On Mon, Nov 9, 2020 at 3:39 PM David Awogbemila <[email protected]> wrote: > > From: Catherine Sullivan <[email protected]> > > Add support to describe device for parsing device options. As > the first device option, add raw addressing. > > "Raw Addressing" mode (as opposed to the current "qpl" mode) is an > operational mode which allows the driver avoid bounce buffer copies > which it currently performs using pre-allocated qpls (queue_page_lists) > when sending and receiving packets. > For egress packets, the provided skb data addresses will be dma_map'ed and > passed to the device, allowing the NIC can perform DMA directly - the > driver will not have to copy the buffer content into pre-allocated > buffers/qpls (as in qpl mode). > For ingress packets, copies are also eliminated as buffers are handed to > the networking stack and then recycled or re-allocated as > necessary, avoiding the use of skb_copy_to_linear_data(). > > This patch only introduces the option to the driver. > Subsequent patches will add the ingress and egress functionality. > > Reviewed-by: Yangchun Fu <[email protected]> > Signed-off-by: Catherine Sullivan <[email protected]> > Signed-off-by: David Awogbemila <[email protected]>
A few minor nits called out below. Otherwise it looks good to me. Reviewed-by: Alexander Duyck <[email protected]> > --- > drivers/net/ethernet/google/gve/gve.h | 1 + > drivers/net/ethernet/google/gve/gve_adminq.c | 64 ++++++++++++++++++++ > drivers/net/ethernet/google/gve/gve_adminq.h | 15 +++-- > drivers/net/ethernet/google/gve/gve_main.c | 9 +++ > 4 files changed, 85 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/google/gve/gve.h > b/drivers/net/ethernet/google/gve/gve.h > index f5c80229ea96..80cdae06ee39 100644 > --- a/drivers/net/ethernet/google/gve/gve.h > +++ b/drivers/net/ethernet/google/gve/gve.h > @@ -199,6 +199,7 @@ struct gve_priv { > u64 num_registered_pages; /* num pages registered with NIC */ > u32 rx_copybreak; /* copy packets smaller than this */ > u16 default_num_queues; /* default num queues to set up */ > + bool raw_addressing; /* true if this dev supports raw addressing */ The use of bool is generally frowned upon in structures if you care about the cache alignment. You should probably just make this a char or u8. > > struct gve_queue_config tx_cfg; > struct gve_queue_config rx_cfg; > diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c > b/drivers/net/ethernet/google/gve/gve_adminq.c > index 24ae6a28a806..3e6de659b274 100644 > --- a/drivers/net/ethernet/google/gve/gve_adminq.c > +++ b/drivers/net/ethernet/google/gve/gve_adminq.c > @@ -14,6 +14,18 @@ > #define GVE_ADMINQ_SLEEP_LEN 20 > #define GVE_MAX_ADMINQ_EVENT_COUNTER_CHECK 100 > > +static inline > +struct gve_device_option *gve_get_next_option(struct gve_device_descriptor > *descriptor, > + struct gve_device_option > *option) > +{ > + void *option_end, *descriptor_end; > + > + option_end = (void *)option + sizeof(*option) + > be16_to_cpu(option->option_length); If I am not mistaken you can make this statement more compact with the following: option_end = (void *)(option + 1) + be16_to_cpu(option->option_length); > + descriptor_end = (void *)descriptor + > be16_to_cpu(descriptor->total_length); > + > + return option_end > descriptor_end ? NULL : (struct gve_device_option > *)option_end; > +} > + > int gve_adminq_alloc(struct device *dev, struct gve_priv *priv) > { > priv->adminq = dma_alloc_coherent(dev, PAGE_SIZE, > @@ -460,11 +472,14 @@ int gve_adminq_destroy_rx_queues(struct gve_priv *priv, > u32 num_queues) > int gve_adminq_describe_device(struct gve_priv *priv) > { > struct gve_device_descriptor *descriptor; > + struct gve_device_option *dev_opt; > union gve_adminq_command cmd; > dma_addr_t descriptor_bus; > + u16 num_options; > int err = 0; > u8 *mac; > u16 mtu; > + int i; > > memset(&cmd, 0, sizeof(cmd)); > descriptor = dma_alloc_coherent(&priv->pdev->dev, PAGE_SIZE, > @@ -518,6 +533,55 @@ int gve_adminq_describe_device(struct gve_priv *priv) > priv->rx_desc_cnt = priv->rx_pages_per_qpl; > } > priv->default_num_queues = > be16_to_cpu(descriptor->default_num_queues); > + dev_opt = (void *)(descriptor + 1); > + > + num_options = be16_to_cpu(descriptor->num_device_options); > + for (i = 0; i < num_options; i++) { > + u16 option_length = be16_to_cpu(dev_opt->option_length); > + u16 option_id = be16_to_cpu(dev_opt->option_id); > + struct gve_device_option *next_opt; > + > + next_opt = gve_get_next_option(descriptor, dev_opt); > + if (!next_opt) { > + dev_err(&priv->dev->dev, > + "options exceed device_descriptor's total > length.\n"); > + err = -EINVAL; > + goto free_device_descriptor; > + } > + > + switch (option_id) { > + case GVE_DEV_OPT_ID_RAW_ADDRESSING: > + /* If the length or feature mask doesn't match, > + * continue without enabling the feature. > + */ > + if (option_length != GVE_DEV_OPT_LEN_RAW_ADDRESSING || > + dev_opt->feat_mask != > + > cpu_to_be32(GVE_DEV_OPT_FEAT_MASK_RAW_ADDRESSING)) { > + dev_warn(&priv->pdev->dev, > + "Raw addressing option error:\n" > + " Expected: length=%d, > feature_mask=%x.\n" > + " Actual: length=%d, > feature_mask=%x.\n", > + GVE_DEV_OPT_LEN_RAW_ADDRESSING, > + > cpu_to_be32(GVE_DEV_OPT_FEAT_MASK_RAW_ADDRESSING), > + option_length, dev_opt->feat_mask); > + priv->raw_addressing = false; > + } else { > + dev_info(&priv->pdev->dev, > + "Raw addressing device option > enabled.\n"); > + priv->raw_addressing = true; > + } > + break; > + default: > + /* If we don't recognize the option just continue > + * without doing anything. > + */ > + dev_dbg(&priv->pdev->dev, > + "Unrecognized device option 0x%hx not > enabled.\n", > + option_id); > + break; > + } > + dev_opt = next_opt; Is there any reason for having this switch statement as a part of the function instead of a function onto itself? Seems like you could take all the code in the switch statement and move it into a seperate function and only need to pass priv and dev_opt. That way you could reduce the indentation a bit and help to make this a bit more readable by possibly not having to fold lines like you did in the if statement above. > + } > > free_device_descriptor: > dma_free_coherent(&priv->pdev->dev, sizeof(*descriptor), descriptor, > diff --git a/drivers/net/ethernet/google/gve/gve_adminq.h > b/drivers/net/ethernet/google/gve/gve_adminq.h > index 281de8326bc5..af5f586167bd 100644 > --- a/drivers/net/ethernet/google/gve/gve_adminq.h > +++ b/drivers/net/ethernet/google/gve/gve_adminq.h > @@ -79,12 +79,17 @@ struct gve_device_descriptor { > > static_assert(sizeof(struct gve_device_descriptor) == 40); > > -struct device_option { > - __be32 option_id; > - __be32 option_length; > +struct gve_device_option { > + __be16 option_id; > + __be16 option_length; > + __be32 feat_mask; > }; > > -static_assert(sizeof(struct device_option) == 8); > +static_assert(sizeof(struct gve_device_option) == 8); > + > +#define GVE_DEV_OPT_ID_RAW_ADDRESSING 0x1 > +#define GVE_DEV_OPT_LEN_RAW_ADDRESSING 0x0 > +#define GVE_DEV_OPT_FEAT_MASK_RAW_ADDRESSING 0x0 > > struct gve_adminq_configure_device_resources { > __be64 counter_array; > @@ -111,6 +116,8 @@ struct gve_adminq_unregister_page_list { > > static_assert(sizeof(struct gve_adminq_unregister_page_list) == 4); > > +#define GVE_RAW_ADDRESSING_QPL_ID 0xFFFFFFFF > + > struct gve_adminq_create_tx_queue { > __be32 queue_id; > __be32 reserved; > diff --git a/drivers/net/ethernet/google/gve/gve_main.c > b/drivers/net/ethernet/google/gve/gve_main.c > index 48a433154ce0..70685c10db0e 100644 > --- a/drivers/net/ethernet/google/gve/gve_main.c > +++ b/drivers/net/ethernet/google/gve/gve_main.c > @@ -678,6 +678,10 @@ static int gve_alloc_qpls(struct gve_priv *priv) > int i, j; > int err; > > + /* Raw addressing means no QPLs */ > + if (priv->raw_addressing) > + return 0; > + > priv->qpls = kvzalloc(num_qpls * sizeof(*priv->qpls), GFP_KERNEL); > if (!priv->qpls) > return -ENOMEM; > @@ -718,6 +722,10 @@ static void gve_free_qpls(struct gve_priv *priv) > int num_qpls = gve_num_tx_qpls(priv) + gve_num_rx_qpls(priv); > int i; > > + /* Raw addressing means no QPLs */ > + if (priv->raw_addressing) > + return; > + > kvfree(priv->qpl_cfg.qpl_id_map); > > for (i = 0; i < num_qpls; i++) > @@ -1078,6 +1086,7 @@ static int gve_init_priv(struct gve_priv *priv, bool > skip_describe_device) > if (skip_describe_device) > goto setup_device; > > + priv->raw_addressing = false; > /* Get the initial information we need from the device */ > err = gve_adminq_describe_device(priv); > if (err) { > -- > 2.29.2.222.g5d2a92d10f8-goog >
