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Message-ID: <5c0a8a41-db58-ac73-da08-681b20156786@linux.dev>
Date:   Fri, 28 Oct 2022 14:18:48 -0500
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Subject: Re: [PATCH V7 3/4] PCI: vmd: Add vmd_device_data
Content-Language: en-US
To:     Bjorn Helgaas <helgaas@kernel.org>,
        "David E. Box" <david.e.box@linux.intel.com>
Cc:     nirmal.patel@linux.intel.com, lorenzo.pieralisi@arm.com,
        hch@infradead.org, kw@linux.com, robh@kernel.org,
        bhelgaas@google.com, michael.a.bottini@intel.com,
        rafael@kernel.org, me@adhityamohan.in, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20221028191308.GA903098@bhelgaas>
From:   Jonathan Derrick <jonathan.derrick@linux.dev>
In-Reply-To: <20221028191308.GA903098@bhelgaas>
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On 10/28/2022 2:13 PM, Bjorn Helgaas wrote:
> On Mon, Oct 24, 2022 at 05:44:10PM -0700, David E. Box wrote:
>> Add vmd_device_data to allow adding additional info for driver data.
> 
>>  	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
>> -		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
>> -				VMD_FEAT_HAS_BUS_RESTRICTIONS |
>> -				VMD_FEAT_OFFSET_FIRST_VECTOR,},
>> +		(kernel_ulong_t)&(struct vmd_device_data) {
>> +			.features = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
>> +				    VMD_FEAT_HAS_BUS_RESTRICTIONS |
>> +				    VMD_FEAT_OFFSET_FIRST_VECTOR,
>> +		},
>> +	},
> 
> It looks like these devices come in families where several device IDs
> share the same features.  I think this would be more readable if you
> defined each family outside this table and simply referenced the
> family here.  E.g., you could do something like:
> 
>   static struct vmd_device_data vmd_v1 = {
>     .features = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
> 		VMD_FEAT_HAS_BUS_RESTRICTIONS |
> 		VMD_FEAT_OFFSET_FIRST_VECTOR,
>   };
I seem to recall it being similar to this in one of the previous revisions
It's fine with me either way

> 
>   {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
>     .driver_data = (kernel_ulong_t) &vmd_v1,
> 
> Then you can add VMD_FEAT_BIOS_PM_QUIRK and the .ltr value in one place
> instead of repeating it a half dozen times.
> 
>>  	{0,}
>>  };
>>  MODULE_DEVICE_TABLE(pci, vmd_ids);
>> -- 
>> 2.25.1
>>