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net: ena: reduce driver load time 

This commit reduces the driver load time by using usec resolution
instead of msec when polling for hardware state change.

Also add back-off mechanism to handle cases where minimal sleep
time is not enough.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arthur Kiyanovski 2020-05-22 12:09:05 +03:00 committed by David S. Miller
parent b0ae3ac484
commit 4bb7f4cf60
4 changed files with 33 additions and 10 deletions
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36
drivers/net/ethernet/amazon/ena/ena_com.c
View File

@ -62,7 +62,9 @@
#define ENA_REGS_ADMIN_INTR_MASK 1
#define ENA_POLL_MS 5
#define ENA_MIN_ADMIN_POLL_US 100
#define ENA_MAX_ADMIN_POLL_US 5000
/*****************************************************************************/
/*****************************************************************************/
@ -540,12 +542,20 @@ static int ena_com_comp_status_to_errno(u8 comp_status)
return -EINVAL;
}
static void ena_delay_exponential_backoff_us(u32 exp, u32 delay_us)
{
delay_us = max_t(u32, ENA_MIN_ADMIN_POLL_US, delay_us);
delay_us = min_t(u32, delay_us * (1U << exp), ENA_MAX_ADMIN_POLL_US);
usleep_range(delay_us, 2 * delay_us);
}
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 = 0;
unsigned long timeout;
int ret;
u32 exp = 0;
timeout = jiffies + usecs_to_jiffies(admin_queue->completion_timeout);
@ -569,7 +579,8 @@ static int ena_com_wait_and_process_admin_cq_polling(struct ena_comp_ctx *comp_c
goto err;
}
msleep(ENA_POLL_MS);
ena_delay_exponential_backoff_us(exp++,
admin_queue->ena_dev->ena_min_poll_delay_us);
}
if (unlikely(comp_ctx->status == ENA_CMD_ABORTED)) {
@ -939,12 +950,13 @@ static void ena_com_io_queue_free(struct ena_com_dev *ena_dev,
static int wait_for_reset_state(struct ena_com_dev *ena_dev, u32 timeout,
u16 exp_state)
{
u32 val, i;
u32 val, exp = 0;
unsigned long timeout_stamp;
/* Convert timeout from resolution of 100ms to ENA_POLL_MS */
timeout = (timeout * 100) / ENA_POLL_MS;
/* Convert timeout from resolution of 100ms to us resolution. */
timeout_stamp = jiffies + usecs_to_jiffies(100 * 1000 * timeout);
for (i = 0; i < timeout; i++) {
while (1) {
val = ena_com_reg_bar_read32(ena_dev, ENA_REGS_DEV_STS_OFF);
if (unlikely(val == ENA_MMIO_READ_TIMEOUT)) {
@ -956,10 +968,11 @@ static int wait_for_reset_state(struct ena_com_dev *ena_dev, u32 timeout,
exp_state)
return 0;
msleep(ENA_POLL_MS);
}
if (time_is_before_jiffies(timeout_stamp))
return -ETIME;
return -ETIME;
ena_delay_exponential_backoff_us(exp++, ena_dev->ena_min_poll_delay_us);
}
}
static bool ena_com_check_supported_feature_id(struct ena_com_dev *ena_dev,
@ -1436,11 +1449,13 @@ void ena_com_wait_for_abort_completion(struct ena_com_dev *ena_dev)
{
struct ena_com_admin_queue *admin_queue = &ena_dev->admin_queue;
unsigned long flags = 0;
u32 exp = 0;
spin_lock_irqsave(&admin_queue->q_lock, flags);
while (atomic_read(&admin_queue->outstanding_cmds) != 0) {
spin_unlock_irqrestore(&admin_queue->q_lock, flags);
msleep(ENA_POLL_MS);
ena_delay_exponential_backoff_us(exp++,
ena_dev->ena_min_poll_delay_us);
spin_lock_irqsave(&admin_queue->q_lock, flags);
}
spin_unlock_irqrestore(&admin_queue->q_lock, flags);
@ -1788,6 +1803,7 @@ int ena_com_admin_init(struct ena_com_dev *ena_dev,
if (ret)
goto error;
admin_queue->ena_dev = ena_dev;
admin_queue->running_state = true;
return 0;

3
drivers/net/ethernet/amazon/ena/ena_com.h
View File

@ -239,6 +239,7 @@ struct ena_com_stats_admin {
struct ena_com_admin_queue {
void *q_dmadev;
struct ena_com_dev *ena_dev;
spinlock_t q_lock; /* spinlock for the admin queue */
struct ena_comp_ctx *comp_ctx;
@ -351,6 +352,8 @@ struct ena_com_dev {
struct ena_intr_moder_entry *intr_moder_tbl;
struct ena_com_llq_info llq_info;
u32 ena_min_poll_delay_us;
};
struct ena_com_dev_get_features_ctx {

2
drivers/net/ethernet/amazon/ena/ena_netdev.c
View File

@ -4166,6 +4166,8 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
goto err_free_region;
}
ena_dev->ena_min_poll_delay_us = ENA_ADMIN_POLL_DELAY_US;
ena_dev->dmadev = &pdev->dev;
rc = ena_device_init(ena_dev, pdev, &get_feat_ctx, &wd_state);

2
drivers/net/ethernet/amazon/ena/ena_netdev.h
View File

@ -129,6 +129,8 @@
#define ENA_IO_IRQ_FIRST_IDX 1
#define ENA_IO_IRQ_IDX(q) (ENA_IO_IRQ_FIRST_IDX + (q))
#define ENA_ADMIN_POLL_DELAY_US 100
/* ENA device should send keep alive msg every 1 sec.
* We wait for 6 sec just to be on the safe side.
*/