@@ -1955,15 +1955,6 @@ static int lan743x_rx_next_index(struct lan743x_rx *rx, int index)
return ((++index) % rx->ring_size);
}
-static struct sk_buff *lan743x_rx_allocate_skb(struct lan743x_rx *rx)
-{
- int length = 0;
-
- length = (LAN743X_MAX_FRAME_SIZE + ETH_HLEN + 4 + RX_HEAD_PADDING);
- return __netdev_alloc_skb(rx->adapter->netdev,
- length, GFP_ATOMIC | GFP_DMA);
-}
-
static void lan743x_rx_update_tail(struct lan743x_rx *rx, int index)
{
/* update the tail once per 8 descriptors */
@@ -1972,36 +1963,40 @@ static void lan743x_rx_update_tail(struct lan743x_rx *rx, int index)
index);
}
-static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index,
- struct sk_buff *skb)
+static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index)
{
+ struct net_device *netdev = rx->adapter->netdev;
+ struct device *dev = &rx->adapter->pdev->dev;
struct lan743x_rx_buffer_info *buffer_info;
struct lan743x_rx_descriptor *descriptor;
- int length = 0;
+ struct sk_buff *skb;
+ dma_addr_t dma_ptr;
+ int length;
+
+ length = netdev->mtu + ETH_HLEN + 4 + RX_HEAD_PADDING;
- length = (LAN743X_MAX_FRAME_SIZE + ETH_HLEN + 4 + RX_HEAD_PADDING);
descriptor = &rx->ring_cpu_ptr[index];
buffer_info = &rx->buffer_info[index];
- buffer_info->skb = skb;
- if (!(buffer_info->skb))
+ skb = __netdev_alloc_skb(netdev, length, GFP_ATOMIC | GFP_DMA);
+ if (!skb)
return -ENOMEM;
- buffer_info->dma_ptr = dma_map_single(&rx->adapter->pdev->dev,
- buffer_info->skb->data,
- length,
- DMA_FROM_DEVICE);
- if (dma_mapping_error(&rx->adapter->pdev->dev,
- buffer_info->dma_ptr)) {
- buffer_info->dma_ptr = 0;
+ dma_ptr = dma_map_single(dev, skb->data, length, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, dma_ptr)) {
+ dev_kfree_skb_any(skb);
return -ENOMEM;
}
+ if (buffer_info->dma_ptr)
+ dma_unmap_single(dev, buffer_info->dma_ptr,
+ buffer_info->buffer_length, DMA_FROM_DEVICE);
+ buffer_info->skb = skb;
+ buffer_info->dma_ptr = dma_ptr;
buffer_info->buffer_length = length;
descriptor->data1 = cpu_to_le32(DMA_ADDR_LOW32(buffer_info->dma_ptr));
descriptor->data2 = cpu_to_le32(DMA_ADDR_HIGH32(buffer_info->dma_ptr));
descriptor->data3 = 0;
descriptor->data0 = cpu_to_le32((RX_DESC_DATA0_OWN_ |
(length & RX_DESC_DATA0_BUF_LENGTH_MASK_)));
- skb_reserve(buffer_info->skb, RX_HEAD_PADDING);
lan743x_rx_update_tail(rx, index);
return 0;
@@ -2050,16 +2045,32 @@ static void lan743x_rx_release_ring_element(struct lan743x_rx *rx, int index)
memset(buffer_info, 0, sizeof(*buffer_info));
}
-static int lan743x_rx_process_packet(struct lan743x_rx *rx)
+static struct sk_buff *
+lan743x_rx_trim_skb(struct sk_buff *skb, int frame_length)
+{
+ if (skb_linearize(skb)) {
+ dev_kfree_skb_irq(skb);
+ return NULL;
+ }
+ frame_length = max_t(int, 0, frame_length - RX_HEAD_PADDING - 2);
+ if (skb->len > frame_length) {
+ skb->tail -= skb->len - frame_length;
+ skb->len = frame_length;
+ }
+ return skb;
+}
+
+static int lan743x_rx_process_buffer(struct lan743x_rx *rx)
{
- struct skb_shared_hwtstamps *hwtstamps = NULL;
- int result = RX_PROCESS_RESULT_NOTHING_TO_DO;
int current_head_index = le32_to_cpu(*rx->head_cpu_ptr);
+ struct lan743x_rx_descriptor *descriptor, *desc_ext;
+ struct net_device *netdev = rx->adapter->netdev;
+ int result = RX_PROCESS_RESULT_NOTHING_TO_DO;
struct lan743x_rx_buffer_info *buffer_info;
- struct lan743x_rx_descriptor *descriptor;
+ int frame_length, buffer_length;
int extension_index = -1;
- int first_index = -1;
- int last_index = -1;
+ bool is_last, is_first;
+ struct sk_buff *skb;
if (current_head_index < 0 || current_head_index >= rx->ring_size)
goto done;
@@ -2067,163 +2078,120 @@ static int lan743x_rx_process_packet(struct lan743x_rx *rx)
if (rx->last_head < 0 || rx->last_head >= rx->ring_size)
goto done;
- if (rx->last_head != current_head_index) {
- descriptor = &rx->ring_cpu_ptr[rx->last_head];
- if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_OWN_)
- goto done;
+ if (rx->last_head == current_head_index)
+ goto done;
- if (!(le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_FS_))
- goto done;
+ descriptor = &rx->ring_cpu_ptr[rx->last_head];
+ if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_OWN_)
+ goto done;
+ buffer_info = &rx->buffer_info[rx->last_head];
- first_index = rx->last_head;
- if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_LS_) {
- last_index = rx->last_head;
- } else {
- int index;
-
- index = lan743x_rx_next_index(rx, first_index);
- while (index != current_head_index) {
- descriptor = &rx->ring_cpu_ptr[index];
- if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_OWN_)
- goto done;
-
- if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_LS_) {
- last_index = index;
- break;
- }
- index = lan743x_rx_next_index(rx, index);
- }
- }
- if (last_index >= 0) {
- descriptor = &rx->ring_cpu_ptr[last_index];
- if (le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_EXT_) {
- /* extension is expected to follow */
- int index = lan743x_rx_next_index(rx,
- last_index);
- if (index != current_head_index) {
- descriptor = &rx->ring_cpu_ptr[index];
- if (le32_to_cpu(descriptor->data0) &
- RX_DESC_DATA0_OWN_) {
- goto done;
- }
- if (le32_to_cpu(descriptor->data0) &
- RX_DESC_DATA0_EXT_) {
- extension_index = index;
- } else {
- goto done;
- }
- } else {
- /* extension is not yet available */
- /* prevent processing of this packet */
- first_index = -1;
- last_index = -1;
- }
- }
- }
- }
- if (first_index >= 0 && last_index >= 0) {
- int real_last_index = last_index;
- struct sk_buff *skb = NULL;
- u32 ts_sec = 0;
- u32 ts_nsec = 0;
-
- /* packet is available */
- if (first_index == last_index) {
- /* single buffer packet */
- struct sk_buff *new_skb = NULL;
- int packet_length;
-
- new_skb = lan743x_rx_allocate_skb(rx);
- if (!new_skb) {
- /* failed to allocate next skb.
- * Memory is very low.
- * Drop this packet and reuse buffer.
- */
- lan743x_rx_reuse_ring_element(rx, first_index);
- goto process_extension;
- }
+ is_last = le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_LS_;
+ is_first = le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_FS_;
- buffer_info = &rx->buffer_info[first_index];
- skb = buffer_info->skb;
- descriptor = &rx->ring_cpu_ptr[first_index];
-
- /* unmap from dma */
- if (buffer_info->dma_ptr) {
- dma_unmap_single(&rx->adapter->pdev->dev,
- buffer_info->dma_ptr,
- buffer_info->buffer_length,
- DMA_FROM_DEVICE);
- buffer_info->dma_ptr = 0;
- buffer_info->buffer_length = 0;
- }
- buffer_info->skb = NULL;
- packet_length = RX_DESC_DATA0_FRAME_LENGTH_GET_
- (le32_to_cpu(descriptor->data0));
- skb_put(skb, packet_length - 4);
- skb->protocol = eth_type_trans(skb,
- rx->adapter->netdev);
- lan743x_rx_init_ring_element(rx, first_index, new_skb);
- } else {
- int index = first_index;
+ if (is_last && le32_to_cpu(descriptor->data0) & RX_DESC_DATA0_EXT_) {
+ /* extension is expected to follow */
+ int index = lan743x_rx_next_index(rx, rx->last_head);
- /* multi buffer packet not supported */
- /* this should not happen since
- * buffers are allocated to be at least jumbo size
- */
+ if (index == current_head_index)
+ /* extension not yet available */
+ goto done;
+ desc_ext = &rx->ring_cpu_ptr[index];
+ if (le32_to_cpu(desc_ext->data0) & RX_DESC_DATA0_OWN_)
+ /* extension not yet available */
+ goto done;
+ if (!(le32_to_cpu(desc_ext->data0) & RX_DESC_DATA0_EXT_))
+ goto move_forward;
+ extension_index = index;
+ }
- /* clean up buffers */
- if (first_index <= last_index) {
- while ((index >= first_index) &&
- (index <= last_index)) {
- lan743x_rx_reuse_ring_element(rx,
- index);
- index = lan743x_rx_next_index(rx,
- index);
- }
- } else {
- while ((index >= first_index) ||
- (index <= last_index)) {
- lan743x_rx_reuse_ring_element(rx,
- index);
- index = lan743x_rx_next_index(rx,
- index);
- }
- }
- }
+ /* Only the last buffer in a multi-buffer frame contains the total frame
+ * length. The chip occasionally sends more buffers than strictly
+ * required to reach the total frame length.
+ * Handle this by adding all buffers to the skb in their entirety.
+ * Once the real frame length is known, trim the skb.
+ */
+ frame_length =
+ RX_DESC_DATA0_FRAME_LENGTH_GET_(le32_to_cpu(descriptor->data0));
+ buffer_length = buffer_info->buffer_length;
+
+ netdev_dbg(netdev, "%s%schunk: %d/%d",
+ is_first ? "first " : " ",
+ is_last ? "last " : " ",
+ frame_length, buffer_length);
+
+ /* save existing skb, allocate new skb and map to dma */
+ skb = buffer_info->skb;
+ if (lan743x_rx_init_ring_element(rx, rx->last_head)) {
+ /* failed to allocate next skb.
+ * Memory is very low.
+ * Drop this packet and reuse buffer.
+ */
+ lan743x_rx_reuse_ring_element(rx, rx->last_head);
+ /* drop packet that was being assembled */
+ dev_kfree_skb_irq(rx->skb_head);
+ rx->skb_head = NULL;
+ goto process_extension;
+ }
+
+ /* add buffers to skb via skb->frag_list */
+ if (is_first) {
+ skb_reserve(skb, RX_HEAD_PADDING);
+ skb_put(skb, buffer_length - RX_HEAD_PADDING);
+ if (rx->skb_head)
+ dev_kfree_skb_irq(rx->skb_head);
+ rx->skb_head = skb;
+ } else if (rx->skb_head) {
+ skb_put(skb, buffer_length);
+ if (skb_shinfo(rx->skb_head)->frag_list)
+ rx->skb_tail->next = skb;
+ else
+ skb_shinfo(rx->skb_head)->frag_list = skb;
+ rx->skb_tail = skb;
+ rx->skb_head->len += skb->len;
+ rx->skb_head->data_len += skb->len;
+ rx->skb_head->truesize += skb->truesize;
+ } else {
+ /* packet to assemble has already been dropped because one or
+ * more of its buffers could not be allocated
+ */
+ netdev_dbg(netdev, "drop buffer intended for dropped packet");
+ dev_kfree_skb_irq(skb);
+ }
process_extension:
- if (extension_index >= 0) {
- descriptor = &rx->ring_cpu_ptr[extension_index];
- buffer_info = &rx->buffer_info[extension_index];
-
- ts_sec = le32_to_cpu(descriptor->data1);
- ts_nsec = (le32_to_cpu(descriptor->data2) &
- RX_DESC_DATA2_TS_NS_MASK_);
- lan743x_rx_reuse_ring_element(rx, extension_index);
- real_last_index = extension_index;
- }
+ if (extension_index >= 0) {
+ u32 ts_sec;
+ u32 ts_nsec;
- if (!skb) {
- result = RX_PROCESS_RESULT_PACKET_DROPPED;
- goto move_forward;
- }
+ ts_sec = le32_to_cpu(desc_ext->data1);
+ ts_nsec = (le32_to_cpu(desc_ext->data2) &
+ RX_DESC_DATA2_TS_NS_MASK_);
+ if (rx->skb_head)
+ skb_hwtstamps(rx->skb_head)->hwtstamp =
+ ktime_set(ts_sec, ts_nsec);
+ lan743x_rx_reuse_ring_element(rx, extension_index);
+ rx->last_head = extension_index;
+ netdev_dbg(netdev, "process extension");
+ }
- if (extension_index < 0)
- goto pass_packet_to_os;
- hwtstamps = skb_hwtstamps(skb);
- if (hwtstamps)
- hwtstamps->hwtstamp = ktime_set(ts_sec, ts_nsec);
+ if (is_last && rx->skb_head)
+ rx->skb_head = lan743x_rx_trim_skb(rx->skb_head, frame_length);
-pass_packet_to_os:
- /* pass packet to OS */
- napi_gro_receive(&rx->napi, skb);
- result = RX_PROCESS_RESULT_PACKET_RECEIVED;
+ if (is_last && rx->skb_head) {
+ rx->skb_head->protocol = eth_type_trans(rx->skb_head,
+ rx->adapter->netdev);
+ netdev_dbg(netdev, "sending %d byte frame to OS",
+ rx->skb_head->len);
+ napi_gro_receive(&rx->napi, rx->skb_head);
+ rx->skb_head = NULL;
+ }
move_forward:
- /* push tail and head forward */
- rx->last_tail = real_last_index;
- rx->last_head = lan743x_rx_next_index(rx, real_last_index);
- }
+ /* push tail and head forward */
+ rx->last_tail = rx->last_head;
+ rx->last_head = lan743x_rx_next_index(rx, rx->last_head);
+ result = RX_PROCESS_RESULT_BUFFER_RECEIVED;
done:
return result;
}
@@ -2242,12 +2210,12 @@ static int lan743x_rx_napi_poll(struct napi_struct *napi, int weight)
DMAC_INT_BIT_RXFRM_(rx->channel_number));
}
for (count = 0; count < weight; count++) {
- result = lan743x_rx_process_packet(rx);
+ result = lan743x_rx_process_buffer(rx);
if (result == RX_PROCESS_RESULT_NOTHING_TO_DO)
break;
}
rx->frame_count += count;
- if (count == weight || result == RX_PROCESS_RESULT_PACKET_RECEIVED)
+ if (count == weight || result == RX_PROCESS_RESULT_BUFFER_RECEIVED)
return weight;
if (!napi_complete_done(napi, count))
@@ -2359,9 +2327,7 @@ static int lan743x_rx_ring_init(struct lan743x_rx *rx)
rx->last_head = 0;
for (index = 0; index < rx->ring_size; index++) {
- struct sk_buff *new_skb = lan743x_rx_allocate_skb(rx);
-
- ret = lan743x_rx_init_ring_element(rx, index, new_skb);
+ ret = lan743x_rx_init_ring_element(rx, index);
if (ret)
goto cleanup;
}
@@ -698,6 +698,8 @@ struct lan743x_rx {
struct napi_struct napi;
u32 frame_count;
+
+ struct sk_buff *skb_head, *skb_tail;
};
struct lan743x_adapter {
@@ -831,8 +833,7 @@ struct lan743x_rx_buffer_info {
#define LAN743X_RX_RING_SIZE (65)
#define RX_PROCESS_RESULT_NOTHING_TO_DO (0)
-#define RX_PROCESS_RESULT_PACKET_RECEIVED (1)
-#define RX_PROCESS_RESULT_PACKET_DROPPED (2)
+#define RX_PROCESS_RESULT_BUFFER_RECEIVED (1)
u32 lan743x_csr_read(struct lan743x_adapter *adapter, int offset);
void lan743x_csr_write(struct lan743x_adapter *adapter, int offset, u32 data);