[PATCH 1/2] RFC drm/xe: Add functions and sysfs for boot survivability

Rodrigo Vivi rodrigo.vivi at intel.com
Thu Dec 12 22:57:27 UTC 2024


On Thu, Dec 12, 2024 at 11:19:44AM +0530, Riana Tauro wrote:
> Boot Survivability is a software based workflow for recovering a system
> in a failed boot state. Here system recoverability is concerned with
> recovering the firmware responsible for boot.
> 
> This is implemented by loading the driver with bare minimum (no drm card)
> to allow the firmware to be flashed through mei/gsc and collect telemetry.
> The driver's probe flow is modified such that it enters survivability mode
> when pcode initialization is incomplete and boot status denotes a failure.
> In this mode, drm card is not exposed and PCI sysfs is used to indicate
> survivability mode and provide additional information required for debug
> 
> This patch adds initialization functions and exposes admin
> readable sysfs entries
> 
> The new sysfs will have the below layout
> 
> 	/sys/bus/.../bdf
> 		     ├── survivability_info
>              	     ├── survivability_mode

Let's make only one file and get all the info inside the survivability_mode
one.

> 
> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
> ---
>  drivers/gpu/drm/xe/Makefile                   |   1 +
>  drivers/gpu/drm/xe/xe_device_types.h          |   4 +
>  drivers/gpu/drm/xe/xe_pcode_api.h             |  14 ++
>  drivers/gpu/drm/xe/xe_survivability_mode.c    | 225 ++++++++++++++++++
>  drivers/gpu/drm/xe/xe_survivability_mode.h    |  17 ++
>  .../gpu/drm/xe/xe_survivability_mode_types.h  |  35 +++
>  6 files changed, 296 insertions(+)
>  create mode 100644 drivers/gpu/drm/xe/xe_survivability_mode.c
>  create mode 100644 drivers/gpu/drm/xe/xe_survivability_mode.h
>  create mode 100644 drivers/gpu/drm/xe/xe_survivability_mode_types.h
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index 7730e0596299..dc60512a5c47 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -95,6 +95,7 @@ xe-y += xe_bb.o \
>  	xe_sa.o \
>  	xe_sched_job.o \
>  	xe_step.o \
> +	xe_survivability_mode.o \
>  	xe_sync.o \
>  	xe_tile.o \
>  	xe_tile_sysfs.o \
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 1373a222f5a5..79bd0bd94e9c 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -21,6 +21,7 @@
>  #include "xe_pt_types.h"
>  #include "xe_sriov_types.h"
>  #include "xe_step_types.h"
> +#include "xe_survivability_mode_types.h"
>  
>  #if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
>  #define TEST_VM_OPS_ERROR
> @@ -341,6 +342,9 @@ struct xe_device {
>  		u8 skip_pcode:1;
>  	} info;
>  
> +	/** @survivability: survivability information for device */
> +	struct xe_survivability survivability;
> +
>  	/** @irq: device interrupt state */
>  	struct {
>  		/** @irq.lock: lock for processing irq's on this device */
> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
> index f153ce96f69a..4e373b8199ca 100644
> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
> @@ -49,6 +49,20 @@
>  /* Domain IDs (param2) */
>  #define     PCODE_MBOX_DOMAIN_HBM		0x2
>  
> +#define PCODE_SCRATCH_ADDR(x)		XE_REG(0x138320 + ((x) * 4))
> +/* PCODE_SCRATCH0 */
> +#define   AUXINFO_REG_OFFSET		REG_GENMASK(17, 15)
> +#define   OVERFLOW_REG_OFFSET		REG_GENMASK(14, 12)
> +#define   HISTORY_TRACKING		REG_BIT(11)
> +#define   OVERFLOW_SUPPORT		REG_BIT(10)
> +#define   AUXINFO_SUPPORT		REG_BIT(9)
> +#define   BOOT_STATUS			REG_GENMASK(3, 1)
> +#define      CRITICAL_FAILURE		4
> +#define      NON_CRITICAL_FAILURE	7
> +
> +/* Auxillary info bits */
> +#define   AUXINFO_HISTORY_OFFSET	REG_GENMASK(31, 29)
> +
>  struct pcode_err_decode {
>  	int errno;
>  	const char *str;
> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.c b/drivers/gpu/drm/xe/xe_survivability_mode.c
> new file mode 100644
> index 000000000000..7e36989efd68
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.c
> @@ -0,0 +1,225 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2024 Intel Corporation
> + */
> +
> +#include <drm/drm_managed.h>

this include moves together the linux group below,
on top of it...

> +
> +#include "xe_survivability_mode_types.h"
> +#include "xe_survivability_mode.h"
> +
> +#include <linux/kobject.h>
> +#include <linux/pci.h>
> +#include <linux/sysfs.h>
> +
> +#include "xe_device.h"
> +#include "xe_gt.h"
> +#include "xe_mmio.h"
> +#include "xe_pcode_api.h"
> +
> +#define MAX_SCRATCH_MMIO 8
> +
> +/**
> + * DOC: Xe Boot Survivability
> + *
> + * Boot Survivability is a software based workflow for recovering a system in a failed boot state
> + * Here system recoverability is concerned with recovering the firmware responsible for boot.
> + *
> + * This is implemented by loading the driver with bare minimum (no drm card) to allow the firmware
> + * to be flashed through mei and collect telemetry. The driver's probe flow is modified
> + * such that it enters survivability mode when pcode initialization is incomplete and boot status
> + * denotes a failure. In this mode, drm card is not exposed and PCI sysfs is used to indicate the
> + * survivability mode and provide additional information required for debug
> + *
> + * Xe KMD exposes below admin-only readable sysfs in survivability mode
> + *
> + * device/survivability_mode: Indicates driver is in survivability mode

We need to make in a way that the presence of the file itself is the indication
of the survivability_mode.  No file, no survivability_mode. No survivability_mode, no file.

Which I believe your code is already doing this below...

> + * device/survivability_info: Provides additional information on why the driver entered
> + *			      survivability mode.
> + *
> + *			      Capability Information - Provides boot status
> + *			      Postcode Information   - Provides information about the failure
> + *			      Overflow Information   - Provides history of previous failures
> + *			      Auxillary Information  - Certain failures may have information in
> + *						       addition to postcode information

then this move into the single file...

> + *
> + * TODO: Notify mei about survivability mode
> + */
> +
> +static void set_survivability_info(struct xe_device *xe, struct xe_survivability_info *info,
> +				   int id, char *name)
> +{
> +	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
> +
> +	strscpy(info[id].name, name, sizeof(info[id].name));
> +	info[id].reg = PCODE_SCRATCH_ADDR(id).raw;
> +	info[id].value = xe_mmio_read32(mmio, PCODE_SCRATCH_ADDR(id));
> +
> +	drm_info(&xe->drm, "%s: 0x%x - 0x%x\n", info[id].name,
> +		 info[id].reg, info[id].value);
> +}
> +
> +static int fill_survivability_info(struct xe_device *xe)
> +{
> +	struct xe_survivability *survivability = &xe->survivability;
> +	struct xe_survivability_info *info = survivability->info;
> +	u32 capability_info;
> +	int id = 0;
> +
> +	drm_info(&xe->drm, "Survivability Mode Information\n");

no need for the drm_info here

> +	set_survivability_info(xe, info, id, "Capability Info");
> +	capability_info = info[id].value;
> +
> +	if (capability_info & HISTORY_TRACKING) {
> +		id++;
> +		set_survivability_info(xe, info, id, "Postcode Info");
> +
> +		if (capability_info & OVERFLOW_SUPPORT) {
> +			id = REG_FIELD_GET(OVERFLOW_REG_OFFSET, capability_info);
> +			/* ID should be within MAX_SCRATCH_MMIO */
> +			if (id >= MAX_SCRATCH_MMIO)
> +				return -EINVAL;
> +			set_survivability_info(xe, info, id, "Overflow Info");
> +		}
> +	}
> +
> +	if (capability_info & AUXINFO_SUPPORT) {
> +		u32 aux_info;
> +		int index = 0;
> +		char name[NAME_MAX];
> +
> +		id = REG_FIELD_GET(AUXINFO_REG_OFFSET, capability_info);
> +		if (id >= MAX_SCRATCH_MMIO)
> +			return -EINVAL;
> +
> +		snprintf(name, NAME_MAX, "Auxiliary Info %d", index);
> +		set_survivability_info(xe, info, id, name);
> +		aux_info = info[id].value;
> +
> +		while ((id = REG_FIELD_GET(AUXINFO_HISTORY_OFFSET, aux_info)) &&
> +		       (id < MAX_SCRATCH_MMIO)) {
> +			index++;
> +			snprintf(name, NAME_MAX, "Prev Auxiliary Info %d", index);
> +			set_survivability_info(xe, info, id, name);
> +			aux_info = info[id].value;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static ssize_t survivability_info_show(struct device *dev,
> +				       struct device_attribute *attr, char *buff)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct xe_device *xe = pdev_to_xe_device(pdev);
> +	struct xe_survivability *survivability = &xe->survivability;
> +	struct xe_survivability_info *info = survivability->info;
> +	int index = 0, count = 0;
> +
> +	for (index = 0; index < MAX_SCRATCH_MMIO; index++) {
> +		if (info[index].reg)
> +			count += sysfs_emit_at(buff, count, "%s: 0x%x - 0x%x\n", info[index].name,
> +					       info[index].reg, info[index].value);
> +	}
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR_ADMIN_RO(survivability_info);
> +
> +static ssize_t survivability_mode_show(struct device *dev,
> +				       struct device_attribute *attr, char *buff)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct xe_device *xe = pdev_to_xe_device(pdev);
> +	struct xe_survivability *survivability = &xe->survivability;
> +
> +	return sysfs_emit(buff, "%d\n", survivability->mode);
> +}
> +
> +static DEVICE_ATTR_ADMIN_RO(survivability_mode);
> +
> +static const struct attribute *survivability_attrs[] = {
> +	&dev_attr_survivability_mode.attr,
> +	&dev_attr_survivability_info.attr,
> +	NULL,
> +};
> +
> +/**
> + * xe_survivability_mode_required- checks if survivability mode is required
> + * @xe: xe device instance
> + *
> + * This function reads the boot status of the capability register and
> + * checks if it is required to enter boot survivability mode.
> + *
> + * Return: true if survivability mode required, false otherwise
> + */
> +bool xe_survivability_mode_required(struct xe_device *xe)
> +{
> +	struct xe_survivability *survivability = &xe->survivability;
> +	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
> +	u32 data;
> +
> +	data = xe_mmio_read32(mmio, PCODE_SCRATCH_ADDR(0));
> +	survivability->boot_status = REG_FIELD_GET(BOOT_STATUS, data);
> +
> +	return (survivability->boot_status == NON_CRITICAL_FAILURE ||
> +		survivability->boot_status == CRITICAL_FAILURE);
> +}
> +
> +/**
> + * xe_survivability_mode_remove - remove survivability mode
> + * @xe: xe device instance
> + *
> + * clean up sysfs entries of survivability mode
> + */
> +void xe_survivability_mode_remove(struct xe_device *xe)
> +{
> +	sysfs_remove_files(&xe->drm.dev->kobj, survivability_attrs);
> +}
> +
> +/**
> + * xe_survivability_mode_init - Initialize the survivability mode
> + * @xe: xe device instance
> + *
> + * Initializes the sysfs and required actions to enter survivability mode
> + */
> +void xe_survivability_mode_init(struct xe_device *xe)
> +{
> +	struct xe_survivability *survivability = &xe->survivability;
> +	struct xe_survivability_info *info;
> +	struct device *dev = xe->drm.dev;
> +	int ret = 0;
> +
> +	survivability->size = MAX_SCRATCH_MMIO;
> +
> +	info = drmm_kcalloc(&xe->drm, survivability->size, sizeof(*info), GFP_KERNEL);
> +	if (!info) {
> +		drm_warn(&xe->drm, "%s failed, err: %d\n", __func__, -ENOMEM);
> +		return;
> +	}
> +
> +	survivability->info = info;
> +
> +	ret = fill_survivability_info(xe);
> +	if (ret)
> +		drm_warn(&xe->drm, "%s failed, err: %d\n", __func__, ret);
> +
> +	/* Only log debug information and exit if it is a critical failure */
> +	if (survivability->boot_status == CRITICAL_FAILURE)
> +		return;
> +
> +	/* set survivability mode */
> +	survivability->mode = true;
> +
> +	drm_info(&xe->drm, "In Survivability Mode\n");

this one is good!

> +
> +	ret = sysfs_create_files(&dev->kobj, survivability_attrs);
> +	if (ret) {
> +		drm_warn(&xe->drm, "Failed to create survivability sysfs files\n");
> +		return;
> +	}
> +
> +	/* TODO: Pass Survivability Mode notification to required child drivers */
> +}
> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.h b/drivers/gpu/drm/xe/xe_survivability_mode.h
> new file mode 100644
> index 000000000000..0d5c325322a2
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2024 Intel Corporation
> + */
> +
> +#ifndef _XE_SURVIVABILITY_MODE_H_
> +#define _XE_SURVIVABILITY_MODE_H_
> +
> +#include <linux/types.h>
> +
> +struct xe_device;
> +
> +void xe_survivability_mode_init(struct xe_device *xe);
> +void xe_survivability_mode_remove(struct xe_device *xe);
> +bool xe_survivability_mode_required(struct xe_device *xe);
> +
> +#endif /* _XE_SURVIVABILITY_MODE_H_ */
> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode_types.h b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> new file mode 100644
> index 000000000000..f9dbb6d80692
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> @@ -0,0 +1,35 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2024 Intel Corporation
> + */
> +
> +#ifndef _XE_SURVIVABILITY_MODE_TYPES_H_
> +#define _XE_SURVIVABILITY_MODE_TYPES_H_
> +
> +#include <linux/limits.h>
> +#include <linux/types.h>
> +
> +struct xe_survivability_info {
> +	char name[NAME_MAX];
> +	u32 reg;
> +	u32 value;
> +};
> +
> +/**
> + * struct xe_survivability: Contains survivability mode information
> + */
> +struct xe_survivability {
> +	/** @info: struct that holds survivability info from scratch registers */
> +	struct xe_survivability_info *info;
> +
> +	/** @size: number of scratch registers */
> +	u32 size;
> +
> +	/** @boot_status: indicates critical/non critical boot failure */
> +	u8 boot_status;
> +
> +	/** mode: boolean to indicate survivability mode */
> +	bool mode;
> +};
> +
> +#endif /* _XE_SURVIVABILITY_MODE_TYPES_H_ */
> -- 
> 2.47.1
> 


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