sfc: Allocate SRAM between buffer table and descriptor caches at init time

Each port has a block of 64-bit SRAM that is divided between buffer
table and descriptor cache regions at initialisation time.  Currently
we use a fixed allocation, but it needs to be changed to support
larger numbers of queues.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/siena.c b/drivers/net/ethernet/sfc/siena.c
index d3c4169..657f3fa 100644
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -225,6 +225,15 @@
 	return rc;
 }
 
+static void siena_dimension_resources(struct efx_nic *efx)
+{
+	/* Each port has a small block of internal SRAM dedicated to
+	 * the buffer table and descriptor caches.  In theory we can
+	 * map both blocks to one port, but we don't.
+	 */
+	efx_nic_dimension_resources(efx, FR_CZ_BUF_FULL_TBL_ROWS / 2);
+}
+
 static int siena_probe_nic(struct efx_nic *efx)
 {
 	struct siena_nic_data *nic_data;
@@ -619,6 +628,7 @@
 	.probe = siena_probe_nic,
 	.remove = siena_remove_nic,
 	.init = siena_init_nic,
+	.dimension_resources = siena_dimension_resources,
 	.fini = efx_port_dummy_op_void,
 	.monitor = NULL,
 	.map_reset_reason = siena_map_reset_reason,
@@ -657,8 +667,6 @@
 				   * interrupt handler only supports 32
 				   * channels */
 	.timer_period_max = 1 << FRF_CZ_TC_TIMER_VAL_WIDTH,
-	.tx_dc_base = 0x88000,
-	.rx_dc_base = 0x68000,
 	.offload_features = (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 			     NETIF_F_RXHASH | NETIF_F_NTUPLE),
 };