[net-next v1 04/16] gve: implement queue api

Mina Almasry
2023-12-08T00:53:04Z

Define a struct that contains all of the memory needed for an RX
queue to function.

Implement the queue-api in GVE using this struct.

Currently the only memory is allocated at the time of queue start are
the RX pages in gve_rx_post_buffers_dqo(). That can be moved up to
queue_mem_alloc() time in the future.

For simplicity the queue API is only supported by the diorite queue
out-of-order (DQO) format without queue-page-lists (QPL). Support for
other GVE formats can be added in the future as well.

Signed-off-by: Mina Almasry <almasrymina@google.com>

---
drivers/net/ethernet/google/gve/gve_adminq.c | 6 +-
drivers/net/ethernet/google/gve/gve_adminq.h | 3 +
drivers/net/ethernet/google/gve/gve_dqo.h | 2 +
drivers/net/ethernet/google/gve/gve_main.c | 286 +++++++++++++++++++
drivers/net/ethernet/google/gve/gve_rx_dqo.c | 5 +-
5 files changed, 296 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c
index 12fbd723ecc6..e515b7278295 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.c
+++ b/drivers/net/ethernet/google/gve/gve_adminq.c
@@ -348,7 +348,7 @@ static int gve_adminq_parse_err(struct gve_priv *priv, u32 status)
/* Flushes all AQ commands currently queued and waits for them to complete.
* If there are failures, it will return the first error.
*/
-static int gve_adminq_kick_and_wait(struct gve_priv *priv)
+int gve_adminq_kick_and_wait(struct gve_priv *priv)
{
int tail, head;
int i;
@@ -591,7 +591,7 @@ int gve_adminq_create_tx_queues(struct gve_priv *priv, u32 start_id, u32 num_que
return gve_adminq_kick_and_wait(priv);
}

-static int gve_adminq_create_rx_queue(struct gve_priv *priv, u32 queue_index)
+int gve_adminq_create_rx_queue(struct gve_priv *priv, u32 queue_index)
{
struct gve_rx_ring *rx = &priv->rx[queue_index];
union gve_adminq_command cmd;
@@ -691,7 +691,7 @@ int gve_adminq_destroy_tx_queues(struct gve_priv *priv, u32 start_id, u32 num_qu
return gve_adminq_kick_and_wait(priv);
}

-static int gve_adminq_destroy_rx_queue(struct gve_priv *priv, u32 queue_index)
+int gve_adminq_destroy_rx_queue(struct gve_priv *priv, u32 queue_index)
{
union gve_adminq_command cmd;
int err;
diff --git a/drivers/net/ethernet/google/gve/gve_adminq.h b/drivers/net/ethernet/google/gve/gve_adminq.h
index 5865ccdccbd0..265beed965dc 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.h
+++ b/drivers/net/ethernet/google/gve/gve_adminq.h
@@ -411,6 +411,7 @@ union gve_adminq_command {

static_assert(sizeof(union gve_adminq_command) == 64);

+int gve_adminq_kick_and_wait(struct gve_priv *priv);
int gve_adminq_alloc(struct device *dev, struct gve_priv *priv);
void gve_adminq_free(struct device *dev, struct gve_priv *priv);
void gve_adminq_release(struct gve_priv *priv);
@@ -424,7 +425,9 @@ int gve_adminq_deconfigure_device_resources(struct gve_priv *priv);
int gve_adminq_create_tx_queues(struct gve_priv *priv, u32 start_id, u32 num_queues);
int gve_adminq_destroy_tx_queues(struct gve_priv *priv, u32 start_id, u32 num_queues);
int gve_adminq_create_rx_queues(struct gve_priv *priv, u32 num_queues);
+int gve_adminq_create_rx_queue(struct gve_priv *priv, u32 queue_index);
int gve_adminq_destroy_rx_queues(struct gve_priv *priv, u32 queue_id);
+int gve_adminq_destroy_rx_queue(struct gve_priv *priv, u32 queue_id);
int gve_adminq_register_page_list(struct gve_priv *priv,
struct gve_queue_page_list *qpl);
int gve_adminq_unregister_page_list(struct gve_priv *priv, u32 page_list_id);
diff --git a/drivers/net/ethernet/google/gve/gve_dqo.h b/drivers/net/ethernet/google/gve/gve_dqo.h
index c36b93f0de15..3eed26a0ed7d 100644
--- a/drivers/net/ethernet/google/gve/gve_dqo.h
+++ b/drivers/net/ethernet/google/gve/gve_dqo.h
@@ -46,6 +46,8 @@ int gve_clean_tx_done_dqo(struct gve_priv *priv, struct gve_tx_ring *tx,
struct napi_struct *napi);
void gve_rx_post_buffers_dqo(struct gve_rx_ring *rx);
void gve_rx_write_doorbell_dqo(const struct gve_priv *priv, int queue_idx);
+void gve_free_page_dqo(struct gve_priv *priv, struct gve_rx_buf_state_dqo *bs,
+ bool free_page);

static inline void
gve_tx_put_doorbell_dqo(const struct gve_priv *priv,
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index 619bf63ec935..5b23d811afd3 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -22,6 +22,7 @@
#include "gve_dqo.h"
#include "gve_adminq.h"
#include "gve_register.h"
+#include "gve_utils.h"

#define GVE_DEFAULT_RX_COPYBREAK (256)

@@ -1702,6 +1703,287 @@ static int gve_xdp(struct net_device *dev, struct netdev_bpf *xdp)
}
}

+struct gve_per_rx_queue_mem_dqo {
+ struct gve_rx_buf_state_dqo *buf_states;
+ u32 num_buf_states;
+
+ struct gve_rx_compl_desc_dqo *complq_desc_ring;
+ dma_addr_t complq_bus;
+
+ struct gve_rx_desc_dqo *bufq_desc_ring;
+ dma_addr_t bufq_bus;
+
+ struct gve_queue_resources *q_resources;
+ dma_addr_t q_resources_bus;
+
+ size_t completion_queue_slots;
+ size_t buffer_queue_slots;
+};
+
+static int gve_rx_queue_stop(struct net_device *dev, int idx,
+ void **out_per_q_mem)
+{
+ struct gve_per_rx_queue_mem_dqo *per_q_mem;
+ struct gve_priv *priv = netdev_priv(dev);
+ struct gve_notify_block *block;
+ struct gve_rx_ring *rx;
+ int ntfy_idx;
+ int err;
+
+ rx = &priv->rx[idx];
+ ntfy_idx = gve_rx_idx_to_ntfy(priv, idx);
+ block = &priv->ntfy_blocks[ntfy_idx];
+
+ if (priv->queue_format != GVE_DQO_RDA_FORMAT)
+ return -EOPNOTSUPP;
+
+ if (!out_per_q_mem)
+ return -EINVAL;
+
+ /* Stopping queue 0 while other queues are running is unfortunately
+ * fails silently for GVE at the moment. Disable the queue-api for
+ * queue 0 until this is resolved.
+ */
+ if (idx == 0)
+ return -ERANGE;
+
+ per_q_mem = kvcalloc(1, sizeof(*per_q_mem), GFP_KERNEL);
+ if (!per_q_mem)
+ return -ENOMEM;
+
+ napi_disable(&block->napi);
+ err = gve_adminq_destroy_rx_queue(priv, idx);
+ if (err)
+ goto err_napi_enable;
+
+ err = gve_adminq_kick_and_wait(priv);
+ if (err)
+ goto err_create_rx_queue;
+
+ gve_remove_napi(priv, ntfy_idx);
+
+ per_q_mem->buf_states = rx->dqo.buf_states;
+ per_q_mem->num_buf_states = rx->dqo.num_buf_states;
+
+ per_q_mem->complq_desc_ring = rx->dqo.complq.desc_ring;
+ per_q_mem->complq_bus = rx->dqo.complq.bus;
+
+ per_q_mem->bufq_desc_ring = rx->dqo.bufq.desc_ring;
+ per_q_mem->bufq_bus = rx->dqo.bufq.bus;
+
+ per_q_mem->q_resources = rx->q_resources;
+ per_q_mem->q_resources_bus = rx->q_resources_bus;
+
+ per_q_mem->buffer_queue_slots = rx->dqo.bufq.mask + 1;
+ per_q_mem->completion_queue_slots = rx->dqo.complq.mask + 1;
+
+ *out_per_q_mem = per_q_mem;
+
+ return 0;
+
+err_create_rx_queue:
+ /* There is nothing we can do here if these fail. */
+ gve_adminq_create_rx_queue(priv, idx);
+ gve_adminq_kick_and_wait(priv);
+
+err_napi_enable:
+ napi_enable(&block->napi);
+ kvfree(per_q_mem);
+
+ return err;
+}
+
+static void gve_rx_queue_mem_free(struct net_device *dev, void *per_q_mem)
+{
+ struct gve_per_rx_queue_mem_dqo *gve_q_mem;
+ struct gve_priv *priv = netdev_priv(dev);
+ struct gve_rx_buf_state_dqo *bs;
+ struct device *hdev;
+ size_t size;
+ int i;
+
+ priv = netdev_priv(dev);
+ gve_q_mem = (struct gve_per_rx_queue_mem_dqo *)per_q_mem;
+ hdev = &priv->pdev->dev;
+
+ if (!gve_q_mem)
+ return;
+
+ if (priv->queue_format != GVE_DQO_RDA_FORMAT)
+ return;
+
+ for (i = 0; i < gve_q_mem->num_buf_states; i++) {
+ bs = &gve_q_mem->buf_states[i];
+ if (bs->page_info.page)
+ gve_free_page_dqo(priv, bs, true);
+ }
+
+ if (gve_q_mem->q_resources)
+ dma_free_coherent(hdev, sizeof(*gve_q_mem->q_resources),
+ gve_q_mem->q_resources,
+ gve_q_mem->q_resources_bus);
+
+ if (gve_q_mem->bufq_desc_ring) {
+ size = sizeof(gve_q_mem->bufq_desc_ring[0]) *
+ gve_q_mem->buffer_queue_slots;
+ dma_free_coherent(hdev, size, gve_q_mem->bufq_desc_ring,
+ gve_q_mem->bufq_bus);
+ }
+
+ if (gve_q_mem->complq_desc_ring) {
+ size = sizeof(gve_q_mem->complq_desc_ring[0]) *
+ gve_q_mem->completion_queue_slots;
+ dma_free_coherent(hdev, size, gve_q_mem->complq_desc_ring,
+ gve_q_mem->complq_bus);
+ }
+
+ kvfree(gve_q_mem->buf_states);
+
+ kvfree(per_q_mem);
+}
+
+static void *gve_rx_queue_mem_alloc(struct net_device *dev, int idx)
+{
+ struct gve_per_rx_queue_mem_dqo *gve_q_mem;
+ struct gve_priv *priv = netdev_priv(dev);
+ struct device *hdev = &priv->pdev->dev;
+ size_t size;
+
+ if (priv->queue_format != GVE_DQO_RDA_FORMAT)
+ return NULL;
+
+ /* See comment in gve_rx_queue_stop() */
+ if (idx == 0)
+ return NULL;
+
+ gve_q_mem = kvcalloc(1, sizeof(*gve_q_mem), GFP_KERNEL);
+ if (!gve_q_mem)
+ goto err;
+
+ gve_q_mem->buffer_queue_slots =
+ priv->options_dqo_rda.rx_buff_ring_entries;
+ gve_q_mem->completion_queue_slots = priv->rx_desc_cnt;
+
+ gve_q_mem->num_buf_states =
+ min_t(s16, S16_MAX, gve_q_mem->buffer_queue_slots * 4);
+
+ gve_q_mem->buf_states = kvcalloc(gve_q_mem->num_buf_states,
+ sizeof(gve_q_mem->buf_states[0]),
+ GFP_KERNEL);
+ if (!gve_q_mem->buf_states)
+ goto err;
+
+ size = sizeof(struct gve_rx_compl_desc_dqo) *
+ gve_q_mem->completion_queue_slots;
+ gve_q_mem->complq_desc_ring = dma_alloc_coherent(hdev, size,
+ &gve_q_mem->complq_bus,
+ GFP_KERNEL);
+ if (!gve_q_mem->complq_desc_ring)
+ goto err;
+
+ size = sizeof(struct gve_rx_desc_dqo) * gve_q_mem->buffer_queue_slots;
+ gve_q_mem->bufq_desc_ring = dma_alloc_coherent(hdev, size,
+ &gve_q_mem->bufq_bus,
+ GFP_KERNEL);
+ if (!gve_q_mem->bufq_desc_ring)
+ goto err;
+
+ gve_q_mem->q_resources = dma_alloc_coherent(hdev,
+ sizeof(*gve_q_mem->q_resources),
+ &gve_q_mem->q_resources_bus,
+ GFP_KERNEL);
+ if (!gve_q_mem->q_resources)
+ goto err;
+
+ return gve_q_mem;
+
+err:
+ gve_rx_queue_mem_free(dev, gve_q_mem);
+ return NULL;
+}
+
+static int gve_rx_queue_start(struct net_device *dev, int idx, void *per_q_mem)
+{
+ struct gve_per_rx_queue_mem_dqo *gve_q_mem;
+ struct gve_priv *priv = netdev_priv(dev);
+ struct gve_rx_ring *rx = &priv->rx[idx];
+ struct gve_notify_block *block;
+ int ntfy_idx;
+ int err;
+ int i;
+
+ if (priv->queue_format != GVE_DQO_RDA_FORMAT)
+ return -EOPNOTSUPP;
+
+ /* See comment in gve_rx_queue_stop() */
+ if (idx == 0)
+ return -ERANGE;
+
+ gve_q_mem = (struct gve_per_rx_queue_mem_dqo *)per_q_mem;
+ ntfy_idx = gve_rx_idx_to_ntfy(priv, idx);
+ block = &priv->ntfy_blocks[ntfy_idx];
+
+ netif_dbg(priv, drv, priv->dev, "starting rx ring DQO\n");
+
+ memset(rx, 0, sizeof(*rx));
+ rx->gve = priv;
+ rx->q_num = idx;
+ rx->dqo.bufq.mask = gve_q_mem->buffer_queue_slots - 1;
+ rx->dqo.complq.num_free_slots = gve_q_mem->completion_queue_slots;
+ rx->dqo.complq.mask = gve_q_mem->completion_queue_slots - 1;
+ rx->ctx.skb_head = NULL;
+ rx->ctx.skb_tail = NULL;
+
+ rx->dqo.num_buf_states = gve_q_mem->num_buf_states;
+
+ rx->dqo.buf_states = gve_q_mem->buf_states;
+
+ /* Set up linked list of buffer IDs */
+ for (i = 0; i < rx->dqo.num_buf_states - 1; i++)
+ rx->dqo.buf_states[i].next = i + 1;
+
+ rx->dqo.buf_states[rx->dqo.num_buf_states - 1].next = -1;
+ rx->dqo.recycled_buf_states.head = -1;
+ rx->dqo.recycled_buf_states.tail = -1;
+ rx->dqo.used_buf_states.head = -1;
+ rx->dqo.used_buf_states.tail = -1;
+
+ rx->dqo.complq.desc_ring = gve_q_mem->complq_desc_ring;
+ rx->dqo.complq.bus = gve_q_mem->complq_bus;
+
+ rx->dqo.bufq.desc_ring = gve_q_mem->bufq_desc_ring;
+ rx->dqo.bufq.bus = gve_q_mem->bufq_bus;
+
+ rx->q_resources = gve_q_mem->q_resources;
+ rx->q_resources_bus = gve_q_mem->q_resources_bus;
+
+ gve_rx_add_to_block(priv, idx);
+
+ err = gve_adminq_create_rx_queue(priv, idx);
+ if (err)
+ return err;
+
+ err = gve_adminq_kick_and_wait(priv);
+ if (err)
+ goto err_destroy_rx_queue;
+
+ /* TODO, pull the memory allocations in this to gve_rx_queue_mem_alloc()
+ */
+ gve_rx_post_buffers_dqo(&priv->rx[idx]);
+
+ napi_enable(&block->napi);
+ gve_set_itr_coalesce_usecs_dqo(priv, block, priv->rx_coalesce_usecs);
+
+ return 0;
+
+err_destroy_rx_queue:
+ /* There is nothing we can do if these fail. */
+ gve_adminq_destroy_rx_queue(priv, idx);
+ gve_adminq_kick_and_wait(priv);
+
+ return err;
+}
+
int gve_adjust_queues(struct gve_priv *priv,
struct gve_queue_config new_rx_config,
struct gve_queue_config new_tx_config)
@@ -1900,6 +2182,10 @@ static const struct net_device_ops gve_netdev_ops = {
.ndo_bpf = gve_xdp,
.ndo_xdp_xmit = gve_xdp_xmit,
.ndo_xsk_wakeup = gve_xsk_wakeup,
+ .ndo_queue_mem_alloc = gve_rx_queue_mem_alloc,
+ .ndo_queue_mem_free = gve_rx_queue_mem_free,
+ .ndo_queue_start = gve_rx_queue_start,
+ .ndo_queue_stop = gve_rx_queue_stop,
};

static void gve_handle_status(struct gve_priv *priv, u32 status)
diff --git a/drivers/net/ethernet/google/gve/gve_rx_dqo.c b/drivers/net/ethernet/google/gve/gve_rx_dqo.c
index f281e42a7ef9..e729f04d3f60 100644
--- a/drivers/net/ethernet/google/gve/gve_rx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_rx_dqo.c
@@ -21,9 +21,8 @@ static int gve_buf_ref_cnt(struct gve_rx_buf_state_dqo *bs)
return page_count(bs->page_info.page) - bs->page_info.pagecnt_bias;
}

-static void gve_free_page_dqo(struct gve_priv *priv,
- struct gve_rx_buf_state_dqo *bs,
- bool free_page)
+void gve_free_page_dqo(struct gve_priv *priv, struct gve_rx_buf_state_dqo *bs,
+ bool free_page)
{
page_ref_sub(bs->page_info.page, bs->page_info.pagecnt_bias - 1);
if (free_page)
--
2.43.0.472.g3155946c3a-goog