Commit 17899358 authored by Michal Wajdeczko's avatar Michal Wajdeczko
Browse files

drm/xe/pf: Add sysfs device symlinks to enabled VFs 



For convenience, for every enabled VF add 'device' symlink from
our SR-IOV admin VF folder to enabled sysfs PCI VF device entry.
Remove all those links when disabling PCI VFs.

For completeness, add static 'device' symlink for the PF itself.

  /sys/bus/pci/drivers/xe/BDF/sriov_admin/
  ├── pf
  │   └── device -> ../../../BDF	# PF BDF
  ├── vf1
  │   └── device -> ../../../BDF'	# VF1 BDF
  ├── vf2
  │   └── device -> ../../../BDF"	# VF2 BDF

Signed-off-by: default avatarMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Link: https://patch.msgid.link/20251030222348.186658-16-michal.wajdeczko@intel.com
parent ae16f18a

drivers/gpu/drm/xe/xe_pci_sriov.c

+5 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include "xe_sriov_pf_control.h"

#include "xe_sriov_pf_helpers.h"

#include "xe_sriov_pf_provision.h"

#include "xe_sriov_pf_sysfs.h"

#include "xe_sriov_printk.h"



static void pf_reset_vfs(struct xe_device *xe, unsigned int num_vfs)
@@ -138,6 +139,8 @@ static int pf_enable_vfs(struct xe_device *xe, int num_vfs) 
	xe_sriov_info(xe, "Enabled %u of %u VF%s\n",

		      num_vfs, total_vfs, str_plural(total_vfs));



	xe_sriov_pf_sysfs_link_vfs(xe, num_vfs);



	pf_engine_activity_stats(xe, num_vfs, true);



	return num_vfs;
@@ -165,6 +168,8 @@ static int pf_disable_vfs(struct xe_device *xe) 


	pf_engine_activity_stats(xe, num_vfs, false);



	xe_sriov_pf_sysfs_unlink_vfs(xe, num_vfs);



	pci_disable_sriov(pdev);



	pf_reset_vfs(xe, num_vfs);

drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c

+93 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <drm/drm_managed.h>



#include "xe_assert.h"

#include "xe_pci_sriov.h"

#include "xe_pm.h"

#include "xe_sriov.h"

#include "xe_sriov_pf.h"
@@ -45,12 +46,14 @@ static int emit_choice(char *buf, int choice, const char * const *array, size_t 
 *     │   └── sched_priority

 *     ├── pf/

 *     │   ├── ...

 *     │   ├── device -> ../../../BDF

 *     │   └── profile

 *     │       ├── exec_quantum_ms

 *     │       ├── preempt_timeout_us

 *     │       └── sched_priority

 *     ├── vf1/

 *     │   ├── ...

 *     │   ├── device -> ../../../BDF.1

 *     │   └── profile

 *     │       ├── exec_quantum_ms

 *     │       ├── preempt_timeout_us
@@ -414,6 +417,11 @@ static int pf_sysfs_error(struct xe_device *xe, int err, const char *what) 
	return err;

}



static void pf_sysfs_note(struct xe_device *xe, int err, const char *what)

{

	xe_sriov_dbg(xe, "Failed to setup sysfs %s (%pe)\n", what, ERR_PTR(err));

}



static void action_put_kobject(void *arg)

{

	struct kobject *kobj = arg;
@@ -480,6 +488,29 @@ static int pf_setup_tree(struct xe_device *xe) 
	return 0;

}



static void action_rm_device_link(void *arg)

{

	struct kobject *kobj = arg;



	sysfs_remove_link(kobj, "device");

}



static int pf_link_pf_device(struct xe_device *xe)

{

	struct kobject *kobj = xe->sriov.pf.vfs[PFID].kobj;

	int err;



	err = sysfs_create_link(kobj, &xe->drm.dev->kobj, "device");

	if (err)

		return pf_sysfs_error(xe, err, "PF device link");



	err = devm_add_action_or_reset(xe->drm.dev, action_rm_device_link, kobj);

	if (err)

		return pf_sysfs_error(xe, err, "PF unlink action");



	return 0;

}



/**

 * xe_sriov_pf_sysfs_init() - Setup PF's SR-IOV sysfs tree.

 * @xe: the PF &xe_device to setup sysfs
@@ -501,5 +532,67 @@ int xe_sriov_pf_sysfs_init(struct xe_device *xe) 
	if (err)

		return err;



	err = pf_link_pf_device(xe);

	if (err)

		return err;



	return 0;

}



/**

 * xe_sriov_pf_sysfs_link_vfs() - Add VF's links in SR-IOV sysfs tree.

 * @xe: the &xe_device where to update sysfs

 * @num_vfs: number of enabled VFs to link

 *

 * This function is specific for the PF driver.

 *

 * This function will add symbolic links between VFs represented in the SR-IOV

 * sysfs tree maintained by the PF and enabled VF PCI devices.

 *

 * The @xe_sriov_pf_sysfs_unlink_vfs() shall be used to remove those links.

 */

void xe_sriov_pf_sysfs_link_vfs(struct xe_device *xe, unsigned int num_vfs)

{

	unsigned int totalvfs = xe_sriov_pf_get_totalvfs(xe);

	struct pci_dev *pf_pdev = to_pci_dev(xe->drm.dev);

	struct pci_dev *vf_pdev = NULL;

	unsigned int n;

	int err;



	xe_assert(xe, IS_SRIOV_PF(xe));

	xe_assert(xe, num_vfs <= totalvfs);



	for (n = 1; n <= num_vfs; n++) {

		vf_pdev = xe_pci_sriov_get_vf_pdev(pf_pdev, VFID(n));

		if (!vf_pdev)

			return pf_sysfs_note(xe, -ENOENT, "VF link");



		err = sysfs_create_link(xe->sriov.pf.vfs[VFID(n)].kobj,

					&vf_pdev->dev.kobj, "device");



		/* must balance xe_pci_sriov_get_vf_pdev() */

		pci_dev_put(vf_pdev);



		if (err)

			return pf_sysfs_note(xe, err, "VF link");

	}

}



/**

 * xe_sriov_pf_sysfs_unlink_vfs() - Remove VF's links from SR-IOV sysfs tree.

 * @xe: the &xe_device where to update sysfs

 * @num_vfs: number of VFs to unlink

 *

 * This function shall be called only on the PF.

 * This function will remove "device" links added by @xe_sriov_sysfs_link_vfs().

 */

void xe_sriov_pf_sysfs_unlink_vfs(struct xe_device *xe, unsigned int num_vfs)

{

	unsigned int n;



	xe_assert(xe, IS_SRIOV_PF(xe));

	xe_assert(xe, num_vfs <= xe_sriov_pf_get_totalvfs(xe));



	for (n = 1; n <= num_vfs; n++)

		sysfs_remove_link(xe->sriov.pf.vfs[VFID(n)].kobj, "device");

}

drivers/gpu/drm/xe/xe_sriov_pf_sysfs.h

+3 −0
Original line number Diff line number Diff line
@@ -10,4 +10,7 @@ struct xe_device; 


int xe_sriov_pf_sysfs_init(struct xe_device *xe);



void xe_sriov_pf_sysfs_link_vfs(struct xe_device *xe, unsigned int num_vfs);

void xe_sriov_pf_sysfs_unlink_vfs(struct xe_device *xe, unsigned int num_vfs);



#endif