sfc: Use proper macros to declare and access MCDI arrays

A few functions are using heap buffers; change them to use stack
buffers as we really don't need to resort to the heap for a 252
byte buffer in process context.

MC_CMD_MEMCPY is quite weird in that it can use inline data placed in
the request buffer after the array of records.  Thus there are two
variable-length arrays and we can't use the normal accessors for
the second.  So we have to use _MCDI_PTR() in efx_sriov_memcpy().

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

1 files changed, 20 insertions, 15 deletions

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index f79f6fb579a1..ec2cf4d7c9b7 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -294,8 +294,7 @@ struct efx_ptp_data {
 	struct work_struct pps_work;
 	struct workqueue_struct *pps_workwq;
 	bool nic_ts_enabled;
-	u8 txbuf[ALIGN(MC_CMD_PTP_IN_TRANSMIT_LEN(
-			       MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM), 4)];
+	MCDI_DECLARE_BUF(txbuf, MC_CMD_PTP_IN_TRANSMIT_LENMAX);
 	struct efx_ptp_timeset
 	timeset[MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_MAXNUM];
 };
@@ -396,7 +395,8 @@ static void efx_ptp_send_times(struct efx_nic *efx,
 }
 
 /* Read a timeset from the MC's results and partial process. */
-static void efx_ptp_read_timeset(u8 *data, struct efx_ptp_timeset *timeset)
+static void efx_ptp_read_timeset(MCDI_DECLARE_STRUCT_PTR(data),
+				 struct efx_ptp_timeset *timeset)
 {
 	unsigned start_ns, end_ns;
 
@@ -425,12 +425,14 @@ static void efx_ptp_read_timeset(u8 *data, struct efx_ptp_timeset *timeset)
  * busy. A number of readings are taken so that, hopefully, at least one good
  * synchronisation will be seen in the results.
  */
-static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
-				 size_t response_length,
-				 const struct pps_event_time *last_time)
+static int
+efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf),
+		      size_t response_length,
+		      const struct pps_event_time *last_time)
 {
-	unsigned number_readings = (response_length /
-			       MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN);
+	unsigned number_readings =
+		MCDI_VAR_ARRAY_LEN(response_length,
+				   PTP_OUT_SYNCHRONIZE_TIMESET);
 	unsigned i;
 	unsigned total;
 	unsigned ngood = 0;
@@ -447,8 +449,10 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
 	 * appera to be erroneous.
 	 */
 	for (i = 0; i < number_readings; i++) {
-		efx_ptp_read_timeset(synch_buf, &ptp->timeset[i]);
-		synch_buf += MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN;
+		efx_ptp_read_timeset(
+			MCDI_ARRAY_STRUCT_PTR(synch_buf,
+					      PTP_OUT_SYNCHRONIZE_TIMESET, i),
+			&ptp->timeset[i]);
 	}
 
 	/* Find the last good host-MC synchronization result. The MC times
@@ -564,15 +568,15 @@ static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings)
 /* Transmit a PTP packet, via the MCDI interface, to the wire. */
 static int efx_ptp_xmit_skb(struct efx_nic *efx, struct sk_buff *skb)
 {
-	u8 *txbuf = efx->ptp_data->txbuf;
+	struct efx_ptp_data *ptp_data = efx->ptp_data;
 	struct skb_shared_hwtstamps timestamps;
 	int rc = -EIO;
 	/* MCDI driver requires word aligned lengths */
 	size_t len = ALIGN(MC_CMD_PTP_IN_TRANSMIT_LEN(skb->len), 4);
 	MCDI_DECLARE_BUF(txtime, MC_CMD_PTP_OUT_TRANSMIT_LEN);
 
-	MCDI_SET_DWORD(txbuf, PTP_IN_OP, MC_CMD_PTP_OP_TRANSMIT);
-	MCDI_SET_DWORD(txbuf, PTP_IN_TRANSMIT_LENGTH, skb->len);
+	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_OP, MC_CMD_PTP_OP_TRANSMIT);
+	MCDI_SET_DWORD(ptp_data->txbuf, PTP_IN_TRANSMIT_LENGTH, skb->len);
 	if (skb_shinfo(skb)->nr_frags != 0) {
 		rc = skb_linearize(skb);
 		if (rc != 0)
@@ -585,9 +589,10 @@ static int efx_ptp_xmit_skb(struct efx_nic *efx, struct sk_buff *skb)
 			goto fail;
 	}
 	skb_copy_from_linear_data(skb,
-				  &txbuf[MC_CMD_PTP_IN_TRANSMIT_PACKET_OFST],
+				  MCDI_PTR(ptp_data->txbuf,
+					   PTP_IN_TRANSMIT_PACKET),
 				  len);
-	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, txbuf, len, txtime,
+	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, ptp_data->txbuf, len, txtime,
 			  sizeof(txtime), &len);
 	if (rc != 0)
 		goto fail;