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Date:   Fri, 30 Sep 2022 07:09:57 -0700 (PDT)
From:   matthew.gerlach@linux.intel.com
To:     Tom Rix <trix@redhat.com>
cc:     hao.wu@intel.com, yilun.xu@intel.com, russell.h.weight@intel.com,
        basheer.ahmed.muddebihal@intel.com, mdf@kernel.org,
        linux-fpga@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, tianfei.zhang@intel.com,
        corbet@lwn.net, gregkh@linuxfoundation.org,
        linux-serial@vger.kernel.org, jirislaby@kernel.org,
        geert+renesas@glider.be, andriy.shevchenko@linux.intel.com,
        niklas.soderlund+renesas@ragnatech.se, phil.edworthy@renesas.com,
        macro@orcam.me.uk, johan@kernel.org, lukas@wunner.de,
        Basheer Ahmed Muddebihal 
        <basheer.ahmed.muddebihal@linux.intel.com>
Subject: Re: [PATCH v2 2/6] fpga: dfl: Move the DFH definitions
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References: <20220923121745.129167-1-matthew.gerlach@linux.intel.com> <20220923121745.129167-3-matthew.gerlach@linux.intel.com> <36342784-34c3-6a08-7cd4-eb185b61061a@redhat.com>
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On Sat, 24 Sep 2022, Tom Rix wrote:

>
> On 9/23/22 5:17 AM, matthew.gerlach@linux.intel.com wrote:
>> From: Basheer Ahmed Muddebihal <basheer.ahmed.muddebihal@linux.intel.com>
>> 
>> Moving the DFH register offset and register definitions from
>> drivers/fpga/dfl.h to include/linux/dfl.h. These definitions
>> need to be accessed by dfl drivers that are outside of
>> drivers/fpga.
>
> This comment does not match what is done.
>
> A move, a change in names and the introduction new defines.
>
> I am not sure if moving these #defines is the best approach, the later use of 
> the in the uart with FIELD_GET's i think should be wrapped as functions and 
> these functions exported rather than the #defines.
>
> So split this patch and justify why #defines are added to the user's 
> includes.
>
> Tom

I agree the original intent "diverged in v2".  I will minimize moving and 
make helper functions to simplify things.


>
>> 
>> Signed-off-by: Basheer Ahmed Muddebihal 
>> <basheer.ahmed.muddebihal@linux.intel.com>
>> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>> ---
>> v2: remove extra space in commit
>>      use uniform number of digits in constants
>>      don't change copyright date because of removed content
>> ---
>>   drivers/fpga/dfl-afu-main.c |  4 ++--
>>   drivers/fpga/dfl.c          |  2 +-
>>   drivers/fpga/dfl.h          | 20 +-------------------
>>   include/linux/dfl.h         | 33 ++++++++++++++++++++++++++++++++-
>>   4 files changed, 36 insertions(+), 23 deletions(-)
>> 
>> diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
>> index 7f621e96d3b8..c26961ee33db 100644
>> --- a/drivers/fpga/dfl-afu-main.c
>> +++ b/drivers/fpga/dfl-afu-main.c
>> @@ -468,8 +468,8 @@ afu_id_show(struct device *dev, struct device_attribute 
>> *attr, char *buf)
>>   		return -EBUSY;
>>   	}
>>   -	guidl = readq(base + GUID_L);
>> -	guidh = readq(base + GUID_H);
>> +	guidl = readq(base + DFH_GUID_L);
>> +	guidh = readq(base + DFH_GUID_H);
>>   	mutex_unlock(&pdata->lock);
>>     	return scnprintf(buf, PAGE_SIZE, "%016llx%016llx\n", guidh, guidl);
>> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
>> index b9aae85ba930..1132f3c10440 100644
>> --- a/drivers/fpga/dfl.c
>> +++ b/drivers/fpga/dfl.c
>> @@ -1163,7 +1163,7 @@ static int parse_feature_fiu(struct 
>> build_feature_devs_info *binfo,
>>   	 * find and parse FIU's child AFU via its NEXT_AFU register.
>>   	 * please note that only Port has valid NEXT_AFU pointer per spec.
>>   	 */
>> -	v = readq(binfo->ioaddr + NEXT_AFU);
>> +	v = readq(binfo->ioaddr + DFH_NEXT_AFU);
>>     	offset = FIELD_GET(NEXT_AFU_NEXT_DFH_OFST, v);
>>   	if (offset)
>> diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
>> index 06cfcd5e84bb..e620fcb02b5a 100644
>> --- a/drivers/fpga/dfl.h
>> +++ b/drivers/fpga/dfl.h
>> @@ -17,6 +17,7 @@
>>   #include <linux/bitfield.h>
>>   #include <linux/cdev.h>
>>   #include <linux/delay.h>
>> +#include <linux/dfl.h>
>>   #include <linux/eventfd.h>
>>   #include <linux/fs.h>
>>   #include <linux/interrupt.h>
>> @@ -53,28 +54,9 @@
>>   #define PORT_FEATURE_ID_UINT		0x12
>>   #define PORT_FEATURE_ID_STP		0x13
>>   -/*
>> - * Device Feature Header Register Set
>> - *
>> - * For FIUs, they all have DFH + GUID + NEXT_AFU as common header 
>> registers.
>> - * For AFUs, they have DFH + GUID as common header registers.
>> - * For private features, they only have DFH register as common header.
>> - */
>> -#define DFH			0x0
>> -#define GUID_L			0x8
>> -#define GUID_H			0x10
>> -#define NEXT_AFU		0x18
>> -
>> -#define DFH_SIZE		0x8
>> -
>>   /* Device Feature Header Register Bitfield */
>> -#define DFH_ID			GENMASK_ULL(11, 0)	/* Feature ID 
>> */
>>   #define DFH_ID_FIU_FME		0
>>   #define DFH_ID_FIU_PORT		1
>> -#define DFH_REVISION		GENMASK_ULL(15, 12)	/* Feature revision 
>> */
>> -#define DFH_NEXT_HDR_OFST	GENMASK_ULL(39, 16)	/* Offset to next DFH 
>> */
>> -#define DFH_EOL			BIT_ULL(40)		/* End of 
>> list */
>> -#define DFH_TYPE		GENMASK_ULL(63, 60)	/* Feature type */
>>   #define DFH_TYPE_AFU		1
>>   #define DFH_TYPE_PRIVATE	3
>>   #define DFH_TYPE_FIU		4
>> diff --git a/include/linux/dfl.h b/include/linux/dfl.h
>> index 431636a0dc78..33d167c53b09 100644
>> --- a/include/linux/dfl.h
>> +++ b/include/linux/dfl.h
>> @@ -2,7 +2,7 @@
>>   /*
>>    * Header file for DFL driver and device API
>>    *
>> - * Copyright (C) 2020 Intel Corporation, Inc.
>> + * Copyright (C) 2020-2022 Intel Corporation, Inc.
>>    */
>>     #ifndef __LINUX_DFL_H
>> @@ -11,6 +11,37 @@
>>   #include <linux/device.h>
>>   #include <linux/mod_devicetable.h>
>>   +/*
>> + * Device Feature Header Register Set
>> + *
>> + * For FIUs, they all have DFH + GUID + NEXT_AFU as common header 
>> registers.
>> + * For AFUs, they have DFH + GUID as common header registers.
>> + * For private features, they only have DFH register as common header.
>> + */
>> +#define DFH			0x00
>> +#define DFH_GUID_L		0x08
>> +#define DFH_GUID_H		0x10
>> +#define DFH_NEXT_AFU		0x18
>> +
>> +/*
>> + * DFHv1 Register Offset definitons
>> + * In DHFv1, DFH + GUID + CSR_START + CSR_SIZE_GROUP + PARAM_HDR + 
>> PARAM_DATA
>> + * as common header registers
>> + */
>> +#define DFHv1_CSR_ADDR		0x18  /* CSR Register start address 
>> */
>> +#define DFHv1_CSR_SIZE_GRP	0x20  /* Size of Reg Block and Group/tag */
>> +#define DFHv1_PARAM_HDR		0x28  /* Optional First Param header 
>> */
>> +#define DFHv1_PARAM_DATA	0x08  /* Offset of Param data from Param 
>> header */
>> +
>> +#define DFH_SIZE		0x08
>> +
>> +/* Device Feature Header Register Bitfield */
>> +#define DFH_ID			GENMASK_ULL(11, 0)	/* Feature ID 
>> */
>> +#define DFH_REVISION		GENMASK_ULL(15, 12)	/* Feature revision 
>> */
>> +#define DFH_NEXT_HDR_OFST	GENMASK_ULL(39, 16)	/* Offset to next DFH 
>> */
>> +#define DFH_EOL			BIT_ULL(40)		/* End of 
>> list */
>> +#define DFH_TYPE		GENMASK_ULL(63, 60)	/* Feature type */
>> +
>>   /**
>>    * enum dfl_id_type - define the DFL FIU types
>>    */
>
>