[PATCH v3 4/4] drm/xe/FLR: Support PCIe FLR
Nilawar, Badal
badal.nilawar at intel.com
Wed Apr 24 11:12:42 UTC 2024
On 24-04-2024 08:42, Aravind Iddamsetty wrote:
>
> On 23/04/24 20:34, Nilawar, Badal wrote:
>>
>>
>> On 22-04-2024 12:27, 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
>>>
>>> v3: declare xe_pci_err_handlers as static(Michal)
>>>
>>> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
>>> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>>> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
>>>
>>> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
>>> Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty at linux.intel.com>
>>> ---
>>> 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 | 88 ++++++++++++++++++++++++++++
>>> drivers/gpu/drm/xe/xe_pci_err.h | 13 ++++
>>> 7 files changed, 119 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 8bc62bfbc679..693971a1fac0 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 509649d0e65e..efba0fbe2f5c 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 a62300990e19..b5a582afc9e7 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"
>>> @@ -738,7 +739,7 @@ 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;
>>> @@ -986,6 +987,11 @@ static const struct dev_pm_ops xe_pm_ops = {
>>> };
>>> #endif
>>> +static const struct pci_error_handlers xe_pci_err_handlers = {
>>> + .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,
>>> @@ -995,6 +1001,7 @@ 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..5306925ea2fa
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/xe/xe_pci_err.c
>>> @@ -0,0 +1,88 @@
>>> +// 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");
>>> + 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);
>>> + xe_gt_idle(gt);
>>> + err = xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL);
>>> + XE_WARN_ON(err);
>>> + }
>>> + xe_pm_runtime_put(xe);
>> Is xe_save_pci_state() needed here?
>
> No, as the state has already been saved post driver probe.
Thanks for clarification. One more doubt I have is in FLR flow what will
happen to buffer objects especially mmaped BOs. Will all the BOs get
destroyed? I couldn't figure out it in the code.
Badal
>
> Regards,
> Aravind.
>>
>> Regards,
>> Badal Nilawar> +
>>> +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
More information about the Intel-xe
mailing list