r(). This enables d-cache for all ARM boards.
As a result some of the arm boards that are not cache-ready
are broken. Revert this change and allow platform code to
take the decision on d-cache enabling.

Also add some documentation for cache usage in ARM.

Signed-off-by: Aneesh V <aneesh@ti.com>
2011-09-04 11:36:16 +02:00

67 lines
1.9 KiB
C

/*
* (C) Copyright 2002
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/* for now: just dummy functions to satisfy the linker */
#include <common.h>
void __flush_cache(unsigned long start, unsigned long size)
{
#if defined(CONFIG_OMAP2420) || defined(CONFIG_ARM1136)
void arm1136_cache_flush(void);
arm1136_cache_flush();
#endif
#ifdef CONFIG_ARM926EJS
/* test and clean, page 2-23 of arm926ejs manual */
asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
/* disable write buffer as well (page 2-22) */
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
#endif
return;
}
void flush_cache(unsigned long start, unsigned long size)
__attribute__((weak, alias("__flush_cache")));
/*
* Default implementation:
* do a range flush for the entire range
*/
void __flush_dcache_all(void)
{
flush_cache(0, ~0);
}
void flush_dcache_all(void)
__attribute__((weak, alias("__flush_dcache_all")));
/*
* Default implementation of enable_caches()
* Real implementation should be in platform code
*/
void __enable_caches(void)
{
puts("WARNING: Caches not enabled\n");
}
void enable_caches(void)
__attribute__((weak, alias("__enable_caches")));