From 652a2e3a1ba0db81ae1814e8c3cb989e9e89c4e0 Mon Sep 17 00:00:00 2001 From: Jens Freimann Date: Mon, 17 Dec 2018 22:31:31 +0100 Subject: [PATCH 02/18] net/virtio: add packed virtqueue helpers [ upstream commit e9f4feb7e6225f671b59375aff44b9d576121577 ] Add helper functions to set/clear and check descriptor flags. Signed-off-by: Jens Freimann Reviewed-by: Maxime Coquelin (cherry picked from commit e9f4feb7e6225f671b59375aff44b9d576121577) Signed-off-by: Jens Freimann --- drivers/net/virtio/virtio_pci.h | 6 +++ drivers/net/virtio/virtqueue.h | 72 ++++++++++++++++++++++++++++++++- 2 files changed, 76 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h index 4c975a531..b22b62dad 100644 --- a/drivers/net/virtio/virtio_pci.h +++ b/drivers/net/virtio/virtio_pci.h @@ -315,6 +315,12 @@ vtpci_with_feature(struct virtio_hw *hw, uint64_t bit) return (hw->guest_features & (1ULL << bit)) != 0; } +static inline int +vtpci_packed_queue(struct virtio_hw *hw) +{ + return vtpci_with_feature(hw, VIRTIO_F_RING_PACKED); +} + /* * Function declaration from virtio_pci.c */ diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h index 1525c7d10..c32812427 100644 --- a/drivers/net/virtio/virtqueue.h +++ b/drivers/net/virtio/virtqueue.h @@ -251,6 +251,31 @@ struct virtio_tx_region { __attribute__((__aligned__(16))); }; +static inline int +desc_is_used(struct vring_packed_desc *desc, struct virtqueue *vq) +{ + uint16_t used, avail, flags; + + flags = desc->flags; + used = !!(flags & VRING_DESC_F_USED(1)); + avail = !!(flags & VRING_DESC_F_AVAIL(1)); + + return avail == used && used == vq->used_wrap_counter; +} + + +static inline void +vring_desc_init_packed(struct virtqueue *vq, int n) +{ + int i; + for (i = 0; i < n - 1; i++) { + vq->ring_packed.desc_packed[i].id = i; + vq->vq_descx[i].next = i + 1; + } + vq->ring_packed.desc_packed[i].id = i; + vq->vq_descx[i].next = VQ_RING_DESC_CHAIN_END; +} + /* Chain all the descriptors in the ring with an END */ static inline void vring_desc_init(struct vring_desc *dp, uint16_t n) @@ -262,13 +287,53 @@ vring_desc_init(struct vring_desc *dp, uint16_t n) dp[i].next = VQ_RING_DESC_CHAIN_END; } +/** + * Tell the backend not to interrupt us. + */ +static inline void +virtqueue_disable_intr_packed(struct virtqueue *vq) +{ + uint16_t *event_flags = &vq->ring_packed.driver_event->desc_event_flags; + + *event_flags = RING_EVENT_FLAGS_DISABLE; +} + + /** * Tell the backend not to interrupt us. */ static inline void virtqueue_disable_intr(struct virtqueue *vq) { - vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; + if (vtpci_packed_queue(vq->hw)) + virtqueue_disable_intr_packed(vq); + else + vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; +} + +/** + * Tell the backend to interrupt. Implementation for packed virtqueues. + */ +static inline void +virtqueue_enable_intr_packed(struct virtqueue *vq) +{ + uint16_t *event_flags = &vq->ring_packed.driver_event->desc_event_flags; + + + if (vq->event_flags_shadow == RING_EVENT_FLAGS_DISABLE) { + virtio_wmb(); + vq->event_flags_shadow = RING_EVENT_FLAGS_ENABLE; + *event_flags = vq->event_flags_shadow; + } +} + +/** + * Tell the backend to interrupt. Implementation for split virtqueues. + */ +static inline void +virtqueue_enable_intr_split(struct virtqueue *vq) +{ + vq->vq_ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT); } /** @@ -277,7 +342,10 @@ virtqueue_disable_intr(struct virtqueue *vq) static inline void virtqueue_enable_intr(struct virtqueue *vq) { - vq->vq_ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT); + if (vtpci_packed_queue(vq->hw)) + virtqueue_enable_intr_packed(vq); + else + virtqueue_enable_intr_split(vq); } /** -- 2.21.0