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Subject[PATCH net-next v3 10/13] virtio_ring: introduce packed ring support
Date
Introduce the packed ring support. Packed ring can only be
created by vring_create_virtqueue() and each chunk of packed
ring will be allocated individually. Packed ring can not be
created on preallocated memory by vring_new_virtqueue() or
the likes currently.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
drivers/virtio/virtio_ring.c | 900 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 870 insertions(+), 30 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index aafe1969b45e..b63eee2034e7 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -83,9 +83,26 @@ struct vring_desc_state_split {
struct vring_desc *indir_desc; /* Indirect descriptor, if any. */
};

+struct vring_desc_state_packed {
+ void *data; /* Data for callback. */
+ struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */
+ u16 num; /* Descriptor list length. */
+ u16 next; /* The next desc state in a list. */
+ u16 last; /* The last desc state in a list. */
+};
+
+struct vring_desc_extra_packed {
+ dma_addr_t addr; /* Buffer DMA addr. */
+ u32 len; /* Buffer length. */
+ u16 flags; /* Descriptor flags. */
+};
+
struct vring_virtqueue {
struct virtqueue vq;

+ /* Is this a packed ring? */
+ bool packed_ring;
+
/* Is DMA API used? */
bool use_dma_api;

@@ -109,23 +126,64 @@ struct vring_virtqueue {
/* Last used index we've seen. */
u16 last_used_idx;

- struct {
- /* Actual memory layout for this queue */
- struct vring vring;
+ union {
+ /* Available for split ring */
+ struct {
+ /* Actual memory layout for this queue. */
+ struct vring vring;

- /* Last written value to avail->flags */
- u16 avail_flags_shadow;
+ /* Last written value to avail->flags */
+ u16 avail_flags_shadow;

- /* Last written value to avail->idx in guest byte order */
- u16 avail_idx_shadow;
+ /*
+ * Last written value to avail->idx in
+ * guest byte order.
+ */
+ u16 avail_idx_shadow;

- /* Per-descriptor state. */
- struct vring_desc_state_split *desc_state;
+ /* Per-descriptor state. */
+ struct vring_desc_state_split *desc_state;

- /* DMA, allocation, and size information */
- size_t queue_size_in_bytes;
- dma_addr_t queue_dma_addr;
- } split;
+ /* DMA address and size information */
+ dma_addr_t queue_dma_addr;
+ size_t queue_size_in_bytes;
+ } split;
+
+ /* Available for packed ring */
+ struct {
+ /* Actual memory layout for this queue. */
+ struct vring_packed vring;
+
+ /* Driver ring wrap counter. */
+ bool avail_wrap_counter;
+
+ /* Device ring wrap counter. */
+ bool used_wrap_counter;
+
+ /* Avail used flags. */
+ u16 avail_used_flags;
+
+ /* Index of the next avail descriptor. */
+ u16 next_avail_idx;
+
+ /*
+ * Last written value to driver->flags in
+ * guest byte order.
+ */
+ u16 event_flags_shadow;
+
+ /* Per-descriptor state. */
+ struct vring_desc_state_packed *desc_state;
+ struct vring_desc_extra_packed *desc_extra;
+
+ /* DMA address and size information */
+ dma_addr_t ring_dma_addr;
+ dma_addr_t driver_event_dma_addr;
+ dma_addr_t device_event_dma_addr;
+ size_t ring_size_in_bytes;
+ size_t event_size_in_bytes;
+ } packed;
+ };

/* How to notify other side. FIXME: commonalize hcalls! */
bool (*notify)(struct virtqueue *vq);
@@ -840,6 +898,717 @@ static struct virtqueue *vring_create_virtqueue_split(
}


+/*
+ * Packed ring specific functions - *_packed().
+ */
+
+static void vring_unmap_state_packed(const struct vring_virtqueue *vq,
+ struct vring_desc_extra_packed *state)
+{
+ u16 flags;
+
+ if (!vq->use_dma_api)
+ return;
+
+ flags = state->flags;
+
+ if (flags & VRING_DESC_F_INDIRECT) {
+ dma_unmap_single(vring_dma_dev(vq),
+ state->addr, state->len,
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ } else {
+ dma_unmap_page(vring_dma_dev(vq),
+ state->addr, state->len,
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ }
+}
+
+static void vring_unmap_desc_packed(const struct vring_virtqueue *vq,
+ struct vring_packed_desc *desc)
+{
+ u16 flags;
+
+ if (!vq->use_dma_api)
+ return;
+
+ flags = le16_to_cpu(desc->flags);
+
+ if (flags & VRING_DESC_F_INDIRECT) {
+ dma_unmap_single(vring_dma_dev(vq),
+ le64_to_cpu(desc->addr),
+ le32_to_cpu(desc->len),
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ } else {
+ dma_unmap_page(vring_dma_dev(vq),
+ le64_to_cpu(desc->addr),
+ le32_to_cpu(desc->len),
+ (flags & VRING_DESC_F_WRITE) ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ }
+}
+
+static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg,
+ gfp_t gfp)
+{
+ struct vring_packed_desc *desc;
+
+ /*
+ * We require lowmem mappings for the descriptors because
+ * otherwise virt_to_phys will give us bogus addresses in the
+ * virtqueue.
+ */
+ gfp &= ~__GFP_HIGHMEM;
+
+ desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp);
+
+ return desc;
+}
+
+static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
+ struct scatterlist *sgs[],
+ unsigned int total_sg,
+ unsigned int out_sgs,
+ unsigned int in_sgs,
+ void *data,
+ gfp_t gfp)
+{
+ struct vring_packed_desc *desc;
+ struct scatterlist *sg;
+ unsigned int i, n, err_idx;
+ u16 head, id;
+ dma_addr_t addr;
+
+ head = vq->packed.next_avail_idx;
+ desc = alloc_indirect_packed(total_sg, gfp);
+
+ if (unlikely(vq->vq.num_free < 1)) {
+ pr_debug("Can't add buf len 1 - avail = 0\n");
+ END_USE(vq);
+ return -ENOSPC;
+ }
+
+ i = 0;
+ id = vq->free_head;
+ BUG_ON(id == vq->packed.vring.num);
+
+ for (n = 0; n < out_sgs + in_sgs; n++) {
+ for (sg = sgs[n]; sg; sg = sg_next(sg)) {
+ addr = vring_map_one_sg(vq, sg, n < out_sgs ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+
+ desc[i].flags = cpu_to_le16(n < out_sgs ?
+ 0 : VRING_DESC_F_WRITE);
+ desc[i].addr = cpu_to_le64(addr);
+ desc[i].len = cpu_to_le32(sg->length);
+ i++;
+ }
+ }
+
+ /* Now that the indirect table is filled in, map it. */
+ addr = vring_map_single(vq, desc,
+ total_sg * sizeof(struct vring_packed_desc),
+ DMA_TO_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+
+ vq->packed.vring.desc[head].addr = cpu_to_le64(addr);
+ vq->packed.vring.desc[head].len = cpu_to_le32(total_sg *
+ sizeof(struct vring_packed_desc));
+ vq->packed.vring.desc[head].id = cpu_to_le16(id);
+
+ if (vq->use_dma_api) {
+ vq->packed.desc_extra[id].addr = addr;
+ vq->packed.desc_extra[id].len = total_sg *
+ sizeof(struct vring_packed_desc);
+ vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT |
+ vq->packed.avail_used_flags;
+ }
+
+ /*
+ * A driver MUST NOT make the first descriptor in the list
+ * available before all subsequent descriptors comprising
+ * the list are made available.
+ */
+ virtio_wmb(vq->weak_barriers);
+ vq->packed.vring.desc[head].flags = cpu_to_le16(VRING_DESC_F_INDIRECT |
+ vq->packed.avail_used_flags);
+
+ /* We're using some buffers from the free list. */
+ vq->vq.num_free -= 1;
+
+ /* Update free pointer */
+ n = head + 1;
+ if (n >= vq->packed.vring.num) {
+ n = 0;
+ vq->packed.avail_wrap_counter ^= 1;
+ vq->packed.avail_used_flags ^=
+ 1 << VRING_PACKED_DESC_F_AVAIL |
+ 1 << VRING_PACKED_DESC_F_USED;
+ }
+ vq->packed.next_avail_idx = n;
+ vq->free_head = vq->packed.desc_state[id].next;
+
+ /* Store token and indirect buffer state. */
+ vq->packed.desc_state[id].num = 1;
+ vq->packed.desc_state[id].data = data;
+ vq->packed.desc_state[id].indir_desc = desc;
+ vq->packed.desc_state[id].last = id;
+
+ vq->num_added += 1;
+
+ pr_debug("Added buffer head %i to %p\n", head, vq);
+ END_USE(vq);
+
+ return 0;
+
+unmap_release:
+ err_idx = i;
+
+ for (i = 0; i < err_idx; i++)
+ vring_unmap_desc_packed(vq, &desc[i]);
+
+ kfree(desc);
+
+ END_USE(vq);
+ return -EIO;
+}
+
+static inline int virtqueue_add_packed(struct virtqueue *_vq,
+ struct scatterlist *sgs[],
+ unsigned int total_sg,
+ unsigned int out_sgs,
+ unsigned int in_sgs,
+ void *data,
+ void *ctx,
+ gfp_t gfp)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ struct vring_packed_desc *desc;
+ struct scatterlist *sg;
+ unsigned int i, n, c, descs_used, err_idx;
+ __le16 uninitialized_var(head_flags), flags;
+ u16 head, id, uninitialized_var(prev), curr, avail_used_flags;
+
+ START_USE(vq);
+
+ BUG_ON(data == NULL);
+ BUG_ON(ctx && vq->indirect);
+
+ if (unlikely(vq->broken)) {
+ END_USE(vq);
+ return -EIO;
+ }
+
+ LAST_ADD_TIME_UPDATE(vq);
+
+ BUG_ON(total_sg == 0);
+
+ if (virtqueue_use_indirect(_vq, total_sg))
+ return virtqueue_add_indirect_packed(vq, sgs, total_sg,
+ out_sgs, in_sgs, data, gfp);
+
+ head = vq->packed.next_avail_idx;
+ avail_used_flags = vq->packed.avail_used_flags;
+
+ WARN_ON_ONCE(total_sg > vq->packed.vring.num && !vq->indirect);
+
+ desc = vq->packed.vring.desc;
+ i = head;
+ descs_used = total_sg;
+
+ if (unlikely(vq->vq.num_free < descs_used)) {
+ pr_debug("Can't add buf len %i - avail = %i\n",
+ descs_used, vq->vq.num_free);
+ END_USE(vq);
+ return -ENOSPC;
+ }
+
+ id = vq->free_head;
+ BUG_ON(id == vq->packed.vring.num);
+
+ curr = id;
+ c = 0;
+ for (n = 0; n < out_sgs + in_sgs; n++) {
+ for (sg = sgs[n]; sg; sg = sg_next(sg)) {
+ dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ if (vring_mapping_error(vq, addr))
+ goto unmap_release;
+
+ flags = cpu_to_le16(vq->packed.avail_used_flags |
+ (++c == total_sg ? 0 : VRING_DESC_F_NEXT) |
+ (n < out_sgs ? 0 : VRING_DESC_F_WRITE));
+ if (i == head)
+ head_flags = flags;
+ else
+ desc[i].flags = flags;
+
+ desc[i].addr = cpu_to_le64(addr);
+ desc[i].len = cpu_to_le32(sg->length);
+ desc[i].id = cpu_to_le16(id);
+
+ if (unlikely(vq->use_dma_api)) {
+ vq->packed.desc_extra[curr].addr = addr;
+ vq->packed.desc_extra[curr].len = sg->length;
+ vq->packed.desc_extra[curr].flags =
+ le16_to_cpu(flags);
+ }
+ prev = curr;
+ curr = vq->packed.desc_state[curr].next;
+
+ if ((unlikely(++i >= vq->packed.vring.num))) {
+ i = 0;
+ vq->packed.avail_used_flags ^=
+ 1 << VRING_PACKED_DESC_F_AVAIL |
+ 1 << VRING_PACKED_DESC_F_USED;
+ }
+ }
+ }
+
+ if (i < head)
+ vq->packed.avail_wrap_counter ^= 1;
+
+ /* We're using some buffers from the free list. */
+ vq->vq.num_free -= descs_used;
+
+ /* Update free pointer */
+ vq->packed.next_avail_idx = i;
+ vq->free_head = curr;
+
+ /* Store token. */
+ vq->packed.desc_state[id].num = descs_used;
+ vq->packed.desc_state[id].data = data;
+ vq->packed.desc_state[id].indir_desc = ctx;
+ vq->packed.desc_state[id].last = prev;
+
+ /*
+ * A driver MUST NOT make the first descriptor in the list
+ * available before all subsequent descriptors comprising
+ * the list are made available.
+ */
+ virtio_wmb(vq->weak_barriers);
+ vq->packed.vring.desc[head].flags = head_flags;
+ vq->num_added += descs_used;
+
+ pr_debug("Added buffer head %i to %p\n", head, vq);
+ END_USE(vq);
+
+ return 0;
+
+unmap_release:
+ err_idx = i;
+ i = head;
+
+ vq->packed.avail_used_flags = avail_used_flags;
+
+ for (n = 0; n < total_sg; n++) {
+ if (i == err_idx)
+ break;
+ vring_unmap_desc_packed(vq, &desc[i]);
+ i++;
+ if (i >= vq->packed.vring.num)
+ i = 0;
+ }
+
+ END_USE(vq);
+ return -EIO;
+}
+
+static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ u16 flags;
+ bool needs_kick;
+ union {
+ struct {
+ __le16 off_wrap;
+ __le16 flags;
+ };
+ u32 u32;
+ } snapshot;
+
+ START_USE(vq);
+
+ /*
+ * We need to expose the new flags value before checking notification
+ * suppressions.
+ */
+ virtio_mb(vq->weak_barriers);
+
+ vq->num_added = 0;
+
+ snapshot.u32 = *(u32 *)vq->packed.vring.device;
+ flags = le16_to_cpu(snapshot.flags);
+
+ LAST_ADD_TIME_CHECK(vq);
+ LAST_ADD_TIME_INVALID(vq);
+
+ needs_kick = (flags != VRING_PACKED_EVENT_FLAG_DISABLE);
+ END_USE(vq);
+ return needs_kick;
+}
+
+static void detach_buf_packed(struct vring_virtqueue *vq,
+ unsigned int id, void **ctx)
+{
+ struct vring_desc_state_packed *state = NULL;
+ struct vring_packed_desc *desc;
+ unsigned int i, curr;
+
+ state = &vq->packed.desc_state[id];
+
+ /* Clear data ptr. */
+ state->data = NULL;
+
+ vq->packed.desc_state[state->last].next = vq->free_head;
+ vq->free_head = id;
+ vq->vq.num_free += state->num;
+
+ if (unlikely(vq->use_dma_api)) {
+ curr = id;
+ for (i = 0; i < state->num; i++) {
+ vring_unmap_state_packed(vq,
+ &vq->packed.desc_extra[curr]);
+ curr = vq->packed.desc_state[curr].next;
+ }
+ }
+
+ if (vq->indirect) {
+ u32 len;
+
+ /* Free the indirect table, if any, now that it's unmapped. */
+ desc = state->indir_desc;
+ if (!desc)
+ return;
+
+ if (vq->use_dma_api) {
+ len = vq->packed.desc_extra[id].len;
+ for (i = 0; i < len / sizeof(struct vring_packed_desc);
+ i++)
+ vring_unmap_desc_packed(vq, &desc[i]);
+ }
+ kfree(desc);
+ state->indir_desc = NULL;
+ } else if (ctx) {
+ *ctx = state->indir_desc;
+ }
+}
+
+static inline bool is_used_desc_packed(const struct vring_virtqueue *vq,
+ u16 idx, bool used_wrap_counter)
+{
+ bool avail, used;
+ u16 flags;
+
+ flags = le16_to_cpu(vq->packed.vring.desc[idx].flags);
+ avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL));
+ used = !!(flags & (1 << VRING_PACKED_DESC_F_USED));
+
+ return avail == used && used == used_wrap_counter;
+}
+
+static inline bool more_used_packed(const struct vring_virtqueue *vq)
+{
+ return is_used_desc_packed(vq, vq->last_used_idx,
+ vq->packed.used_wrap_counter);
+}
+
+static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq,
+ unsigned int *len,
+ void **ctx)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ u16 last_used, id;
+ void *ret;
+
+ START_USE(vq);
+
+ if (unlikely(vq->broken)) {
+ END_USE(vq);
+ return NULL;
+ }
+
+ if (!more_used_packed(vq)) {
+ pr_debug("No more buffers in queue\n");
+ END_USE(vq);
+ return NULL;
+ }
+
+ /* Only get used elements after they have been exposed by host. */
+ virtio_rmb(vq->weak_barriers);
+
+ last_used = vq->last_used_idx;
+ id = le16_to_cpu(vq->packed.vring.desc[last_used].id);
+ *len = le32_to_cpu(vq->packed.vring.desc[last_used].len);
+
+ if (unlikely(id >= vq->packed.vring.num)) {
+ BAD_RING(vq, "id %u out of range\n", id);
+ return NULL;
+ }
+ if (unlikely(!vq->packed.desc_state[id].data)) {
+ BAD_RING(vq, "id %u is not a head!\n", id);
+ return NULL;
+ }
+
+ /* detach_buf_packed clears data, so grab it now. */
+ ret = vq->packed.desc_state[id].data;
+ detach_buf_packed(vq, id, ctx);
+
+ vq->last_used_idx += vq->packed.desc_state[id].num;
+ if (unlikely(vq->last_used_idx >= vq->packed.vring.num)) {
+ vq->last_used_idx -= vq->packed.vring.num;
+ vq->packed.used_wrap_counter ^= 1;
+ }
+
+ LAST_ADD_TIME_INVALID(vq);
+
+ END_USE(vq);
+ return ret;
+}
+
+static void virtqueue_disable_cb_packed(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ if (vq->packed.event_flags_shadow != VRING_PACKED_EVENT_FLAG_DISABLE) {
+ vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
+ vq->packed.vring.driver->flags =
+ cpu_to_le16(vq->packed.event_flags_shadow);
+ }
+}
+
+static unsigned virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ START_USE(vq);
+
+ /*
+ * We optimistically turn back on interrupts, then check if there was
+ * more to do.
+ */
+
+ if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) {
+ vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_ENABLE;
+ vq->packed.vring.driver->flags =
+ cpu_to_le16(vq->packed.event_flags_shadow);
+ }
+
+ END_USE(vq);
+ return vq->last_used_idx | ((u16)vq->packed.used_wrap_counter <<
+ VRING_PACKED_EVENT_F_WRAP_CTR);
+}
+
+static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ bool wrap_counter;
+ u16 used_idx;
+
+ wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR;
+ used_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR);
+
+ return is_used_desc_packed(vq, used_idx, wrap_counter);
+}
+
+static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ u16 used_idx, wrap_counter;
+
+ START_USE(vq);
+
+ /*
+ * We optimistically turn back on interrupts, then check if there was
+ * more to do.
+ */
+
+ used_idx = vq->last_used_idx;
+ wrap_counter = vq->packed.used_wrap_counter;
+
+ if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) {
+ vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_ENABLE;
+ vq->packed.vring.driver->flags =
+ cpu_to_le16(vq->packed.event_flags_shadow);
+ }
+
+ /*
+ * We need to update event suppression structure first
+ * before re-checking for more used buffers.
+ */
+ virtio_mb(vq->weak_barriers);
+
+ if (is_used_desc_packed(vq, used_idx, wrap_counter)) {
+ END_USE(vq);
+ return false;
+ }
+
+ END_USE(vq);
+ return true;
+}
+
+static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ unsigned int i;
+ void *buf;
+
+ START_USE(vq);
+
+ for (i = 0; i < vq->packed.vring.num; i++) {
+ if (!vq->packed.desc_state[i].data)
+ continue;
+ /* detach_buf clears data, so grab it now. */
+ buf = vq->packed.desc_state[i].data;
+ detach_buf_packed(vq, i, NULL);
+ END_USE(vq);
+ return buf;
+ }
+ /* That should have freed everything. */
+ BUG_ON(vq->vq.num_free != vq->packed.vring.num);
+
+ END_USE(vq);
+ return NULL;
+}
+
+static struct virtqueue *vring_create_virtqueue_packed(
+ unsigned int index,
+ unsigned int num,
+ unsigned int vring_align,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool may_reduce_num,
+ bool context,
+ bool (*notify)(struct virtqueue *),
+ void (*callback)(struct virtqueue *),
+ const char *name)
+{
+ struct vring_virtqueue *vq;
+ struct vring_packed_desc *ring;
+ struct vring_packed_desc_event *driver, *device;
+ dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
+ size_t ring_size_in_bytes, event_size_in_bytes;
+ unsigned int i;
+
+ ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
+
+ ring = vring_alloc_queue(vdev, ring_size_in_bytes,
+ &ring_dma_addr,
+ GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+ if (!ring)
+ goto err_ring;
+
+ event_size_in_bytes = sizeof(struct vring_packed_desc_event);
+
+ driver = vring_alloc_queue(vdev, event_size_in_bytes,
+ &driver_event_dma_addr,
+ GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+ if (!driver)
+ goto err_driver;
+
+ device = vring_alloc_queue(vdev, event_size_in_bytes,
+ &device_event_dma_addr,
+ GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+ if (!device)
+ goto err_device;
+
+ vq = kmalloc(sizeof(*vq), GFP_KERNEL);
+ if (!vq)
+ goto err_vq;
+
+ vq->vq.callback = callback;
+ vq->vq.vdev = vdev;
+ vq->vq.name = name;
+ vq->vq.num_free = num;
+ vq->vq.index = index;
+ vq->we_own_ring = true;
+ vq->notify = notify;
+ vq->weak_barriers = weak_barriers;
+ vq->broken = false;
+ vq->last_used_idx = 0;
+ vq->num_added = 0;
+ vq->packed_ring = true;
+ vq->use_dma_api = vring_use_dma_api(vdev);
+ list_add_tail(&vq->vq.list, &vdev->vqs);
+#ifdef DEBUG
+ vq->in_use = false;
+ vq->last_add_time_valid = false;
+#endif
+
+ vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
+ !context;
+ vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
+
+ vq->packed.ring_dma_addr = ring_dma_addr;
+ vq->packed.driver_event_dma_addr = driver_event_dma_addr;
+ vq->packed.device_event_dma_addr = device_event_dma_addr;
+
+ vq->packed.ring_size_in_bytes = ring_size_in_bytes;
+ vq->packed.event_size_in_bytes = event_size_in_bytes;
+
+ vq->packed.vring.num = num;
+ vq->packed.vring.desc = ring;
+ vq->packed.vring.driver = driver;
+ vq->packed.vring.device = device;
+
+ vq->packed.next_avail_idx = 0;
+ vq->packed.avail_wrap_counter = 1;
+ vq->packed.used_wrap_counter = 1;
+ vq->packed.event_flags_shadow = 0;
+ vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;
+
+ vq->packed.desc_state = kmalloc_array(num,
+ sizeof(struct vring_desc_state_packed),
+ GFP_KERNEL);
+ if (!vq->packed.desc_state)
+ goto err_desc_state;
+
+ memset(vq->packed.desc_state, 0,
+ num * sizeof(struct vring_desc_state_packed));
+
+ /* Put everything in free lists. */
+ vq->free_head = 0;
+ for (i = 0; i < num-1; i++)
+ vq->packed.desc_state[i].next = i + 1;
+
+ vq->packed.desc_extra = kmalloc_array(num,
+ sizeof(struct vring_desc_extra_packed),
+ GFP_KERNEL);
+ if (!vq->packed.desc_extra)
+ goto err_desc_extra;
+
+ memset(vq->packed.desc_extra, 0,
+ num * sizeof(struct vring_desc_extra_packed));
+
+ /* No callback? Tell other side not to bother us. */
+ if (!callback) {
+ vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
+ vq->packed.vring.driver->flags =
+ cpu_to_le16(vq->packed.event_flags_shadow);
+ }
+
+ return &vq->vq;
+
+err_desc_extra:
+ kfree(vq->packed.desc_state);
+err_desc_state:
+ kfree(vq);
+err_vq:
+ vring_free_queue(vdev, event_size_in_bytes, device, ring_dma_addr);
+err_device:
+ vring_free_queue(vdev, event_size_in_bytes, driver, ring_dma_addr);
+err_driver:
+ vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
+err_ring:
+ return NULL;
+}
+
+
/*
* Generic functions and exported symbols.
*/
@@ -853,8 +1622,12 @@ static inline int virtqueue_add(struct virtqueue *_vq,
void *ctx,
gfp_t gfp)
{
- return virtqueue_add_split(_vq, sgs, total_sg,
- out_sgs, in_sgs, data, ctx, gfp);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg,
+ out_sgs, in_sgs, data, ctx, gfp) :
+ virtqueue_add_split(_vq, sgs, total_sg,
+ out_sgs, in_sgs, data, ctx, gfp);
}

/**
@@ -973,7 +1746,10 @@ EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
*/
bool virtqueue_kick_prepare(struct virtqueue *_vq)
{
- return virtqueue_kick_prepare_split(_vq);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) :
+ virtqueue_kick_prepare_split(_vq);
}
EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);

@@ -1040,7 +1816,10 @@ EXPORT_SYMBOL_GPL(virtqueue_kick);
void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
void **ctx)
{
- return virtqueue_get_buf_ctx_split(_vq, len, ctx);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
+ virtqueue_get_buf_ctx_split(_vq, len, ctx);
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);

@@ -1049,7 +1828,6 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
return virtqueue_get_buf_ctx(_vq, len, NULL);
}
EXPORT_SYMBOL_GPL(virtqueue_get_buf);
-
/**
* virtqueue_disable_cb - disable callbacks
* @vq: the struct virtqueue we're talking about.
@@ -1061,7 +1839,12 @@ EXPORT_SYMBOL_GPL(virtqueue_get_buf);
*/
void virtqueue_disable_cb(struct virtqueue *_vq)
{
- virtqueue_disable_cb_split(_vq);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ if (vq->packed_ring)
+ virtqueue_disable_cb_packed(_vq);
+ else
+ virtqueue_disable_cb_split(_vq);
}
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);

@@ -1079,7 +1862,10 @@ EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
*/
unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
{
- return virtqueue_enable_cb_prepare_split(_vq);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) :
+ virtqueue_enable_cb_prepare_split(_vq);
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);

@@ -1097,7 +1883,8 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
struct vring_virtqueue *vq = to_vvq(_vq);

virtio_mb(vq->weak_barriers);
- return virtqueue_poll_split(_vq, last_used_idx);
+ return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) :
+ virtqueue_poll_split(_vq, last_used_idx);
}
EXPORT_SYMBOL_GPL(virtqueue_poll);

@@ -1135,7 +1922,10 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
*/
bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
{
- return virtqueue_enable_cb_delayed_split(_vq);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) :
+ virtqueue_enable_cb_delayed_split(_vq);
}
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);

@@ -1149,13 +1939,16 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
*/
void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
{
- return virtqueue_detach_unused_buf_split(_vq);
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) :
+ virtqueue_detach_unused_buf_split(_vq);
}
EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);

static inline bool more_used(const struct vring_virtqueue *vq)
{
- return more_used_split(vq);
+ return vq->packed_ring ? more_used_packed(vq) : more_used_split(vq);
}

irqreturn_t vring_interrupt(int irq, void *_vq)
@@ -1178,6 +1971,7 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
}
EXPORT_SYMBOL_GPL(vring_interrupt);

+/* Only available for split ring */
struct virtqueue *__vring_new_virtqueue(unsigned int index,
struct vring vring,
struct virtio_device *vdev,
@@ -1190,10 +1984,14 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
unsigned int i;
struct vring_virtqueue *vq;

+ if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
+ return NULL;
+
vq = kmalloc(sizeof(*vq), GFP_KERNEL);
if (!vq)
return NULL;

+ vq->packed_ring = false;
vq->vq.callback = callback;
vq->vq.vdev = vdev;
vq->vq.name = name;
@@ -1261,12 +2059,19 @@ struct virtqueue *vring_create_virtqueue(
void (*callback)(struct virtqueue *),
const char *name)
{
+
+ if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
+ return vring_create_virtqueue_packed(index, num, vring_align,
+ vdev, weak_barriers, may_reduce_num,
+ context, notify, callback, name);
+
return vring_create_virtqueue_split(index, num, vring_align,
vdev, weak_barriers, may_reduce_num,
context, notify, callback, name);
}
EXPORT_SYMBOL_GPL(vring_create_virtqueue);

+/* Only available for split ring */
struct virtqueue *vring_new_virtqueue(unsigned int index,
unsigned int num,
unsigned int vring_align,
@@ -1279,6 +2084,10 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
const char *name)
{
struct vring vring;
+
+ if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
+ return NULL;
+
vring_init(&vring, num, pages, vring_align);
return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
notify, callback, name);
@@ -1290,11 +2099,32 @@ void vring_del_virtqueue(struct virtqueue *_vq)
struct vring_virtqueue *vq = to_vvq(_vq);

if (vq->we_own_ring) {
- vring_free_queue(vq->vq.vdev,
- vq->split.queue_size_in_bytes,
- vq->split.vring.desc,
- vq->split.queue_dma_addr);
- kfree(vq->split.desc_state);
+ if (vq->packed_ring) {
+ vring_free_queue(vq->vq.vdev,
+ vq->packed.ring_size_in_bytes,
+ vq->packed.vring.desc,
+ vq->packed.ring_dma_addr);
+
+ vring_free_queue(vq->vq.vdev,
+ vq->packed.event_size_in_bytes,
+ vq->packed.vring.driver,
+ vq->packed.driver_event_dma_addr);
+
+ vring_free_queue(vq->vq.vdev,
+ vq->packed.event_size_in_bytes,
+ vq->packed.vring.device,
+ vq->packed.device_event_dma_addr);
+
+ kfree(vq->packed.desc_state);
+ kfree(vq->packed.desc_extra);
+ } else {
+ vring_free_queue(vq->vq.vdev,
+ vq->split.queue_size_in_bytes,
+ vq->split.vring.desc,
+ vq->split.queue_dma_addr);
+
+ kfree(vq->split.desc_state);
+ }
}
list_del(&_vq->list);
kfree(vq);
@@ -1336,7 +2166,7 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)

struct vring_virtqueue *vq = to_vvq(_vq);

- return vq->split.vring.num;
+ return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num;
}
EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);

@@ -1369,6 +2199,9 @@ dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq)

BUG_ON(!vq->we_own_ring);

+ if (vq->packed_ring)
+ return vq->packed.ring_dma_addr;
+
return vq->split.queue_dma_addr;
}
EXPORT_SYMBOL_GPL(virtqueue_get_desc_addr);
@@ -1379,6 +2212,9 @@ dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq)

BUG_ON(!vq->we_own_ring);

+ if (vq->packed_ring)
+ return vq->packed.driver_event_dma_addr;
+
return vq->split.queue_dma_addr +
((char *)vq->split.vring.avail - (char *)vq->split.vring.desc);
}
@@ -1390,11 +2226,15 @@ dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq)

BUG_ON(!vq->we_own_ring);

+ if (vq->packed_ring)
+ return vq->packed.device_event_dma_addr;
+
return vq->split.queue_dma_addr +
((char *)vq->split.vring.used - (char *)vq->split.vring.desc);
}
EXPORT_SYMBOL_GPL(virtqueue_get_used_addr);

+/* Only available for split ring */
const struct vring *virtqueue_get_vring(struct virtqueue *vq)
{
return &to_vvq(vq)->split.vring;
--
2.14.5
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  Last update: 2018-11-21 11:07    [W:0.201 / U:0.208 seconds]
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