Commit 146e4384 authored by Michal Wajdeczko's avatar Michal Wajdeczko
Browse files

drm/xe: Add proper detection of the SR-IOV PF mode 



SR-IOV PF mode detection is based on PCI capability as reported by
the PCI dev_is_pf() function and additionally on 'max_vfs' module
parameter which could be also used to disable PF capability even
if SR-IOV PF capability is reported by the hardware.

Signed-off-by: default avatarMichal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240404154431.583-3-michal.wajdeczko@intel.com
parent e806fac0

drivers/gpu/drm/xe/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -159,7 +159,8 @@ xe-$(CONFIG_PCI_IOV) += \ 
	xe_gt_sriov_pf_control.o \

	xe_lmtt.o \

	xe_lmtt_2l.o \

	xe_lmtt_ml.o

	xe_lmtt_ml.o \

	xe_sriov_pf.o



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

ifdef CONFIG_DRM_XE_KUNIT_TEST

drivers/gpu/drm/xe/xe_device_types.h

+4 −0
Original line number Diff line number Diff line
@@ -321,6 +321,10 @@ struct xe_device { 
	struct {

		/** @sriov.__mode: SR-IOV mode (Don't access directly!) */

		enum xe_sriov_mode __mode;



		/** @sriov.pf: PF specific data */

		struct xe_device_pf pf;



		/** @sriov.wq: workqueue used by the virtualization workers */

		struct workqueue_struct *wq;

	} sriov;

drivers/gpu/drm/xe/xe_sriov.c

+3 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "xe_device.h"

#include "xe_mmio.h"

#include "xe_sriov.h"

#include "xe_sriov_pf.h"



/**

 * xe_sriov_mode_to_string - Convert enum value to string.
@@ -58,6 +59,8 @@ void xe_sriov_probe_early(struct xe_device *xe) 
	if (has_sriov) {

		if (test_is_vf(xe))

			mode = XE_SRIOV_MODE_VF;

		else if (xe_sriov_pf_readiness(xe))

			mode = XE_SRIOV_MODE_PF;

	}



	xe_assert(xe, !xe->sriov.__mode);

drivers/gpu/drm/xe/xe_sriov_pf.c

0 → 100644
+89 −0
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// SPDX-License-Identifier: MIT

/*

 * Copyright © 2023-2024 Intel Corporation

 */



#include "xe_assert.h"

#include "xe_device.h"

#include "xe_module.h"

#include "xe_sriov.h"

#include "xe_sriov_pf.h"

#include "xe_sriov_printk.h"



static unsigned int wanted_max_vfs(struct xe_device *xe)

{

	return xe_modparam.max_vfs;

}



static int pf_reduce_totalvfs(struct xe_device *xe, int limit)

{

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

	struct pci_dev *pdev = to_pci_dev(dev);

	int err;



	err = pci_sriov_set_totalvfs(pdev, limit);

	if (err)

		xe_sriov_notice(xe, "Failed to set number of VFs to %d (%pe)\n",

				limit, ERR_PTR(err));

	return err;

}



static bool pf_continue_as_native(struct xe_device *xe, const char *why)

{

	xe_sriov_dbg(xe, "%s, continuing as native\n", why);

	pf_reduce_totalvfs(xe, 0);

	return false;

}



/**

 * xe_sriov_pf_readiness - Check if PF functionality can be enabled.

 * @xe: the &xe_device to check

 *

 * This function is called as part of the SR-IOV probe to validate if all

 * PF prerequisites are satisfied and we can continue with enabling PF mode.

 *

 * Return: true if the PF mode can be turned on.

 */

bool xe_sriov_pf_readiness(struct xe_device *xe)

{

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

	struct pci_dev *pdev = to_pci_dev(dev);

	int totalvfs = pci_sriov_get_totalvfs(pdev);

	int newlimit = min_t(u16, wanted_max_vfs(xe), totalvfs);



	xe_assert(xe, totalvfs <= U16_MAX);



	if (!dev_is_pf(dev))

		return false;



	if (!xe_device_uc_enabled(xe))

		return pf_continue_as_native(xe, "Guc submission disabled");



	if (!newlimit)

		return pf_continue_as_native(xe, "all VFs disabled");



	pf_reduce_totalvfs(xe, newlimit);



	xe->sriov.pf.device_total_vfs = totalvfs;

	xe->sriov.pf.driver_max_vfs = newlimit;



	return true;

}



/**

 * xe_sriov_pf_print_vfs_summary - Print SR-IOV PF information.

 * @xe: the &xe_device to print info from

 * @p: the &drm_printer

 *

 * Print SR-IOV PF related information into provided DRM printer.

 */

void xe_sriov_pf_print_vfs_summary(struct xe_device *xe, struct drm_printer *p)

{

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



	xe_assert(xe, IS_SRIOV_PF(xe));



	drm_printf(p, "total: %u\n", xe->sriov.pf.device_total_vfs);

	drm_printf(p, "supported: %u\n", xe->sriov.pf.driver_max_vfs);

	drm_printf(p, "enabled: %u\n", pci_num_vf(pdev));

}

drivers/gpu/drm/xe/xe_sriov_pf.h

0 → 100644
+24 −0
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/* SPDX-License-Identifier: MIT */

/*

 * Copyright © 2023-2024 Intel Corporation

 */



#ifndef _XE_SRIOV_PF_H_

#define _XE_SRIOV_PF_H_



#include <linux/types.h>



struct drm_printer;

struct xe_device;



#ifdef CONFIG_PCI_IOV

bool xe_sriov_pf_readiness(struct xe_device *xe);

void xe_sriov_pf_print_vfs_summary(struct xe_device *xe, struct drm_printer *p);

#else

static inline bool xe_sriov_pf_readiness(struct xe_device *xe)

{

	return false;

}

#endif



#endif