Re: [PATCH v2 4/4] drm/xe/ras: Introduce correctable error handling

["Mallesh, Koujalagi" <mallesh.koujalagi@intel.com>]

On 13-02-2026 01:46 pm, Raag Jadav wrote:
> Add initial support for correctable error handling which is serviced
> using system controller event. Currently we only log the errors in
> dmesg but this serves as a foundation for RAS infrastructure and will
> be further extended to facilitate other RAS features.
>
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> ---
>   drivers/gpu/drm/xe/Makefile           |  1 +
>   drivers/gpu/drm/xe/xe_ras.c           | 87 +++++++++++++++++++++++++++
>   drivers/gpu/drm/xe/xe_ras.h           | 14 +++++
>   drivers/gpu/drm/xe/xe_ras_types.h     | 79 ++++++++++++++++++++++++
>   drivers/gpu/drm/xe/xe_sysctrl_event.c |  3 +-
>   5 files changed, 183 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/gpu/drm/xe/xe_ras.c
>   create mode 100644 drivers/gpu/drm/xe/xe_ras.h
>   create mode 100644 drivers/gpu/drm/xe/xe_ras_types.h
>
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index 59e083f90d7e..7fc67c320086 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -111,6 +111,7 @@ xe-y += xe_bb.o \
>   	xe_pxp_submit.o \
>   	xe_query.o \
>   	xe_range_fence.o \
> +	xe_ras.o \
>   	xe_reg_sr.o \
>   	xe_reg_whitelist.o \
>   	xe_ring_ops.o \
> diff --git a/drivers/gpu/drm/xe/xe_ras.c b/drivers/gpu/drm/xe/xe_ras.c
> new file mode 100644
> index 000000000000..413c6e62cd50
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_ras.c
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2026 Intel Corporation
> + */
> +
> +#include "xe_assert.h"
> +#include "xe_printk.h"
> +#include "xe_ras.h"
> +#include "xe_ras_types.h"
> +#include "xe_sysctrl_event_types.h"
> +
> +/* Severity of detected errors  */
> +enum xe_ras_severity {
> +	XE_RAS_SEV_NOT_SUPPORTED		= 0x00,
> +	XE_RAS_SEV_CORRECTABLE			= 0x01,
> +	XE_RAS_SEV_UNCORRECTABLE		= 0x02,
> +	XE_RAS_SEV_INFORMATIONAL		= 0x03,
> +	XE_RAS_SEV_MAX
> +};
> +
> +/* Major IP blocks/components where errors can originate */
> +enum xe_ras_component {
> +	XE_RAS_COMP_NOT_SUPPORTED		= 0x00,
> +	XE_RAS_COMP_DEVICE_MEMORY		= 0x01,
> +	XE_RAS_COMP_CORE_COMPUTE		= 0x02,
> +	XE_RAS_COMP_RESERVED			= 0x03,
> +	XE_RAS_COMP_PCIE			= 0x04,
> +	XE_RAS_COMP_FABRIC			= 0x05,
> +	XE_RAS_COMP_SOC_INTERNAL		= 0x06,
> +	XE_RAS_COMP_MAX
> +};
> +
> +static const char *const xe_ras_severities[] = {
> +	[XE_RAS_SEV_NOT_SUPPORTED]		= "Not Supported",
> +	[XE_RAS_SEV_CORRECTABLE]		= "Correctable",
> +	[XE_RAS_SEV_UNCORRECTABLE]		= "Uncorrectable",
> +	[XE_RAS_SEV_INFORMATIONAL]		= "Informational",
> +};
> +static_assert(ARRAY_SIZE(xe_ras_severities) == XE_RAS_SEV_MAX);
> +
> +static const char *const xe_ras_components[] = {
> +	[XE_RAS_COMP_NOT_SUPPORTED]		= "Not Supported",
> +	[XE_RAS_COMP_DEVICE_MEMORY]		= "Device Memory",
> +	[XE_RAS_COMP_CORE_COMPUTE]		= "Core Compute",
> +	[XE_RAS_COMP_RESERVED]			= "Reserved",
> +	[XE_RAS_COMP_PCIE]			= "PCIe",
> +	[XE_RAS_COMP_FABRIC]			= "Fabric",
> +	[XE_RAS_COMP_SOC_INTERNAL]		= "SoC Internal",
> +};
> +static_assert(ARRAY_SIZE(xe_ras_components) == XE_RAS_COMP_MAX);
> +
> +static inline const char *sev_to_str(struct xe_device *xe, u32 sev)
> +{
> +	xe_assert(xe, sev < XE_RAS_SEV_MAX);
> +
> +	return xe_ras_severities[sev];
> +}
> +
> +static inline const char *comp_to_str(struct xe_device *xe, u32 comp)
> +{
> +	xe_assert(xe, comp < XE_RAS_COMP_MAX);
> +
> +	return xe_ras_components[comp];
> +}
> +
> +void xe_ras_event_log(struct xe_device *xe, struct xe_sysctrl_event_response *response)
> +{
> +	struct xe_ras_event_threshold_crossed *pending = (void *)&response->data;
> +	struct xe_ras_error *errors = pending->counters;
> +	u32 cid, sev, comp, inst, cause;
> +	u8 tile;
> +
> +	xe_warn(xe, "[RAS]: error counter threshold crossed\n");
> +	xe_assert(xe, pending->ncounters < XE_RAS_NUM_COUNTERS);
> +
> +	for (cid = 0; cid < pending->ncounters; cid++) {
> +		sev = errors[cid].common.severity;
> +		comp = errors[cid].common.component;
> +
> +		tile = errors[cid].product.unit.tile;
> +		inst = errors[cid].product.unit.instance;
> +		cause = errors[cid].product.cause.cause;
> +
Unaligned access of member cause penalty, we need to check.
> +		xe_warn(xe, "[RAS]: Error:%s Tile:%u Component:%s Instance:%u Cause:%#x\n",
> +			sev_to_str(xe, sev), tile, comp_to_str(xe, comp), inst, cause);

Spam kernel Log, we can use rate limit right?

Thanks

-/Mallesh

> +	}
> +}
> diff --git a/drivers/gpu/drm/xe/xe_ras.h b/drivers/gpu/drm/xe/xe_ras.h
> new file mode 100644
> index 000000000000..fdefe0e2fe98
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_ras.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2026 Intel Corporation
> + */
> +
> +#ifndef _XE_RAS_H_
> +#define _XE_RAS_H_
> +
> +struct xe_device;
> +struct xe_sysctrl_event_response;
> +
> +void xe_ras_event_log(struct xe_device *xe, struct xe_sysctrl_event_response *response);
> +
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_ras_types.h b/drivers/gpu/drm/xe/xe_ras_types.h
> new file mode 100644
> index 000000000000..0afcf8bf982d
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_ras_types.h
> @@ -0,0 +1,79 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2026 Intel Corporation
> + */
> +
> +#ifndef _XE_RAS_TYPES_H_
> +#define _XE_RAS_TYPES_H_
> +
> +#include <linux/types.h>
> +
> +#define XE_RAS_NUM_COUNTERS			21
> +
> +/**
> + * struct xe_ras_error_common - Error fields that are common across all products
> + */
> +struct xe_ras_error_common {
> +	/** @severity: Error severity */
> +	u8 severity;
> +	/** @component: IP block where error originated */
> +	u8 component;
> +} __packed;
> +
> +/**
> + * struct xe_ras_error_unit - Error unit information
> + */
> +struct xe_ras_error_unit {
> +	/** @tile: Tile identifier */
> +	u8 tile;
> +	/** @instance: Instance identifier specific to IP */
> +	u32 instance;
> +} __packed;
> +
> +/**
> + * struct xe_ras_error_cause - Error cause information
> + */
> +struct xe_ras_error_cause {
> +	/** @cause: Cause/checker */
> +	u32 cause;
> +	/** @reserved: For future use */
> +	u8 reserved;
> +} __packed;
> +
> +/**
> + * struct xe_ras_error_product - Error fields that are specific to the product
> + */
> +struct xe_ras_error_product {
> +	/** @unit: Unit within IP block */
> +	struct xe_ras_error_unit unit;
> +	/** @cause: Cause/checker */
> +	struct xe_ras_error_cause cause;
> +} __packed;
> +
> +/**
> + * struct xe_ras_error - Combines common and product-specific parts
> + */
> +struct xe_ras_error {
> +	/** @common: Common error type and component */
> +	struct xe_ras_error_common common;
> +	/** @product: Product-specific unit and cause */
> +	struct xe_ras_error_product product;
> +} __packed;
> +
> +/**
> + * struct xe_ras_event_threshold_crossed - Event data for counter threshold crossed event
> + */
> +struct xe_ras_event_threshold_crossed {
> +	/** @ncounters: Number of counters that crossed thresholds */
> +	u32 ncounters;
> +	/** @ts_high: Higher 32 bits of event timestamp */
> +	u32 ts_high;
> +	/** @ts_low: Lower 32 bits of event timestamp */
> +	u32 ts_low;
> +	/** @reason: Threshold cross reason */
> +	u32 reason;
> +	/** @counters: Array of error counters that crossed threshold */
> +	struct xe_ras_error counters[XE_RAS_NUM_COUNTERS];
> +} __packed;
> +
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_sysctrl_event.c b/drivers/gpu/drm/xe/xe_sysctrl_event.c
> index 7c3041f4196a..876754f9fe35 100644
> --- a/drivers/gpu/drm/xe/xe_sysctrl_event.c
> +++ b/drivers/gpu/drm/xe/xe_sysctrl_event.c
> @@ -7,6 +7,7 @@
>   #include "xe_device.h"
>   #include "xe_irq.h"
>   #include "xe_printk.h"
> +#include "xe_ras.h"
>   #include "xe_sysctrl.h"
>   #include "xe_sysctrl_event_types.h"
>   #include "xe_sysctrl_mailbox.h"
> @@ -37,7 +38,7 @@ static void xe_sysctrl_get_pending_event(struct xe_device *xe,
>   		}
>   
>   		if (response.event == XE_SYSCTRL_EVENT_THRESHOLD_CROSSED) {
> -			xe_warn(xe, "[RAS]: error counter threshold crossed\n");
> +			xe_ras_event_log(xe, &response);
>   		} else {
>   			xe_err(xe, "sysctrl: unexpected event %#x\n", response.event);
>   			return;