Re: [PATCH v2 1/3] bcm-vk: add bcm_vk UAPI

[Scott Branden <scott.branden@broadcom.com>]

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.
>
>> 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.
>
> thanks,
>
> greg k-h