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Diffstat (limited to 'drivers/net/xenvirt/virtqueue.h')
| -rw-r--r-- | drivers/net/xenvirt/virtqueue.h | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/drivers/net/xenvirt/virtqueue.h b/drivers/net/xenvirt/virtqueue.h new file mode 100644 index 00000000..350eae3e --- /dev/null +++ b/drivers/net/xenvirt/virtqueue.h @@ -0,0 +1,273 @@ +/*- + * BSD LICENSE + * + * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _VIRTQUEUE_H_ +#define _VIRTQUEUE_H_ + +#include <stdint.h> +#include <linux/virtio_ring.h> +#include <linux/virtio_net.h> + +#include <rte_atomic.h> +#include <rte_memory.h> +#include <rte_memzone.h> +#include <rte_mempool.h> + +#include "virtio_logs.h" + +struct rte_mbuf; + +/* The alignment to use between consumer and producer parts of vring. */ +#define VIRTIO_PCI_VRING_ALIGN 4096 + +enum { VTNET_RQ = 0, VTNET_TQ = 1, VTNET_CQ = 2 }; + +/** + * The maximum virtqueue size is 2^15. Use that value as the end of + * descriptor chain terminator since it will never be a valid index + * in the descriptor table. This is used to verify we are correctly + * handling vq_free_cnt. + */ +#define VQ_RING_DESC_CHAIN_END 32768 + +#define VIRTQUEUE_MAX_NAME_SZ 32 + +struct pmd_internals { + struct rte_eth_stats eth_stats; + int port_id; + int virtio_idx; +}; + + +struct virtqueue { + char vq_name[VIRTQUEUE_MAX_NAME_SZ]; + struct rte_mempool *mpool; /**< mempool for mbuf allocation */ + uint16_t queue_id; /**< DPDK queue index. */ + uint16_t vq_queue_index; /**< PCI queue index */ + uint8_t port_id; /**< Device port identifier. */ + + void *vq_ring_virt_mem; /**< virtual address of vring*/ + int vq_alignment; + int vq_ring_size; + + struct vring vq_ring; /**< vring keeping desc, used and avail */ + struct pmd_internals *internals; /**< virtio device internal info. */ + uint16_t vq_nentries; /**< vring desc numbers */ + uint16_t vq_desc_head_idx; + uint16_t vq_free_cnt; /**< num of desc available */ + uint16_t vq_used_cons_idx; /**< Last consumed desc in used table, trails vq_ring.used->idx*/ + + struct vq_desc_extra { + void *cookie; + uint16_t ndescs; + } vq_descx[0] __rte_cache_aligned; +}; + + +#ifdef RTE_LIBRTE_XENVIRT_DEBUG_DUMP +#define VIRTQUEUE_DUMP(vq) do { \ + uint16_t used_idx, nused; \ + used_idx = (vq)->vq_ring.used->idx; \ + nused = (uint16_t)(used_idx - (vq)->vq_used_cons_idx); \ + PMD_INIT_LOG(DEBUG, \ + "VQ: %s - size=%d; free=%d; used=%d; desc_head_idx=%d;" \ + " avail.idx=%d; used_cons_idx=%d; used.idx=%d;" \ + " avail.flags=0x%x; used.flags=0x%x\n", \ + (vq)->vq_name, (vq)->vq_nentries, (vq)->vq_free_cnt, nused, \ + (vq)->vq_desc_head_idx, (vq)->vq_ring.avail->idx, \ + (vq)->vq_used_cons_idx, (vq)->vq_ring.used->idx, \ + (vq)->vq_ring.avail->flags, (vq)->vq_ring.used->flags); \ +} while (0) +#else +#define VIRTQUEUE_DUMP(vq) do { } while (0) +#endif + + +/** + * Dump virtqueue internal structures, for debug purpose only. + */ +void virtqueue_dump(struct virtqueue *vq); + +/** + * Get all mbufs to be freed. + */ +struct rte_mbuf * virtqueue_detatch_unused(struct virtqueue *vq); + +static inline int __attribute__((always_inline)) +virtqueue_full(const struct virtqueue *vq) +{ + return vq->vq_free_cnt == 0; +} + +#define VIRTQUEUE_NUSED(vq) ((uint16_t)((vq)->vq_ring.used->idx - (vq)->vq_used_cons_idx)) + +static inline void __attribute__((always_inline)) +vq_ring_update_avail(struct virtqueue *vq, uint16_t desc_idx) +{ + uint16_t avail_idx; + /* + * Place the head of the descriptor chain into the next slot and make + * it usable to the host. The chain is made available now rather than + * deferring to virtqueue_notify() in the hopes that if the host is + * currently running on another CPU, we can keep it processing the new + * descriptor. + */ + avail_idx = (uint16_t)(vq->vq_ring.avail->idx & (vq->vq_nentries - 1)); + vq->vq_ring.avail->ring[avail_idx] = desc_idx; + rte_smp_wmb(); + vq->vq_ring.avail->idx++; +} + +static inline void __attribute__((always_inline)) +vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx) +{ + struct vring_desc *dp; + struct vq_desc_extra *dxp; + + dp = &vq->vq_ring.desc[desc_idx]; + dxp = &vq->vq_descx[desc_idx]; + vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs); + while (dp->flags & VRING_DESC_F_NEXT) { + dp = &vq->vq_ring.desc[dp->next]; + } + dxp->ndescs = 0; + + /* + * We must append the existing free chain, if any, to the end of + * newly freed chain. If the virtqueue was completely used, then + * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above). + */ + dp->next = vq->vq_desc_head_idx; + vq->vq_desc_head_idx = desc_idx; +} + +static inline int __attribute__((always_inline)) +virtqueue_enqueue_recv_refill(struct virtqueue *rxvq, struct rte_mbuf *cookie) +{ + const uint16_t needed = 1; + const uint16_t head_idx = rxvq->vq_desc_head_idx; + struct vring_desc *start_dp = rxvq->vq_ring.desc; + struct vq_desc_extra *dxp; + + if (unlikely(rxvq->vq_free_cnt == 0)) + return -ENOSPC; + if (unlikely(rxvq->vq_free_cnt < needed)) + return -EMSGSIZE; + if (unlikely(head_idx >= rxvq->vq_nentries)) + return -EFAULT; + + dxp = &rxvq->vq_descx[head_idx]; + dxp->cookie = (void *)cookie; + dxp->ndescs = needed; + + start_dp[head_idx].addr = + (uint64_t) ((uintptr_t)cookie->buf_addr + RTE_PKTMBUF_HEADROOM - sizeof(struct virtio_net_hdr)); + start_dp[head_idx].len = cookie->buf_len - RTE_PKTMBUF_HEADROOM + sizeof(struct virtio_net_hdr); + start_dp[head_idx].flags = VRING_DESC_F_WRITE; + rxvq->vq_desc_head_idx = start_dp[head_idx].next; + rxvq->vq_free_cnt = (uint16_t)(rxvq->vq_free_cnt - needed); + vq_ring_update_avail(rxvq, head_idx); + + return 0; +} + +static inline int __attribute__((always_inline)) +virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie) +{ + + const uint16_t needed = 2; + struct vring_desc *start_dp = txvq->vq_ring.desc; + uint16_t head_idx = txvq->vq_desc_head_idx; + uint16_t idx = head_idx; + struct vq_desc_extra *dxp; + + if (unlikely(txvq->vq_free_cnt == 0)) + return -ENOSPC; + if (unlikely(txvq->vq_free_cnt < needed)) + return -EMSGSIZE; + if (unlikely(head_idx >= txvq->vq_nentries)) + return -EFAULT; + + dxp = &txvq->vq_descx[idx]; + dxp->cookie = (void *)cookie; + dxp->ndescs = needed; + + start_dp = txvq->vq_ring.desc; + start_dp[idx].addr = 0; +/* + * TODO: save one desc here? + */ + start_dp[idx].len = sizeof(struct virtio_net_hdr); + start_dp[idx].flags = VRING_DESC_F_NEXT; + start_dp[idx].addr = (uintptr_t)NULL; + idx = start_dp[idx].next; + start_dp[idx].addr = (uint64_t)rte_pktmbuf_mtod(cookie, uintptr_t); + start_dp[idx].len = cookie->data_len; + start_dp[idx].flags = 0; + idx = start_dp[idx].next; + txvq->vq_desc_head_idx = idx; + txvq->vq_free_cnt = (uint16_t)(txvq->vq_free_cnt - needed); + vq_ring_update_avail(txvq, head_idx); + + return 0; +} + +static inline uint16_t __attribute__((always_inline)) +virtqueue_dequeue_burst(struct virtqueue *vq, struct rte_mbuf **rx_pkts, uint32_t *len, uint16_t num) +{ + struct vring_used_elem *uep; + struct rte_mbuf *cookie; + uint16_t used_idx, desc_idx; + uint16_t i; + /* Caller does the check */ + for (i = 0; i < num ; i ++) { + used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1)); + uep = &vq->vq_ring.used->ring[used_idx]; + desc_idx = (uint16_t) uep->id; + cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie; + if (unlikely(cookie == NULL)) { + PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u\n", + vq->vq_used_cons_idx); + RTE_LOG(ERR, PMD, "%s: inconsistent (%u, %u)\n", __func__, used_idx , desc_idx); + break; + } + len[i] = uep->len; + rx_pkts[i] = cookie; + vq->vq_used_cons_idx++; + vq_ring_free_chain(vq, desc_idx); + vq->vq_descx[desc_idx].cookie = NULL; + } + return i; +} + +#endif /* _VIRTQUEUE_H_ */ |