u-boot/cpu/blackfin/cache.S
Mike Frysinger fdce83c108 Blackfin: rewrite cache handling functions
Take the cache flush functions from the kernel as they use hardware loops in
order to get optimal performance.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2009-02-02 12:24:44 -05:00

87 lines
2 KiB
ArmAsm

/*
* Blackfin cache control code
*
* Copyright 2003-2008 Analog Devices Inc.
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Licensed under the GPL-2 or later.
*/
#include <asm/linkage.h>
#include <config.h>
#include <asm/blackfin.h>
.text
/* Since all L1 caches work the same way, we use the same method for flushing
* them. Only the actual flush instruction differs. We write this in asm as
* GCC can be hard to coax into writing nice hardware loops.
*
* Also, we assume the following register setup:
* R0 = start address
* R1 = end address
*/
.macro do_flush flushins:req optflushins optnopins label
R2 = -L1_CACHE_BYTES;
/* start = (start & -L1_CACHE_BYTES) */
R0 = R0 & R2;
/* end = ((end - 1) & -L1_CACHE_BYTES) + L1_CACHE_BYTES; */
R1 += -1;
R1 = R1 & R2;
R1 += L1_CACHE_BYTES;
/* count = (end - start) >> L1_CACHE_SHIFT */
R2 = R1 - R0;
R2 >>= L1_CACHE_SHIFT;
P1 = R2;
.ifnb \label
\label :
.endif
P0 = R0;
LSETUP (1f, 2f) LC1 = P1;
1:
.ifnb \optflushins
\optflushins [P0];
.endif
#if ANOMALY_05000443
.ifb \optnopins
2:
.endif
\flushins [P0++];
.ifnb \optnopins
2: \optnopins;
.endif
#else
2: \flushins [P0++];
#endif
RTS;
.endm
/* Invalidate all instruction cache lines assocoiated with this memory area */
ENTRY(_blackfin_icache_flush_range)
do_flush IFLUSH, , nop
ENDPROC(_blackfin_icache_flush_range)
/* Flush all cache lines assocoiated with this area of memory. */
ENTRY(_blackfin_icache_dcache_flush_range)
do_flush FLUSH, IFLUSH
ENDPROC(_blackfin_icache_dcache_flush_range)
/* Throw away all D-cached data in specified region without any obligation to
* write them back. Since the Blackfin ISA does not have an "invalidate"
* instruction, we use flush/invalidate. Perhaps as a speed optimization we
* could bang on the DTEST MMRs ...
*/
ENTRY(_blackfin_dcache_flush_invalidate_range)
do_flush FLUSHINV
ENDPROC(_blackfin_dcache_flush_invalidate_range)
/* Flush all data cache lines assocoiated with this memory area */
ENTRY(_blackfin_dcache_flush_range)
do_flush FLUSH, , , .Ldfr
ENDPROC(_blackfin_dcache_flush_range)