Commit ca0ed3b1 authored by Michal Wajdeczko's avatar Michal Wajdeczko Committed by Lucas De Marchi
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drm/xe/configfs: Allow adding configurations for future VFs 



Since we are expecting that all configuration directory names
will match some of the existing devices, we can't provide any
configuration for the VFs until they are actually enabled.

But we can relax that restriction by just checking if there
is a PF device that could create given VF. This is easy since
all our PF devices are always present at function 0 and we can
query PF device for number of VFs it could support.

Then for some system with PF device at 0000:00:02.0 we can add
configs for all VFs:

  /sys/kernel/config/xe/
  ├── 0000:00:02.0
  │   └── ...
  ├── 0000:00:02.1
  │   └── ...
  ├── 0000:00:02.2
  │   └── ...
  :
  └── 0000:00:02.7
      └── ...

Signed-off-by: default avatarMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250731212145.179898-1-michal.wajdeczko@intel.com
Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
parent b4687422

drivers/gpu/drm/xe/xe_configfs.c

+30 −3
Original line number Diff line number Diff line
@@ -12,9 +12,9 @@ 
#include <linux/string.h>



#include "xe_configfs.h"

#include "xe_module.h"



#include "xe_hw_engine_types.h"

#include "xe_module.h"

#include "xe_pci_types.h"



/**

 * DOC: Xe Configfs
@@ -280,6 +280,15 @@ static const struct xe_device_desc *xe_match_desc(struct pci_dev *pdev) 
	return found ? (const void *)found->driver_data : NULL;

}



static struct pci_dev *get_physfn_instead(struct pci_dev *virtfn)

{

	struct pci_dev *physfn = pci_physfn(virtfn);



	pci_dev_get(physfn);

	pci_dev_put(virtfn);

	return physfn;

}



static struct config_group *xe_config_make_device_group(struct config_group *group,

							const char *name)

{
@@ -288,6 +297,7 @@ static struct config_group *xe_config_make_device_group(struct config_group *gro 
	const struct xe_device_desc *match;

	struct pci_dev *pdev;

	char canonical[16];

	int vfnumber = 0;

	int ret;



	ret = sscanf(name, "%x:%x:%x.%x", &domain, &bus, &slot, &function);
@@ -301,12 +311,29 @@ static struct config_group *xe_config_make_device_group(struct config_group *gro 
		return ERR_PTR(-EINVAL);



	pdev = pci_get_domain_bus_and_slot(domain, bus, PCI_DEVFN(slot, function));

	if (!pdev && function)

		pdev = pci_get_domain_bus_and_slot(domain, bus, PCI_DEVFN(slot, 0));

	if (!pdev && slot)

		pdev = pci_get_domain_bus_and_slot(domain, bus, PCI_DEVFN(0, 0));

	if (!pdev)

		return ERR_PTR(-ENODEV);



	if (PCI_DEVFN(slot, function) != pdev->devfn) {

		pdev = get_physfn_instead(pdev);

		vfnumber = PCI_DEVFN(slot, function) - pdev->devfn;

		if (!dev_is_pf(&pdev->dev) || vfnumber > pci_sriov_get_totalvfs(pdev)) {

			pci_dev_put(pdev);

			return ERR_PTR(-ENODEV);

		}

	}



	match = xe_match_desc(pdev);

	if (!match)

	if (match && vfnumber && !match->has_sriov) {

		pci_info(pdev, "xe driver does not support VFs on this device\n");

		match = NULL;

	} else if (!match) {

		pci_info(pdev, "xe driver does not support configuration of this device\n");

	}



	pci_dev_put(pdev);