diff mbox series

[v2,17/17] ibmvfc: provide modules parameters for MQ settings

Message ID 20201202005329.4538-18-tyreld@linux.ibm.com (mailing list archive)
State Superseded
Headers show
Series ibmvfc: initial MQ development | expand

Commit Message

Tyrel Datwyler Dec. 2, 2020, 12:53 a.m. UTC 
Add the various module parameter toggles for adjusting the MQ
characteristics at boot/load time as well as a device attribute for
changing the client scsi channel request amount.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 75 +++++++++++++++++++++++++++++-----
 1 file changed, 65 insertions(+), 10 deletions(-)

Comments

Brian King Dec. 2, 2020, 6:40 p.m. UTC | #1 
On 12/1/20 6:53 PM, Tyrel Datwyler wrote:
> +module_param_named(mig_channels_only, mig_channels_only, uint, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(mig_channels_only, "Prevent migration to non-channelized system. "
> +		 "[Default=" __stringify(IBMVFC_MIG_NO_SUB_TO_CRQ) "]");
> +module_param_named(mig_no_less_channels, mig_no_less_channels, uint, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(mig_no_less_channels, "Prevent migration to system with less channels. "
> +		 "[Default=" __stringify(IBMVFC_MIG_NO_N_TO_M) "]");

Both of these are writeable, but it doesn't look like you do any re-negotiation
with the VIOS for these changed settings to take effect if someone changes
them at runtime.

> +
>  module_param_named(init_timeout, init_timeout, uint, S_IRUGO | S_IWUSR);
>  MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds. "
>  		 "[Default=" __stringify(IBMVFC_INIT_TIMEOUT) "]");

> @@ -3228,6 +3250,36 @@ static ssize_t ibmvfc_store_log_level(struct device *dev,
>  	return strlen(buf);
>  }
>  
> +static ssize_t ibmvfc_show_scsi_channels(struct device *dev,
> +					 struct device_attribute *attr, char *buf)
> +{
> +	struct Scsi_Host *shost = class_to_shost(dev);
> +	struct ibmvfc_host *vhost = shost_priv(shost);
> +	unsigned long flags = 0;
> +	int len;
> +
> +	spin_lock_irqsave(shost->host_lock, flags);
> +	len = snprintf(buf, PAGE_SIZE, "%d\n", vhost->client_scsi_channels);
> +	spin_unlock_irqrestore(shost->host_lock, flags);
> +	return len;
> +}
> +
> +static ssize_t ibmvfc_store_scsi_channels(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t count)
> +{
> +	struct Scsi_Host *shost = class_to_shost(dev);
> +	struct ibmvfc_host *vhost = shost_priv(shost);
> +	unsigned long flags = 0;
> +	unsigned int channels;
> +
> +	spin_lock_irqsave(shost->host_lock, flags);
> +	channels = simple_strtoul(buf, NULL, 10);
> +	vhost->client_scsi_channels = min(channels, nr_scsi_hw_queues);

Don't we need to do a LIP here for this new setting to go into effect?

> +	spin_unlock_irqrestore(shost->host_lock, flags);
> +	return strlen(buf);
> +}
> +
>  static DEVICE_ATTR(partition_name, S_IRUGO, ibmvfc_show_host_partition_name, NULL);
>  static DEVICE_ATTR(device_name, S_IRUGO, ibmvfc_show_host_device_name, NULL);
>  static DEVICE_ATTR(port_loc_code, S_IRUGO, ibmvfc_show_host_loc_code, NULL);
Tyrel Datwyler Dec. 2, 2020, 10:17 p.m. UTC | #2 
On 12/2/20 10:40 AM, Brian King wrote:
> On 12/1/20 6:53 PM, Tyrel Datwyler wrote:
>> +module_param_named(mig_channels_only, mig_channels_only, uint, S_IRUGO | S_IWUSR);
>> +MODULE_PARM_DESC(mig_channels_only, "Prevent migration to non-channelized system. "
>> +		 "[Default=" __stringify(IBMVFC_MIG_NO_SUB_TO_CRQ) "]");
>> +module_param_named(mig_no_less_channels, mig_no_less_channels, uint, S_IRUGO | S_IWUSR);
>> +MODULE_PARM_DESC(mig_no_less_channels, "Prevent migration to system with less channels. "
>> +		 "[Default=" __stringify(IBMVFC_MIG_NO_N_TO_M) "]");
> 
> Both of these are writeable, but it doesn't look like you do any re-negotiation
> with the VIOS for these changed settings to take effect if someone changes
> them at runtime.

For some reason I convinced myself that these could just be changed on the fly,
but yes for them to actually take effect we need to re-negotiate the channels setup.

> 
>> +
>>  module_param_named(init_timeout, init_timeout, uint, S_IRUGO | S_IWUSR);
>>  MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds. "
>>  		 "[Default=" __stringify(IBMVFC_INIT_TIMEOUT) "]");
> 
>> @@ -3228,6 +3250,36 @@ static ssize_t ibmvfc_store_log_level(struct device *dev,
>>  	return strlen(buf);
>>  }
>>  
>> +static ssize_t ibmvfc_show_scsi_channels(struct device *dev,
>> +					 struct device_attribute *attr, char *buf)
>> +{
>> +	struct Scsi_Host *shost = class_to_shost(dev);
>> +	struct ibmvfc_host *vhost = shost_priv(shost);
>> +	unsigned long flags = 0;
>> +	int len;
>> +
>> +	spin_lock_irqsave(shost->host_lock, flags);
>> +	len = snprintf(buf, PAGE_SIZE, "%d\n", vhost->client_scsi_channels);
>> +	spin_unlock_irqrestore(shost->host_lock, flags);
>> +	return len;
>> +}
>> +
>> +static ssize_t ibmvfc_store_scsi_channels(struct device *dev,
>> +					 struct device_attribute *attr,
>> +					 const char *buf, size_t count)
>> +{
>> +	struct Scsi_Host *shost = class_to_shost(dev);
>> +	struct ibmvfc_host *vhost = shost_priv(shost);
>> +	unsigned long flags = 0;
>> +	unsigned int channels;
>> +
>> +	spin_lock_irqsave(shost->host_lock, flags);
>> +	channels = simple_strtoul(buf, NULL, 10);
>> +	vhost->client_scsi_channels = min(channels, nr_scsi_hw_queues);
> 
> Don't we need to do a LIP here for this new setting to go into effect?

Actually, we need a hard reset to break the CRQ Pair. A LIP will only do a NPIV
Logout/Login which keeps the existing channel setup.

-Tyrel

> 
>> +	spin_unlock_irqrestore(shost->host_lock, flags);
>> +	return strlen(buf);
>> +}
>> +
>>  static DEVICE_ATTR(partition_name, S_IRUGO, ibmvfc_show_host_partition_name, NULL);
>>  static DEVICE_ATTR(device_name, S_IRUGO, ibmvfc_show_host_device_name, NULL);
>>  static DEVICE_ATTR(port_loc_code, S_IRUGO, ibmvfc_show_host_loc_code, NULL);
> 
> 
>
diff mbox series

Patch

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 97e8eed04b01..bc7c2dcd902c 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -40,6 +40,12 @@  static unsigned int disc_threads = IBMVFC_MAX_DISC_THREADS;
 static unsigned int ibmvfc_debug = IBMVFC_DEBUG;
 static unsigned int log_level = IBMVFC_DEFAULT_LOG_LEVEL;
 static unsigned int cls3_error = IBMVFC_CLS3_ERROR;
+static unsigned int mq_enabled = IBMVFC_MQ;
+static unsigned int nr_scsi_hw_queues = IBMVFC_SCSI_HW_QUEUES;
+static unsigned int nr_scsi_channels = IBMVFC_SCSI_CHANNELS;
+static unsigned int mig_channels_only = IBMVFC_MIG_NO_SUB_TO_CRQ;
+static unsigned int mig_no_less_channels = IBMVFC_MIG_NO_N_TO_M;
+
 static LIST_HEAD(ibmvfc_head);
 static DEFINE_SPINLOCK(ibmvfc_driver_lock);
 static struct scsi_transport_template *ibmvfc_transport_template;
@@ -49,6 +55,22 @@  MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(IBMVFC_DRIVER_VERSION);
 
+module_param_named(mq, mq_enabled, uint, S_IRUGO);
+MODULE_PARM_DESC(mq, "Enable multiqueue support. "
+		 "[Default=" __stringify(IBMVFC_MQ) "]");
+module_param_named(scsi_host_queues, nr_scsi_hw_queues, uint, S_IRUGO);
+MODULE_PARM_DESC(scsi_host_queues, "Number of SCSI Host submission queues. "
+		 "[Default=" __stringify(IBMVFC_SCSI_HW_QUEUES) "]");
+module_param_named(scsi_hw_channels, nr_scsi_channels, uint, S_IRUGO);
+MODULE_PARM_DESC(scsi_hw_channels, "Number of hw scsi channels to request. "
+		 "[Default=" __stringify(IBMVFC_SCSI_CHANNELS) "]");
+module_param_named(mig_channels_only, mig_channels_only, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(mig_channels_only, "Prevent migration to non-channelized system. "
+		 "[Default=" __stringify(IBMVFC_MIG_NO_SUB_TO_CRQ) "]");
+module_param_named(mig_no_less_channels, mig_no_less_channels, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(mig_no_less_channels, "Prevent migration to system with less channels. "
+		 "[Default=" __stringify(IBMVFC_MIG_NO_N_TO_M) "]");
+
 module_param_named(init_timeout, init_timeout, uint, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds. "
 		 "[Default=" __stringify(IBMVFC_INIT_TIMEOUT) "]");
@@ -823,7 +845,7 @@  static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
 	crq->cur = 0;
 
 	if (vhost->scsi_scrqs.scrqs) {
-		for (i = 0; i < IBMVFC_SCSI_HW_QUEUES; i++) {
+		for (i = 0; i < nr_scsi_hw_queues; i++) {
 			scrq = &vhost->scsi_scrqs.scrqs[i];
 			memset(scrq->msgs, 0, PAGE_SIZE);
 			scrq->cur = 0;
@@ -3228,6 +3250,36 @@  static ssize_t ibmvfc_store_log_level(struct device *dev,
 	return strlen(buf);
 }
 
+static ssize_t ibmvfc_show_scsi_channels(struct device *dev,
+					 struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvfc_host *vhost = shost_priv(shost);
+	unsigned long flags = 0;
+	int len;
+
+	spin_lock_irqsave(shost->host_lock, flags);
+	len = snprintf(buf, PAGE_SIZE, "%d\n", vhost->client_scsi_channels);
+	spin_unlock_irqrestore(shost->host_lock, flags);
+	return len;
+}
+
+static ssize_t ibmvfc_store_scsi_channels(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ibmvfc_host *vhost = shost_priv(shost);
+	unsigned long flags = 0;
+	unsigned int channels;
+
+	spin_lock_irqsave(shost->host_lock, flags);
+	channels = simple_strtoul(buf, NULL, 10);
+	vhost->client_scsi_channels = min(channels, nr_scsi_hw_queues);
+	spin_unlock_irqrestore(shost->host_lock, flags);
+	return strlen(buf);
+}
+
 static DEVICE_ATTR(partition_name, S_IRUGO, ibmvfc_show_host_partition_name, NULL);
 static DEVICE_ATTR(device_name, S_IRUGO, ibmvfc_show_host_device_name, NULL);
 static DEVICE_ATTR(port_loc_code, S_IRUGO, ibmvfc_show_host_loc_code, NULL);
@@ -3236,6 +3288,8 @@  static DEVICE_ATTR(npiv_version, S_IRUGO, ibmvfc_show_host_npiv_version, NULL);
 static DEVICE_ATTR(capabilities, S_IRUGO, ibmvfc_show_host_capabilities, NULL);
 static DEVICE_ATTR(log_level, S_IRUGO | S_IWUSR,
 		   ibmvfc_show_log_level, ibmvfc_store_log_level);
+static DEVICE_ATTR(nr_scsi_channels, S_IRUGO | S_IWUSR,
+		   ibmvfc_show_scsi_channels, ibmvfc_store_scsi_channels);
 
 #ifdef CONFIG_SCSI_IBMVFC_TRACE
 /**
@@ -3292,6 +3346,7 @@  static struct device_attribute *ibmvfc_attrs[] = {
 	&dev_attr_npiv_version,
 	&dev_attr_capabilities,
 	&dev_attr_log_level,
+	&dev_attr_nr_scsi_channels,
 	NULL
 };
 
@@ -4676,9 +4731,9 @@  static void ibmvfc_channel_enquiry(struct ibmvfc_host *vhost)
 	mad->common.opcode = cpu_to_be32(IBMVFC_CHANNEL_ENQUIRY);
 	mad->common.length = cpu_to_be16(sizeof(*mad));
 
-	if (IBMVFC_MIG_NO_SUB_TO_CRQ)
+	if (mig_channels_only)
 		mad->flags |= cpu_to_be32(IBMVFC_NO_CHANNELS_TO_CRQ_SUPPORT);
-	if (IBMVFC_MIG_NO_N_TO_M)
+	if (mig_no_less_channels)
 		mad->flags |= cpu_to_be32(IBMVFC_NO_N_TO_M_CHANNELS_SUPPORT);
 
 	ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT_WAIT);
@@ -5416,13 +5471,13 @@  static int ibmvfc_init_sub_crqs(struct ibmvfc_host *vhost)
 
 	ENTER;
 
-	vhost->scsi_scrqs.scrqs = kcalloc(IBMVFC_SCSI_HW_QUEUES,
+	vhost->scsi_scrqs.scrqs = kcalloc(nr_scsi_hw_queues,
 					  sizeof(*vhost->scsi_scrqs.scrqs),
 					  GFP_KERNEL);
 	if (!vhost->scsi_scrqs.scrqs)
 		return -1;
 
-	for (i = 0; i < IBMVFC_SCSI_HW_QUEUES; i++) {
+	for (i = 0; i < nr_scsi_hw_queues; i++) {
 		if (ibmvfc_register_scsi_channel(vhost, i)) {
 			for (j = i; j > 0; j--)
 				ibmvfc_deregister_scsi_channel(vhost, j - 1);
@@ -5446,7 +5501,7 @@  static void ibmvfc_release_sub_crqs(struct ibmvfc_host *vhost)
 	if (!vhost->scsi_scrqs.scrqs)
 		return;
 
-	for (i = 0; i < IBMVFC_SCSI_HW_QUEUES; i++)
+	for (i = 0; i < nr_scsi_hw_queues; i++)
 		ibmvfc_deregister_scsi_channel(vhost, i);
 
 	kfree(vhost->scsi_scrqs.scrqs);
@@ -5658,13 +5713,13 @@  static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 	}
 
 	shost->transportt = ibmvfc_transport_template;
-	shost->can_queue = (max_requests / IBMVFC_SCSI_HW_QUEUES);
+	shost->can_queue = (max_requests / nr_scsi_hw_queues);
 	shost->max_lun = max_lun;
 	shost->max_id = max_targets;
 	shost->max_sectors = IBMVFC_MAX_SECTORS;
 	shost->max_cmd_len = IBMVFC_MAX_CDB_LEN;
 	shost->unique_id = shost->host_no;
-	shost->nr_hw_queues = IBMVFC_SCSI_HW_QUEUES;
+	shost->nr_hw_queues = nr_scsi_hw_queues;
 
 	vhost = shost_priv(shost);
 	INIT_LIST_HEAD(&vhost->sent);
@@ -5677,8 +5732,8 @@  static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 	vhost->log_level = log_level;
 	vhost->task_set = 1;
 
-	vhost->mq_enabled = IBMVFC_MQ;
-	vhost->client_scsi_channels = IBMVFC_SCSI_CHANNELS;
+	vhost->mq_enabled = mq_enabled;
+	vhost->client_scsi_channels = min(nr_scsi_hw_queues, nr_scsi_channels);
 	vhost->using_channels = 0;
 	vhost->do_enquiry = 1;