@@ -112,12 +112,20 @@ struct gve_tx_iovec {
u32 iov_padding; /* padding associated with this segment */
};
+struct gve_tx_dma_buf {
+ DEFINE_DMA_UNMAP_ADDR(dma);
+ DEFINE_DMA_UNMAP_LEN(len);
+};
+
/* Tracks the memory in the fifo occupied by the skb. Mapped 1:1 to a desc
* ring entry but only used for a pkt_desc not a seg_desc
*/
struct gve_tx_buffer_state {
struct sk_buff *skb; /* skb for this pkt */
- struct gve_tx_iovec iov[GVE_TX_MAX_IOVEC]; /* segments of this pkt */
+ union {
+ struct gve_tx_iovec iov[GVE_TX_MAX_IOVEC]; /* segments of this pkt */
+ struct gve_tx_dma_buf buf;
+ };
};
/* A TX buffer - each queue has one */
@@ -140,13 +148,16 @@ struct gve_tx_ring {
__be32 last_nic_done ____cacheline_aligned; /* NIC tail pointer */
u64 pkt_done; /* free-running - total packets completed */
u64 bytes_done; /* free-running - total bytes completed */
+ u32 dropped_pkt; /* free-running - total packets dropped */
/* Cacheline 2 -- Read-mostly fields */
union gve_tx_desc *desc ____cacheline_aligned;
struct gve_tx_buffer_state *info; /* Maps 1:1 to a desc */
struct netdev_queue *netdev_txq;
struct gve_queue_resources *q_resources; /* head and tail pointer idx */
+ struct device *dev;
u32 mask; /* masks req and done down to queue size */
+ bool raw_addressing; /* use raw_addressing? */
/* Slow-path fields */
u32 q_num ____cacheline_aligned; /* queue idx */
@@ -442,7 +453,10 @@ static inline u32 gve_rx_idx_to_ntfy(struct gve_priv *priv, u32 queue_idx)
*/
static inline u32 gve_num_tx_qpls(struct gve_priv *priv)
{
- return priv->tx_cfg.num_queues;
+ if (priv->raw_addressing)
+ return 0;
+ else
+ return priv->tx_cfg.num_queues;
}
/* Returns the number of rx queue page lists
@@ -318,8 +318,10 @@ static int gve_adminq_create_tx_queue(struct gve_priv *priv, u32 queue_index)
{
struct gve_tx_ring *tx = &priv->tx[queue_index];
union gve_adminq_command cmd;
+ u32 qpl_id;
int err;
+ qpl_id = priv->raw_addressing ? GVE_RAW_ADDRESSING_QPL_ID : tx->tx_fifo.qpl->id;
memset(&cmd, 0, sizeof(cmd));
cmd.opcode = cpu_to_be32(GVE_ADMINQ_CREATE_TX_QUEUE);
cmd.create_tx_queue = (struct gve_adminq_create_tx_queue) {
@@ -328,7 +330,7 @@ static int gve_adminq_create_tx_queue(struct gve_priv *priv, u32 queue_index)
.queue_resources_addr =
cpu_to_be64(tx->q_resources_bus),
.tx_ring_addr = cpu_to_be64(tx->bus),
- .queue_page_list_id = cpu_to_be32(tx->tx_fifo.qpl->id),
+ .queue_page_list_id = cpu_to_be32(qpl_id),
.ntfy_id = cpu_to_be32(tx->ntfy_id),
};
@@ -16,9 +16,11 @@
* Base addresses encoded in seg_addr are not assumed to be physical
* addresses. The ring format assumes these come from some linear address
* space. This could be physical memory, kernel virtual memory, user virtual
- * memory. gVNIC uses lists of registered pages. Each queue is assumed
- * to be associated with a single such linear address space to ensure a
- * consistent meaning for seg_addrs posted to its rings.
+ * memory.
+ * If raw dma addressing is not supported then gVNIC uses lists of registered
+ * pages. Each queue is assumed to be associated with a single such linear
+ * address space to ensure a consistent meaning for seg_addrs posted to its
+ * rings.
*/
struct gve_tx_pkt_desc {
@@ -158,9 +158,11 @@ static void gve_tx_free_ring(struct gve_priv *priv, int idx)
tx->q_resources, tx->q_resources_bus);
tx->q_resources = NULL;
- gve_tx_fifo_release(priv, &tx->tx_fifo);
- gve_unassign_qpl(priv, tx->tx_fifo.qpl->id);
- tx->tx_fifo.qpl = NULL;
+ if (!tx->raw_addressing) {
+ gve_tx_fifo_release(priv, &tx->tx_fifo);
+ gve_unassign_qpl(priv, tx->tx_fifo.qpl->id);
+ tx->tx_fifo.qpl = NULL;
+ }
bytes = sizeof(*tx->desc) * slots;
dma_free_coherent(hdev, bytes, tx->desc, tx->bus);
@@ -206,11 +208,15 @@ static int gve_tx_alloc_ring(struct gve_priv *priv, int idx)
if (!tx->desc)
goto abort_with_info;
- tx->tx_fifo.qpl = gve_assign_tx_qpl(priv);
+ tx->raw_addressing = priv->raw_addressing;
+ tx->dev = &priv->pdev->dev;
+ if (!tx->raw_addressing) {
+ tx->tx_fifo.qpl = gve_assign_tx_qpl(priv);
- /* map Tx FIFO */
- if (gve_tx_fifo_init(priv, &tx->tx_fifo))
- goto abort_with_desc;
+ /* map Tx FIFO */
+ if (gve_tx_fifo_init(priv, &tx->tx_fifo))
+ goto abort_with_desc;
+ }
tx->q_resources =
dma_alloc_coherent(hdev,
@@ -228,7 +234,8 @@ static int gve_tx_alloc_ring(struct gve_priv *priv, int idx)
return 0;
abort_with_fifo:
- gve_tx_fifo_release(priv, &tx->tx_fifo);
+ if (!tx->raw_addressing)
+ gve_tx_fifo_release(priv, &tx->tx_fifo);
abort_with_desc:
dma_free_coherent(hdev, bytes, tx->desc, tx->bus);
tx->desc = NULL;
@@ -301,27 +308,47 @@ static inline int gve_skb_fifo_bytes_required(struct gve_tx_ring *tx,
return bytes;
}
-/* The most descriptors we could need are 3 - 1 for the headers, 1 for
- * the beginning of the payload at the end of the FIFO, and 1 if the
- * payload wraps to the beginning of the FIFO.
+/* The most descriptors we could need is MAX_SKB_FRAGS + 3 : 1 for each skb frag,
+ * +1 for the skb linear portion, +1 for when tcp hdr needs to be in separate descriptor,
+ * and +1 if the payload wraps to the beginning of the FIFO.
*/
-#define MAX_TX_DESC_NEEDED 3
+#define MAX_TX_DESC_NEEDED (MAX_SKB_FRAGS + 3)
+static void gve_tx_unmap_buf(struct device *dev, struct gve_tx_buffer_state *info)
+{
+ if (info->skb) {
+ dma_unmap_single(dev, dma_unmap_addr(&info->buf, dma),
+ dma_unmap_len(&info->buf, len),
+ DMA_TO_DEVICE);
+ dma_unmap_len_set(&info->buf, len, 0);
+ } else {
+ dma_unmap_page(dev, dma_unmap_addr(&info->buf, dma),
+ dma_unmap_len(&info->buf, len),
+ DMA_TO_DEVICE);
+ dma_unmap_len_set(&info->buf, len, 0);
+ }
+}
/* Check if sufficient resources (descriptor ring space, FIFO space) are
* available to transmit the given number of bytes.
*/
static inline bool gve_can_tx(struct gve_tx_ring *tx, int bytes_required)
{
- return (gve_tx_avail(tx) >= MAX_TX_DESC_NEEDED &&
- gve_tx_fifo_can_alloc(&tx->tx_fifo, bytes_required));
+ bool can_alloc = true;
+
+ if (!tx->raw_addressing)
+ can_alloc = gve_tx_fifo_can_alloc(&tx->tx_fifo, bytes_required);
+
+ return (gve_tx_avail(tx) >= MAX_TX_DESC_NEEDED && can_alloc);
}
/* Stops the queue if the skb cannot be transmitted. */
static int gve_maybe_stop_tx(struct gve_tx_ring *tx, struct sk_buff *skb)
{
- int bytes_required;
+ int bytes_required = 0;
+
+ if (!tx->raw_addressing)
+ bytes_required = gve_skb_fifo_bytes_required(tx, skb);
- bytes_required = gve_skb_fifo_bytes_required(tx, skb);
if (likely(gve_can_tx(tx, bytes_required)))
return 0;
@@ -390,22 +417,22 @@ static void gve_tx_fill_seg_desc(union gve_tx_desc *seg_desc,
seg_desc->seg.seg_addr = cpu_to_be64(addr);
}
-static void gve_dma_sync_for_device(struct device *dev, dma_addr_t *page_buses,
+static void gve_dma_sync_for_device(struct gve_priv *priv,
+ dma_addr_t *page_buses,
u64 iov_offset, u64 iov_len)
{
u64 last_page = (iov_offset + iov_len - 1) / PAGE_SIZE;
u64 first_page = iov_offset / PAGE_SIZE;
- dma_addr_t dma;
u64 page;
for (page = first_page; page <= last_page; page++) {
- dma = page_buses[page];
- dma_sync_single_for_device(dev, dma, PAGE_SIZE, DMA_TO_DEVICE);
+ dma_addr_t dma = page_buses[page];
+
+ dma_sync_single_for_device(&priv->pdev->dev, dma, PAGE_SIZE, DMA_TO_DEVICE);
}
}
-static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb,
- struct device *dev)
+static int gve_tx_add_skb_copy(struct gve_priv *priv, struct gve_tx_ring *tx, struct sk_buff *skb)
{
int pad_bytes, hlen, hdr_nfrags, payload_nfrags, l4_hdr_offset;
union gve_tx_desc *pkt_desc, *seg_desc;
@@ -447,7 +474,7 @@ static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb,
skb_copy_bits(skb, 0,
tx->tx_fifo.base + info->iov[hdr_nfrags - 1].iov_offset,
hlen);
- gve_dma_sync_for_device(dev, tx->tx_fifo.qpl->page_buses,
+ gve_dma_sync_for_device(priv, tx->tx_fifo.qpl->page_buses,
info->iov[hdr_nfrags - 1].iov_offset,
info->iov[hdr_nfrags - 1].iov_len);
copy_offset = hlen;
@@ -463,7 +490,7 @@ static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb,
skb_copy_bits(skb, copy_offset,
tx->tx_fifo.base + info->iov[i].iov_offset,
info->iov[i].iov_len);
- gve_dma_sync_for_device(dev, tx->tx_fifo.qpl->page_buses,
+ gve_dma_sync_for_device(priv, tx->tx_fifo.qpl->page_buses,
info->iov[i].iov_offset,
info->iov[i].iov_len);
copy_offset += info->iov[i].iov_len;
@@ -472,6 +499,98 @@ static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb,
return 1 + payload_nfrags;
}
+static int gve_tx_add_skb_no_copy(struct gve_priv *priv, struct gve_tx_ring *tx,
+ struct sk_buff *skb)
+{
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int hlen, payload_nfrags, l4_hdr_offset, seg_idx_bias;
+ union gve_tx_desc *pkt_desc, *seg_desc;
+ struct gve_tx_buffer_state *info;
+ bool is_gso = skb_is_gso(skb);
+ u32 idx = tx->req & tx->mask;
+ struct gve_tx_dma_buf *buf;
+ int last_mapped = 0;
+ u64 addr;
+ u32 len;
+ int i;
+
+ info = &tx->info[idx];
+ pkt_desc = &tx->desc[idx];
+
+ l4_hdr_offset = skb_checksum_start_offset(skb);
+ /* If the skb is gso, then we want only up to the tcp header in the first segment
+ * to efficiently replicate on each segment otherwise we want the linear portion
+ * of the skb (which will contain the checksum because skb->csum_start and
+ * skb->csum_offset are given relative to skb->head) in the first segment.
+ */
+ hlen = is_gso ? l4_hdr_offset + tcp_hdrlen(skb) :
+ skb_headlen(skb);
+ len = skb_headlen(skb);
+
+ info->skb = skb;
+
+ addr = dma_map_single(tx->dev, skb->data, len, DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(tx->dev, addr))) {
+ priv->dma_mapping_error++;
+ goto drop;
+ }
+ buf = &info->buf;
+ dma_unmap_len_set(buf, len, len);
+ dma_unmap_addr_set(buf, dma, addr);
+
+ payload_nfrags = shinfo->nr_frags;
+ if (hlen < len) {
+ /* For gso the rest of the linear portion of the skb needs to
+ * be in its own descriptor.
+ */
+ payload_nfrags++;
+ gve_tx_fill_pkt_desc(pkt_desc, skb, is_gso, l4_hdr_offset,
+ 1 + payload_nfrags, hlen, addr);
+
+ len -= hlen;
+ addr += hlen;
+ seg_desc = &tx->desc[(tx->req + 1) & tx->mask];
+ seg_idx_bias = 2;
+ gve_tx_fill_seg_desc(seg_desc, skb, is_gso, len, addr);
+ } else {
+ seg_idx_bias = 1;
+ gve_tx_fill_pkt_desc(pkt_desc, skb, is_gso, l4_hdr_offset,
+ 1 + payload_nfrags, hlen, addr);
+ }
+ idx = (tx->req + seg_idx_bias) & tx->mask;
+
+ for (i = 0; i < payload_nfrags - (seg_idx_bias - 1); i++) {
+ const skb_frag_t *frag = &shinfo->frags[i];
+
+ seg_desc = &tx->desc[idx];
+ len = skb_frag_size(frag);
+ addr = skb_frag_dma_map(tx->dev, frag, 0, len, DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(tx->dev, addr))) {
+ priv->dma_mapping_error++;
+ goto unmap_drop;
+ }
+ buf = &tx->info[idx].buf;
+ tx->info[idx].skb = NULL;
+ dma_unmap_len_set(buf, len, len);
+ dma_unmap_addr_set(buf, dma, addr);
+
+ gve_tx_fill_seg_desc(seg_desc, skb, is_gso, len, addr);
+ idx = (idx + 1) & tx->mask;
+ }
+
+ return 1 + payload_nfrags;
+
+unmap_drop:
+ i--;
+ for (last_mapped = i + seg_idx_bias; last_mapped >= 0; last_mapped--) {
+ idx = (tx->req + last_mapped) & tx->mask;
+ gve_tx_unmap_buf(tx->dev, &tx->info[idx]);
+ }
+drop:
+ tx->dropped_pkt++;
+ return 0;
+}
+
netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev)
{
struct gve_priv *priv = netdev_priv(dev);
@@ -490,12 +609,20 @@ netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev)
gve_tx_put_doorbell(priv, tx->q_resources, tx->req);
return NETDEV_TX_BUSY;
}
- nsegs = gve_tx_add_skb(tx, skb, &priv->pdev->dev);
-
- netdev_tx_sent_queue(tx->netdev_txq, skb->len);
- skb_tx_timestamp(skb);
+ if (tx->raw_addressing)
+ nsegs = gve_tx_add_skb_no_copy(priv, tx, skb);
+ else
+ nsegs = gve_tx_add_skb_copy(priv, tx, skb);
+
+ /* If the packet is getting sent, we need to update the skb */
+ if (nsegs) {
+ netdev_tx_sent_queue(tx->netdev_txq, skb->len);
+ skb_tx_timestamp(skb);
+ }
- /* give packets to NIC */
+ /* Give packets to NIC. Even if this packet failed to send the doorbell
+ * might need to be rung because of xmit_more.
+ */
tx->req += nsegs;
if (!netif_xmit_stopped(tx->netdev_txq) && netdev_xmit_more())
@@ -525,24 +652,30 @@ static int gve_clean_tx_done(struct gve_priv *priv, struct gve_tx_ring *tx,
info = &tx->info[idx];
skb = info->skb;
+ /* Unmap the buffer */
+ if (tx->raw_addressing)
+ gve_tx_unmap_buf(tx->dev, info);
/* Mark as free */
if (skb) {
info->skb = NULL;
bytes += skb->len;
pkts++;
dev_consume_skb_any(skb);
- /* FIFO free */
- for (i = 0; i < ARRAY_SIZE(info->iov); i++) {
- space_freed += info->iov[i].iov_len +
- info->iov[i].iov_padding;
- info->iov[i].iov_len = 0;
- info->iov[i].iov_padding = 0;
+ if (!tx->raw_addressing) {
+ /* FIFO free */
+ for (i = 0; i < ARRAY_SIZE(info->iov); i++) {
+ space_freed += info->iov[i].iov_len +
+ info->iov[i].iov_padding;
+ info->iov[i].iov_len = 0;
+ info->iov[i].iov_padding = 0;
+ }
}
}
tx->done++;
}
- gve_tx_free_fifo(&tx->tx_fifo, space_freed);
+ if (!tx->raw_addressing)
+ gve_tx_free_fifo(&tx->tx_fifo, space_freed);
u64_stats_update_begin(&tx->statss);
tx->bytes_done += bytes;
tx->pkt_done += pkts;