diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 2509ca916880b968aa84994423e9834f82599aa8..d6b8a77f5b226499a25bba6b0cd736b74721e50b 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -82,6 +82,7 @@ int efx_mcdi_init(struct efx_nic *efx)
 	mcdi->logging_enabled = mcdi_logging_default;
 #endif
 	init_waitqueue_head(&mcdi->wq);
+	init_waitqueue_head(&mcdi->proxy_rx_wq);
 	spin_lock_init(&mcdi->iface_lock);
 	mcdi->state = MCDI_STATE_QUIESCENT;
 	mcdi->mode = MCDI_MODE_POLL;
@@ -622,10 +623,30 @@ efx_mcdi_check_supported(struct efx_nic *efx, unsigned int cmd, size_t inlen)
 	return 0;
 }
 
-static int _efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
+static bool efx_mcdi_get_proxy_handle(struct efx_nic *efx,
+				      size_t hdr_len, size_t data_len,
+				      u32 *proxy_handle)
+{
+	MCDI_DECLARE_BUF_ERR(testbuf);
+	const size_t buflen = sizeof(testbuf);
+
+	if (!proxy_handle || data_len < buflen)
+		return false;
+
+	efx->type->mcdi_read_response(efx, testbuf, hdr_len, buflen);
+	if (MCDI_DWORD(testbuf, ERR_CODE) == MC_CMD_ERR_PROXY_PENDING) {
+		*proxy_handle = MCDI_DWORD(testbuf, ERR_PROXY_PENDING_HANDLE);
+		return true;
+	}
+
+	return false;
+}
+
+static int _efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned int cmd,
+				size_t inlen,
 				efx_dword_t *outbuf, size_t outlen,
 				size_t *outlen_actual, bool quiet,
-				int *raw_rc)
+				u32 *proxy_handle, int *raw_rc)
 {
 	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
 	MCDI_DECLARE_BUF_ERR(errbuf);
@@ -659,6 +680,9 @@ static int _efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 		spin_unlock_bh(&mcdi->iface_lock);
 	}
 
+	if (proxy_handle)
+		*proxy_handle = 0;
+
 	if (rc != 0) {
 		if (outlen_actual)
 			*outlen_actual = 0;
@@ -693,6 +717,12 @@ static int _efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 			netif_err(efx, hw, efx->net_dev, "MC fatal error %d\n",
 				  -rc);
 			efx_schedule_reset(efx, RESET_TYPE_MC_FAILURE);
+		} else if (proxy_handle && (rc == -EPROTO) &&
+			   efx_mcdi_get_proxy_handle(efx, hdr_len, data_len,
+						     proxy_handle)) {
+			mcdi->proxy_rx_status = 0;
+			mcdi->proxy_rx_handle = 0;
+			mcdi->state = MCDI_STATE_PROXY_WAIT;
 		} else if (rc && !quiet) {
 			efx_mcdi_display_error(efx, cmd, inlen, errbuf, err_len,
 					       rc);
@@ -705,23 +735,119 @@ static int _efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 		}
 	}
 
-	efx_mcdi_release(mcdi);
+	if (!proxy_handle || !*proxy_handle)
+		efx_mcdi_release(mcdi);
 	return rc;
 }
 
-static int _efx_mcdi_rpc(struct efx_nic *efx, unsigned cmd,
+static void efx_mcdi_proxy_abort(struct efx_mcdi_iface *mcdi)
+{
+	if (mcdi->state == MCDI_STATE_PROXY_WAIT) {
+		/* Interrupt the proxy wait. */
+		mcdi->proxy_rx_status = -EINTR;
+		wake_up(&mcdi->proxy_rx_wq);
+	}
+}
+
+static void efx_mcdi_ev_proxy_response(struct efx_nic *efx,
+				       u32 handle, int status)
+{
+	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
+
+	WARN_ON(mcdi->state != MCDI_STATE_PROXY_WAIT);
+
+	mcdi->proxy_rx_status = efx_mcdi_errno(status);
+	/* Ensure the status is written before we update the handle, since the
+	 * latter is used to check if we've finished.
+	 */
+	wmb();
+	mcdi->proxy_rx_handle = handle;
+	wake_up(&mcdi->proxy_rx_wq);
+}
+
+static int efx_mcdi_proxy_wait(struct efx_nic *efx, u32 handle, bool quiet)
+{
+	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
+	int rc;
+
+	/* Wait for a proxy event, or timeout. */
+	rc = wait_event_timeout(mcdi->proxy_rx_wq,
+				mcdi->proxy_rx_handle != 0 ||
+				mcdi->proxy_rx_status == -EINTR,
+				MCDI_RPC_TIMEOUT);
+
+	if (rc <= 0) {
+		netif_dbg(efx, hw, efx->net_dev,
+			  "MCDI proxy timeout %d\n", handle);
+		return -ETIMEDOUT;
+	} else if (mcdi->proxy_rx_handle != handle) {
+		netif_warn(efx, hw, efx->net_dev,
+			   "MCDI proxy unexpected handle %d (expected %d)\n",
+			   mcdi->proxy_rx_handle, handle);
+		return -EINVAL;
+	}
+
+	return mcdi->proxy_rx_status;
+}
+
+static int _efx_mcdi_rpc(struct efx_nic *efx, unsigned int cmd,
 			 const efx_dword_t *inbuf, size_t inlen,
 			 efx_dword_t *outbuf, size_t outlen,
 			 size_t *outlen_actual, bool quiet, int *raw_rc)
 {
+	u32 proxy_handle = 0; /* Zero is an invalid proxy handle. */
 	int rc;
 
+	if (inbuf && inlen && (inbuf == outbuf)) {
+		/* The input buffer can't be aliased with the output. */
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
 	rc = efx_mcdi_rpc_start(efx, cmd, inbuf, inlen);
 	if (rc)
 		return rc;
 
-	return _efx_mcdi_rpc_finish(efx, cmd, inlen, outbuf, outlen,
-				    outlen_actual, quiet, raw_rc);
+	rc = _efx_mcdi_rpc_finish(efx, cmd, inlen, outbuf, outlen,
+				  outlen_actual, quiet, &proxy_handle, raw_rc);
+
+	if (proxy_handle) {
+		/* Handle proxy authorisation. This allows approval of MCDI
+		 * operations to be delegated to the admin function, allowing
+		 * fine control over (eg) multicast subscriptions.
+		 */
+		struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
+
+		netif_dbg(efx, hw, efx->net_dev,
+			  "MCDI waiting for proxy auth %d\n",
+			  proxy_handle);
+		rc = efx_mcdi_proxy_wait(efx, proxy_handle, quiet);
+
+		if (rc == 0) {
+			netif_dbg(efx, hw, efx->net_dev,
+				  "MCDI proxy retry %d\n", proxy_handle);
+
+			/* We now retry the original request. */
+			mcdi->state = MCDI_STATE_RUNNING_SYNC;
+			efx_mcdi_send_request(efx, cmd, inbuf, inlen);
+
+			rc = _efx_mcdi_rpc_finish(efx, cmd, inlen,
+						  outbuf, outlen, outlen_actual,
+						  quiet, NULL, raw_rc);
+		} else {
+			netif_printk(efx, hw,
+				     rc == -EPERM ? KERN_DEBUG : KERN_ERR,
+				     efx->net_dev,
+				     "MC command 0x%x failed after proxy auth rc=%d\n",
+				     cmd, rc);
+
+			if (rc == -EINTR || rc == -EIO)
+				efx_schedule_reset(efx, RESET_TYPE_MC_FAILURE);
+			efx_mcdi_release(mcdi);
+		}
+	}
+
+	return rc;
 }
 
 static int _efx_mcdi_rpc_evb_retry(struct efx_nic *efx, unsigned cmd,
@@ -935,7 +1061,7 @@ int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 			size_t *outlen_actual)
 {
 	return _efx_mcdi_rpc_finish(efx, cmd, inlen, outbuf, outlen,
-				    outlen_actual, false, NULL);
+				    outlen_actual, false, NULL, NULL);
 }
 
 int efx_mcdi_rpc_finish_quiet(struct efx_nic *efx, unsigned cmd, size_t inlen,
@@ -943,7 +1069,7 @@ int efx_mcdi_rpc_finish_quiet(struct efx_nic *efx, unsigned cmd, size_t inlen,
 			      size_t *outlen_actual)
 {
 	return _efx_mcdi_rpc_finish(efx, cmd, inlen, outbuf, outlen,
-				    outlen_actual, true, NULL);
+				    outlen_actual, true, NULL, NULL);
 }
 
 void efx_mcdi_display_error(struct efx_nic *efx, unsigned cmd,
@@ -1083,8 +1209,13 @@ static void efx_mcdi_ev_death(struct efx_nic *efx, int rc)
 	 * receiving a REBOOT event after posting the MCDI
 	 * request. Did the mc reboot before or after the copyout? The
 	 * best we can do always is just return failure.
+	 *
+	 * If there is an outstanding proxy response expected it is not going
+	 * to arrive. We should thus abort it.
 	 */
 	spin_lock(&mcdi->iface_lock);
+	efx_mcdi_proxy_abort(mcdi);
+
 	if (efx_mcdi_complete_sync(mcdi)) {
 		if (mcdi->mode == MCDI_MODE_EVENTS) {
 			mcdi->resprc = rc;
@@ -1132,6 +1263,8 @@ static void efx_mcdi_ev_bist(struct efx_nic *efx)
 
 	spin_lock(&mcdi->iface_lock);
 	efx->mc_bist_for_other_fn = true;
+	efx_mcdi_proxy_abort(mcdi);
+
 	if (efx_mcdi_complete_sync(mcdi)) {
 		if (mcdi->mode == MCDI_MODE_EVENTS) {
 			mcdi->resprc = -EIO;
@@ -1240,6 +1373,11 @@ void efx_mcdi_process_event(struct efx_channel *channel,
 			  EFX_QWORD_VAL(*event));
 		efx_schedule_reset(efx, RESET_TYPE_DMA_ERROR);
 		break;
+	case MCDI_EVENT_CODE_PROXY_RESPONSE:
+		efx_mcdi_ev_proxy_response(efx,
+				MCDI_EVENT_FIELD(*event, PROXY_RESPONSE_HANDLE),
+				MCDI_EVENT_FIELD(*event, PROXY_RESPONSE_RC));
+		break;
 	default:
 		netif_err(efx, hw, efx->net_dev, "Unknown MCDI event 0x%x\n",
 			  code);
diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index 397660d1b3de0b809b274137a583901a91e097d9..c9aeb0701c9a664a8cb265d75ddea8b4b6090547 100644
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -17,6 +17,8 @@
  * @MCDI_STATE_RUNNING_SYNC: There is a synchronous MCDI request pending.
  *	Only the thread that moved into this state is allowed to move out of it.
  * @MCDI_STATE_RUNNING_ASYNC: There is an asynchronous MCDI request pending.
+ * @MCDI_STATE_PROXY_WAIT: An MCDI request has completed with a response that
+ *	indicates we must wait for a proxy try again message.
  * @MCDI_STATE_COMPLETED: An MCDI request has completed, but the owning thread
  *	has not yet consumed the result. For all other threads, equivalent to
  *	%MCDI_STATE_RUNNING.
@@ -25,6 +27,7 @@ enum efx_mcdi_state {
 	MCDI_STATE_QUIESCENT,
 	MCDI_STATE_RUNNING_SYNC,
 	MCDI_STATE_RUNNING_ASYNC,
+	MCDI_STATE_PROXY_WAIT,
 	MCDI_STATE_COMPLETED,
 };
 
@@ -60,6 +63,9 @@ enum efx_mcdi_mode {
  * @async_timer: Timer for asynchronous request timeout
  * @logging_buffer: buffer that may be used to build MCDI tracing messages
  * @logging_enabled: whether to trace MCDI
+ * @proxy_rx_handle: Most recently received proxy authorisation handle
+ * @proxy_rx_status: Status of most recent proxy authorisation
+ * @proxy_rx_wq: Wait queue for updates to proxy_rx_handle
  */
 struct efx_mcdi_iface {
 	struct efx_nic *efx;
@@ -81,6 +87,9 @@ struct efx_mcdi_iface {
 	char *logging_buffer;
 	bool logging_enabled;
 #endif
+	unsigned int proxy_rx_handle;
+	int proxy_rx_status;
+	wait_queue_head_t proxy_rx_wq;
 };
 
 struct efx_mcdi_mon {