Re: [PATCH i-g-t] lib: sync PCI ID macros with kernel

[Jani Nikula <jani.nikula@intel.com>]

On Tue, 12 Nov 2024, Zbigniew Kempczyński <zbigniew.kempczynski@intel.com> wrote:
> On Thu, Nov 07, 2024 at 10:49:30PM +0200, Jani Nikula wrote:
>> On Thu, 07 Nov 2024, Kamil Konieczny <kamil.konieczny@linux.intel.com> wrote:
>> > On 2024-11-06 at 10:58:46 -0800, Ngai-Mint Kwan wrote:
>> >> diff --git a/lib/i915_pciids.h b/lib/pciids.h
>> >> similarity index 93%
>> >> rename from lib/i915_pciids.h
>> >> rename to lib/pciids.h
>> >> index 3e39d644e..7632507af 100644
>> >> --- a/lib/i915_pciids.h
>> >> +++ b/lib/pciids.h
>> >> @@ -22,30 +22,23 @@
>> >>   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
>> >>   * DEALINGS IN THE SOFTWARE.
>> >>   */
>> >> -#ifndef _I915_PCIIDS_H
>> >> -#define _I915_PCIIDS_H
>> >> -
>> >> -/*
>> >> - * A pci_device_id struct {
>> >> - *	__u32 vendor, device;
>> >> - *      __u32 subvendor, subdevice;
>> >> - *	__u32 class, class_mask;
>> >> - *	kernel_ulong_t driver_data;
>> >> - * };
>> >> - * Don't use C99 here because "class" is reserved and we want to
>> >> - * give userspace flexibility.
>> >> - */
>> >> -#define INTEL_VGA_DEVICE(id, info) { \
>> >> -	0x8086,	id, \
>> >> -	~0, ~0, \
>> >> -	0x030000, 0xff0000, \
>> >> -	(unsigned long) info }
>> >> -
>> >> -#define INTEL_QUANTA_VGA_DEVICE(info) { \
>> >> -	0x8086,	0x16a, \
>> >> -	0x152d,	0x8990, \
>> >> -	0x030000, 0xff0000, \
>> >> -	(unsigned long) info }
>> >> +#ifndef __PCIIDS_H__
>> >> +#define __PCIIDS_H__
>> >> +
>> >> +#ifdef __KERNEL__
>> >
>> > I am not sure if we want a kernel defs, this is for userspace
>> > so imho this ifdef KERNEL/endif should be deleted. Or write
>> > a rationale why you included it here, or make it a comment?
>> > +cc Zbigniew
>> 
>> The file comes verbatim from kernel.
>
> I have mixed feelings about copying kernel headers here directly
> if they are not uapi. However __KERNEL__ conditional was added to
> this header intentionally so copying this file outside the kernel
> and further reuse in userspace code is harmless. But I would add
> some explanation to README.md about pciids.h copying procedure
> for the future.

We've been doing this for PCI IDs for at least 10 years, and for
intel_vbt_defs.h for at least 7 years.

Please feel free to send documentation patches.


BR,
Jani.

-- 
Jani Nikula, Intel