Commit 1186c6b3 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

sfc: falcon: use padding to fix alignment in loopback test 



Add two bytes of padding to the start of struct ef4_loopback_payload,
 which are not sent on the wire.  This ensures the 'ip' member is
 4-byte aligned, preventing the following W=1 warning:
net/ethernet/sfc/falcon/selftest.c:43:15: error: field ip within 'struct ef4_loopback_payload' is less aligned than 'struct iphdr' and is usually due to 'struct ef4_loopback_payload' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
        struct iphdr ip;

Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarEdward Cree <ecree.xilinx@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 30c24dd8

drivers/net/ethernet/sfc/falcon/selftest.c

+28 −19
Original line number Diff line number Diff line
@@ -39,12 +39,16 @@ 
 * Falcon only performs RSS on TCP/UDP packets.

 */

struct ef4_loopback_payload {

	char pad[2]; /* Ensures ip is 4-byte aligned */

	struct ethhdr header;

	struct iphdr ip;

	struct udphdr udp;

	__be16 iteration;

	char msg[64];

} __packed;

} __packed __aligned(4);

#define EF4_LOOPBACK_PAYLOAD_LEN	(sizeof(struct ef4_loopback_payload) - \

					 offsetof(struct ef4_loopback_payload, \

						  header))



/* Loopback test source MAC address */

static const u8 payload_source[ETH_ALEN] __aligned(2) = {
@@ -284,7 +288,7 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 
			    const char *buf_ptr, int pkt_len)

{

	struct ef4_loopback_state *state = efx->loopback_selftest;

	struct ef4_loopback_payload *received;

	struct ef4_loopback_payload received;

	struct ef4_loopback_payload *payload;



	BUG_ON(!buf_ptr);
@@ -295,13 +299,14 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 


	payload = &state->payload;



	received = (struct ef4_loopback_payload *) buf_ptr;

	received->ip.saddr = payload->ip.saddr;

	memcpy(&received.header, buf_ptr,

	       min_t(int, pkt_len, EF4_LOOPBACK_PAYLOAD_LEN));

	received.ip.saddr = payload->ip.saddr;

	if (state->offload_csum)

		received->ip.check = payload->ip.check;

		received.ip.check = payload->ip.check;



	/* Check that header exists */

	if (pkt_len < sizeof(received->header)) {

	if (pkt_len < sizeof(received.header)) {

		netif_err(efx, drv, efx->net_dev,

			  "saw runt RX packet (length %d) in %s loopback "

			  "test\n", pkt_len, LOOPBACK_MODE(efx));
@@ -309,7 +314,7 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 
	}



	/* Check that the ethernet header exists */

	if (memcmp(&received->header, &payload->header, ETH_HLEN) != 0) {

	if (memcmp(&received.header, &payload->header, ETH_HLEN) != 0) {

		netif_err(efx, drv, efx->net_dev,

			  "saw non-loopback RX packet in %s loopback test\n",

			  LOOPBACK_MODE(efx));
@@ -317,16 +322,16 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 
	}



	/* Check packet length */

	if (pkt_len != sizeof(*payload)) {

	if (pkt_len != EF4_LOOPBACK_PAYLOAD_LEN) {

		netif_err(efx, drv, efx->net_dev,

			  "saw incorrect RX packet length %d (wanted %d) in "

			  "%s loopback test\n", pkt_len, (int)sizeof(*payload),

			  LOOPBACK_MODE(efx));

			  "%s loopback test\n", pkt_len,

			  (int)EF4_LOOPBACK_PAYLOAD_LEN, LOOPBACK_MODE(efx));

		goto err;

	}



	/* Check that IP header matches */

	if (memcmp(&received->ip, &payload->ip, sizeof(payload->ip)) != 0) {

	if (memcmp(&received.ip, &payload->ip, sizeof(payload->ip)) != 0) {

		netif_err(efx, drv, efx->net_dev,

			  "saw corrupted IP header in %s loopback test\n",

			  LOOPBACK_MODE(efx));
@@ -334,7 +339,7 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 
	}



	/* Check that msg and padding matches */

	if (memcmp(&received->msg, &payload->msg, sizeof(received->msg)) != 0) {

	if (memcmp(&received.msg, &payload->msg, sizeof(received.msg)) != 0) {

		netif_err(efx, drv, efx->net_dev,

			  "saw corrupted RX packet in %s loopback test\n",

			  LOOPBACK_MODE(efx));
@@ -342,10 +347,10 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 
	}



	/* Check that iteration matches */

	if (received->iteration != payload->iteration) {

	if (received.iteration != payload->iteration) {

		netif_err(efx, drv, efx->net_dev,

			  "saw RX packet from iteration %d (wanted %d) in "

			  "%s loopback test\n", ntohs(received->iteration),

			  "%s loopback test\n", ntohs(received.iteration),

			  ntohs(payload->iteration), LOOPBACK_MODE(efx));

		goto err;

	}
@@ -365,7 +370,8 @@ void ef4_loopback_rx_packet(struct ef4_nic *efx, 
			       buf_ptr, pkt_len, 0);

		netif_err(efx, drv, efx->net_dev, "expected packet:\n");

		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 0x10, 1,

			       &state->payload, sizeof(state->payload), 0);

			       &state->payload.header, EF4_LOOPBACK_PAYLOAD_LEN,

			       0);

	}

#endif

	atomic_inc(&state->rx_bad);
@@ -387,14 +393,15 @@ static void ef4_iterate_state(struct ef4_nic *efx) 
	payload->ip.daddr = htonl(INADDR_LOOPBACK);

	payload->ip.ihl = 5;

	payload->ip.check = (__force __sum16) htons(0xdead);

	payload->ip.tot_len = htons(sizeof(*payload) - sizeof(struct ethhdr));

	payload->ip.tot_len = htons(sizeof(*payload) -

				    offsetof(struct ef4_loopback_payload, ip));

	payload->ip.version = IPVERSION;

	payload->ip.protocol = IPPROTO_UDP;



	/* Initialise udp header */

	payload->udp.source = 0;

	payload->udp.len = htons(sizeof(*payload) - sizeof(struct ethhdr) -

				 sizeof(struct iphdr));

	payload->udp.len = htons(sizeof(*payload) -

				 offsetof(struct ef4_loopback_payload, udp));

	payload->udp.check = 0;	/* checksum ignored */



	/* Fill out payload */
@@ -420,7 +427,7 @@ static int ef4_begin_loopback(struct ef4_tx_queue *tx_queue) 
	for (i = 0; i < state->packet_count; i++) {

		/* Allocate an skb, holding an extra reference for

		 * transmit completion counting */

		skb = alloc_skb(sizeof(state->payload), GFP_KERNEL);

		skb = alloc_skb(EF4_LOOPBACK_PAYLOAD_LEN, GFP_KERNEL);

		if (!skb)

			return -ENOMEM;

		state->skbs[i] = skb;
@@ -431,6 +438,8 @@ static int ef4_begin_loopback(struct ef4_tx_queue *tx_queue) 
		payload = skb_put(skb, sizeof(state->payload));

		memcpy(payload, &state->payload, sizeof(state->payload));

		payload->ip.saddr = htonl(INADDR_LOOPBACK | (i << 2));

		/* Strip off the leading padding */

		skb_pull(skb, offsetof(struct ef4_loopback_payload, header));



		/* Ensure everything we've written is visible to the

		 * interrupt handler. */