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7f6b2e7b1f
Make sure IFLUSH is not the last instruction in the hardware loop to avoid infinite core stall. The dcache/icache function that only gets used in writeback mode was putting IFLUSH as the last instruction in the hardware loop ... we know from design that this may often lead to inifite core stalling, so switch the FLUSH/IFLUSH order. Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org>
96 lines
2.4 KiB
ArmAsm
96 lines
2.4 KiB
ArmAsm
/*
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* Blackfin cache control code
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*
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* Copyright 2004-2008 Analog Devices Inc.
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*
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* Enter bugs at http://blackfin.uclinux.org/
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/linkage.h>
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#include <asm/blackfin.h>
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#include <asm/cache.h>
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#include <asm/page.h>
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.text
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/* Since all L1 caches work the same way, we use the same method for flushing
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* them. Only the actual flush instruction differs. We write this in asm as
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* GCC can be hard to coax into writing nice hardware loops.
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*
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* Also, we assume the following register setup:
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* R0 = start address
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* R1 = end address
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*/
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.macro do_flush flushins:req optflushins optnopins label
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R2 = -L1_CACHE_BYTES;
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/* start = (start & -L1_CACHE_BYTES) */
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R0 = R0 & R2;
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/* end = ((end - 1) & -L1_CACHE_BYTES) + L1_CACHE_BYTES; */
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R1 += -1;
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R1 = R1 & R2;
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R1 += L1_CACHE_BYTES;
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/* count = (end - start) >> L1_CACHE_SHIFT */
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R2 = R1 - R0;
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R2 >>= L1_CACHE_SHIFT;
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P1 = R2;
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.ifnb \label
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\label :
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.endif
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P0 = R0;
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LSETUP (1f, 2f) LC1 = P1;
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1:
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.ifnb \optflushins
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\optflushins [P0];
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.endif
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.ifb \optnopins
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2:
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.endif
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\flushins [P0++];
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.ifnb \optnopins
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2: \optnopins;
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.endif
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RTS;
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.endm
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/* Invalidate all instruction cache lines assocoiated with this memory area */
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ENTRY(_blackfin_icache_flush_range)
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do_flush IFLUSH, , nop
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ENDPROC(_blackfin_icache_flush_range)
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/* Flush all cache lines assocoiated with this area of memory. */
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ENTRY(_blackfin_icache_dcache_flush_range)
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do_flush FLUSH, IFLUSH
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ENDPROC(_blackfin_icache_dcache_flush_range)
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/* Throw away all D-cached data in specified region without any obligation to
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* write them back. Since the Blackfin ISA does not have an "invalidate"
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* instruction, we use flush/invalidate. Perhaps as a speed optimization we
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* could bang on the DTEST MMRs ...
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*/
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ENTRY(_blackfin_dcache_invalidate_range)
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do_flush FLUSHINV
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ENDPROC(_blackfin_dcache_invalidate_range)
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/* Flush all data cache lines assocoiated with this memory area */
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ENTRY(_blackfin_dcache_flush_range)
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do_flush FLUSH, , , .Ldfr
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ENDPROC(_blackfin_dcache_flush_range)
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/* Our headers convert the page structure to an address, so just need to flush
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* its contents like normal. We know the start address is page aligned (which
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* greater than our cache alignment), as is the end address. So just jump into
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* the middle of the dcache flush function.
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*/
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ENTRY(_blackfin_dflush_page)
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P1 = 1 << (PAGE_SHIFT - L1_CACHE_SHIFT);
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jump .Ldfr;
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ENDPROC(_blackfin_dflush_page)
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