[PATCH v2] drm/xe/pf: Implement pci_driver.sriov_configure callback

[Piotr Piórkowski]

Michal Wajdeczko <michal.wajdeczko at intel.com> wrote on pią [2024-kwi-26 15:22:17 +0200]:
> 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: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Piotr Piórkowski <piotr.piorkowski at intel.com>
> ---
> v2: check result of VFs provisioning (Piotr)
>     use xe_sriov_pf_get_totalvfs consistently (Piotr)
>     prefer VFID instead of plain a VF number (Piotr)
> ---
>  drivers/gpu/drm/xe/Makefile       |   1 +
>  drivers/gpu/drm/xe/xe_pci.c       |   4 +
>  drivers/gpu/drm/xe/xe_pci_sriov.c | 138 ++++++++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_pci_sriov.h |  13 +++
>  4 files changed, 156 insertions(+)
>  create mode 100644 drivers/gpu/drm/xe/xe_pci_sriov.c
>  create mode 100644 drivers/gpu/drm/xe/xe_pci_sriov.h
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index a67977edff5b..6acde66f0827 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -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
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index a0cf5dd803c2..f3efde939df4 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -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"
> @@ -952,6 +953,9 @@ 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
> diff --git a/drivers/gpu/drm/xe/xe_pci_sriov.c b/drivers/gpu/drm/xe/xe_pci_sriov.c
> new file mode 100644
> index 000000000000..75248fdd6cee
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_pci_sriov.c
> @@ -0,0 +1,138 @@
> +// 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));
> +
> +	/*
> +	 * hold additional reference to the runtime PM as long as VFs are
> +	 * enabled to keep GuC alive - will be released in pf_disable_vfs()
> +	 */
> +	xe_pm_runtime_get(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;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_pci_sriov.h b/drivers/gpu/drm/xe/xe_pci_sriov.h
> new file mode 100644
> index 000000000000..3b8bfbf7e1d9
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_pci_sriov.h
> @@ -0,0 +1,13 @@
> +/* 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


LGTM:
Reviewed-by: Piotr Piórkowski <piotr.piorkowski at intel.com>

> -- 
> 2.43.0
> 

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