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Date:   Thu,  7 Dec 2023 16:52:35 -0800
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Message-ID: <20231208005250.2910004-5-almasrymina@google.com>
Subject: [net-next v1 04/16] gve: implement queue api
From:   Mina Almasry <almasrymina@google.com>
To:     Shailend Chand <shailend@google.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org,
        bpf@vger.kernel.org, linux-media@vger.kernel.org,
        dri-devel@lists.freedesktop.org
Cc:     Mina Almasry <almasrymina@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Jeroen de Borst <jeroendb@google.com>,
        Praveen Kaligineedi <pkaligineedi@google.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        David Ahern <dsahern@kernel.org>,
        Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
        Shuah Khan <shuah@kernel.org>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        "=?UTF-8?q?Christian=20K=C3=B6nig?=" <christian.koenig@amd.com>,
        Yunsheng Lin <linyunsheng@huawei.com>,
        Harshitha Ramamurthy <hramamurthy@google.com>,
        Shakeel Butt <shakeelb@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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