diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c b/drivers/platform/mellanox/mlxbf-tmfifo.c index b600b77d91ef2..5c1f859b682a8 100644 --- a/drivers/platform/mellanox/mlxbf-tmfifo.c +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c @@ -59,6 +59,7 @@ struct mlxbf_tmfifo; * @vq: pointer to the virtio virtqueue * @desc: current descriptor of the pending packet * @desc_head: head descriptor of the pending packet + * @drop_desc: dummy desc for packet dropping * @cur_len: processed length of the current descriptor * @rem_len: remaining length of the pending packet * @pkt_len: total length of the pending packet @@ -75,6 +76,7 @@ struct mlxbf_tmfifo_vring { struct virtqueue *vq; struct vring_desc *desc; struct vring_desc *desc_head; + struct vring_desc drop_desc; int cur_len; int rem_len; u32 pkt_len; @@ -86,6 +88,14 @@ struct mlxbf_tmfifo_vring { struct mlxbf_tmfifo *fifo; }; +/* Check whether vring is in drop mode. */ +#define IS_VRING_DROP(_r) ({ \ + typeof(_r) (r) = (_r); \ + (r->desc_head == &r->drop_desc ? true : false); }) + +/* A stub length to drop maximum length packet. */ +#define VRING_DROP_DESC_MAX_LEN GENMASK(15, 0) + /* Interrupt types. */ enum { MLXBF_TM_RX_LWM_IRQ, @@ -262,6 +272,7 @@ static int mlxbf_tmfifo_alloc_vrings(struct mlxbf_tmfifo *fifo, vring->align = SMP_CACHE_BYTES; vring->index = i; vring->vdev_id = tm_vdev->vdev.id.device; + vring->drop_desc.len = VRING_DROP_DESC_MAX_LEN; dev = &tm_vdev->vdev.dev; size = vring_size(vring->num, vring->align); @@ -367,7 +378,7 @@ static u32 mlxbf_tmfifo_get_pkt_len(struct mlxbf_tmfifo_vring *vring, return len; } -static void mlxbf_tmfifo_release_pending_pkt(struct mlxbf_tmfifo_vring *vring) +static void mlxbf_tmfifo_release_pkt(struct mlxbf_tmfifo_vring *vring) { struct vring_desc *desc_head; u32 len = 0; @@ -596,19 +607,25 @@ static void mlxbf_tmfifo_rxtx_word(struct mlxbf_tmfifo_vring *vring, if (vring->cur_len + sizeof(u64) <= len) { /* The whole word. */ - if (is_rx) - memcpy(addr + vring->cur_len, &data, sizeof(u64)); - else - memcpy(&data, addr + vring->cur_len, sizeof(u64)); + if (!IS_VRING_DROP(vring)) { + if (is_rx) + memcpy(addr + vring->cur_len, &data, + sizeof(u64)); + else + memcpy(&data, addr + vring->cur_len, + sizeof(u64)); + } vring->cur_len += sizeof(u64); } else { /* Leftover bytes. */ - if (is_rx) - memcpy(addr + vring->cur_len, &data, - len - vring->cur_len); - else - memcpy(&data, addr + vring->cur_len, - len - vring->cur_len); + if (!IS_VRING_DROP(vring)) { + if (is_rx) + memcpy(addr + vring->cur_len, &data, + len - vring->cur_len); + else + memcpy(&data, addr + vring->cur_len, + len - vring->cur_len); + } vring->cur_len = len; } @@ -709,8 +726,16 @@ static bool mlxbf_tmfifo_rxtx_one_desc(struct mlxbf_tmfifo_vring *vring, /* Get the descriptor of the next packet. */ if (!vring->desc) { desc = mlxbf_tmfifo_get_next_pkt(vring, is_rx); - if (!desc) - return false; + if (!desc) { + /* Drop next Rx packet to avoid stuck. */ + if (is_rx) { + desc = &vring->drop_desc; + vring->desc_head = desc; + vring->desc = desc; + } else { + return false; + } + } } else { desc = vring->desc; } @@ -743,17 +768,24 @@ static bool mlxbf_tmfifo_rxtx_one_desc(struct mlxbf_tmfifo_vring *vring, vring->rem_len -= len; /* Get the next desc on the chain. */ - if (vring->rem_len > 0 && + if (!IS_VRING_DROP(vring) && vring->rem_len > 0 && (virtio16_to_cpu(vdev, desc->flags) & VRING_DESC_F_NEXT)) { idx = virtio16_to_cpu(vdev, desc->next); desc = &vr->desc[idx]; goto mlxbf_tmfifo_desc_done; } - /* Done and release the pending packet. */ - mlxbf_tmfifo_release_pending_pkt(vring); + /* Done and release the packet. */ desc = NULL; fifo->vring[is_rx] = NULL; + if (!IS_VRING_DROP(vring)) { + mlxbf_tmfifo_release_pkt(vring); + } else { + vring->pkt_len = 0; + vring->desc_head = NULL; + vring->desc = NULL; + return false; + } /* * Make sure the load/store are in order before @@ -933,7 +965,7 @@ static void mlxbf_tmfifo_virtio_del_vqs(struct virtio_device *vdev) /* Release the pending packet. */ if (vring->desc) - mlxbf_tmfifo_release_pending_pkt(vring); + mlxbf_tmfifo_release_pkt(vring); vq = vring->vq; if (vq) { vring->vq = NULL;