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Commit 212868d3 authored by David Brownell's avatar David Brownell Committed by Haavard Skinnemoen
Browse files

[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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarHaavard Skinnemoen <hskinnemoen@atmel.com>
parent 58febc0b

arch/avr32/mm/cache.c

+24 −8
Original line number Diff line number Diff line
@@ -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)