[PATCH net-next 1/3] gve: Add header split device option

From: Ziwei Xiao
Date: Thu Feb 29 2024 - 16:24:15 EST


From: Jeroen de Borst <jeroendb@xxxxxxxxxx>

To enable header split via ethtool, we first need to query the device to
get the max rx buffer size and header buffer size. Add a device option
to get these values and store them in the driver. If the header buffer
size received from the device is non-zero, it means header split is
supported in the device.

Currently the max rx buffer size will only be used when header split is
enabled which will set the data_buffer_size_dqo to be the max rx buffer
size. Also change the data_buffer_size_dqo from int to u16 since we are
modifying it and making it to be consistent with max_rx_buffer_size.

Co-developed-by: Ziwei Xiao <ziweixiao@xxxxxxxxxx>
Signed-off-by: Ziwei Xiao <ziweixiao@xxxxxxxxxx>
Signed-off-by: Jeroen de Borst <jeroendb@xxxxxxxxxx>
Reviewed-by: Praveen Kaligineedi <pkaligineedi@xxxxxxxxxx>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@xxxxxxxxxx>
Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>
---
drivers/net/ethernet/google/gve/gve.h | 9 +++-
drivers/net/ethernet/google/gve/gve_adminq.c | 47 +++++++++++++++++---
drivers/net/ethernet/google/gve/gve_adminq.h | 20 ++++++++-
drivers/net/ethernet/google/gve/gve_main.c | 8 +---
drivers/net/ethernet/google/gve/gve_rx_dqo.c | 2 +-
5 files changed, 70 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve.h b/drivers/net/ethernet/google/gve/gve.h
index fd290f3ad6ec..5305404516fc 100644
--- a/drivers/net/ethernet/google/gve/gve.h
+++ b/drivers/net/ethernet/google/gve/gve.h
@@ -51,12 +51,16 @@

#define GVE_DEFAULT_RX_BUFFER_SIZE 2048

+#define GVE_MAX_RX_BUFFER_SIZE 4096
+
#define GVE_DEFAULT_RX_BUFFER_OFFSET 2048

#define GVE_XDP_ACTIONS 5

#define GVE_GQ_TX_MIN_PKT_DESC_BYTES 182

+#define GVE_DEFAULT_HEADER_BUFFER_SIZE 128
+
#define DQO_QPL_DEFAULT_TX_PAGES 512
#define DQO_QPL_DEFAULT_RX_PAGES 2048

@@ -778,13 +782,16 @@ struct gve_priv {
struct gve_ptype_lut *ptype_lut_dqo;

/* Must be a power of two. */
- int data_buffer_size_dqo;
+ u16 data_buffer_size_dqo;
+ u16 max_rx_buffer_size; /* device limit */

enum gve_queue_format queue_format;

/* Interrupt coalescing settings */
u32 tx_coalesce_usecs;
u32 rx_coalesce_usecs;
+
+ u16 header_buf_size; /* device configured, header-split supported if non-zero */
};

enum gve_service_task_flags_bit {
diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c
index 12fbd723ecc6..e2c27bbb56e6 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.c
+++ b/drivers/net/ethernet/google/gve/gve_adminq.c
@@ -40,7 +40,8 @@ void gve_parse_device_option(struct gve_priv *priv,
struct gve_device_option_gqi_qpl **dev_op_gqi_qpl,
struct gve_device_option_dqo_rda **dev_op_dqo_rda,
struct gve_device_option_jumbo_frames **dev_op_jumbo_frames,
- struct gve_device_option_dqo_qpl **dev_op_dqo_qpl)
+ struct gve_device_option_dqo_qpl **dev_op_dqo_qpl,
+ struct gve_device_option_buffer_sizes **dev_op_buffer_sizes)
{
u32 req_feat_mask = be32_to_cpu(option->required_features_mask);
u16 option_length = be16_to_cpu(option->option_length);
@@ -147,6 +148,23 @@ void gve_parse_device_option(struct gve_priv *priv,
}
*dev_op_jumbo_frames = (void *)(option + 1);
break;
+ case GVE_DEV_OPT_ID_BUFFER_SIZES:
+ if (option_length < sizeof(**dev_op_buffer_sizes) ||
+ req_feat_mask != GVE_DEV_OPT_REQ_FEAT_MASK_BUFFER_SIZES) {
+ dev_warn(&priv->pdev->dev, GVE_DEVICE_OPTION_ERROR_FMT,
+ "Buffer Sizes",
+ (int)sizeof(**dev_op_buffer_sizes),
+ GVE_DEV_OPT_REQ_FEAT_MASK_BUFFER_SIZES,
+ option_length, req_feat_mask);
+ break;
+ }
+
+ if (option_length > sizeof(**dev_op_buffer_sizes))
+ dev_warn(&priv->pdev->dev,
+ GVE_DEVICE_OPTION_TOO_BIG_FMT,
+ "Buffer Sizes");
+ *dev_op_buffer_sizes = (void *)(option + 1);
+ break;
default:
/* If we don't recognize the option just continue
* without doing anything.
@@ -164,7 +182,8 @@ gve_process_device_options(struct gve_priv *priv,
struct gve_device_option_gqi_qpl **dev_op_gqi_qpl,
struct gve_device_option_dqo_rda **dev_op_dqo_rda,
struct gve_device_option_jumbo_frames **dev_op_jumbo_frames,
- struct gve_device_option_dqo_qpl **dev_op_dqo_qpl)
+ struct gve_device_option_dqo_qpl **dev_op_dqo_qpl,
+ struct gve_device_option_buffer_sizes **dev_op_buffer_sizes)
{
const int num_options = be16_to_cpu(descriptor->num_device_options);
struct gve_device_option *dev_opt;
@@ -185,7 +204,7 @@ 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_jumbo_frames,
- dev_op_dqo_qpl);
+ dev_op_dqo_qpl, dev_op_buffer_sizes);
dev_opt = next_opt;
}

@@ -755,7 +774,9 @@ static void gve_enable_supported_features(struct gve_priv *priv,
const struct gve_device_option_jumbo_frames
*dev_op_jumbo_frames,
const struct gve_device_option_dqo_qpl
- *dev_op_dqo_qpl)
+ *dev_op_dqo_qpl,
+ const struct gve_device_option_buffer_sizes
+ *dev_op_buffer_sizes)
{
/* Before control reaches this point, the page-size-capped max MTU from
* the gve_device_descriptor field has already been stored in
@@ -779,10 +800,22 @@ static void gve_enable_supported_features(struct gve_priv *priv,
if (priv->rx_pages_per_qpl == 0)
priv->rx_pages_per_qpl = DQO_QPL_DEFAULT_RX_PAGES;
}
+
+ if (dev_op_buffer_sizes &&
+ (supported_features_mask & GVE_SUP_BUFFER_SIZES_MASK)) {
+ priv->max_rx_buffer_size =
+ be16_to_cpu(dev_op_buffer_sizes->packet_buffer_size);
+ priv->header_buf_size =
+ be16_to_cpu(dev_op_buffer_sizes->header_buffer_size);
+ dev_info(&priv->pdev->dev,
+ "BUFFER SIZES device option enabled with max_rx_buffer_size of %u, header_buf_size of %u.\n",
+ priv->max_rx_buffer_size, priv->header_buf_size);
+ }
}

int gve_adminq_describe_device(struct gve_priv *priv)
{
+ struct gve_device_option_buffer_sizes *dev_op_buffer_sizes = NULL;
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;
@@ -816,7 +849,8 @@ int gve_adminq_describe_device(struct gve_priv *priv)
err = gve_process_device_options(priv, descriptor, &dev_op_gqi_rda,
&dev_op_gqi_qpl, &dev_op_dqo_rda,
&dev_op_jumbo_frames,
- &dev_op_dqo_qpl);
+ &dev_op_dqo_qpl,
+ &dev_op_buffer_sizes);
if (err)
goto free_device_descriptor;

@@ -885,7 +919,8 @@ 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, dev_op_dqo_qpl);
+ dev_op_jumbo_frames, dev_op_dqo_qpl,
+ dev_op_buffer_sizes);

free_device_descriptor:
dma_pool_free(priv->adminq_pool, descriptor, descriptor_bus);
diff --git a/drivers/net/ethernet/google/gve/gve_adminq.h b/drivers/net/ethernet/google/gve/gve_adminq.h
index 5865ccdccbd0..5ac972e45ff8 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.h
+++ b/drivers/net/ethernet/google/gve/gve_adminq.h
@@ -125,6 +125,15 @@ struct gve_device_option_jumbo_frames {

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

+struct gve_device_option_buffer_sizes {
+ /* GVE_SUP_BUFFER_SIZES_MASK bit should be set */
+ __be32 supported_features_mask;
+ __be16 packet_buffer_size;
+ __be16 header_buffer_size;
+};
+
+static_assert(sizeof(struct gve_device_option_buffer_sizes) == 8);
+
/* Terminology:
*
* RDA - Raw DMA Addressing - Buffers associated with SKBs are directly DMA
@@ -140,6 +149,7 @@ enum gve_dev_opt_id {
GVE_DEV_OPT_ID_DQO_RDA = 0x4,
GVE_DEV_OPT_ID_DQO_QPL = 0x7,
GVE_DEV_OPT_ID_JUMBO_FRAMES = 0x8,
+ GVE_DEV_OPT_ID_BUFFER_SIZES = 0xa,
};

enum gve_dev_opt_req_feat_mask {
@@ -149,10 +159,12 @@ enum gve_dev_opt_req_feat_mask {
GVE_DEV_OPT_REQ_FEAT_MASK_DQO_RDA = 0x0,
GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES = 0x0,
GVE_DEV_OPT_REQ_FEAT_MASK_DQO_QPL = 0x0,
+ GVE_DEV_OPT_REQ_FEAT_MASK_BUFFER_SIZES = 0x0,
};

enum gve_sup_feature_mask {
GVE_SUP_JUMBO_FRAMES_MASK = 1 << 2,
+ GVE_SUP_BUFFER_SIZES_MASK = 1 << 4,
};

#define GVE_DEV_OPT_LEN_GQI_RAW_ADDRESSING 0x0
@@ -165,6 +177,7 @@ enum gve_driver_capbility {
gve_driver_capability_dqo_qpl = 2, /* reserved for future use */
gve_driver_capability_dqo_rda = 3,
gve_driver_capability_alt_miss_compl = 4,
+ gve_driver_capability_flexible_buffer_size = 5,
};

#define GVE_CAP1(a) BIT((int)a)
@@ -176,7 +189,8 @@ enum gve_driver_capbility {
(GVE_CAP1(gve_driver_capability_gqi_qpl) | \
GVE_CAP1(gve_driver_capability_gqi_rda) | \
GVE_CAP1(gve_driver_capability_dqo_rda) | \
- GVE_CAP1(gve_driver_capability_alt_miss_compl))
+ GVE_CAP1(gve_driver_capability_alt_miss_compl) | \
+ GVE_CAP1(gve_driver_capability_flexible_buffer_size))

#define GVE_DRIVER_CAPABILITY_FLAGS2 0x0
#define GVE_DRIVER_CAPABILITY_FLAGS3 0x0
@@ -260,7 +274,9 @@ struct gve_adminq_create_rx_queue {
__be16 packet_buffer_size;
__be16 rx_buff_ring_size;
u8 enable_rsc;
- u8 padding[5];
+ u8 padding1;
+ __be16 header_buffer_size;
+ u8 padding2[2];
};

static_assert(sizeof(struct gve_adminq_create_rx_queue) == 56);
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index db6d9ae7cd78..02d12aa50885 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -1448,12 +1448,6 @@ static int gve_queues_start(struct gve_priv *priv,
if (err)
goto reset;

- if (!gve_is_gqi(priv)) {
- /* Hard code this for now. This may be tuned in the future for
- * performance.
- */
- priv->data_buffer_size_dqo = GVE_DEFAULT_RX_BUFFER_SIZE;
- }
err = gve_create_rings(priv);
if (err)
goto reset;
@@ -2511,6 +2505,8 @@ static int gve_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
priv->service_task_flags = 0x0;
priv->state_flags = 0x0;
priv->ethtool_flags = 0x0;
+ priv->data_buffer_size_dqo = GVE_DEFAULT_RX_BUFFER_SIZE;
+ priv->max_rx_buffer_size = GVE_DEFAULT_RX_BUFFER_SIZE;

gve_set_probe_in_progress(priv);
priv->gve_wq = alloc_ordered_workqueue("gve", 0);
diff --git a/drivers/net/ethernet/google/gve/gve_rx_dqo.c b/drivers/net/ethernet/google/gve/gve_rx_dqo.c
index 8e6aeb5b3ed4..c3ce819ee5ab 100644
--- a/drivers/net/ethernet/google/gve/gve_rx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_rx_dqo.c
@@ -458,7 +458,7 @@ void gve_rx_post_buffers_dqo(struct gve_rx_ring *rx)
static void gve_try_recycle_buf(struct gve_priv *priv, struct gve_rx_ring *rx,
struct gve_rx_buf_state_dqo *buf_state)
{
- const int data_buffer_size = priv->data_buffer_size_dqo;
+ const u16 data_buffer_size = priv->data_buffer_size_dqo;
int pagecount;

/* Can't reuse if we only fit one buffer per page */
--
2.44.0.rc1.240.g4c46232300-goog