Re: [PATCH V2 net 08/20] net/ena: add hardware hints capability to the driver

[Netanel Belgazal <netanel@annapurnalabs.com>]

On 12/05/2016 06:31 AM, Matt Wilson wrote:
> 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.

I'll submit this patch as a new feature.
There is a patch that sets the new defaults.

> --msw
>
>> In case the device does not support this capability, the driver
>> will use its own defines.
>>
>> Signed-off-by: Netanel Belgazal <netanel@annapurnalabs.com>
>> ---
>>   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