Re: [PATCH V2 net 08/20] net/ena: add hardware hints capability to the driver
From: Matt Wilson
Date: Sun Dec 04 2016 - 23:31:57 EST
On Sun, Dec 04, 2016 at 03:19:26PM +0200, Netanel Belgazal wrote:
> The ENA device can update the ena driver about the desire timeouts.
> The hardware hints are transmitted as Asynchronous event to the driver.
This is really a new feature, not a bugfix - correct? If it is a new
feature, submit it separately. If the built-in defaults need to be
changed, submit that as a bugfix.
--msw
> In case the device does not support this capability, the driver
> will use its own defines.
>
> Signed-off-by: Netanel Belgazal <netanel@xxxxxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/amazon/ena/ena_admin_defs.h | 31 +++++++++
> drivers/net/ethernet/amazon/ena/ena_com.c | 41 ++++++++---
> drivers/net/ethernet/amazon/ena/ena_com.h | 5 ++
> drivers/net/ethernet/amazon/ena/ena_ethtool.c | 1 -
> drivers/net/ethernet/amazon/ena/ena_netdev.c | 86 +++++++++++++++++++-----
> drivers/net/ethernet/amazon/ena/ena_netdev.h | 19 +++++-
> drivers/net/ethernet/amazon/ena/ena_regs_defs.h | 2 +
> 7 files changed, 157 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/net/ethernet/amazon/ena/ena_admin_defs.h b/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
> index 6d70bf5..35ae511 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
> +++ b/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
> @@ -70,6 +70,8 @@ enum ena_admin_aq_feature_id {
>
> ENA_ADMIN_MAX_QUEUES_NUM = 2,
>
> + ENA_ADMIN_HW_HINTS = 3,
> +
> ENA_ADMIN_RSS_HASH_FUNCTION = 10,
>
> ENA_ADMIN_STATELESS_OFFLOAD_CONFIG = 11,
> @@ -749,6 +751,31 @@ struct ena_admin_feature_rss_ind_table {
> struct ena_admin_rss_ind_table_entry inline_entry;
> };
>
> +/* When hint value is 0, driver should use it's own predefined value */
> +struct ena_admin_ena_hw_hints {
> + /* value in ms */
> + u16 mmio_read_timeout;
> +
> + /* value in ms */
> + u16 driver_watchdog_timeout;
> +
> + /* Per packet tx completion timeout. value in ms */
> + u16 missing_tx_completion_timeout;
> +
> + u16 missed_tx_completion_count_threshold_to_reset;
> +
> + /* value in ms */
> + u16 admin_completion_tx_timeout;
> +
> + u16 netdev_wd_timeout;
> +
> + u16 max_tx_sgl_size;
> +
> + u16 max_rx_sgl_size;
> +
> + u16 reserved[8];
> +};
> +
> struct ena_admin_get_feat_cmd {
> struct ena_admin_aq_common_desc aq_common_descriptor;
>
> @@ -782,6 +809,8 @@ struct ena_admin_get_feat_resp {
> struct ena_admin_feature_rss_ind_table ind_table;
>
> struct ena_admin_feature_intr_moder_desc intr_moderation;
> +
> + struct ena_admin_ena_hw_hints hw_hints;
> } u;
> };
>
> @@ -857,6 +886,8 @@ enum ena_admin_aenq_notification_syndrom {
> ENA_ADMIN_SUSPEND = 0,
>
> ENA_ADMIN_RESUME = 1,
> +
> + ENA_ADMIN_UPDATE_HINTS = 2,
> };
>
> struct ena_admin_aenq_entry {
> diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
> index 46aad3a..f1e4f04 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_com.c
> +++ b/drivers/net/ethernet/amazon/ena/ena_com.c
> @@ -508,15 +508,13 @@ static int ena_com_comp_status_to_errno(u8 comp_status)
> static int ena_com_wait_and_process_admin_cq_polling(struct ena_comp_ctx *comp_ctx,
> struct ena_com_admin_queue *admin_queue)
> {
> - unsigned long flags;
> - u32 start_time;
> + unsigned long flags, timeout;
> int ret;
>
> - start_time = ((u32)jiffies_to_usecs(jiffies));
> + timeout = jiffies + usecs_to_jiffies(admin_queue->completion_timeout);
>
> while (comp_ctx->status == ENA_CMD_SUBMITTED) {
> - if ((((u32)jiffies_to_usecs(jiffies)) - start_time) >
> - ADMIN_CMD_TIMEOUT_US) {
> + if (time_is_before_jiffies(timeout)) {
> pr_err("Wait for completion (polling) timeout\n");
> /* ENA didn't have any completion */
> spin_lock_irqsave(&admin_queue->q_lock, flags);
> @@ -560,7 +558,8 @@ static int ena_com_wait_and_process_admin_cq_interrupts(struct ena_comp_ctx *com
> int ret;
>
> wait_for_completion_timeout(&comp_ctx->wait_event,
> - usecs_to_jiffies(ADMIN_CMD_TIMEOUT_US));
> + usecs_to_jiffies(
> + admin_queue->completion_timeout));
>
> /* In case the command wasn't completed find out the root cause.
> * There might be 2 kinds of errors
> @@ -600,12 +599,14 @@ static u32 ena_com_reg_bar_read32(struct ena_com_dev *ena_dev, u16 offset)
> struct ena_com_mmio_read *mmio_read = &ena_dev->mmio_read;
> volatile struct ena_admin_ena_mmio_req_read_less_resp *read_resp =
> mmio_read->read_resp;
> - u32 mmio_read_reg, ret;
> + u32 mmio_read_reg, timeout, ret;
> unsigned long flags;
> int i;
>
> might_sleep();
>
> + timeout = mmio_read->reg_read_to ? : ENA_REG_READ_TIMEOUT;
> +
> /* If readless is disabled, perform regular read */
> if (!mmio_read->readless_supported)
> return readl(ena_dev->reg_bar + offset);
> @@ -626,14 +627,14 @@ static u32 ena_com_reg_bar_read32(struct ena_com_dev *ena_dev, u16 offset)
>
> writel(mmio_read_reg, ena_dev->reg_bar + ENA_REGS_MMIO_REG_READ_OFF);
>
> - for (i = 0; i < ENA_REG_READ_TIMEOUT; i++) {
> + for (i = 0; i < timeout; i++) {
> if (read_resp->req_id == mmio_read->seq_num)
> break;
>
> udelay(1);
> }
>
> - if (unlikely(i == ENA_REG_READ_TIMEOUT)) {
> + if (unlikely(i == timeout)) {
> pr_err("reading reg failed for timeout. expected: req id[%hu] offset[%hu] actual: req id[%hu] offset[%hu]\n",
> mmio_read->seq_num, offset, read_resp->req_id,
> read_resp->reg_off);
> @@ -1717,6 +1718,20 @@ int ena_com_get_dev_attr_feat(struct ena_com_dev *ena_dev,
> memcpy(&get_feat_ctx->offload, &get_resp.u.offload,
> sizeof(get_resp.u.offload));
>
> + /* Driver hints isn't mandatory admin command. So in case the
> + * command isn't supported set driver hints to 0
> + */
> + rc = ena_com_get_feature(ena_dev, &get_resp, ENA_ADMIN_HW_HINTS);
> +
> + if (!rc)
> + memcpy(&get_feat_ctx->hw_hints, &get_resp.u.hw_hints,
> + sizeof(get_resp.u.hw_hints));
> + else if (rc == -EPERM)
> + memset(&get_feat_ctx->hw_hints, 0x0,
> + sizeof(get_feat_ctx->hw_hints));
> + else
> + return rc;
> +
> return 0;
> }
>
> @@ -1842,6 +1857,14 @@ int ena_com_dev_reset(struct ena_com_dev *ena_dev)
> return rc;
> }
>
> + timeout = (cap & ENA_REGS_CAPS_ADMIN_CMD_TO_MASK) >>
> + ENA_REGS_CAPS_ADMIN_CMD_TO_SHIFT;
> + if (timeout)
> + /* the resolution of timeout reg is 100ms */
> + ena_dev->admin_queue.completion_timeout = timeout * 100000;
> + else
> + ena_dev->admin_queue.completion_timeout = ADMIN_CMD_TIMEOUT_US;
> +
> return 0;
> }
>
> diff --git a/drivers/net/ethernet/amazon/ena/ena_com.h b/drivers/net/ethernet/amazon/ena/ena_com.h
> index 509d7b8..6883ee5 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_com.h
> +++ b/drivers/net/ethernet/amazon/ena/ena_com.h
> @@ -96,6 +96,8 @@
> #define ENA_INTR_MODER_LEVEL_STRIDE 2
> #define ENA_INTR_BYTE_COUNT_NOT_SUPPORTED 0xFFFFFF
>
> +#define ENA_HW_HINTS_NO_TIMEOUT 0xFFFF
> +
> enum ena_intr_moder_level {
> ENA_INTR_MODER_LOWEST = 0,
> ENA_INTR_MODER_LOW,
> @@ -232,6 +234,7 @@ struct ena_com_admin_queue {
> void *q_dmadev;
> spinlock_t q_lock; /* spinlock for the admin queue */
> struct ena_comp_ctx *comp_ctx;
> + u32 completion_timeout;
> u16 q_depth;
> struct ena_com_admin_cq cq;
> struct ena_com_admin_sq sq;
> @@ -266,6 +269,7 @@ struct ena_com_aenq {
> struct ena_com_mmio_read {
> struct ena_admin_ena_mmio_req_read_less_resp *read_resp;
> dma_addr_t read_resp_dma_addr;
> + u32 reg_read_to; /* in us */
> u16 seq_num;
> bool readless_supported;
> /* spin lock to ensure a single outstanding read */
> @@ -335,6 +339,7 @@ struct ena_com_dev_get_features_ctx {
> struct ena_admin_device_attr_feature_desc dev_attr;
> struct ena_admin_feature_aenq_desc aenq;
> struct ena_admin_feature_offload_desc offload;
> + struct ena_admin_ena_hw_hints hw_hints;
> };
>
> struct ena_com_create_io_ctx {
> diff --git a/drivers/net/ethernet/amazon/ena/ena_ethtool.c b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
> index 67b2338f..a1fbfc2 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c
> +++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
> @@ -80,7 +80,6 @@ static const struct ena_stats ena_stats_tx_strings[] = {
> ENA_STAT_TX_ENTRY(tx_poll),
> ENA_STAT_TX_ENTRY(doorbells),
> ENA_STAT_TX_ENTRY(prepare_ctx_err),
> - ENA_STAT_TX_ENTRY(missing_tx_comp),
> ENA_STAT_TX_ENTRY(bad_req_id),
> };
>
> diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> index 962ffb5..0b718ee 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> @@ -1981,6 +1981,7 @@ static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev)
>
> tx_info->tx_descs = nb_hw_desc;
> tx_info->last_jiffies = jiffies;
> + tx_info->print_once = 0;
>
> tx_ring->next_to_use = ENA_TX_RING_IDX_NEXT(next_to_use,
> tx_ring->ring_size);
> @@ -2554,33 +2555,34 @@ static void check_for_missing_tx_completions(struct ena_adapter *adapter)
> if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
> return;
>
> + if (adapter->missing_tx_completion_to == ENA_HW_HINTS_NO_TIMEOUT)
> + return;
> +
> budget = ENA_MONITORED_TX_QUEUES;
>
> for (i = adapter->last_monitored_tx_qid; i < adapter->num_queues; i++) {
> tx_ring = &adapter->tx_ring[i];
>
> + missed_tx = 0;
> +
> for (j = 0; j < tx_ring->ring_size; j++) {
> tx_buf = &tx_ring->tx_buffer_info[j];
> last_jiffies = tx_buf->last_jiffies;
> - if (unlikely(last_jiffies && time_is_before_jiffies(last_jiffies + TX_TIMEOUT))) {
> - netif_notice(adapter, tx_err, adapter->netdev,
> - "Found a Tx that wasn't completed on time, qid %d, index %d.\n",
> - tx_ring->qid, j);
> + if (unlikely(last_jiffies && time_is_before_jiffies(last_jiffies + adapter->missing_tx_completion_to))) {
> + if (!tx_buf->print_once)
> + netif_notice(adapter, tx_err, adapter->netdev,
> + "Found a Tx that wasn't completed on time, qid %d, index %d.\n",
> + tx_ring->qid, j);
>
> - u64_stats_update_begin(&tx_ring->syncp);
> - missed_tx = tx_ring->tx_stats.missing_tx_comp++;
> - u64_stats_update_end(&tx_ring->syncp);
> + tx_buf->print_once = 1;
> + missed_tx++;
>
> - /* Clear last jiffies so the lost buffer won't
> - * be counted twice.
> - */
> - tx_buf->last_jiffies = 0;
> -
> - if (unlikely(missed_tx > MAX_NUM_OF_TIMEOUTED_PACKETS)) {
> + if (unlikely(missed_tx > adapter->missing_tx_completion_threshold)) {
> netif_err(adapter, tx_err, adapter->netdev,
> "The number of lost tx completion is above the threshold (%d > %d). Reset the device\n",
> - missed_tx, MAX_NUM_OF_TIMEOUTED_PACKETS);
> + missed_tx, adapter->missing_tx_completion_threshold);
> set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
> + return;
> }
> }
> }
> @@ -2601,8 +2603,11 @@ static void check_for_missing_keep_alive(struct ena_adapter *adapter)
> if (!adapter->wd_state)
> return;
>
> - keep_alive_expired = round_jiffies(adapter->last_keep_alive_jiffies
> - + ENA_DEVICE_KALIVE_TIMEOUT);
> + if (adapter->keep_alive_timeout == ENA_HW_HINTS_NO_TIMEOUT)
> + return;
> +
> + keep_alive_expired = round_jiffies(adapter->last_keep_alive_jiffies +
> + adapter->keep_alive_timeout);
> if (unlikely(time_is_before_jiffies(keep_alive_expired))) {
> netif_err(adapter, drv, adapter->netdev,
> "Keep alive watchdog timeout.\n");
> @@ -2625,6 +2630,44 @@ static void check_for_admin_com_state(struct ena_adapter *adapter)
> }
> }
>
> +static void ena_update_hints(struct ena_adapter *adapter,
> + struct ena_admin_ena_hw_hints *hints)
> +{
> + struct net_device *netdev = adapter->netdev;
> +
> + if (hints->admin_completion_tx_timeout)
> + adapter->ena_dev->admin_queue.completion_timeout =
> + hints->admin_completion_tx_timeout * 1000;
> +
> + if (hints->mmio_read_timeout)
> + /* convert to usec */
> + adapter->ena_dev->mmio_read.reg_read_to =
> + hints->mmio_read_timeout * 1000;
> +
> + if (hints->missed_tx_completion_count_threshold_to_reset)
> + adapter->missing_tx_completion_threshold =
> + hints->missed_tx_completion_count_threshold_to_reset;
> +
> + if (hints->missing_tx_completion_timeout) {
> + if (hints->missing_tx_completion_timeout == ENA_HW_HINTS_NO_TIMEOUT)
> + adapter->missing_tx_completion_to = ENA_HW_HINTS_NO_TIMEOUT;
> + else
> + adapter->missing_tx_completion_to =
> + msecs_to_jiffies(hints->missing_tx_completion_timeout);
> + }
> +
> + if (hints->netdev_wd_timeout)
> + netdev->watchdog_timeo = msecs_to_jiffies(hints->netdev_wd_timeout);
> +
> + if (hints->driver_watchdog_timeout) {
> + if (hints->driver_watchdog_timeout == ENA_HW_HINTS_NO_TIMEOUT)
> + adapter->keep_alive_timeout = ENA_HW_HINTS_NO_TIMEOUT;
> + else
> + adapter->keep_alive_timeout =
> + msecs_to_jiffies(hints->driver_watchdog_timeout);
> + }
> +}
> +
> static void ena_update_host_info(struct ena_admin_host_info *host_info,
> struct net_device *netdev)
> {
> @@ -3036,6 +3079,11 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> INIT_WORK(&adapter->reset_task, ena_fw_reset_device);
>
> adapter->last_keep_alive_jiffies = jiffies;
> + adapter->keep_alive_timeout = ENA_DEVICE_KALIVE_TIMEOUT;
> + adapter->missing_tx_completion_to = TX_TIMEOUT;
> + adapter->missing_tx_completion_threshold = MAX_NUM_OF_TIMEOUTED_PACKETS;
> +
> + ena_update_hints(adapter, &get_feat_ctx.hw_hints);
>
> init_timer(&adapter->timer_service);
> adapter->timer_service.expires = round_jiffies(jiffies + HZ);
> @@ -3256,6 +3304,7 @@ static void ena_notification(void *adapter_data,
> struct ena_admin_aenq_entry *aenq_e)
> {
> struct ena_adapter *adapter = (struct ena_adapter *)adapter_data;
> + struct ena_admin_ena_hw_hints *hints;
>
> WARN(aenq_e->aenq_common_desc.group != ENA_ADMIN_NOTIFICATION,
> "Invalid group(%x) expected %x\n",
> @@ -3273,6 +3322,11 @@ static void ena_notification(void *adapter_data,
> case ENA_ADMIN_RESUME:
> queue_work(ena_wq, &adapter->resume_io_task);
> break;
> + case ENA_ADMIN_UPDATE_HINTS:
> + hints = (struct ena_admin_ena_hw_hints *)
> + (&aenq_e->inline_data_w4);
> + ena_update_hints(adapter, hints);
> + break;
> default:
> netif_err(adapter, drv, adapter->netdev,
> "Invalid aenq notification link state %d\n",
> diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
> index f0ddc11..2897fab 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
> +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
> @@ -146,7 +146,18 @@ struct ena_tx_buffer {
> u32 tx_descs;
> /* num of buffers used by this skb */
> u32 num_of_bufs;
> - /* Save the last jiffies to detect missing tx packets */
> +
> + /* Used for detect missing tx packets to limit the number of prints */
> + u32 print_once;
> + /* Save the last jiffies to detect missing tx packets
> + *
> + * sets to non zero value on ena_start_xmit and set to zero on
> + * napi and timer_Service_routine.
> + *
> + * while this value is not protected by lock,
> + * a given packet is not expected to be handled by ena_start_xmit
> + * and by napi/timer_service at the same time.
> + */
> unsigned long last_jiffies;
> struct ena_com_buf bufs[ENA_PKT_MAX_BUFS];
> } ____cacheline_aligned;
> @@ -170,7 +181,6 @@ struct ena_stats_tx {
> u64 napi_comp;
> u64 tx_poll;
> u64 doorbells;
> - u64 missing_tx_comp;
> u64 bad_req_id;
> };
>
> @@ -270,6 +280,8 @@ struct ena_adapter {
> struct msix_entry *msix_entries;
> int msix_vecs;
>
> + u32 missing_tx_completion_threshold;
> +
> u32 tx_usecs, rx_usecs; /* interrupt moderation */
> u32 tx_frames, rx_frames; /* interrupt moderation */
>
> @@ -283,6 +295,9 @@ struct ena_adapter {
>
> u8 mac_addr[ETH_ALEN];
>
> + unsigned long keep_alive_timeout;
> + unsigned long missing_tx_completion_to;
> +
> char name[ENA_NAME_MAX_LEN];
>
> unsigned long flags;
> diff --git a/drivers/net/ethernet/amazon/ena/ena_regs_defs.h b/drivers/net/ethernet/amazon/ena/ena_regs_defs.h
> index 26097a2..c3891c5 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_regs_defs.h
> +++ b/drivers/net/ethernet/amazon/ena/ena_regs_defs.h
> @@ -78,6 +78,8 @@
> #define ENA_REGS_CAPS_RESET_TIMEOUT_MASK 0x3e
> #define ENA_REGS_CAPS_DMA_ADDR_WIDTH_SHIFT 8
> #define ENA_REGS_CAPS_DMA_ADDR_WIDTH_MASK 0xff00
> +#define ENA_REGS_CAPS_ADMIN_CMD_TO_SHIFT 16
> +#define ENA_REGS_CAPS_ADMIN_CMD_TO_MASK 0xf0000
>
> /* aq_caps register */
> #define ENA_REGS_AQ_CAPS_AQ_DEPTH_MASK 0xffff