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: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ben Hutchings 2010-10-08 10:36:10 -07:00 committed by David S. Miller
parent 4e7f79511e
commit 993284dfff
1 changed files with 10 additions and 1 deletions

View File

@ -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 */
@ -183,7 +189,8 @@ static int efx_filter_search(struct efx_filter_table *table,
incr = efx_filter_increment(key);
for (depth = 1, filter_idx = hash & (table->size - 1);
test_bit(filter_idx, table->used_bitmap);
depth <= FILTER_CTL_SRCH_MAX &&
test_bit(filter_idx, table->used_bitmap);
++depth) {
cmp = &table->spec[filter_idx];
if (efx_filter_equal(spec, cmp))
@ -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;