Re: [PATCH v4 3/3] drm/xe/ras: Introduce correctable error handling

[Raag Jadav <raag.jadav@intel.com>]

On Wed, Apr 01, 2026 at 03:01:56PM +0530, Mallesh, Koujalagi wrote:
> On 31-03-2026 03:53 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>
> > ---
> > v4: Fix Severity/Component logging (Mallesh)
> > v4: s/xe_ras_error/xe_ras_error_class (Riana)
> > ---
> >   drivers/gpu/drm/xe/Makefile           |  1 +
> >   drivers/gpu/drm/xe/xe_ras.c           | 90 +++++++++++++++++++++++++++
> >   drivers/gpu/drm/xe/xe_ras.h           | 14 +++++
> >   drivers/gpu/drm/xe/xe_ras_types.h     | 73 ++++++++++++++++++++++
> >   drivers/gpu/drm/xe/xe_sysctrl_event.c |  3 +-
> >   5 files changed, 180 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 593b359bbaca..1ecafb854355 100644
> > --- a/drivers/gpu/drm/xe/Makefile
> > +++ b/drivers/gpu/drm/xe/Makefile
> > @@ -113,6 +113,7 @@ 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..4048350def97
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xe/xe_ras.c
> > @@ -0,0 +1,90 @@
> > +// 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.h"
> > +#include "xe_sysctrl_event_types.h"
> > +
> > +/* Severity of detected errors  */
> > +enum xe_ras_severity {
> > +	XE_RAS_SEV_NOT_SUPPORTED = 0,
> > +	XE_RAS_SEV_CORRECTABLE,
> > +	XE_RAS_SEV_UNCORRECTABLE,
> > +	XE_RAS_SEV_INFORMATIONAL,
> > +	XE_RAS_SEV_MAX
> > +};
> > +
> > +/* Major IP blocks/components where errors can originate */
> > +enum xe_ras_component {
> > +	XE_RAS_COMP_NOT_SUPPORTED = 0,
> > +	XE_RAS_COMP_DEVICE_MEMORY,
> > +	XE_RAS_COMP_CORE_COMPUTE,
> > +	XE_RAS_COMP_RESERVED,
> > +	XE_RAS_COMP_PCIE,
> > +	XE_RAS_COMP_FABRIC,
> > +	XE_RAS_COMP_SOC_INTERNAL,
> > +	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",
> > +};
> Please use a blank line after structure declaration

Most likely it'll be redundant, so unless there are readability concerns
I'd like to keep this way.

> > +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",
> > +};
> Same here
> > +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 sev < XE_RAS_SEV_MAX ? xe_ras_severities[sev] : "Unknown";
> > +}
> > +
> > +static inline const char *comp_to_str(struct xe_device *xe, u32 comp)
> > +{
> > +	xe_assert(xe, comp < XE_RAS_COMP_MAX);
> > +
> > +	return comp < XE_RAS_COMP_MAX ? xe_ras_components[comp] : "Unknown";
> > +}
> > +
> > +void xe_ras_threshold_crossed(struct xe_sysctrl *sc, struct xe_sysctrl_event_response *response)
> > +{
> > +	struct xe_ras_threshold_crossed_data *pending = (void *)&response->data;
> > +	struct xe_ras_error_class *errors = pending->counters;
> > +	struct xe_device *xe = sc_to_xe(sc);
> > +	u32 cid, sev, comp, inst, cause;
> > +	u8 tile;
> > +
> > +	BUILD_BUG_ON(sizeof(response->data) < sizeof(*pending));
> > +	xe_assert(xe, pending->ncounters < XE_RAS_NUM_COUNTERS);
> 
> Boundary check is required, in production line xe_assert as no_op.

We already do, but I can a separate xe_err() if it helps.

Raag

> > +	xe_warn(xe, "[RAS]: counter threshold crossed, %u new errors\n", pending->ncounters);
> > +
> > +	for (cid = 0; cid < pending->ncounters && cid < XE_RAS_NUM_COUNTERS; 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;
> > +
> > +		xe_warn(xe, "[RAS]: Tile:%u Instance:%u Component:%s Error:%s Cause:%#x\n",
> > +			tile, inst, comp_to_str(xe, comp), sev_to_str(xe, sev), cause);
> > +	}
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_ras.h b/drivers/gpu/drm/xe/xe_ras.h
> > new file mode 100644
> > index 000000000000..92ee93d4e877
> > --- /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_sysctrl;
> > +struct xe_sysctrl_event_response;
> > +
> > +void xe_ras_threshold_crossed(struct xe_sysctrl *sc, 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..0e3ba9e81538
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xe/xe_ras_types.h
> > @@ -0,0 +1,73 @@
> > +/* 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			16
> > +
> > +/**
> > + * 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_class - Combines common and product-specific parts
> > + */
> > +struct xe_ras_error_class {
> > +	/** @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_threshold_crossed_data - Data for threshold crossed event
> > + */
> > +struct xe_ras_threshold_crossed_data {
> > +	/** @ncounters: Number of error counters that crossed thresholds */
> > +	u32 ncounters;
> > +	/** @counters: Array of error counters that crossed threshold */
> > +	struct xe_ras_error_class 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 800d100f09c5..139ecd4aafcd 100644
> > --- a/drivers/gpu/drm/xe/xe_sysctrl_event.c
> > +++ b/drivers/gpu/drm/xe/xe_sysctrl_event.c
> > @@ -6,6 +6,7 @@
> >   #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"
> > @@ -38,7 +39,7 @@ static void xe_sysctrl_get_pending_event(struct xe_sysctrl *sc,
> >   		}
> >   		if (response.event == XE_SYSCTRL_EVENT_THRESHOLD_CROSSED) {
> > -			xe_warn(xe, "[RAS]: error counter threshold crossed\n");
> > +			xe_ras_threshold_crossed(sc, &response);
> >   		} else {
> >   			xe_err(xe, "sysctrl: unexpected event %#x\n", response.event);
> >   			return;