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/*
* Blackfin cache control code
*
* Copyright 2004-2008 Analog Devices Inc.
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Licensed under the GPL-2 or later.
*/
#include <linux/linkage.h>
#include <asm/blackfin.h>
#include <asm/cache.h>
#include <asm/page.h>
.text
/* 05000443 - IFLUSH cannot be last instruction in hardware loop */
#if ANOMALY_05000443
# define BROK_FLUSH_INST "IFLUSH"
#else
# define BROK_FLUSH_INST "no anomaly! yeah!"
#endif
/* 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 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:
.ifeqs "\flushins", BROK_FLUSH_INST
\flushins [P0++];
2: nop;
.else
2: \flushins [P0++];
.endif
RTS;
.endm
/* Invalidate all instruction cache lines assocoiated with this memory area */
ENTRY(_blackfin_icache_flush_range)
/*
* Walkaround to avoid loading wrong instruction after invalidating icache
* and following sequence is met.
*
* 1) One instruction address is cached in the instruction cache.
* 2) This instruction in SDRAM is changed.
* 3) IFLASH[P0] is executed only once in blackfin_icache_flush_range().
* 4) This instruction is executed again, but the old one is loaded.
*/
P0 = R0;
IFLUSH[P0];
do_flush IFLUSH
ENDPROC(_blackfin_icache_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_invalidate_range)
do_flush FLUSHINV
ENDPROC(_blackfin_dcache_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)
/* Our headers convert the page structure to an address, so just need to flush
* its contents like normal. We know the start address is page aligned (which
* greater than our cache alignment), as is the end address. So just jump into
* the middle of the dcache flush function.
*/
ENTRY(_blackfin_dflush_page)
P1 = 1 << (PAGE_SHIFT - L1_CACHE_SHIFT);
jump .Ldfr;
ENDPROC(_blackfin_dflush_page)
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