[AVR32] Fix bug in invalidate_dcache_region()

If (start + size) is not cacheline aligned and (start & mask) > (end &
mask), the last but one cacheline won't be invalidated as it should.
Fix this by rounding `end' down to the nearest cacheline boundary if
it gets adjusted due to misalignment.

Also flush the write buffer unconditionally -- if the dcache wrote
back a line just before we invalidated it, the dirty data may be
sitting in the write buffer waiting to corrupt our buffer later.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This commit is contained in:
Haavard Skinnemoen 2007-06-18 14:08:18 +02:00
parent 75154f402e
commit ab61f7d21a

View file

@ -23,7 +23,6 @@
void invalidate_dcache_region(void *start, size_t size)
{
unsigned long v, begin, end, linesz, mask;
int flush = 0;
linesz = boot_cpu_data.dcache.linesz;
mask = linesz - 1;
@ -32,23 +31,20 @@ void invalidate_dcache_region(void *start, size_t size)
* instead of invalidating ... never discard valid data!
*/
begin = (unsigned long)start;
end = begin + size - 1;
end = begin + size;
if (begin & mask) {
flush_dcache_line(start);
begin += linesz;
flush = 1;
}
if ((end & mask) != mask) {
if (end & mask) {
flush_dcache_line((void *)end);
end -= linesz;
flush = 1;
end &= ~mask;
}
/* remaining cachelines only need invalidation */
for (v = begin; v <= end; v += linesz)
for (v = begin; v < end; v += linesz)
invalidate_dcache_line((void *)v);
if (flush)
flush_write_buffer();
}