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[AVR32] Fix incorrect invalidation of shared cachelines 

Fix bug in dma_map_single(..., DMA_FROM_DEVICE) caused by incorrect
invalidation of shared cachelines at the beginning and/or end of
the specified buffer.  Those shared cachelines need to be flushed,
since they may hold valid data (which must not be discarded).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This commit is contained in:
David Brownell 2007-01-28 12:56:42 -08:00 committed by Haavard Skinnemoen
parent 58febc0b13
commit 212868d387
1 changed files with 22 additions and 6 deletions
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28
arch/avr32/mm/cache.c
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@ -22,18 +22,34 @@
void invalidate_dcache_region(void *start, size_t size)
{
unsigned long v, begin, end, linesz;
unsigned long v, begin, end, linesz, mask;
int flush = 0;
linesz = boot_cpu_data.dcache.linesz;
mask = linesz - 1;
//printk("invalidate dcache: %p + %u\n", start, size);
/* when first and/or last cachelines are shared, flush them
* instead of invalidating ... never discard valid data!
*/
begin = (unsigned long)start;
end = begin + size - 1;
/* You asked for it, you got it */
begin = (unsigned long)start & ~(linesz - 1);
end = ((unsigned long)start + size + linesz - 1) & ~(linesz - 1);
if (begin & mask) {
flush_dcache_line(start);
begin += linesz;
flush = 1;
}
if ((end & mask) != mask) {
flush_dcache_line((void *)end);
end -= linesz;
flush = 1;
}
for (v = begin; v < end; v += linesz)
/* remaining cachelines only need invalidation */
for (v = begin; v <= end; v += linesz)
invalidate_dcache_line((void *)v);
if (flush)
flush_write_buffer();
}
void clean_dcache_region(void *start, size_t size)