net: lan966x: Split function lan966x_fdma_rx_get_frame

The function lan966x_fdma_rx_get_frame was unmapping the frame from
device and check also if the frame was received on a valid port. And
only after that it tried to generate the skb.
Move this check in a different function, in preparation for xdp
support. Such that xdp to be added here and the
lan966x_fdma_rx_get_frame to be used only when giving the skb to upper
layers.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 6c102ee20f1d7e5866661a3170a32bfd231e1838..d37765ddd53ae700ca4ea6f34ca97a6693d709b0 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -54,6 +54,17 @@ static void lan966x_fdma_rx_free_pages(struct lan966x_rx *rx)
        }
 }
 
+static void lan966x_fdma_rx_free_page(struct lan966x_rx *rx)
+{
+       struct page *page;
+
+       page = rx->page[rx->dcb_index][rx->db_index];
+       if (unlikely(!page))
+               return;
+
+       __free_pages(page, rx->page_order);
+}
+
 static void lan966x_fdma_rx_add_dcb(struct lan966x_rx *rx,
                                    struct lan966x_rx_dcb *dcb,
                                    u64 nextptr)
@@ -116,6 +127,12 @@ static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
        return 0;
 }
 
+static void lan966x_fdma_rx_advance_dcb(struct lan966x_rx *rx)
+{
+       rx->dcb_index++;
+       rx->dcb_index &= FDMA_DCB_MAX - 1;
+}
+
 static void lan966x_fdma_rx_free(struct lan966x_rx *rx)
 {
        struct lan966x *lan966x = rx->lan966x;
@@ -403,38 +420,53 @@ static bool lan966x_fdma_rx_more_frames(struct lan966x_rx *rx)
        return true;
 }
 
-static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
+static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
 {
        struct lan966x *lan966x = rx->lan966x;
-       u64 src_port, timestamp;
        struct lan966x_db *db;
-       struct sk_buff *skb;
        struct page *page;
 
-       /* Get the received frame and unmap it */
        db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
        page = rx->page[rx->dcb_index][rx->db_index];
+       if (unlikely(!page))
+               return FDMA_ERROR;
 
        dma_sync_single_for_cpu(lan966x->dev, (dma_addr_t)db->dataptr,
                                FDMA_DCB_STATUS_BLOCKL(db->status),
                                DMA_FROM_DEVICE);
 
+       dma_unmap_single_attrs(lan966x->dev, (dma_addr_t)db->dataptr,
+                              PAGE_SIZE << rx->page_order, DMA_FROM_DEVICE,
+                              DMA_ATTR_SKIP_CPU_SYNC);
+
+       lan966x_ifh_get_src_port(page_address(page), src_port);
+       if (WARN_ON(*src_port >= lan966x->num_phys_ports))
+               return FDMA_ERROR;
+
+       return FDMA_PASS;
+}
+
+static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
+                                                u64 src_port)
+{
+       struct lan966x *lan966x = rx->lan966x;
+       struct lan966x_db *db;
+       struct sk_buff *skb;
+       struct page *page;
+       u64 timestamp;
+
+       /* Get the received frame and unmap it */
+       db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
+       page = rx->page[rx->dcb_index][rx->db_index];
+
        skb = build_skb(page_address(page), PAGE_SIZE << rx->page_order);
        if (unlikely(!skb))
-               goto unmap_page;
+               goto free_page;
 
        skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
 
-       lan966x_ifh_get_src_port(skb->data, &src_port);
        lan966x_ifh_get_timestamp(skb->data, &timestamp);
 
-       if (WARN_ON(src_port >= lan966x->num_phys_ports))
-               goto free_skb;
-
-       dma_unmap_single_attrs(lan966x->dev, (dma_addr_t)db->dataptr,
-                              PAGE_SIZE << rx->page_order, DMA_FROM_DEVICE,
-                              DMA_ATTR_SKIP_CPU_SYNC);
-
        skb->dev = lan966x->ports[src_port]->dev;
        skb_pull(skb, IFH_LEN_BYTES);
 
@@ -457,12 +489,7 @@ static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
 
        return skb;
 
-free_skb:
-       kfree_skb(skb);
-unmap_page:
-       dma_unmap_single_attrs(lan966x->dev, (dma_addr_t)db->dataptr,
-                              PAGE_SIZE << rx->page_order, DMA_FROM_DEVICE,
-                              DMA_ATTR_SKIP_CPU_SYNC);
+free_page:
        __free_pages(page, rx->page_order);
 
        return NULL;
@@ -478,6 +505,7 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
        struct sk_buff *skb;
        struct page *page;
        int counter = 0;
+       u64 src_port;
        u64 nextptr;
 
        lan966x_fdma_tx_clear_buf(lan966x, weight);
@@ -487,19 +515,26 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
                if (!lan966x_fdma_rx_more_frames(rx))
                        break;
 
-               skb = lan966x_fdma_rx_get_frame(rx);
+               counter++;
 
-               rx->page[rx->dcb_index][rx->db_index] = NULL;
-               rx->dcb_index++;
-               rx->dcb_index &= FDMA_DCB_MAX - 1;
+               switch (lan966x_fdma_rx_check_frame(rx, &src_port)) {
+               case FDMA_PASS:
+                       break;
+               case FDMA_ERROR:
+                       lan966x_fdma_rx_free_page(rx);
+                       lan966x_fdma_rx_advance_dcb(rx);
+                       goto allocate_new;
+               }
 
+               skb = lan966x_fdma_rx_get_frame(rx, src_port);
+               lan966x_fdma_rx_advance_dcb(rx);
                if (!skb)
-                       break;
+                       goto allocate_new;
 
                napi_gro_receive(&lan966x->napi, skb);
-               counter++;
        }
 
+allocate_new:
        /* Allocate new pages and map them */
        while (dcb_reload != rx->dcb_index) {
                db = &rx->dcbs[dcb_reload].db[rx->db_index];

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index 4ec33999e4df60e7ac6afda2717c5ac62e48af5c..464fb5e4a8ff6ceb4903ea9e7c251074cdb01af6 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -100,6 +100,15 @@ enum macaccess_entry_type {
        ENTRYTYPE_MACV6,
 };
 
+/* FDMA return action codes for checking if the frame is valid
+ * FDMA_PASS, frame is valid and can be used
+ * FDMA_ERROR, something went wrong, stop getting more frames
+ */
+enum lan966x_fdma_action {
+       FDMA_PASS = 0,
+       FDMA_ERROR,
+};
+
 struct lan966x_port;
 
 struct lan966x_db {