Re: [PATCH V4 02/11] megaraid_sas: 128 MSIX Support

[Tomas Henzl <thenzl@redhat.com>]

On 20.12.2016 02:50, Sasikumar PC wrote:
> Hi Tomas,
>
> Please see my response inline
>
> Thanks
> sasi
>
> -----Original Message-----
> From: Sasikumar PC [mailto:sasikumar.pc@broadcom.com]
> Sent: Wednesday, December 14, 2016 4:43 PM
> To: 'Tomas Henzl'; 'jejb@kernel.org'; 'hch@infradead.org'
> Cc: 'linux-scsi@vger.kernel.org'; Sathya Prakash Veerichetty;
> 'linux-kernel@vger.kernel.org'; Christopher Owens; Kiran Kumar Kasturi
> Subject: RE: [PATCH V4 02/11] megaraid_sas: 128 MSIX Support
>
> Hi Tomas,
>
> Please see my response inline
>
> Thanks
> sasi
>
> -----Original Message-----
> From: Tomas Henzl [mailto:thenzl@redhat.com]
> Sent: Thursday, December 08, 2016 10:35 AM
> To: Sasikumar Chandrasekaran; jejb@kernel.org; hch@infradead.org
> Cc: linux-scsi@vger.kernel.org; Sathya.Prakash@broadcom.com;
> linux-kernel@vger.kernel.org; christopher.owens@broadcom.com;
> kiran-kumar.kasturi@broadcom.com
> Subject: Re: [PATCH V4 02/11] megaraid_sas: 128 MSIX Support
>
> On 7.12.2016 00:00, Sasikumar Chandrasekaran wrote:
>> SAS3.5 Generic Megaraid based Controllers will have the support for
>> 128 MSI-X vectors, resulting in the need to support 128 reply queues
>>
>> This patch is depending on patch 1
>>
>> Signed-off-by: Sasikumar Chandrasekaran <sasikumar.pc@broadcom.com>
>> ---
>>  drivers/scsi/megaraid/megaraid_sas.h        |  1 +
>>  drivers/scsi/megaraid/megaraid_sas_base.c   | 24
> +++++++++++++++++-------
>>  drivers/scsi/megaraid/megaraid_sas_fusion.c |  4 ++--
>>  3 files changed, 20 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/scsi/megaraid/megaraid_sas.h
>> b/drivers/scsi/megaraid/megaraid_sas.h
>> index 72e16c2..9d4ca8d 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas.h
>> +++ b/drivers/scsi/megaraid/megaraid_sas.h
>> @@ -2149,6 +2149,7 @@ struct megasas_instance {
>>  	bool dev_handle;
>>  	bool fw_sync_cache_support;
>>  	bool is_ventura;
>> +	bool msix_combined;
>>  };
>>  struct MR_LD_VF_MAP {
>>  	u32 size;
>> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c
>> b/drivers/scsi/megaraid/megaraid_sas_base.c
>> index efccf98..c583e0b 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
>> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
>> @@ -5086,13 +5086,7 @@ static int megasas_init_fw(struct
> megasas_instance *instance)
>>  			goto fail_ready_state;
>>  	}
>>
>> -	/*
>> -	 * MSI-X host index 0 is common for all adapter.
>> -	 * It is used for all MPT based Adapters.
>> -	 */
>> -	instance->reply_post_host_index_addr[0] =
>> -		(u32 __iomem *)((u8 __iomem *)instance->reg_set +
>> -		MPI2_REPLY_POST_HOST_INDEX_OFFSET);
>> +
>>
>>  	/* Check if MSI-X is supported while in ready state */
>>  	msix_enable = (instance->instancet->read_fw_status_reg(reg_set) &
> @@
>> -5110,6 +5104,9 @@ static int megasas_init_fw(struct megasas_instance
> *instance)
>>  				instance->msix_vectors = ((scratch_pad_2
>>  					& MR_MAX_REPLY_QUEUES_EXT_OFFSET)
>>  					>>
> MR_MAX_REPLY_QUEUES_EXT_OFFSET_SHIFT) + 1;
>> +				if (instance->msix_vectors > 16)
>> +					instance->msix_combined = true;
>> +
>>  				if (rdpq_enable)
>>  					instance->is_rdpq = (scratch_pad_2
> & MR_RDPQ_MODE_OFFSET) ?
>>  								1 : 0;
>> @@ -5143,6 +5140,19 @@ static int megasas_init_fw(struct
> megasas_instance *instance)
>>  		else
>>  			instance->msix_vectors = 0;
>>  	}
> Have you tested this patch with the pci=nomsi kernel option?
> Sasi - Driver is tested with pci=nomsi option and looking good
>
> is it safe when msix_combined is true and pci_enable_msix_range fails so
> instance->msix_vectors is zero?
>
> msix_combined mode is dependent on how many vectors adapter supports, not
> the actual vectors used.
> It is correct to be in combined mode even if actual number of msix_vectors
> used are fewer than 16, if hardware is in combined mode

Ok,  thanks for explanation.

>
> Sasi
>
>
> tomash
>
>> +	/*
>> +	 * MSI-X host index 0 is common for all adapter.
>> +	 * It is used for all MPT based Adapters.
>> +	 */
>> +	if (instance->msix_combined) {
>> +		instance->reply_post_host_index_addr[0] =
>> +				(u32 *)((u8 *)instance->reg_set +
>> +				MPI2_SUP_REPLY_POST_HOST_INDEX_OFFSET);
>> +	} else {
>> +		instance->reply_post_host_index_addr[0] =
>> +			(u32 *)((u8 *)instance->reg_set +
>> +			MPI2_REPLY_POST_HOST_INDEX_OFFSET);
>> +	}
>>
>>  	dev_info(&instance->pdev->dev,
>>  		"firmware supports msix\t: (%d)", fw_msix_count); diff
> --git
>> a/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> b/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> index 8d7a397..413e2030 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> @@ -2391,7 +2391,7 @@ static void megasas_build_ld_nonrw_fusion(struct
> megasas_instance *instance,
>>  		 * pending to be completed
>>  		 */
>>  		if (threshold_reply_count >= THRESHOLD_REPLY_COUNT) {
>> -			if (fusion->adapter_type == INVADER_SERIES)
>> +			if (instance->msix_combined)
>>  				writel(((MSIxIndex & 0x7) << 24) |
>>  					fusion->last_reply_idx[MSIxIndex],
>>
> instance->reply_post_host_index_addr[MSIxIndex/8]);
>> @@ -2407,7 +2407,7 @@ static void megasas_build_ld_nonrw_fusion(struct
> megasas_instance *instance,
>>  		return IRQ_NONE;
>>
>>  	wmb();
>> -	if (fusion->adapter_type == INVADER_SERIES)
>> +	if (instance->msix_combined)
>>  		writel(((MSIxIndex & 0x7) << 24) |
>>  			fusion->last_reply_idx[MSIxIndex],
>>
> instance->reply_post_host_index_addr[MSIxIndex/8]);
> --
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