Commit 9aa85860 authored by Michal Wajdeczko's avatar Michal Wajdeczko
Browse files

drm/xe/pf: Implement pci_driver.sriov_configure callback 



The PCI subsystem already exposes the "sriov_numvfs" attribute
that users can use to enable or disable SR-IOV VFs. Add custom
implementation of the .sriov_configure callback defined by the
pci_driver to perform additional steps, including fair VFs
provisioning with the resources, as required by our platforms.

Signed-off-by: default avatarMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Cc: Badal Nilawar <badal.nilawar@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com> #v2
Reviewed-by: default avatarBadal Nilawar <badal.nilawar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240506184121.2615-1-michal.wajdeczko@intel.com
parent 75fe5f34

drivers/gpu/drm/xe/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -169,6 +169,7 @@ xe-$(CONFIG_PCI_IOV) += \ 
	xe_lmtt.o \

	xe_lmtt_2l.o \

	xe_lmtt_ml.o \

	xe_pci_sriov.o \

	xe_sriov_pf.o



# include helpers for tests even when XE is built-in

drivers/gpu/drm/xe/xe_pci.c

+4 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include "xe_macros.h"

#include "xe_mmio.h"

#include "xe_module.h"

#include "xe_pci_sriov.h"

#include "xe_pci_types.h"

#include "xe_pm.h"

#include "xe_sriov.h"
@@ -960,6 +961,9 @@ static struct pci_driver xe_pci_driver = { 
	.probe = xe_pci_probe,

	.remove = xe_pci_remove,

	.shutdown = xe_pci_shutdown,

#ifdef CONFIG_PCI_IOV

	.sriov_configure = xe_pci_sriov_configure,

#endif

#ifdef CONFIG_PM_SLEEP

	.driver.pm = &xe_pm_ops,

#endif

drivers/gpu/drm/xe/xe_pci_sriov.c

0 → 100644
+143 −0
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// SPDX-License-Identifier: MIT

/*

 * Copyright © 2023-2024 Intel Corporation

 */



#include "xe_assert.h"

#include "xe_device.h"

#include "xe_gt_sriov_pf_config.h"

#include "xe_pci_sriov.h"

#include "xe_pm.h"

#include "xe_sriov.h"

#include "xe_sriov_pf_helpers.h"

#include "xe_sriov_printk.h"



static int pf_provision_vfs(struct xe_device *xe, unsigned int num_vfs)

{

	struct xe_gt *gt;

	unsigned int id;

	int result = 0, err;



	for_each_gt(gt, xe, id) {

		err = xe_gt_sriov_pf_config_set_fair(gt, VFID(1), num_vfs);

		result = result ?: err;

	}



	return result;

}



static void pf_unprovision_vfs(struct xe_device *xe, unsigned int num_vfs)

{

	struct xe_gt *gt;

	unsigned int id;

	unsigned int n;



	for_each_gt(gt, xe, id)

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

			xe_gt_sriov_pf_config_release(gt, n, true);

}



static int pf_enable_vfs(struct xe_device *xe, int num_vfs)

{

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

	int total_vfs = xe_sriov_pf_get_totalvfs(xe);

	int err;



	xe_assert(xe, IS_SRIOV_PF(xe));

	xe_assert(xe, num_vfs > 0);

	xe_assert(xe, num_vfs <= total_vfs);

	xe_sriov_dbg(xe, "enabling %u VF%s\n", num_vfs, str_plural(num_vfs));



	/*

	 * We must hold additional reference to the runtime PM to keep PF in D0

	 * during VFs lifetime, as our VFs do not implement the PM capability.

	 *

	 * With PF being in D0 state, all VFs will also behave as in D0 state.

	 * This will also keep GuC alive with all VFs' configurations.

	 *

	 * We will release this additional PM reference in pf_disable_vfs().

	 */

	xe_pm_runtime_get_noresume(xe);



	err = pf_provision_vfs(xe, num_vfs);

	if (err < 0)

		goto failed;



	err = pci_enable_sriov(pdev, num_vfs);

	if (err < 0)

		goto failed;



	xe_sriov_info(xe, "Enabled %u of %u VF%s\n",

		      num_vfs, total_vfs, str_plural(total_vfs));

	return num_vfs;



failed:

	pf_unprovision_vfs(xe, num_vfs);

	xe_pm_runtime_put(xe);



	xe_sriov_notice(xe, "Failed to enable %u VF%s (%pe)\n",

			num_vfs, str_plural(num_vfs), ERR_PTR(err));

	return err;

}



static int pf_disable_vfs(struct xe_device *xe)

{

	struct device *dev = xe->drm.dev;

	struct pci_dev *pdev = to_pci_dev(dev);

	u16 num_vfs = pci_num_vf(pdev);



	xe_assert(xe, IS_SRIOV_PF(xe));

	xe_sriov_dbg(xe, "disabling %u VF%s\n", num_vfs, str_plural(num_vfs));



	if (!num_vfs)

		return 0;



	pci_disable_sriov(pdev);



	pf_unprovision_vfs(xe, num_vfs);



	/* not needed anymore - see pf_enable_vfs() */

	xe_pm_runtime_put(xe);



	xe_sriov_info(xe, "Disabled %u VF%s\n", num_vfs, str_plural(num_vfs));

	return 0;

}



/**

 * xe_pci_sriov_configure - Configure SR-IOV (enable/disable VFs).

 * @pdev: the &pci_dev

 * @num_vfs: number of VFs to enable or zero to disable all VFs

 *

 * This is the Xe implementation of struct pci_driver.sriov_configure callback.

 *

 * This callback will be called by the PCI subsystem to enable or disable SR-IOV

 * Virtual Functions (VFs) as requested by the used via the PCI sysfs interface.

 *

 * Return: number of configured VFs or a negative error code on failure.

 */

int xe_pci_sriov_configure(struct pci_dev *pdev, int num_vfs)

{

	struct xe_device *xe = pdev_to_xe_device(pdev);

	int ret;



	if (!IS_SRIOV_PF(xe))

		return -ENODEV;



	if (num_vfs < 0)

		return -EINVAL;



	if (num_vfs > xe_sriov_pf_get_totalvfs(xe))

		return -ERANGE;



	if (num_vfs && pci_num_vf(pdev))

		return -EBUSY;



	xe_pm_runtime_get(xe);

	if (num_vfs > 0)

		ret = pf_enable_vfs(xe, num_vfs);

	else

		ret = pf_disable_vfs(xe);

	xe_pm_runtime_put(xe);



	return ret;

}

drivers/gpu/drm/xe/xe_pci_sriov.h

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/* SPDX-License-Identifier: MIT */

/*

 * Copyright © 2023-2024 Intel Corporation

 */



#ifndef _XE_PCI_SRIOV_H_

#define _XE_PCI_SRIOV_H_



struct pci_dev;



int xe_pci_sriov_configure(struct pci_dev *pdev, int num_vfs);



#endif