56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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* (C) Copyright 2010
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* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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/*
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* This is a workaround for issues on the MPC5200, where unaligned
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* 32-bit-accesses to the local bus will deliver corrupted data. This
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* happens for example when trying to use memcpy() from an odd NOR
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* flash address; the behaviour can be also seen when using "md" on an
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* odd NOR flash address (but there it is not a bug in U-Boot, which
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* only shows the behaviour of this processor).
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*
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* For memcpy(), we test if either the source or the target address
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* are not 32 bit aligned, and - if so - if the source address is in
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* NOR flash: in this case we perform a byte-wise (slow) then; for
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* aligned operations of non-flash areas we use the optimized (fast)
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* real __memcpy(). This way we minimize the performance impact of
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* this workaround.
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*
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*/
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#include <common.h>
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#include <flash.h>
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#include <linux/types.h>
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void *memcpy(void *trg, const void *src, size_t len)
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{
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extern void* __memcpy(void *, const void *, size_t);
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char *s = (char *)src;
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char *t = (char *)trg;
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void *dest = (void *)trg;
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/*
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* Check is source address is in flash:
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* If not, we use the fast assembler code
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*/
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if (((((unsigned long)s & 3) == 0) /* source aligned */
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&& /* AND */
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(((unsigned long)t & 3) == 0)) /* target aligned, */
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|| /* or */
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(addr2info((ulong)s) == NULL)) { /* source not in flash */
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return __memcpy(trg, src, len);
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}
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/*
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* Copying from flash, perform byte by byte copy.
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*/
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while (len-- > 0)
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*t++ = *s++;
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return dest;
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}
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