Commit 993284df authored by Ben Hutchings's avatar Ben Hutchings Committed by David S. Miller
Browse files

sfc: Don't try to set filters with search depths we know won't work 



The filter engine will time-out and ignore filters beyond
200-something hops.  We also need to avoid infinite loops in
efx_filter_search() when the table is full.

Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4e7f7951

drivers/net/sfc/filter.c

+10 −1
Original line number Diff line number Diff line
@@ -20,6 +20,12 @@ 
#define FILTER_CTL_SRCH_FUDGE_WILD 3

#define FILTER_CTL_SRCH_FUDGE_FULL 1



/* Hard maximum hop limit.  Hardware will time-out beyond 200-something.

 * We also need to avoid infinite loops in efx_filter_search() when the

 * table is full.

 */

#define FILTER_CTL_SRCH_MAX 200



struct efx_filter_table {

	u32		offset;		/* address of table relative to BAR */

	unsigned	size;		/* number of entries */
@@ -183,6 +189,7 @@ static int efx_filter_search(struct efx_filter_table *table, 
	incr = efx_filter_increment(key);



	for (depth = 1, filter_idx = hash & (table->size - 1);

	     depth <= FILTER_CTL_SRCH_MAX &&

		     test_bit(filter_idx, table->used_bitmap);

	     ++depth) {

		cmp = &table->spec[filter_idx];
@@ -192,6 +199,8 @@ static int efx_filter_search(struct efx_filter_table *table, 
	}

	if (!for_insert)

		return -ENOENT;

	if (depth > FILTER_CTL_SRCH_MAX)

		return -EBUSY;

found:

	*depth_required = depth;

	return filter_idx;