sfc: Add flag for stack-owned RX MAC filters

MAC filters inserted on request from the stack (ndo_set_rx_mode)
should allow manual steering but not removal.  Currently we have a
special case for Siena's all-multicast and all-unicast MAC filters,
but on EF10 we need to allow for steering of precise MAC filters as
well.

The EFX_FILTER_FLAG_RX_STACK flag changes the behaviour of replacement
and removal requests:

- Replacement *of* a filter with this flag never clears the flag but
  does change steering and saved priority
- Replacement *by* a filter with this flag only sets the flag but does
  not change steering
- Removal with priority < EFX_FILTER_PRI_REQUIRED really resets RX
  steering and saved priority

This could support precise MAC filtering on Siena in future.

As a side-benefit, the default MAC filters are hidden from ethtool
until they are steered.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index d91bced..1e21e51 100644 (file)
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -2186,23 +2186,17 @@ efx_farch_filter_to_gen_spec(struct efx_filter_spec *gen_spec,
 }
 
 static void
-efx_farch_filter_reset_rx_def(struct efx_nic *efx, unsigned filter_idx)
+efx_farch_filter_init_rx_for_stack(struct efx_nic *efx,
+                                  struct efx_farch_filter_spec *spec)
 {
-       struct efx_farch_filter_state *state = efx->filter_state;
-       struct efx_farch_filter_table *table =
-               &state->table[EFX_FARCH_FILTER_TABLE_RX_DEF];
-       struct efx_farch_filter_spec *spec = &table->spec[filter_idx];
-
        /* If there's only one channel then disable RSS for non VF
         * traffic, thereby allowing VFs to use RSS when the PF can't.
         */
-       spec->type = EFX_FARCH_FILTER_UC_DEF + filter_idx;
-       spec->priority = EFX_FILTER_PRI_MANUAL;
-       spec->flags = (EFX_FILTER_FLAG_RX |
+       spec->priority = EFX_FILTER_PRI_REQUIRED;
+       spec->flags = (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_RX_STACK |
                       (efx->n_rx_channels > 1 ? EFX_FILTER_FLAG_RX_RSS : 0) |
                       (efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0));
        spec->dmaq_id = 0;
-       table->used_bitmap[0] |= 1 << filter_idx;
 }
 
 /* Build a filter entry and return its n-tuple key. */
@@ -2464,10 +2458,20 @@ s32 efx_farch_filter_insert(struct efx_nic *efx,
                        rc = -EEXIST;
                        goto out;
                }
-               if (spec.priority < saved_spec->priority) {
+               if (spec.priority < saved_spec->priority &&
+                   !(saved_spec->priority == EFX_FILTER_PRI_REQUIRED &&
+                     saved_spec->flags & EFX_FILTER_FLAG_RX_STACK)) {
                        rc = -EPERM;
                        goto out;
                }
+               if (spec.flags & EFX_FILTER_FLAG_RX_STACK) {
+                       /* Just make sure it won't be removed */
+                       saved_spec->flags |= EFX_FILTER_FLAG_RX_STACK;
+                       rc = 0;
+                       goto out;
+               }
+               /* Retain the RX_STACK flag */
+               spec.flags |= saved_spec->flags & EFX_FILTER_FLAG_RX_STACK;
        }
 
        /* Insert the filter */
@@ -2517,6 +2521,7 @@ efx_farch_filter_table_clear_entry(struct efx_nic *efx,
        static efx_oword_t filter;
 
        EFX_WARN_ON_PARANOID(!test_bit(filter_idx, table->used_bitmap));
+       BUG_ON(table->offset == 0); /* can't clear MAC default filters */
 
        __clear_bit(filter_idx, table->used_bitmap);
        --table->used;
@@ -2550,9 +2555,8 @@ static int efx_farch_filter_remove(struct efx_nic *efx,
            spec->priority > priority)
                return -ENOENT;
 
-       if (table->id == EFX_FARCH_FILTER_TABLE_RX_DEF) {
-               /* RX default filters must always exist */
-               efx_farch_filter_reset_rx_def(efx, filter_idx);
+       if (spec->flags & EFX_FILTER_FLAG_RX_STACK) {
+               efx_farch_filter_init_rx_for_stack(efx, spec);
                efx_farch_filter_push_rx_config(efx);
        } else {
                efx_farch_filter_table_clear_entry(efx, table, filter_idx);
@@ -2647,6 +2651,8 @@ void efx_farch_filter_clear_rx(struct efx_nic *efx,
                                     priority);
        efx_farch_filter_table_clear(efx, EFX_FARCH_FILTER_TABLE_RX_MAC,
                                     priority);
+       efx_farch_filter_table_clear(efx, EFX_FARCH_FILTER_TABLE_RX_DEF,
+                                    priority);
 }
 
 u32 efx_farch_filter_count_rx_used(struct efx_nic *efx,
@@ -2806,11 +2812,18 @@ int efx_farch_filter_table_probe(struct efx_nic *efx)
                        goto fail;
        }
 
-       if (state->table[EFX_FARCH_FILTER_TABLE_RX_DEF].size) {
+       table = &state->table[EFX_FARCH_FILTER_TABLE_RX_DEF];
+       if (table->size) {
                /* RX default filters must always exist */
+               struct efx_farch_filter_spec *spec;
                unsigned i;
-               for (i = 0; i < EFX_FARCH_FILTER_SIZE_RX_DEF; i++)
-                       efx_farch_filter_reset_rx_def(efx, i);
+
+               for (i = 0; i < EFX_FARCH_FILTER_SIZE_RX_DEF; i++) {
+                       spec = &table->spec[i];
+                       spec->type = EFX_FARCH_FILTER_UC_DEF + i;
+                       efx_farch_filter_init_rx_for_stack(efx, spec);
+                       __set_bit(i, table->used_bitmap);
+               }
        }
 
        efx_farch_filter_push_rx_config(efx);

diff --git a/drivers/net/ethernet/sfc/filter.h b/drivers/net/ethernet/sfc/filter.h
index 1b410de..e459e43 100644 (file)
--- a/drivers/net/ethernet/sfc/filter.h
+++ b/drivers/net/ethernet/sfc/filter.h
@@ -78,12 +78,19 @@ enum efx_filter_priority {
  *     according to the indirection table.
  * @EFX_FILTER_FLAG_RX_SCATTER: Enable DMA scatter on the receiving
  *     queue.
+ * @EFX_FILTER_FLAG_RX_STACK: Indicates a filter inserted for the
+ *     network stack.  The filter must have a priority of
+ *     %EFX_FILTER_PRI_REQUIRED.  It can be steered by a replacement
+ *     request with priority %EFX_FILTER_PRI_MANUAL, and a removal
+ *     request with priority %EFX_FILTER_PRI_MANUAL will reset the
+ *     steering (but not remove the filter).
  * @EFX_FILTER_FLAG_RX: Filter is for RX
  * @EFX_FILTER_FLAG_TX: Filter is for TX
  */
 enum efx_filter_flags {
        EFX_FILTER_FLAG_RX_RSS = 0x01,
        EFX_FILTER_FLAG_RX_SCATTER = 0x02,
+       EFX_FILTER_FLAG_RX_STACK = 0x04,
        EFX_FILTER_FLAG_RX = 0x08,
        EFX_FILTER_FLAG_TX = 0x10,
 };