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Subject: Re: [PATCH v2 1/3] bcm-vk: add bcm_vk UAPI
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
        linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com
References: <20200806004631.8102-1-scott.branden@broadcom.com>
 <20200806004631.8102-2-scott.branden@broadcom.com>
 <20200818135313.GB495837@kroah.com>
 <8894c3c4-4d5c-cb94-bc90-a26833ebf268@broadcom.com>
 <20200818174451.GA749919@kroah.com>
 <4adbd70e-c49b-c2d4-84c7-5e910f05e449@broadcom.com>
 <20200819070044.GA1004396@kroah.com>
From:   Scott Branden <scott.branden@broadcom.com>
Message-ID: <fdbb7404-03c3-22b1-d409-5b6d8745ff2b@broadcom.com>
Date:   Thu, 20 Aug 2020 09:37:46 -0700
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Hi Greg,

On 2020-08-19 12:00 a.m., Greg Kroah-Hartman wrote:
> On Tue, Aug 18, 2020 at 05:35:04PM -0700, Scott Branden wrote:
>>
>> On 2020-08-18 10:44 a.m., Greg Kroah-Hartman wrote:
>>> On Tue, Aug 18, 2020 at 10:23:42AM -0700, Scott Branden wrote:
>>>> Hi Greg,
>>>>
>>>> On 2020-08-18 6:53 a.m., Greg Kroah-Hartman wrote:
>>>>> On Wed, Aug 05, 2020 at 05:46:29PM -0700, Scott Branden wrote:
>>>>>> Add user space api for bcm-vk driver.
>>>>>>
>>>>>> Signed-off-by: Scott Branden <scott.branden@broadcom.com>
>>>>>> ---
>>>>>>  include/uapi/linux/misc/bcm_vk.h | 99 ++++++++++++++++++++++++++++++++
>>>>>>  1 file changed, 99 insertions(+)
>>>>>>  create mode 100644 include/uapi/linux/misc/bcm_vk.h
>>>>>>
>>>>>> diff --git a/include/uapi/linux/misc/bcm_vk.h b/include/uapi/linux/misc/bcm_vk.h
>>>>>> new file mode 100644
>>>>>> index 000000000000..783087b7c31f
>>>>>> --- /dev/null
>>>>>> +++ b/include/uapi/linux/misc/bcm_vk.h
>>>>>> @@ -0,0 +1,99 @@
>>>>>> +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) */
>>>>>> +/*
>>>>>> + * Copyright 2018-2020 Broadcom.
>>>>>> + */
>>>>>> +
>>>>>> +#ifndef __UAPI_LINUX_MISC_BCM_VK_H
>>>>>> +#define __UAPI_LINUX_MISC_BCM_VK_H
>>>>>> +
>>>>>> +#include <linux/ioctl.h>
>>>>>> +#include <linux/types.h>
>>>>>> +
>>>>>> +#define BCM_VK_MAX_FILENAME 64
>>>>>> +
>>>>>> +struct vk_image {
>>>>>> +	__u32 type; /* Type of image */
>>>>>> +#define VK_IMAGE_TYPE_BOOT1 1 /* 1st stage (load to SRAM) */
>>>>>> +#define VK_IMAGE_TYPE_BOOT2 2 /* 2nd stage (load to DDR) */
>>>>>> +	char filename[BCM_VK_MAX_FILENAME]; /* Filename of image */
>>>>>> +};
>>>>>> +
>>>>>> +struct vk_reset {
>>>>>> +	__u32 arg1;
>>>>>> +	__u32 arg2;
>>>>>> +};
>>>>>> +
>>>>>> +#define VK_MAGIC		0x5e
>>>>>> +
>>>>>> +/* Load image to Valkyrie */
>>>>>> +#define VK_IOCTL_LOAD_IMAGE	_IOW(VK_MAGIC, 0x2, struct vk_image)
>>>>>> +
>>>>>> +/* Send Reset to Valkyrie */
>>>>>> +#define VK_IOCTL_RESET		_IOW(VK_MAGIC, 0x4, struct vk_reset)
>>>>>> +
>>>>>> +/*
>>>>>> + * message block - basic unit in the message where a message's size is always
>>>>>> + *		   N x sizeof(basic_block)
>>>>>> + */
>>>>>> +struct vk_msg_blk {
>>>>>> +	__u8 function_id;
>>>>>> +#define VK_FID_TRANS_BUF	5
>>>>>> +#define VK_FID_SHUTDOWN		8
>>>>>> +	__u8 size;
>>>>>> +	__u16 trans_id; /* transport id, queue & msg_id */
>>>>>> +	__u32 context_id;
>>>>>> +	__u32 args[2];
>>>>>> +#define VK_CMD_PLANES_MASK	0x000f /* number of planes to up/download */
>>>>>> +#define VK_CMD_UPLOAD		0x0400 /* memory transfer to vk */
>>>>>> +#define VK_CMD_DOWNLOAD		0x0500 /* memory transfer from vk */
>>>>>> +#define VK_CMD_MASK		0x0f00 /* command mask */
>>>>>> +};
>>>>>> +
>>>>>> +#define VK_BAR_FWSTS			0x41c
>>>>>> +#define VK_BAR_COP_FWSTS		0x428
>>>>>> +/* VK_FWSTS definitions */
>>>>>> +#define VK_FWSTS_RELOCATION_ENTRY	BIT(0)
>>>>> <snip>
>>>>>
>>>>> I thought BIT() was not allowed in uapi .h files, this really works
>>>>> properly???
>>>> I did some investigation and it looks like a few other header files in include/uapi also use the BIT() macro:
>>>> include/uapi/misc/uacce/uacce.h
>>>> include/uapi/linux/psci.h
>>>> include/uapi/linux/v4l2-subdev.h
>>> Does the header install test target now fail for these?
>> I do not understand the question above.  make headers_install works.
>> But I guess the above headers would have similar issue with the BIT macro.
> Try enabling CONFIG_UAPI_HEADER_TEST and see what happens :)
I enabled CONFIG_UAPI_HEADER_TEST and then
built using "make" and "make headers_install".

There didn't appear to be any issue with the BIT macro in the headers.
>
>>>> tools/include/uapi/linux/pkt_sched.h
>>> That doesn't count :)
>>>
>>>> It does look like we end up defining the BIT() macro in our user space app that includes the header file.
>>>>
>>>> So, what is the proper thing to be done?
>>>> 1) Move the BIT() macro somewhere in include/uapi and include it in the necessary header files
>>>> 2) Use the _BITUL macro in include/uapi/linux/const.h instead?
>>>> 3) something else?
>>> open-code it for now please, that's the best way as I am pretty sure we
>>> can not contaminate the global C namespace with out BIT() macro, no
>>> matter how much we would like to...
>> OK, I will open-code it instead.
> Great!
>
> greg k-h