[UNIKRAFT/LWIP PATCH v5 3/5] uknetdev: Per device RX and TX headroom

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Store required rx and tx headroom on `lwip_data` by storing the
device info per device.

Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
---
 uknetdev.c | 40 ++++++++++------------------------------
 1 file changed, 10 insertions(+), 30 deletions(-)

diff --git a/uknetdev.c b/uknetdev.c
index ff61462..1d8c5e8 100644
--- a/uknetdev.c
+++ b/uknetdev.c
@@ -79,7 +79,6 @@
 #define UKNETDEV_NETIF_NAME1 'n'
 
 struct lwip_netdev_data {
-       uint32_t features;
        /*
         * NOTE: For now we use the same allocator for RX and TX packets.
         *       However, the uknetdev API enables us to use individual ones
@@ -88,6 +87,7 @@ struct lwip_netdev_data {
         *       this lwip setup can be reconsidered.
         */
        struct uk_alloc *pkt_a;
+       struct uk_netdev_info dev_info;
 #ifdef CONFIG_HAVE_SCHED
        struct uk_thread *poll_thread; /* Thread per device */
        char *_name; /* Thread name */
@@ -104,18 +104,6 @@ struct lwip_netdev_data {
  */
 UK_CTASSERT((sizeof(struct lwip_netdev_data)) <= 
CONFIG_UK_NETDEV_SCRATCH_SIZE);
 
-/*
- * Global headroom settings for buffer allocations used on receive
- * and transmit. We are taking the maximum of all uknetdev devices as
- * simplification.
- * TODO: A per-device setting might be more efficient but requires more data
- *       fields for `netif->state`. For now we point directly to the according
- *       `struct uk_netdev` in order to avoid another allocation for these
- *       per-device fields.
- */
-static uint16_t rx_headroom = 0;
-static uint16_t tx_headroom = 0;
-
 #define netif_to_uknetdev(nf) \
        ((struct uk_netdev *) (nf)->state)
 
@@ -132,7 +120,7 @@ static uint16_t netif_alloc_rxpkts(void *argp, struct 
uk_netbuf *nb[],
        for (i = 0; i < count; ++i) {
                nb[i] = lwip_alloc_netbuf(lwip_data->pkt_a,
                                          UKNETDEV_BUFLEN,
-                                         rx_headroom);
+                                         lwip_data->dev_info.nb_encap_rx);
                if (!nb[i]) {
                        /* we run out of memory */
                        break;
@@ -162,7 +150,7 @@ static err_t uknetdev_output(struct netif *nf, struct pbuf 
*p)
        if (!allocation)
                return ERR_MEM;
        nb = uk_netbuf_prepare_buf(allocation, UKNETDEV_BUFLEN,
-                                  tx_headroom, 0, NULL);
+                                  lwip_data->dev_info.nb_encap_tx, 0, NULL);
        UK_ASSERT(nb);
        nb->_a = a; /* register allocator for free operation */
        nb->_b = allocation;
@@ -366,7 +354,7 @@ static void uknetdev_updown(struct netif *nf)
        /* Enable and disable interrupts according to netif's up/down status */
 
        if (nf->flags & NETIF_FLAG_UP) {
-               if (uk_netdev_rxintr_supported(lwip_data->features)) {
+               if (uk_netdev_rxintr_supported(lwip_data->dev_info.features)) {
                        ret = uk_netdev_rxq_intr_enable(dev, 0);
                        if (ret < 0) {
                                LWIP_DEBUGF(NETIF_DEBUG,
@@ -413,7 +401,7 @@ static void uknetdev_updown(struct netif *nf)
                 * TODO:
                 * Cleanup the thread on stopping the network interface.
                 */
-               if (uk_netdev_rxintr_supported(lwip_data->features)) {
+               if (uk_netdev_rxintr_supported(lwip_data->dev_info.features)) {
                        uk_netdev_rxq_intr_disable(dev, 0);
                        LWIP_DEBUGF(NETIF_DEBUG,
                                        ("%s: %c%c%u: Disabled rx interrupts on 
netdev %u\n",
@@ -447,7 +435,6 @@ err_t uknetdev_init(struct netif *nf)
        struct uk_netdev_conf dev_conf;
        struct uk_netdev_rxqueue_conf rxq_conf;
        struct uk_netdev_txqueue_conf txq_conf;
-       struct uk_netdev_info info;
        struct lwip_netdev_data *lwip_data;
        const struct uk_hwaddr *hwaddr;
        unsigned int i;
@@ -487,24 +474,17 @@ err_t uknetdev_init(struct netif *nf)
                return ERR_MEM;
 
        /* Get device information */
-       uk_netdev_info_get(dev, &info);
-       if (!info.max_rx_queues || !info.max_tx_queues)
+       uk_netdev_info_get(dev, &lwip_data->dev_info);
+       if (!lwip_data->dev_info.max_rx_queues
+           || !lwip_data->dev_info.max_tx_queues)
                return ERR_IF;
-       lwip_data->features = info.features;
        lwip_data->pkt_a = a;
 
-       /*
-        * Update our global (rx|tx)_headroom setting that we use for
-        * buffer allocations
-        */
-       rx_headroom = (rx_headroom < info.nb_encap_rx)
-                     ? info.nb_encap_rx : rx_headroom;
-       tx_headroom = (tx_headroom < info.nb_encap_tx)
-                     ? info.nb_encap_tx : tx_headroom;
        LWIP_DEBUGF(NETIF_DEBUG,
                    ("%s: %c%c%u: Need headroom rx:%"PRIu16", tx:%"PRIu16"\n",
                     __func__, nf->name[0], nf->name[1], nf->num,
-                    info.nb_encap_rx, info.nb_encap_tx));
+                    lwip_data->dev_info.nb_encap_rx,
+                    lwip_data->dev_info.nb_encap_tx));
 
        /*
         * Device configuration,
-- 
2.20.1