[PATCH 1/2] Add device enumeration interface (v2)

[Emil Velikov]

Hi Jammy, Frank

As far as I can see you're trying to get a different version of
drmGetBusid(). With the DRM_IOCTL_{G,S}ET_UNIQUE ioctl being lovely as
it is I do see your point, but I'm not sure that the current design will
be too useful.

Do we have any upcoming users for this new function, can you share a bit
about the usecase ?

On 24/04/15 03:44, Jammy Zhou wrote:
> drmGetDevices interface is added to enumernate GPU devices on the system
> 
> v2: rebase the code and some improvement for the coding style
> 
> Signed-off-by: Frank Min <Frank.Min at amd.com>
> Signed-off-by: Jammy Zhou <Jammy.Zhou at amd.com> (v2)
> ---
>  Makefile.am |  3 ++-
>  xf86drm.c   | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
>  xf86drm.h   | 18 ++++++++++++++++++
>  3 files changed, 68 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile.am b/Makefile.am
> index 42d3d7f..8236ed8 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -89,7 +89,8 @@ SUBDIRS = \
>  libdrm_la_LTLIBRARIES = libdrm.la
>  libdrm_ladir = $(libdir)
>  libdrm_la_LDFLAGS = -version-number 2:4:0 -no-undefined
> -libdrm_la_LIBADD = @CLOCK_LIB@
> +libdrm_la_LIBADD = @CLOCK_LIB@ \
> +		@PCIACCESS_LIBS@
>  
>  libdrm_la_CPPFLAGS = -I$(top_srcdir)/include/drm
>  AM_CFLAGS = \
> diff --git a/xf86drm.c b/xf86drm.c
> index ffc53b8..4d67861 100644
> --- a/xf86drm.c
> +++ b/xf86drm.c
> @@ -63,6 +63,7 @@
>  
>  #include "xf86drm.h"
>  #include "libdrm.h"
> +#include <pciaccess.h>
>  
>  #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
>  #define DRM_MAJOR 145
> @@ -2817,3 +2818,50 @@ char *drmGetRenderDeviceNameFromFd(int fd)
>  {
>  	return drmGetMinorNameForFD(fd, DRM_NODE_RENDER);
>  }
> +
> +/**
> + * Enumerate the GPU devices on the system
> + *
> + * \param devs device array set to return the device information
> + * (if NULL, the number of device is returned)
> + * \param vendor the vendor ID for GPU devices to list
> + * (optional, if not specified, all GPU devices are returned)
> + *
> + * \return the number of GPU devices
> + */
> +int drmGetDevices(drmDevicePtr devs, uint16_t vendor)
> +{
> +	struct pci_device_iterator * iter;
> +	struct pci_device * dev;
> +	uint32_t count = 0;
> +
> +	if (pci_system_init())
> +		return -EINVAL;
> +
> +	iter = pci_slot_match_iterator_create(NULL);
> +	if (!iter)
> +		return -EINVAL;
> +
> +	while ((dev = pci_device_next(iter))) {
> +		if (((dev->device_class == 0x30000) ||
> +			(dev->device_class == 0x38000)) &&
Any particular reason why "3D controller" (0x32000) is omitted ?

> +			((vendor == 0) || (dev->vendor_id == vendor))){
> +			if (devs) {
> +				devs[count].domain = dev->domain;
> +				devs[count].bus = dev->bus;
> +				devs[count].dev = dev->dev;
> +				devs[count].func = dev->func;
> +				devs[count].vendor_id = dev->vendor_id;
> +				devs[count].device_id = dev->device_id;
> +				devs[count].subvendor_id = dev->subvendor_id;
> +				devs[count].subdevice_id = dev->subdevice_id;
> +				devs[count].revision_id = dev->revision;
> +			}
> +			count++;
> +		}
> +	}
> +
> +	pci_iterator_destroy(iter);
> +	pci_system_cleanup();
Using libpciaccess, will give you the number of PCI devices available on
the system rather than the ones accessible - think about platform
devices and/or devices without a drm driver.

Another solution will be to get the information based on the
primary/control/render nodes available. This will also allow one to know
what the device can be used for - be that via a separate parameter set
by the function or having different functions altogether.

Cheers
Emil