Re: [PATCH v3 4/4] drm/xe/ras: Introduce correctable error handling

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

On Thu, Mar 19, 2026 at 07:30:06PM +0530, Tauro, Riana wrote:
> On 3/12/2026 2:36 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           | 89 +++++++++++++++++++++++++++
> >   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, 179 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 373adb20afb2..9811cf732260 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..37a996a6abf8
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xe/xe_ras.c
> > @@ -0,0 +1,89 @@
> > +// 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",
> > +};
> > +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 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_event_log(struct xe_sysctrl *sc, struct xe_sysctrl_event_response *response)
> > +{
> > +	struct xe_ras_event_threshold_crossed *pending = (void *)&response->data;
> > +	struct xe_ras_error *errors = pending->counters;
> > +	struct xe_device *xe = sc_to_xe(sc);
> > +	u32 cid, sev, comp, inst, cause;
> > +	u8 tile;
> > +
> > +	xe_assert(xe, pending->ncounters < XE_RAS_NUM_COUNTERS);
> > +	xe_warn(xe, "[RAS]: 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, sev), sev_to_str(xe, comp), cause);
> 
> We can have minimal logging here with only severity and component and add
> additional logging
> 
> in following patches.

I plan to remove it entirely once we have cper in place, but until that
happens (and given the fragility of things) it'll good for debugging.

> > +	}
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_ras.h b/drivers/gpu/drm/xe/xe_ras.h
> > new file mode 100644
> > index 000000000000..22f035fa498d
> > --- /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_event_log(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..2982c4696b6d
> > --- /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 - Combines common and product-specific parts
> > + */
> > +struct xe_ras_error {
> 
> error_class ?

I know that how it's in the spec, but it's full of needless verbiage that
doesn't add much to the meaning. I'm fine either way.

Raag

> > +	/** @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 threshold crossed event
> > + */
> > +struct xe_ras_event_threshold_crossed {
> > +	/** @ncounters: Number of error counters that crossed thresholds */
> > +	u32 ncounters;
> > +	/** @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 47afca586bd1..1833ecadd9a1 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_event_log(sc, &response);
> >   		} else {
> >   			xe_err(xe, "sysctrl: unexpected event %#x\n", response.event);
> >   			return;