Re: [PATCH 8/9] scsi: megaraid: convert private reply queue to blk-mq hw queue

[Hannes Reinecke <hare@suse.de>]

On 5/31/19 4:28 AM, Ming Lei wrote:
> SCSI's reply qeueue is very similar with blk-mq's hw queue, both
> assigned by IRQ vector, so map te private reply queue into blk-mq's hw
> queue via .host_tagset.
> 
> Then the private reply mapping can be removed.
> 
> Another benefit is that the request/irq lost issue may be solved in
> generic approach because managed IRQ may be shutdown during CPU
> hotplug.
> 
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
>  drivers/scsi/megaraid/megaraid_sas_base.c   | 50 ++++++++-------------
>  drivers/scsi/megaraid/megaraid_sas_fusion.c |  4 +-
>  2 files changed, 20 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
> index 3dd1df472dc6..b49999b90231 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
> @@ -33,6 +33,7 @@
>  #include <linux/fs.h>
>  #include <linux/compat.h>
>  #include <linux/blkdev.h>
> +#include <linux/blk-mq-pci.h>
>  #include <linux/mutex.h>
>  #include <linux/poll.h>
>  #include <linux/vmalloc.h>
> @@ -3165,6 +3166,19 @@ megasas_fw_cmds_outstanding_show(struct device *cdev,
>  	return snprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&instance->fw_outstanding));
>  }
>  
> +static int megasas_map_queues(struct Scsi_Host *shost)
> +{
> +	struct megasas_instance *instance = (struct megasas_instance *)
> +		shost->hostdata;
> +	struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
> +
> +	if (smp_affinity_enable && instance->msix_vectors)
> +		return blk_mq_pci_map_queues(qmap, instance->pdev, 0);
> +	else
> +		return blk_mq_map_queues(qmap);
> +}
> +
> +
>  static DEVICE_ATTR(fw_crash_buffer, S_IRUGO | S_IWUSR,
>  	megasas_fw_crash_buffer_show, megasas_fw_crash_buffer_store);
>  static DEVICE_ATTR(fw_crash_buffer_size, S_IRUGO,

As mentioned, we should be using a common function here.

> @@ -3207,7 +3221,9 @@ static struct scsi_host_template megasas_template = {
>  	.shost_attrs = megaraid_host_attrs,
>  	.bios_param = megasas_bios_param,
>  	.change_queue_depth = scsi_change_queue_depth,
> +	.map_queues =  megasas_map_queues,
>  	.no_write_same = 1,
> +	.host_tagset = 1,
>  };
>  
>  /**
> @@ -5407,26 +5423,6 @@ megasas_setup_jbod_map(struct megasas_instance *instance)
>  		instance->use_seqnum_jbod_fp = false;
>  }
>  
> -static void megasas_setup_reply_map(struct megasas_instance *instance)
> -{
> -	const struct cpumask *mask;
> -	unsigned int queue, cpu;
> -
> -	for (queue = 0; queue < instance->msix_vectors; queue++) {
> -		mask = pci_irq_get_affinity(instance->pdev, queue);
> -		if (!mask)
> -			goto fallback;
> -
> -		for_each_cpu(cpu, mask)
> -			instance->reply_map[cpu] = queue;
> -	}
> -	return;
> -
> -fallback:
> -	for_each_possible_cpu(cpu)
> -		instance->reply_map[cpu] = cpu % instance->msix_vectors;
> -}
> -
>  /**
>   * megasas_get_device_list -	Get the PD and LD device list from FW.
>   * @instance:			Adapter soft state
> @@ -5666,8 +5662,6 @@ static int megasas_init_fw(struct megasas_instance *instance)
>  			goto fail_init_adapter;
>  	}
>  
> -	megasas_setup_reply_map(instance);
> -
>  	dev_info(&instance->pdev->dev,
>  		"firmware supports msix\t: (%d)", fw_msix_count);
>  	dev_info(&instance->pdev->dev,
> @@ -6298,6 +6292,8 @@ static int megasas_io_attach(struct megasas_instance *instance)
>  	host->max_lun = MEGASAS_MAX_LUN;
>  	host->max_cmd_len = 16;
>  
> +	host->nr_hw_queues = instance->msix_vectors ?: 1;
> +
>  	/*
>  	 * Notify the mid-layer about the new controller
>  	 */
> @@ -6464,11 +6460,6 @@ static inline int megasas_alloc_mfi_ctrl_mem(struct megasas_instance *instance)
>   */
>  static int megasas_alloc_ctrl_mem(struct megasas_instance *instance)
>  {
> -	instance->reply_map = kcalloc(nr_cpu_ids, sizeof(unsigned int),
> -				      GFP_KERNEL);
> -	if (!instance->reply_map)
> -		return -ENOMEM;
> -
>  	switch (instance->adapter_type) {
>  	case MFI_SERIES:
>  		if (megasas_alloc_mfi_ctrl_mem(instance))
> @@ -6485,8 +6476,6 @@ static int megasas_alloc_ctrl_mem(struct megasas_instance *instance)
>  
>  	return 0;
>   fail:
> -	kfree(instance->reply_map);
> -	instance->reply_map = NULL;
>  	return -ENOMEM;
>  }
>  
> @@ -6499,7 +6488,6 @@ static int megasas_alloc_ctrl_mem(struct megasas_instance *instance)
>   */
>  static inline void megasas_free_ctrl_mem(struct megasas_instance *instance)
>  {
> -	kfree(instance->reply_map);
>  	if (instance->adapter_type == MFI_SERIES) {
>  		if (instance->producer)
>  			dma_free_coherent(&instance->pdev->dev, sizeof(u32),
> @@ -7142,8 +7130,6 @@ megasas_resume(struct pci_dev *pdev)
>  	if (rval < 0)
>  		goto fail_reenable_msix;
>  
> -	megasas_setup_reply_map(instance);
> -
>  	if (instance->adapter_type != MFI_SERIES) {
>  		megasas_reset_reply_desc(instance);
>  		if (megasas_ioc_init_fusion(instance)) {
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> index 4dfa0685a86c..4f909f32bf5c 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> @@ -2699,7 +2699,7 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
>  	}
>  
>  	cmd->request_desc->SCSIIO.MSIxIndex =
> -		instance->reply_map[raw_smp_processor_id()];
> +		scsi_cmnd_hctx_index(instance->host, scp);
>  
>  	if (instance->adapter_type >= VENTURA_SERIES) {
>  		/* FP for Optimal raid level 1.
> @@ -3013,7 +3013,7 @@ megasas_build_syspd_fusion(struct megasas_instance *instance,
>  	cmd->request_desc->SCSIIO.DevHandle = io_request->DevHandle;
>  
>  	cmd->request_desc->SCSIIO.MSIxIndex =
> -		instance->reply_map[raw_smp_processor_id()];
> +		scsi_cmnd_hctx_index(instance->host, scmd);
>  
>  	if (!fp_possible) {
>  		/* system pd firmware path */
> 
Otherwise:

Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
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