#include <rte_ether.h>
#include <rte_ethdev.h>
+#include <rte_ethdev_pci.h>
#include <rte_tcp.h>
#include <rte_atomic.h>
#include <rte_dev.h>
#include <rte_errno.h>
#include <rte_version.h>
+#include <rte_eal_memconfig.h>
+#include <rte_net.h>
#include "ena_ethdev.h"
#include "ena_logs.h"
#define PCI_DEVICE_ID_ENA_VF 0xEC20
#define PCI_DEVICE_ID_ENA_LLQ_VF 0xEC21
-static struct rte_pci_id pci_id_ena_map[] = {
-#define RTE_PCI_DEV_ID_DECL_ENA(vend, dev) {RTE_PCI_DEVICE(vend, dev)},
- RTE_PCI_DEV_ID_DECL_ENA(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_ENA_VF)
- RTE_PCI_DEV_ID_DECL_ENA(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_ENA_LLQ_VF)
- {.device_id = 0},
+#define ENA_TX_OFFLOAD_MASK (\
+ PKT_TX_L4_MASK | \
+ PKT_TX_IP_CKSUM | \
+ PKT_TX_TCP_SEG)
+
+#define ENA_TX_OFFLOAD_NOTSUP_MASK \
+ (PKT_TX_OFFLOAD_MASK ^ ENA_TX_OFFLOAD_MASK)
+
+static const struct rte_pci_id pci_id_ena_map[] = {
+ { RTE_PCI_DEVICE(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_ENA_VF) },
+ { RTE_PCI_DEVICE(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_ENA_LLQ_VF) },
+ { .device_id = 0 },
};
static int ena_device_init(struct ena_com_dev *ena_dev,
static int ena_dev_configure(struct rte_eth_dev *dev);
static uint16_t eth_ena_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
uint16_t nb_pkts);
+static uint16_t eth_ena_prep_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+ uint16_t nb_pkts);
static int ena_tx_queue_setup(struct rte_eth_dev *dev, uint16_t queue_idx,
uint16_t nb_desc, unsigned int socket_id,
const struct rte_eth_txconf *tx_conf);
uint16_t reta_size);
static int ena_get_sset_count(struct rte_eth_dev *dev, int sset);
-static struct eth_dev_ops ena_dev_ops = {
+static const struct eth_dev_ops ena_dev_ops = {
.dev_configure = ena_dev_configure,
.dev_infos_get = ena_infos_get,
.rx_queue_setup = ena_rx_queue_setup,
.reta_query = ena_rss_reta_query,
};
+#define NUMA_NO_NODE SOCKET_ID_ANY
+
+static inline int ena_cpu_to_node(int cpu)
+{
+ struct rte_config *config = rte_eal_get_configuration();
+
+ if (likely(cpu < RTE_MAX_MEMZONE))
+ return config->mem_config->memzone[cpu].socket_id;
+
+ return NUMA_NO_NODE;
+}
+
static inline void ena_rx_mbuf_prepare(struct rte_mbuf *mbuf,
struct ena_com_rx_ctx *ena_rx_ctx)
{
host_info->os_type = ENA_ADMIN_OS_DPDK;
host_info->kernel_ver = RTE_VERSION;
- strncpy((char *)host_info->kernel_ver_str, rte_version(),
- strlen(rte_version()));
+ snprintf((char *)host_info->kernel_ver_str,
+ sizeof(host_info->kernel_ver_str),
+ "%s", rte_version());
host_info->os_dist = RTE_VERSION;
- strncpy((char *)host_info->os_dist_str, rte_version(),
- strlen(rte_version()));
+ snprintf((char *)host_info->os_dist_str,
+ sizeof(host_info->os_dist_str),
+ "%s", rte_version());
host_info->driver_version =
(DRV_MODULE_VER_MAJOR) |
(DRV_MODULE_VER_MINOR << ENA_ADMIN_HOST_INFO_MINOR_SHIFT) |
rc = ena_com_set_host_attributes(ena_dev);
if (rc) {
- if (rc == -EPERM)
- RTE_LOG(ERR, PMD, "Cannot set host attributes\n");
- else
- RTE_LOG(ERR, PMD, "Cannot set host attributes\n");
-
- goto err;
+ RTE_LOG(ERR, PMD, "Cannot set host attributes\n");
+ if (rc != -EPERM)
+ goto err;
}
return;
rc = ena_com_set_host_attributes(&adapter->ena_dev);
if (rc) {
- if (rc == -EPERM)
- RTE_LOG(WARNING, PMD, "Cannot set host attributes\n");
- else
- RTE_LOG(ERR, PMD, "Cannot set host attributes\n");
- goto err;
+ RTE_LOG(WARNING, PMD, "Cannot set host attributes\n");
+ if (rc != -EPERM)
+ goto err;
}
return;
ring->rx_buffer_info[ring->next_to_clean & ring_mask];
if (m)
- __rte_mbuf_raw_free(m);
+ rte_mbuf_raw_free(m);
- ring->next_to_clean =
- ENA_CIRC_INC(ring->next_to_clean, 1, ring->ring_size);
+ ring->next_to_clean++;
}
}
if (tx_buf->mbuf)
rte_pktmbuf_free(tx_buf->mbuf);
- ring->next_to_clean =
- ENA_CIRC_INC(ring->next_to_clean, 1, ring->ring_size);
+ ring->next_to_clean++;
}
}
if (rc) {
PMD_INIT_LOG(ERR,
- "failed to restart queue %d type(%d)\n",
+ "failed to restart queue %d type(%d)",
i, ring_type);
return -1;
}
uint32_t max_frame_len = ena_get_mtu_conf(adapter);
if (max_frame_len > adapter->max_mtu) {
- PMD_INIT_LOG(ERR, "Unsupported MTU of %d\n", max_frame_len);
+ PMD_INIT_LOG(ERR, "Unsupported MTU of %d", max_frame_len);
return -1;
}
queue_size = rte_align32pow2(queue_size >> 1);
if (queue_size == 0) {
- PMD_INIT_LOG(ERR, "Invalid queue size\n");
+ PMD_INIT_LOG(ERR, "Invalid queue size");
return -EFAULT;
}
static int ena_queue_restart(struct ena_ring *ring)
{
- int rc;
+ int rc, bufs_num;
ena_assert_msg(ring->configured == 1,
"Trying to restart unconfigured queue\n");
if (ring->type == ENA_RING_TYPE_TX)
return 0;
- rc = ena_populate_rx_queue(ring, ring->ring_size - 1);
- if ((unsigned int)rc != ring->ring_size - 1) {
- PMD_INIT_LOG(ERR, "Failed to populate rx ring !\n");
+ bufs_num = ring->ring_size - 1;
+ rc = ena_populate_rx_queue(ring, bufs_num);
+ if (rc != bufs_num) {
+ PMD_INIT_LOG(ERR, "Failed to populate rx ring !");
return (-1);
}
return -1;
}
+ if (!rte_is_power_of_2(nb_desc)) {
+ RTE_LOG(ERR, PMD,
+ "Unsupported size of RX queue: %d is not a power of 2.",
+ nb_desc);
+ return -EINVAL;
+ }
+
if (nb_desc > adapter->tx_ring_size) {
RTE_LOG(ERR, PMD,
"Unsupported size of TX queue (max size: %d)\n",
ctx.msix_vector = -1; /* admin interrupts not used */
ctx.mem_queue_type = ena_dev->tx_mem_queue_type;
ctx.queue_size = adapter->tx_ring_size;
+ ctx.numa_node = ena_cpu_to_node(queue_idx);
rc = ena_com_create_io_queue(ena_dev, &ctx);
if (rc) {
return -1;
}
+ if (!rte_is_power_of_2(nb_desc)) {
+ RTE_LOG(ERR, PMD,
+ "Unsupported size of TX queue: %d is not a power of 2.",
+ nb_desc);
+ return -EINVAL;
+ }
+
if (nb_desc > adapter->rx_ring_size) {
RTE_LOG(ERR, PMD,
"Unsupported size of RX queue (max size: %d)\n",
ctx.mem_queue_type = ENA_ADMIN_PLACEMENT_POLICY_HOST;
ctx.msix_vector = -1; /* admin interrupts not used */
ctx.queue_size = adapter->rx_ring_size;
+ ctx.numa_node = ena_cpu_to_node(queue_idx);
rc = ena_com_create_io_queue(ena_dev, &ctx);
if (rc)
{
unsigned int i;
int rc;
- unsigned int ring_size = rxq->ring_size;
- unsigned int ring_mask = ring_size - 1;
- int next_to_use = rxq->next_to_use & ring_mask;
+ uint16_t ring_size = rxq->ring_size;
+ uint16_t ring_mask = ring_size - 1;
+ uint16_t next_to_use = rxq->next_to_use;
+ uint16_t in_use;
struct rte_mbuf **mbufs = &rxq->rx_buffer_info[0];
if (unlikely(!count))
return 0;
- ena_assert_msg((((ENA_CIRC_COUNT(rxq->next_to_use, rxq->next_to_clean,
- rxq->ring_size)) +
- count) < rxq->ring_size), "bad ring state");
+ in_use = rxq->next_to_use - rxq->next_to_clean;
+ ena_assert_msg(((in_use + count) < ring_size), "bad ring state");
- count = RTE_MIN(count, ring_size - next_to_use);
+ count = RTE_MIN(count,
+ (uint16_t)(ring_size - (next_to_use & ring_mask)));
/* get resources for incoming packets */
rc = rte_mempool_get_bulk(rxq->mb_pool,
- (void **)(&mbufs[next_to_use]), count);
+ (void **)(&mbufs[next_to_use & ring_mask]),
+ count);
if (unlikely(rc < 0)) {
rte_atomic64_inc(&rxq->adapter->drv_stats->rx_nombuf);
PMD_RX_LOG(DEBUG, "there are no enough free buffers");
}
for (i = 0; i < count; i++) {
- struct rte_mbuf *mbuf = mbufs[next_to_use];
+ uint16_t next_to_use_masked = next_to_use & ring_mask;
+ struct rte_mbuf *mbuf = mbufs[next_to_use_masked];
struct ena_com_buf ebuf;
rte_prefetch0(mbufs[((next_to_use + 4) & ring_mask)]);
ebuf.len = mbuf->buf_len - RTE_PKTMBUF_HEADROOM;
/* pass resource to device */
rc = ena_com_add_single_rx_desc(rxq->ena_com_io_sq,
- &ebuf, next_to_use);
+ &ebuf, next_to_use_masked);
if (unlikely(rc)) {
+ rte_mempool_put_bulk(rxq->mb_pool, (void **)(&mbuf),
+ count - i);
RTE_LOG(WARNING, PMD, "failed adding rx desc\n");
break;
}
- next_to_use = ENA_RX_RING_IDX_NEXT(next_to_use, ring_size);
+ next_to_use++;
}
- rte_wmb();
- rxq->next_to_use = next_to_use;
- /* let HW know that it can fill buffers with data */
- ena_com_write_sq_doorbell(rxq->ena_com_io_sq);
+ /* When we submitted free recources to device... */
+ if (i > 0) {
+ /* ...let HW know that it can fill buffers with data */
+ rte_wmb();
+ ena_com_write_sq_doorbell(rxq->ena_com_io_sq);
+
+ rxq->next_to_use = next_to_use;
+ }
return i;
}
goto err_mmio_read_less;
}
- ena_config_host_info(ena_dev);
-
/* To enable the msix interrupts the driver needs to know the number
* of queues. So the driver uses polling mode to retrieve this
* information.
*/
ena_com_set_admin_polling_mode(ena_dev, true);
+ ena_config_host_info(ena_dev);
+
/* Get Device Attributes and features */
rc = ena_com_get_dev_attr_feat(ena_dev, get_feat_ctx);
if (rc) {
eth_dev->dev_ops = &ena_dev_ops;
eth_dev->rx_pkt_burst = ð_ena_recv_pkts;
eth_dev->tx_pkt_burst = ð_ena_xmit_pkts;
+ eth_dev->tx_pkt_prepare = ð_ena_prep_pkts;
adapter->rte_eth_dev_data = eth_dev->data;
adapter->rte_dev = eth_dev;
if (rte_eal_process_type() != RTE_PROC_PRIMARY)
return 0;
- pci_dev = eth_dev->pci_dev;
+ pci_dev = RTE_DEV_TO_PCI(eth_dev->device);
adapter->pdev = pci_dev;
- PMD_INIT_LOG(INFO, "Initializing %x:%x:%x.%d\n",
+ PMD_INIT_LOG(INFO, "Initializing %x:%x:%x.%d",
pci_dev->addr.domain,
pci_dev->addr.bus,
pci_dev->addr.devid,
else if (adapter->regs)
ena_dev->tx_mem_queue_type = ENA_ADMIN_PLACEMENT_POLICY_HOST;
else
- PMD_INIT_LOG(CRIT, "Failed to access registers BAR(%d)\n",
+ PMD_INIT_LOG(CRIT, "Failed to access registers BAR(%d)",
ENA_REGS_BAR);
ena_dev->reg_bar = adapter->regs;
/* device specific initialization routine */
rc = ena_device_init(ena_dev, &get_feat_ctx);
if (rc) {
- PMD_INIT_LOG(CRIT, "Failed to init ENA device\n");
+ PMD_INIT_LOG(CRIT, "Failed to init ENA device");
return -1;
}
if (get_feat_ctx.max_queues.max_llq_num == 0) {
PMD_INIT_LOG(ERR,
"Trying to use LLQ but llq_num is 0.\n"
- "Fall back into regular queues.\n");
+ "Fall back into regular queues.");
ena_dev->tx_mem_queue_type =
ENA_ADMIN_PLACEMENT_POLICY_HOST;
adapter->num_queues =
/* Set max MTU for this device */
adapter->max_mtu = get_feat_ctx.dev_attr.max_mtu;
+ /* set device support for TSO */
+ adapter->tso4_supported = get_feat_ctx.offload.tx &
+ ENA_ADMIN_FEATURE_OFFLOAD_DESC_TSO_IPV4_MASK;
+
/* Copy MAC address and point DPDK to it */
eth_dev->data->mac_addrs = (struct ether_addr *)adapter->mac_addr;
ether_addr_copy((struct ether_addr *)get_feat_ctx.dev_attr.mac_addr,
if (!(adapter->state == ENA_ADAPTER_STATE_INIT ||
adapter->state == ENA_ADAPTER_STATE_STOPPED)) {
- PMD_INIT_LOG(ERR, "Illegal adapter state: %d\n",
+ PMD_INIT_LOG(ERR, "Illegal adapter state: %d",
adapter->state);
return -1;
}
ena_dev = &adapter->ena_dev;
ena_assert_msg(ena_dev != NULL, "Uninitialized device");
+ dev_info->pci_dev = RTE_DEV_TO_PCI(dev->device);
+
dev_info->speed_capa =
ETH_LINK_SPEED_1G |
ETH_LINK_SPEED_2_5G |
DEV_TX_OFFLOAD_UDP_CKSUM |
DEV_TX_OFFLOAD_TCP_CKSUM;
- if (feat.offload.tx &
+ if (feat.offload.rx_supported &
ENA_ADMIN_FEATURE_OFFLOAD_DESC_RX_L4_IPV4_CSUM_MASK)
rx_feat |= DEV_RX_OFFLOAD_IPV4_CKSUM |
DEV_RX_OFFLOAD_UDP_CKSUM |
unsigned int ring_size = rx_ring->ring_size;
unsigned int ring_mask = ring_size - 1;
uint16_t next_to_clean = rx_ring->next_to_clean;
- int desc_in_use = 0;
+ uint16_t desc_in_use = 0;
unsigned int recv_idx = 0;
struct rte_mbuf *mbuf = NULL;
struct rte_mbuf *mbuf_head = NULL;
return 0;
}
- desc_in_use = ENA_CIRC_COUNT(rx_ring->next_to_use,
- next_to_clean, ring_size);
+ desc_in_use = rx_ring->next_to_use - next_to_clean;
if (unlikely(nb_pkts > desc_in_use))
nb_pkts = desc_in_use;
mbuf_prev = mbuf;
segments++;
- next_to_clean =
- ENA_RX_RING_IDX_NEXT(next_to_clean, ring_size);
+ next_to_clean++;
}
/* fill mbuf attributes if any */
recv_idx++;
}
- /* Burst refill to save doorbells, memory barriers, const interval */
- if (ring_size - desc_in_use - 1 > ENA_RING_DESCS_RATIO(ring_size))
- ena_populate_rx_queue(rx_ring, ring_size - desc_in_use - 1);
+ rx_ring->next_to_clean = next_to_clean;
- rx_ring->next_to_clean = next_to_clean & ring_mask;
+ desc_in_use = desc_in_use - completed + 1;
+ /* Burst refill to save doorbells, memory barriers, const interval */
+ if (ring_size - desc_in_use > ENA_RING_DESCS_RATIO(ring_size))
+ ena_populate_rx_queue(rx_ring, ring_size - desc_in_use);
return recv_idx;
}
+static uint16_t
+eth_ena_prep_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+ uint16_t nb_pkts)
+{
+ int32_t ret;
+ uint32_t i;
+ struct rte_mbuf *m;
+ struct ena_ring *tx_ring = (struct ena_ring *)(tx_queue);
+ struct ipv4_hdr *ip_hdr;
+ uint64_t ol_flags;
+ uint16_t frag_field;
+
+ for (i = 0; i != nb_pkts; i++) {
+ m = tx_pkts[i];
+ ol_flags = m->ol_flags;
+
+ if (!(ol_flags & PKT_TX_IPV4))
+ continue;
+
+ /* If there was not L2 header length specified, assume it is
+ * length of the ethernet header.
+ */
+ if (unlikely(m->l2_len == 0))
+ m->l2_len = sizeof(struct ether_hdr);
+
+ ip_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
+ m->l2_len);
+ frag_field = rte_be_to_cpu_16(ip_hdr->fragment_offset);
+
+ if ((frag_field & IPV4_HDR_DF_FLAG) != 0) {
+ m->packet_type |= RTE_PTYPE_L4_NONFRAG;
+
+ /* If IPv4 header has DF flag enabled and TSO support is
+ * disabled, partial chcecksum should not be calculated.
+ */
+ if (!tx_ring->adapter->tso4_supported)
+ continue;
+ }
+
+ if ((ol_flags & ENA_TX_OFFLOAD_NOTSUP_MASK) != 0 ||
+ (ol_flags & PKT_TX_L4_MASK) ==
+ PKT_TX_SCTP_CKSUM) {
+ rte_errno = -ENOTSUP;
+ return i;
+ }
+
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+ ret = rte_validate_tx_offload(m);
+ if (ret != 0) {
+ rte_errno = ret;
+ return i;
+ }
+#endif
+
+ /* In case we are supposed to TSO and have DF not set (DF=0)
+ * hardware must be provided with partial checksum, otherwise
+ * it will take care of necessary calculations.
+ */
+
+ ret = rte_net_intel_cksum_flags_prepare(m,
+ ol_flags & ~PKT_TX_TCP_SEG);
+ if (ret != 0) {
+ rte_errno = ret;
+ return i;
+ }
+ }
+
+ return i;
+}
+
static uint16_t eth_ena_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
uint16_t nb_pkts)
{
struct ena_ring *tx_ring = (struct ena_ring *)(tx_queue);
- unsigned int next_to_use = tx_ring->next_to_use;
+ uint16_t next_to_use = tx_ring->next_to_use;
+ uint16_t next_to_clean = tx_ring->next_to_clean;
struct rte_mbuf *mbuf;
unsigned int ring_size = tx_ring->ring_size;
unsigned int ring_mask = ring_size - 1;
struct ena_tx_buffer *tx_info;
struct ena_com_buf *ebuf;
uint16_t rc, req_id, total_tx_descs = 0;
- int sent_idx = 0;
+ uint16_t sent_idx = 0, empty_tx_reqs;
int nb_hw_desc;
/* Check adapter state */
return 0;
}
+ empty_tx_reqs = ring_size - (next_to_use - next_to_clean);
+ if (nb_pkts > empty_tx_reqs)
+ nb_pkts = empty_tx_reqs;
+
for (sent_idx = 0; sent_idx < nb_pkts; sent_idx++) {
mbuf = tx_pkts[sent_idx];
- req_id = tx_ring->empty_tx_reqs[next_to_use];
+ req_id = tx_ring->empty_tx_reqs[next_to_use & ring_mask];
tx_info = &tx_ring->tx_buffer_info[req_id];
tx_info->mbuf = mbuf;
tx_info->num_of_bufs = 0;
tx_info->tx_descs = nb_hw_desc;
- next_to_use = ENA_TX_RING_IDX_NEXT(next_to_use, ring_size);
+ next_to_use++;
}
- /* Let HW do it's best :-) */
- rte_wmb();
- ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
+ /* If there are ready packets to be xmitted... */
+ if (sent_idx > 0) {
+ /* ...let HW do its best :-) */
+ rte_wmb();
+ ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
+
+ tx_ring->next_to_use = next_to_use;
+ }
/* Clear complete packets */
while (ena_com_tx_comp_req_id_get(tx_ring->ena_com_io_cq, &req_id) >= 0) {
rte_pktmbuf_free(mbuf);
/* Put back descriptor to the ring for reuse */
- tx_ring->empty_tx_reqs[tx_ring->next_to_clean] = req_id;
- tx_ring->next_to_clean =
- ENA_TX_RING_IDX_NEXT(tx_ring->next_to_clean,
- tx_ring->ring_size);
+ tx_ring->empty_tx_reqs[next_to_clean & ring_mask] = req_id;
+ next_to_clean++;
/* If too many descs to clean, leave it for another run */
if (unlikely(total_tx_descs > ENA_RING_DESCS_RATIO(ring_size)))
break;
}
- /* acknowledge completion of sent packets */
- ena_com_comp_ack(tx_ring->ena_com_io_sq, total_tx_descs);
- tx_ring->next_to_use = next_to_use;
+ if (total_tx_descs > 0) {
+ /* acknowledge completion of sent packets */
+ ena_com_comp_ack(tx_ring->ena_com_io_sq, total_tx_descs);
+ tx_ring->next_to_clean = next_to_clean;
+ }
+
return sent_idx;
}
-static struct eth_driver rte_ena_pmd = {
- {
- .name = "rte_ena_pmd",
- .id_table = pci_id_ena_map,
- .drv_flags = RTE_PCI_DRV_NEED_MAPPING,
- },
- .eth_dev_init = eth_ena_dev_init,
- .dev_private_size = sizeof(struct ena_adapter),
-};
+static int eth_ena_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
+ struct rte_pci_device *pci_dev)
+{
+ return rte_eth_dev_pci_generic_probe(pci_dev,
+ sizeof(struct ena_adapter), eth_ena_dev_init);
+}
-static int
-rte_ena_pmd_init(const char *name __rte_unused,
- const char *params __rte_unused)
+static int eth_ena_pci_remove(struct rte_pci_device *pci_dev)
{
- rte_eth_driver_register(&rte_ena_pmd);
- return 0;
-};
+ return rte_eth_dev_pci_generic_remove(pci_dev, NULL);
+}
-struct rte_driver ena_pmd_drv = {
- .type = PMD_PDEV,
- .init = rte_ena_pmd_init,
+static struct rte_pci_driver rte_ena_pmd = {
+ .id_table = pci_id_ena_map,
+ .drv_flags = RTE_PCI_DRV_NEED_MAPPING,
+ .probe = eth_ena_pci_probe,
+ .remove = eth_ena_pci_remove,
};
-PMD_REGISTER_DRIVER(ena_pmd_drv, ena);
-DRIVER_REGISTER_PCI_TABLE(ena, pci_id_ena_map);
+RTE_PMD_REGISTER_PCI(net_ena, rte_ena_pmd);
+RTE_PMD_REGISTER_PCI_TABLE(net_ena, pci_id_ena_map);
+RTE_PMD_REGISTER_KMOD_DEP(net_ena, "* igb_uio | uio_pci_generic | vfio-pci");
git.droids-corp.org / dpdk.git / blobdiff