vmxnet3: add support for out of order rx completion

Currently, vmxnet3 processes rx completions in-order i.e. no
out of order completion descriptor is expected. With UPT, if
hardware supports LRO, then hardware can report out of order
rx completions. This patch enhances vmxnet3 to add this support.
This supports gets effective only when the corresponding feature
bit is set.

Also, minor enhancements are done for performance.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 93f237db463d7cbf7eed548cb9ff8813f4ea0fd6..94ca3bc1d5401f5653521c8d3bfe0549a36fd9a9 100644 (file)
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -585,6 +585,7 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx,
 
                rbi = rbi_base + ring->next2fill;
                gd = ring->base + ring->next2fill;
+               rbi->comp_state = VMXNET3_RXD_COMP_PENDING;
 
                if (rbi->buf_type == VMXNET3_RX_BUF_SKB) {
                        if (rbi->skb == NULL) {
@@ -644,8 +645,10 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx,
 
                /* Fill the last buffer but dont mark it ready, or else the
                 * device will think that the queue is full */
-               if (num_allocated == num_to_alloc)
+               if (num_allocated == num_to_alloc) {
+                       rbi->comp_state = VMXNET3_RXD_COMP_DONE;
                        break;
+               }
 
                gd->dword[2] |= cpu_to_le32(ring->gen << VMXNET3_RXD_GEN_SHIFT);
                num_allocated++;
@@ -1367,6 +1370,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq,
        struct Vmxnet3_RxCompDesc *rcd;
        struct vmxnet3_rx_ctx *ctx = &rq->rx_ctx;
        u16 segCnt = 0, mss = 0;
+       int comp_offset, fill_offset;
 #ifdef __BIG_ENDIAN_BITFIELD
        struct Vmxnet3_RxDesc rxCmdDesc;
        struct Vmxnet3_RxCompDesc rxComp;
@@ -1639,9 +1643,15 @@ not_lro:
 
 rcd_done:
                /* device may have skipped some rx descs */
-               ring->next2comp = idx;
-               num_to_alloc = vmxnet3_cmd_ring_desc_avail(ring);
                ring = rq->rx_ring + ring_idx;
+               rbi->comp_state = VMXNET3_RXD_COMP_DONE;
+
+               comp_offset = vmxnet3_cmd_ring_desc_avail(ring);
+               fill_offset = (idx > ring->next2fill ? 0 : ring->size) +
+                             idx - ring->next2fill - 1;
+               if (!ring->isOutOfOrder || fill_offset >= comp_offset)
+                       ring->next2comp = idx;
+               num_to_alloc = vmxnet3_cmd_ring_desc_avail(ring);
 
                /* Ensure that the writes to rxd->gen bits will be observed
                 * after all other writes to rxd objects.
@@ -1649,18 +1659,38 @@ rcd_done:
                dma_wmb();
 
                while (num_to_alloc) {
-                       vmxnet3_getRxDesc(rxd, &ring->base[ring->next2fill].rxd,
-                                         &rxCmdDesc);
-                       BUG_ON(!rxd->addr);
-
-                       /* Recv desc is ready to be used by the device */
-                       rxd->gen = ring->gen;
-                       vmxnet3_cmd_ring_adv_next2fill(ring);
-                       num_to_alloc--;
+                       rbi = rq->buf_info[ring_idx] + ring->next2fill;
+                       if (!(adapter->dev_caps[0] & (1UL << VMXNET3_CAP_OOORX_COMP)))
+                               goto refill_buf;
+                       if (ring_idx == 0) {
+                               /* ring0 Type1 buffers can get skipped; re-fill them */
+                               if (rbi->buf_type != VMXNET3_RX_BUF_SKB)
+                                       goto refill_buf;
+                       }
+                       if (rbi->comp_state == VMXNET3_RXD_COMP_DONE) {
+refill_buf:
+                               vmxnet3_getRxDesc(rxd, &ring->base[ring->next2fill].rxd,
+                                                 &rxCmdDesc);
+                               WARN_ON(!rxd->addr);
+
+                               /* Recv desc is ready to be used by the device */
+                               rxd->gen = ring->gen;
+                               vmxnet3_cmd_ring_adv_next2fill(ring);
+                               rbi->comp_state = VMXNET3_RXD_COMP_PENDING;
+                               num_to_alloc--;
+                       } else {
+                               /* rx completion hasn't occurred */
+                               ring->isOutOfOrder = 1;
+                               break;
+                       }
+               }
+
+               if (num_to_alloc == 0) {
+                       ring->isOutOfOrder = 0;
                }
 
                /* if needed, update the register */
-               if (unlikely(rq->shared->updateRxProd)) {
+               if (unlikely(rq->shared->updateRxProd) && (ring->next2fill & 0xf) == 0) {
                        VMXNET3_WRITE_BAR0_REG(adapter,
                                               rxprod_reg[ring_idx] + rq->qid * 8,
                                               ring->next2fill);
@@ -1824,6 +1854,7 @@ vmxnet3_rq_init(struct vmxnet3_rx_queue *rq,
                memset(rq->rx_ring[i].base, 0, rq->rx_ring[i].size *
                       sizeof(struct Vmxnet3_RxDesc));
                rq->rx_ring[i].gen = VMXNET3_INIT_GEN;
+               rq->rx_ring[i].isOutOfOrder = 0;
        }
        if (vmxnet3_rq_alloc_rx_buf(rq, 0, rq->rx_ring[0].size - 1,
                                    adapter) == 0) {
@@ -2014,8 +2045,17 @@ vmxnet3_poll_rx_only(struct napi_struct *napi, int budget)
        rxd_done = vmxnet3_rq_rx_complete(rq, adapter, budget);
 
        if (rxd_done < budget) {
+               struct Vmxnet3_RxCompDesc *rcd;
+#ifdef __BIG_ENDIAN_BITFIELD
+               struct Vmxnet3_RxCompDesc rxComp;
+#endif
                napi_complete_done(napi, rxd_done);
                vmxnet3_enable_intr(adapter, rq->comp_ring.intr_idx);
+               /* after unmasking the interrupt, check if any descriptors were completed */
+               vmxnet3_getRxComp(rcd, &rq->comp_ring.base[rq->comp_ring.next2proc].rcd,
+                                 &rxComp);
+               if (rcd->gen == rq->comp_ring.gen && napi_reschedule(napi))
+                       vmxnet3_disable_intr(adapter, rq->comp_ring.intr_idx);
        }
        return rxd_done;
 }
@@ -3612,6 +3652,12 @@ vmxnet3_probe_device(struct pci_dev *pdev,
                        adapter->dev_caps[0] = adapter->devcap_supported[0] &
                                                        (1UL << VMXNET3_CAP_LARGE_BAR);
                }
+               if (!(adapter->ptcap_supported[0] & (1UL << VMXNET3_DCR_ERROR)) &&
+                   adapter->ptcap_supported[0] & (1UL << VMXNET3_CAP_OOORX_COMP) &&
+                   adapter->devcap_supported[0] & (1UL << VMXNET3_CAP_OOORX_COMP)) {
+                       adapter->dev_caps[0] |= adapter->devcap_supported[0] &
+                                               (1UL << VMXNET3_CAP_OOORX_COMP);
+               }
                if (adapter->dev_caps[0])
                        VMXNET3_WRITE_BAR1_REG(adapter, VMXNET3_REG_DCR, adapter->dev_caps[0]);
 

diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h
index a4f832f0ad5bcbe697045a569ad20cfdcb73ee05..5b495ef253e8c6bcfaa83f7a4ed0fc3d56dd7463 100644 (file)
--- a/drivers/net/vmxnet3/vmxnet3_int.h
+++ b/drivers/net/vmxnet3/vmxnet3_int.h
@@ -136,6 +136,7 @@ struct vmxnet3_cmd_ring {
        u32             next2fill;
        u32             next2comp;
        u8              gen;
+       u8              isOutOfOrder;
        dma_addr_t      basePA;
 };
 
@@ -260,9 +261,13 @@ enum vmxnet3_rx_buf_type {
        VMXNET3_RX_BUF_PAGE = 2
 };
 
+#define VMXNET3_RXD_COMP_PENDING        0
+#define VMXNET3_RXD_COMP_DONE           1
+
 struct vmxnet3_rx_buf_info {
        enum vmxnet3_rx_buf_type buf_type;
        u16     len;
+       u8      comp_state;
        union {
                struct sk_buff *skb;
                struct page    *page;