Commit 255489f5 authored by Shailend Chand's avatar Shailend Chand Committed by David S. Miller
Browse files

gve: Add a jumbo-frame device option. 



A widely deployed driver has a bug that will cause the driver not
to load when a max_mtu > 2048 is present in the device descriptor.

To avoid this bug while still enabling jumbo frames, we present a lower
max_mtu in the device descriptor and pass the actual max_mtu in
a separate device option.

The driver supports 2 different queue formats. To enable features
on one queue format, but not the other, a supported_features mask
was added to the device options in the device descriptor.

Signed-off-by: default avatarShailend Chand <shailend@google.com>
Signed-off-by: default avatarJeroen de Borst <jeroendb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 37149e93

drivers/net/ethernet/google/gve/gve_adminq.c

+54 −4
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ void gve_parse_device_option(struct gve_priv *priv, 
			     struct gve_device_option *option,

			     struct gve_device_option_gqi_rda **dev_op_gqi_rda,

			     struct gve_device_option_gqi_qpl **dev_op_gqi_qpl,

			     struct gve_device_option_dqo_rda **dev_op_dqo_rda)

			     struct gve_device_option_dqo_rda **dev_op_dqo_rda,

			     struct gve_device_option_jumbo_frames **dev_op_jumbo_frames)

{

	u32 req_feat_mask = be32_to_cpu(option->required_features_mask);

	u16 option_length = be16_to_cpu(option->option_length);
@@ -111,6 +112,24 @@ void gve_parse_device_option(struct gve_priv *priv, 
		}

		*dev_op_dqo_rda = (void *)(option + 1);

		break;

	case GVE_DEV_OPT_ID_JUMBO_FRAMES:

		if (option_length < sizeof(**dev_op_jumbo_frames) ||

		    req_feat_mask != GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES) {

			dev_warn(&priv->pdev->dev, GVE_DEVICE_OPTION_ERROR_FMT,

				 "Jumbo Frames",

				 (int)sizeof(**dev_op_jumbo_frames),

				 GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES,

				 option_length, req_feat_mask);

			break;

		}



		if (option_length > sizeof(**dev_op_jumbo_frames)) {

			dev_warn(&priv->pdev->dev,

				 GVE_DEVICE_OPTION_TOO_BIG_FMT,

				 "Jumbo Frames");

		}

		*dev_op_jumbo_frames = (void *)(option + 1);

		break;

	default:

		/* If we don't recognize the option just continue

		 * without doing anything.
@@ -126,7 +145,8 @@ gve_process_device_options(struct gve_priv *priv, 
			   struct gve_device_descriptor *descriptor,

			   struct gve_device_option_gqi_rda **dev_op_gqi_rda,

			   struct gve_device_option_gqi_qpl **dev_op_gqi_qpl,

			   struct gve_device_option_dqo_rda **dev_op_dqo_rda)

			   struct gve_device_option_dqo_rda **dev_op_dqo_rda,

			   struct gve_device_option_jumbo_frames **dev_op_jumbo_frames)

{

	const int num_options = be16_to_cpu(descriptor->num_device_options);

	struct gve_device_option *dev_opt;
@@ -146,7 +166,7 @@ gve_process_device_options(struct gve_priv *priv, 


		gve_parse_device_option(priv, descriptor, dev_opt,

					dev_op_gqi_rda, dev_op_gqi_qpl,

					dev_op_dqo_rda);

					dev_op_dqo_rda, dev_op_jumbo_frames);

		dev_opt = next_opt;

	}
@@ -661,12 +681,31 @@ gve_set_desc_cnt_dqo(struct gve_priv *priv, 
	return 0;

}



static void gve_enable_supported_features(struct gve_priv *priv,

					  u32 supported_features_mask,

					  const struct gve_device_option_jumbo_frames

						  *dev_op_jumbo_frames)

{

	/* Before control reaches this point, the page-size-capped max MTU from

	 * the gve_device_descriptor field has already been stored in

	 * priv->dev->max_mtu. We overwrite it with the true max MTU below.

	 */

	if (dev_op_jumbo_frames &&

	    (supported_features_mask & GVE_SUP_JUMBO_FRAMES_MASK)) {

		dev_info(&priv->pdev->dev,

			 "JUMBO FRAMES device option enabled.\n");

		priv->dev->max_mtu = be16_to_cpu(dev_op_jumbo_frames->max_mtu);

	}

}



int gve_adminq_describe_device(struct gve_priv *priv)

{

	struct gve_device_option_jumbo_frames *dev_op_jumbo_frames = NULL;

	struct gve_device_option_gqi_rda *dev_op_gqi_rda = NULL;

	struct gve_device_option_gqi_qpl *dev_op_gqi_qpl = NULL;

	struct gve_device_option_dqo_rda *dev_op_dqo_rda = NULL;

	struct gve_device_descriptor *descriptor;

	u32 supported_features_mask = 0;

	union gve_adminq_command cmd;

	dma_addr_t descriptor_bus;

	int err = 0;
@@ -690,7 +729,8 @@ int gve_adminq_describe_device(struct gve_priv *priv) 
		goto free_device_descriptor;



	err = gve_process_device_options(priv, descriptor, &dev_op_gqi_rda,

					 &dev_op_gqi_qpl, &dev_op_dqo_rda);

					 &dev_op_gqi_qpl, &dev_op_dqo_rda,

					 &dev_op_jumbo_frames);

	if (err)

		goto free_device_descriptor;
@@ -705,12 +745,19 @@ int gve_adminq_describe_device(struct gve_priv *priv) 
		priv->queue_format = GVE_DQO_RDA_FORMAT;

		dev_info(&priv->pdev->dev,

			 "Driver is running with DQO RDA queue format.\n");

		supported_features_mask =

			be32_to_cpu(dev_op_dqo_rda->supported_features_mask);

	} else if (dev_op_gqi_rda) {

		priv->queue_format = GVE_GQI_RDA_FORMAT;

		dev_info(&priv->pdev->dev,

			 "Driver is running with GQI RDA queue format.\n");

		supported_features_mask =

			be32_to_cpu(dev_op_gqi_rda->supported_features_mask);

	} else {

		priv->queue_format = GVE_GQI_QPL_FORMAT;

		if (dev_op_gqi_qpl)

			supported_features_mask =

				be32_to_cpu(dev_op_gqi_qpl->supported_features_mask);

		dev_info(&priv->pdev->dev,

			 "Driver is running with GQI QPL queue format.\n");

	}
@@ -747,6 +794,9 @@ int gve_adminq_describe_device(struct gve_priv *priv) 
	}

	priv->default_num_queues = be16_to_cpu(descriptor->default_num_queues);



	gve_enable_supported_features(priv, supported_features_mask,

				      dev_op_jumbo_frames);



free_device_descriptor:

	dma_free_coherent(&priv->pdev->dev, PAGE_SIZE, descriptor,

			  descriptor_bus);

drivers/net/ethernet/google/gve/gve_adminq.h

+14 −0
Original line number Diff line number Diff line
@@ -108,6 +108,14 @@ struct gve_device_option_dqo_rda { 


static_assert(sizeof(struct gve_device_option_dqo_rda) == 8);



struct gve_device_option_jumbo_frames {

	__be32 supported_features_mask;

	__be16 max_mtu;

	u8 padding[2];

};



static_assert(sizeof(struct gve_device_option_jumbo_frames) == 8);



/* Terminology:

 *

 * RDA - Raw DMA Addressing - Buffers associated with SKBs are directly DMA
@@ -121,6 +129,7 @@ enum gve_dev_opt_id { 
	GVE_DEV_OPT_ID_GQI_RDA = 0x2,

	GVE_DEV_OPT_ID_GQI_QPL = 0x3,

	GVE_DEV_OPT_ID_DQO_RDA = 0x4,

	GVE_DEV_OPT_ID_JUMBO_FRAMES = 0x8,

};



enum gve_dev_opt_req_feat_mask {
@@ -128,6 +137,11 @@ enum gve_dev_opt_req_feat_mask { 
	GVE_DEV_OPT_REQ_FEAT_MASK_GQI_RDA = 0x0,

	GVE_DEV_OPT_REQ_FEAT_MASK_GQI_QPL = 0x0,

	GVE_DEV_OPT_REQ_FEAT_MASK_DQO_RDA = 0x0,

	GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES = 0x0,

};



enum gve_sup_feature_mask {

	GVE_SUP_JUMBO_FRAMES_MASK = 1 << 2,

};



#define GVE_DEV_OPT_LEN_GQI_RAW_ADDRESSING 0x0