Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue

Tony Nguyen says:

====================
This series lowers the CPU usage of the ice driver when using its
provided /dev/gnss*.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 36 insertions, 53 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
index c2fda4fa4188..0157f6e98d3e 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.c
+++ b/drivers/net/ethernet/intel/ice/ice_common.c
@@ -1619,7 +1619,6 @@ ice_sq_send_cmd_retry(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 {
 	struct ice_aq_desc desc_cpy;
 	bool is_cmd_for_retry;
-	u8 *buf_cpy = NULL;
 	u8 idx = 0;
 	u16 opcode;
 	int status;
@@ -1629,11 +1628,8 @@ ice_sq_send_cmd_retry(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 	memset(&desc_cpy, 0, sizeof(desc_cpy));
 
 	if (is_cmd_for_retry) {
-		if (buf) {
-			buf_cpy = kzalloc(buf_size, GFP_KERNEL);
-			if (!buf_cpy)
-				return -ENOMEM;
-		}
+		/* All retryable cmds are direct, without buf. */
+		WARN_ON(buf);
 
 		memcpy(&desc_cpy, desc, sizeof(desc_cpy));
 	}
@@ -1645,17 +1641,12 @@ ice_sq_send_cmd_retry(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 		    hw->adminq.sq_last_status != ICE_AQ_RC_EBUSY)
 			break;
 
-		if (buf_cpy)
-			memcpy(buf, buf_cpy, buf_size);
-
 		memcpy(desc, &desc_cpy, sizeof(desc_cpy));
 
-		mdelay(ICE_SQ_SEND_DELAY_TIME_MS);
+		msleep(ICE_SQ_SEND_DELAY_TIME_MS);
 
 	} while (++idx < ICE_SQ_SEND_MAX_EXECUTE);
 
-	kfree(buf_cpy);
-
 	return status;
 }
 
@@ -1992,19 +1983,19 @@ ice_acquire_res_exit:
  */
 void ice_release_res(struct ice_hw *hw, enum ice_aq_res_ids res)
 {
-	u32 total_delay = 0;
+	unsigned long timeout;
 	int status;
 
-	status = ice_aq_release_res(hw, res, 0, NULL);
-
 	/* there are some rare cases when trying to release the resource
 	 * results in an admin queue timeout, so handle them correctly
 	 */
-	while ((status == -EIO) && (total_delay < hw->adminq.sq_cmd_timeout)) {
-		mdelay(1);
+	timeout = jiffies + 10 * ICE_CTL_Q_SQ_CMD_TIMEOUT;
+	do {
 		status = ice_aq_release_res(hw, res, 0, NULL);
-		total_delay++;
-	}
+		if (status != -EIO)
+			break;
+		usleep_range(1000, 2000);
+	} while (time_before(jiffies, timeout));
 }
 
 /**
diff --git a/drivers/net/ethernet/intel/ice/ice_controlq.c b/drivers/net/ethernet/intel/ice/ice_controlq.c
index 6bcfee295991..d2faf1baad2f 100644
--- a/drivers/net/ethernet/intel/ice/ice_controlq.c
+++ b/drivers/net/ethernet/intel/ice/ice_controlq.c
@@ -637,9 +637,6 @@ static int ice_init_ctrlq(struct ice_hw *hw, enum ice_ctl_q q_type)
 		return -EIO;
 	}
 
-	/* setup SQ command write back timeout */
-	cq->sq_cmd_timeout = ICE_CTL_Q_SQ_CMD_TIMEOUT;
-
 	/* allocate the ATQ */
 	ret_code = ice_init_sq(hw, cq);
 	if (ret_code)
@@ -967,7 +964,7 @@ ice_sq_send_cmd(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 	struct ice_aq_desc *desc_on_ring;
 	bool cmd_completed = false;
 	struct ice_sq_cd *details;
-	u32 total_delay = 0;
+	unsigned long timeout;
 	int status = 0;
 	u16 retval = 0;
 	u32 val = 0;
@@ -1060,13 +1057,14 @@ ice_sq_send_cmd(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 		cq->sq.next_to_use = 0;
 	wr32(hw, cq->sq.tail, cq->sq.next_to_use);
 
+	timeout = jiffies + ICE_CTL_Q_SQ_CMD_TIMEOUT;
 	do {
 		if (ice_sq_done(hw, cq))
 			break;
 
-		udelay(ICE_CTL_Q_SQ_CMD_USEC);
-		total_delay++;
-	} while (total_delay < cq->sq_cmd_timeout);
+		usleep_range(ICE_CTL_Q_SQ_CMD_USEC,
+			     ICE_CTL_Q_SQ_CMD_USEC * 3 / 2);
+	} while (time_before(jiffies, timeout));
 
 	/* if ready, copy the desc back to temp */
 	if (ice_sq_done(hw, cq)) {
diff --git a/drivers/net/ethernet/intel/ice/ice_controlq.h b/drivers/net/ethernet/intel/ice/ice_controlq.h
index c07e9cc9fc6e..950b7f4a7a05 100644
--- a/drivers/net/ethernet/intel/ice/ice_controlq.h
+++ b/drivers/net/ethernet/intel/ice/ice_controlq.h
@@ -34,7 +34,7 @@ enum ice_ctl_q {
 };
 
 /* Control Queue timeout settings - max delay 1s */
-#define ICE_CTL_Q_SQ_CMD_TIMEOUT	10000 /* Count 10000 times */
+#define ICE_CTL_Q_SQ_CMD_TIMEOUT	HZ    /* Wait max 1s */
 #define ICE_CTL_Q_SQ_CMD_USEC		100   /* Check every 100usec */
 #define ICE_CTL_Q_ADMIN_INIT_TIMEOUT	10    /* Count 10 times */
 #define ICE_CTL_Q_ADMIN_INIT_MSEC	100   /* Check every 100msec */
@@ -87,7 +87,6 @@ struct ice_ctl_q_info {
 	enum ice_ctl_q qtype;
 	struct ice_ctl_q_ring rq;	/* receive queue */
 	struct ice_ctl_q_ring sq;	/* send queue */
-	u32 sq_cmd_timeout;		/* send queue cmd write back timeout */
 	u16 num_rq_entries;		/* receive queue depth */
 	u16 num_sq_entries;		/* send queue depth */
 	u16 rq_buf_size;		/* receive queue buffer size */
diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c
index 8dec748bb53a..2ea8a2b11bcd 100644
--- a/drivers/net/ethernet/intel/ice/ice_gnss.c
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.c
@@ -117,6 +117,7 @@ static void ice_gnss_read(struct kthread_work *work)
 {
 	struct gnss_serial *gnss = container_of(work, struct gnss_serial,
 						read_work.work);
+	unsigned long delay = ICE_GNSS_POLL_DATA_DELAY_TIME;
 	unsigned int i, bytes_read, data_len, count;
 	struct ice_aqc_link_topo_addr link_topo;
 	struct ice_pf *pf;
@@ -136,11 +137,6 @@ static void ice_gnss_read(struct kthread_work *work)
 		return;
 
 	hw = &pf->hw;
-	buf = (char *)get_zeroed_page(GFP_KERNEL);
-	if (!buf) {
-		err = -ENOMEM;
-		goto exit;
-	}
 
 	memset(&link_topo, 0, sizeof(struct ice_aqc_link_topo_addr));
 	link_topo.topo_params.index = ICE_E810T_GNSS_I2C_BUS;
@@ -151,25 +147,24 @@ static void ice_gnss_read(struct kthread_work *work)
 	i2c_params = ICE_GNSS_UBX_DATA_LEN_WIDTH |
 		     ICE_AQC_I2C_USE_REPEATED_START;
 
-	/* Read data length in a loop, when it's not 0 the data is ready */
-	for (i = 0; i < ICE_MAX_UBX_READ_TRIES; i++) {
-		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
-				      cpu_to_le16(ICE_GNSS_UBX_DATA_LEN_H),
-				      i2c_params, (u8 *)&data_len_b, NULL);
-		if (err)
-			goto exit_buf;
+	err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
+			      cpu_to_le16(ICE_GNSS_UBX_DATA_LEN_H),
+			      i2c_params, (u8 *)&data_len_b, NULL);
+	if (err)
+		goto requeue;
 
-		data_len = be16_to_cpu(data_len_b);
-		if (data_len != 0 && data_len != U16_MAX)
-			break;
+	data_len = be16_to_cpu(data_len_b);
+	if (data_len == 0 || data_len == U16_MAX)
+		goto requeue;
 
-		mdelay(10);
-	}
+	/* The u-blox has data_len bytes for us to read */
 
 	data_len = min_t(typeof(data_len), data_len, PAGE_SIZE);
-	if (!data_len) {
+
+	buf = (char *)get_zeroed_page(GFP_KERNEL);
+	if (!buf) {
 		err = -ENOMEM;
-		goto exit_buf;
+		goto requeue;
 	}
 
 	/* Read received data */
@@ -183,7 +178,7 @@ static void ice_gnss_read(struct kthread_work *work)
 				      cpu_to_le16(ICE_GNSS_UBX_EMPTY_DATA),
 				      bytes_read, &buf[i], NULL);
 		if (err)
-			goto exit_buf;
+			goto free_buf;
 	}
 
 	count = gnss_insert_raw(pf->gnss_dev, buf, i);
@@ -191,10 +186,11 @@ static void ice_gnss_read(struct kthread_work *work)
 		dev_warn(ice_pf_to_dev(pf),
 			 "gnss_insert_raw ret=%d size=%d\n",
 			 count, i);
-exit_buf:
+	delay = ICE_GNSS_TIMER_DELAY_TIME;
+free_buf:
 	free_page((unsigned long)buf);
-	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work,
-				   ICE_GNSS_TIMER_DELAY_TIME);
+requeue:
+	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, delay);
 exit:
 	if (err)
 		dev_dbg(ice_pf_to_dev(pf), "GNSS failed to read err=%d\n", err);
diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.h b/drivers/net/ethernet/intel/ice/ice_gnss.h
index 4d49e5b0b4b8..b8bb8b63d081 100644
--- a/drivers/net/ethernet/intel/ice/ice_gnss.h
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.h
@@ -5,6 +5,7 @@
 #define _ICE_GNSS_H_
 
 #define ICE_E810T_GNSS_I2C_BUS		0x2
+#define ICE_GNSS_POLL_DATA_DELAY_TIME	(HZ / 50) /* poll every 20 ms */
 #define ICE_GNSS_TIMER_DELAY_TIME	(HZ / 10) /* 0.1 second per message */
 #define ICE_GNSS_TTY_WRITE_BUF		250
 #define ICE_MAX_I2C_DATA_SIZE		FIELD_MAX(ICE_AQC_I2C_DATA_SIZE_M)
@@ -20,8 +21,6 @@
  * passed as I2C addr parameter.
  */
 #define ICE_GNSS_UBX_WRITE_BYTES	(ICE_MAX_I2C_WRITE_BYTES + 1)
-#define ICE_MAX_UBX_READ_TRIES		255
-#define ICE_MAX_UBX_ACK_READ_TRIES	4095
 
 struct gnss_write_buf {
 	struct list_head queue;