[PATCH 2/3] drm/xe: Add proper detection of the SR-IOV PF mode
Rodrigo Vivi
rodrigo.vivi at intel.com
Tue Apr 9 17:47:20 UTC 2024
On Thu, Apr 04, 2024 at 05:44:30PM +0200, Michal Wajdeczko wrote:
> 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: Michal Wajdeczko <michal.wajdeczko at intel.com>
> ---
> drivers/gpu/drm/xe/Makefile | 3 +-
> drivers/gpu/drm/xe/xe_device_types.h | 4 ++
> drivers/gpu/drm/xe/xe_sriov.c | 3 +
> drivers/gpu/drm/xe/xe_sriov_pf.c | 89 ++++++++++++++++++++++++++++
> drivers/gpu/drm/xe/xe_sriov_pf.h | 24 ++++++++
> drivers/gpu/drm/xe/xe_sriov_types.h | 15 +++++
> 6 files changed, 137 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf.c
> create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf.h
>
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index e5b1715f721e..8d79df05b84f 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -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
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index c710cec835a7..8244b177a6a3 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -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;
> diff --git a/drivers/gpu/drm/xe/xe_sriov.c b/drivers/gpu/drm/xe/xe_sriov.c
> index 3e103edf7174..94fa98d8206e 100644
> --- a/drivers/gpu/drm/xe/xe_sriov.c
> +++ b/drivers/gpu/drm/xe/xe_sriov.c
> @@ -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);
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf.c b/drivers/gpu/drm/xe/xe_sriov_pf.c
> new file mode 100644
> index 000000000000..030c2b69ecc4
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf.c
> @@ -0,0 +1,89 @@
> +// 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);
perhaps we should do this check before the min_t?
should we also check what we are getting from the params?
> +
> + 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);
do we really need to always call this or only when newlimit != totalvfs?
> +
> + 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));
> +}
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf.h b/drivers/gpu/drm/xe/xe_sriov_pf.h
> new file mode 100644
> index 000000000000..ebef2e01838a
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf.h
> @@ -0,0 +1,24 @@
> +/* 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;
> +}
missing the vfs_summary function in this block?!
> +#endif
> +
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_sriov_types.h b/drivers/gpu/drm/xe/xe_sriov_types.h
> index 1a138108d139..fa583e8fa0c2 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_types.h
> +++ b/drivers/gpu/drm/xe/xe_sriov_types.h
> @@ -7,6 +7,7 @@
> #define _XE_SRIOV_TYPES_H_
>
> #include <linux/build_bug.h>
> +#include <linux/types.h>
>
> /**
> * VFID - Virtual Function Identifier
> @@ -37,4 +38,18 @@ enum xe_sriov_mode {
> };
> static_assert(XE_SRIOV_MODE_NONE);
>
> +/**
> + * struct xe_device_pf - Xe PF related data
> + *
> + * The data in this structure is valid only if driver is running in the
> + * @XE_SRIOV_MODE_PF mode.
> + */
> +struct xe_device_pf {
> + /** @device_total_vfs: Maximum number of VFs supported by the device. */
> + u16 device_total_vfs;
> +
> + /** @driver_max_vfs: Maximum number of VFs supported by the driver. */
> + u16 driver_max_vfs;
> +};
> +
> #endif
> --
> 2.43.0
>
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