On 17.04.2024 10:41, Aravind Iddamsetty wrote:
> PCI subsystem provides callbacks to inform the driver about a request to
> do function level reset by user, initiated by writing to sysfs entry
> /sys/bus/pci/devices/.../reset. This will allow the driver to handle FLR
> without the need to do unbind and rebind as the driver needs to
> reinitialize the device afresh post FLR.
>
> v2:
> 1. separate out gt idle and pci save/restore to a separate patch (Lucas)
> 2. Fixed the warnings seen around xe_guc_submit_stop, xe_guc_puc_fini
>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/xe/Makefile | 1 +
> drivers/gpu/drm/xe/xe_device_types.h | 3 +
> drivers/gpu/drm/xe/xe_guc_pc.c | 4 ++
> drivers/gpu/drm/xe/xe_pci.c | 9 ++-
> drivers/gpu/drm/xe/xe_pci.h | 2 +
> drivers/gpu/drm/xe/xe_pci_err.c | 93 ++++++++++++++++++++++++++++
> drivers/gpu/drm/xe/xe_pci_err.h | 13 ++++
> 7 files changed, 124 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpu/drm/xe/xe_pci_err.c
> create mode 100644 drivers/gpu/drm/xe/xe_pci_err.h
>
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index 522bffa5c4e1..9686ea181ad1 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -117,6 +117,7 @@ xe-y += xe_bb.o \
> xe_module.o \
> xe_pat.o \
> xe_pci.o \
> + xe_pci_err.o \
> xe_pcode.o \
> xe_pm.o \
> xe_preempt_fence.o \
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 0a66555229e9..8c749b378a92 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -465,6 +465,9 @@ struct xe_device {
> /** @pci_state: PCI state of device */
> struct pci_saved_state *pci_state;
>
> + /** @pci_device_is_reset: device went through PCIe FLR */
> + bool pci_device_is_reset;
> +
> /* private: */
>
> #if IS_ENABLED(CONFIG_DRM_XE_DISPLAY)
> diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
> index 521ae24f2314..6108a4dfa05f 100644
> --- a/drivers/gpu/drm/xe/xe_guc_pc.c
> +++ b/drivers/gpu/drm/xe/xe_guc_pc.c
> @@ -902,6 +902,10 @@ static void xe_guc_pc_fini(struct drm_device *drm, void *arg)
> return;
> }
>
> + /* We already have done this before going through a reset, so skip here */
> + if (xe->pci_device_is_reset)
> + return;
> +
> XE_WARN_ON(xe_force_wake_get(gt_to_fw(pc_to_gt(pc)), XE_FORCEWAKE_ALL));
> XE_WARN_ON(xe_guc_pc_gucrc_disable(pc));
> XE_WARN_ON(xe_guc_pc_stop(pc));
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index f9957cd16356..d986ae7fc7f7 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_err.h"
> #include "xe_pci_types.h"
> #include "xe_pm.h"
> #include "xe_sriov.h"
> @@ -736,7 +737,7 @@ static void xe_pci_remove(struct pci_dev *pdev)
> pci_set_drvdata(pdev, NULL);
> }
>
> -static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> +int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> {
> const struct xe_device_desc *desc = (const void *)ent->driver_data;
> const struct xe_subplatform_desc *subplatform_desc;
> @@ -976,6 +977,11 @@ static const struct dev_pm_ops xe_pm_ops = {
> };
> #endif
>
> +const struct pci_error_handlers xe_pci_err_handlers = {
static ?
> + .reset_prepare = xe_pci_reset_prepare,
> + .reset_done = xe_pci_reset_done,
> +};
> +
> static struct pci_driver xe_pci_driver = {
> .name = DRIVER_NAME,
> .id_table = pciidlist,
> @@ -985,6 +991,7 @@ static struct pci_driver xe_pci_driver = {
> #ifdef CONFIG_PM_SLEEP
> .driver.pm = &xe_pm_ops,
> #endif
> + .err_handler = &xe_pci_err_handlers,
> };
>
> int xe_register_pci_driver(void)
> diff --git a/drivers/gpu/drm/xe/xe_pci.h b/drivers/gpu/drm/xe/xe_pci.h
> index 73b90a430d1f..9faf5380a09e 100644
> --- a/drivers/gpu/drm/xe/xe_pci.h
> +++ b/drivers/gpu/drm/xe/xe_pci.h
> @@ -7,8 +7,10 @@
> #define _XE_PCI_H_
>
> struct pci_dev;
> +struct pci_device_id;
>
> int xe_register_pci_driver(void);
> void xe_unregister_pci_driver(void);
> void xe_load_pci_state(struct pci_dev *pdev);
> +int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
> #endif
> diff --git a/drivers/gpu/drm/xe/xe_pci_err.c b/drivers/gpu/drm/xe/xe_pci_err.c
> new file mode 100644
> index 000000000000..81c440e08fbc
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_pci_err.c
> @@ -0,0 +1,93 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2024 Intel Corporation
> + */
> +
> +#include <linux/pci.h>
> +#include <drm/drm_drv.h>
> +
> +#include "xe_device.h"
> +#include "xe_gt.h"
> +#include "xe_gt_printk.h"
> +#include "xe_pci.h"
> +#include "xe_pci_err.h"
> +#include "xe_pm.h"
> +#include "xe_uc.h"
> +
> +/**
> + * xe_pci_reset_prepare - Called when user issued a PCIe reset
> + * via /sys/bus/pci/devices/.../reset.
> + * @pdev: PCI device struct
> + */
> +void xe_pci_reset_prepare(struct pci_dev *pdev)
> +{
> + struct xe_device *xe = pci_get_drvdata(pdev);
> + struct xe_gt *gt;
> + int id, err;
> +
> + pci_warn(pdev, "preparing for PCIe reset\n");
> +
> + drm_warn(&xe->drm, "removing device access to userspace\n");
do we need two separate warnings here?
[ ] xe 0000:4d:00.0: preparing for PCIe FLR reset
[ ] xe 0000:4d:00.0: [drm] removing device access to userspace
> + drm_dev_unplug(&xe->drm);
> +
> + xe_pm_runtime_get(xe);
> + /* idle the GTs */
> + for_each_gt(gt, xe, id) {
> + err = xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
> + if (err)
> + goto reset;
> + xe_uc_reset_prepare(>->uc);
> + err = xe_gt_idle(gt);
> + if (err) {
> + xe_gt_err(gt, "failed to idle gt (%pe)\n", ERR_PTR(err));
> + goto reset;
> + }
> +
> + err = xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL);
> + XE_WARN_ON(err);
> + }
> + xe_pm_runtime_put(xe);
> +
> +reset:
> + pci_disable_device(pdev);
> +}
> +
> +/**
> + * xe_pci_reset_done - Called when PCIe reset is done.
> + * @pdev: PCI device struct
> + */
> +void xe_pci_reset_done(struct pci_dev *pdev)
> +{
> + const struct pci_device_id *ent = pci_match_id(pdev->driver->id_table, pdev);
> + struct xe_device *xe = pci_get_drvdata(pdev);
> +
> + dev_info(&pdev->dev,
> + "device went through PCIe reset, reenabling the device\n");
> +
> + if (pci_enable_device(pdev)) {
> + dev_err(&pdev->dev,
> + "Cannot re-enable PCI device after reset\n");
> + return;
> + }
> + pci_set_master(pdev);
> + xe_load_pci_state(pdev);
> +
> + xe->pci_device_is_reset = true;
> + /*
> + * We want to completely clean the driver and even destroy
> + * the xe private data and reinitialize afresh similar to
> + * probe
> + */
> + pdev->driver->remove(pdev);
> + if (pci_dev_msi_enabled(pdev))
> + pci_free_irq_vectors(pdev);
> +
> + devm_drm_dev_release_action(&xe->drm);
> + pci_disable_device(pdev);
> +
> + /*
> + * if this fails the driver might be in a stale state, only option is
> + * to unbind and rebind
> + */
> + xe_pci_probe(pdev, ent);
> +}
> diff --git a/drivers/gpu/drm/xe/xe_pci_err.h b/drivers/gpu/drm/xe/xe_pci_err.h
> new file mode 100644
> index 000000000000..95a4c8ce9cf1
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_pci_err.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2024 Intel Corporation
> + */
> +
> +#ifndef _XE_PCI_ERR_H_
> +#define _XE_PCI_ERR_H_
> +
> +struct pci_dev;
> +
> +void xe_pci_reset_prepare(struct pci_dev *pdev);
> +void xe_pci_reset_done(struct pci_dev *pdev);
> +#endif
