Re: [PATCH v8 08/15] drm/xe/xe_ras: Add support for uncorrectable core-compute errors

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

On 08-06-2026 02:17 pm, Riana Tauro wrote:
> Add structures and command for get soc error and process uncorrectable
> core-compute errors.
>
> Uncorrectable core-compute errors are classified into global and local
> errors.
>
> Global error is an error that affects the entire device requiring a
> reset. This type of error is not isolated. When an AER is reported and
> error_detected is invoked return PCI_ERS_RESULT_NEED_RESET.
>
> Local error is confined to a specific component or context like a
> engine. These errors can be contained and recovered by resetting
> only the affected part without disrupting the rest of the device.
>
> Upon detection of an uncorrectable local core-compute error, an AER is
> generated and GuC is notified of the error to trigger engine reset.
> Return recovered from PCI error callbacks for these errors as no
> action is needed.
>
> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
> ---
> v2: add newline and fix log
>      add bounds check (Mallesh)
>      add ras specific enum (Raag)
>      helper for sysctrl prepare command
>      process all errors before deciding recovery action
>
> v3: remove TODO from commit message
>      remove redundant rlen check
>      fix loop
>      add check for sysctrl flooding (Raag)
>      do not use xe_ras prefix for static functions (Soham)
>
> v4: remove rlen initialization to 0
>      remove local variable
>      add error message for length mismatch (Raag)
>      reset on sysctrl flooding
>      fix sysctrl flood condition
>
> v5: rebase
>      modify log and move it to process_errors
>      modify sysctrl flood check
>      remove whitespace
>      simplify structure (Raag)
>      fix typo in commit message
>
> v6: remove xe parameter
>      remove error_class local variable (Mallesh)
>      move prepare_sysctrl_command to sysctrl layer (Raag)
>      shorten structure member names
>      rename count to remaining
>      fix sparse warnings
>
> v7: rename sysctrl_build_command (Raag)
> ---
>   drivers/gpu/drm/xe/xe_ras.c                   | 110 ++++++++++++++++++
>   drivers/gpu/drm/xe/xe_ras.h                   |   3 +
>   drivers/gpu/drm/xe/xe_ras_types.h             |  55 +++++++++
>   drivers/gpu/drm/xe/xe_sysctrl_mailbox.c       |  28 +++++
>   drivers/gpu/drm/xe/xe_sysctrl_mailbox.h       |   4 +-
>   drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h |   2 +
>   6 files changed, 201 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_ras.c b/drivers/gpu/drm/xe/xe_ras.c
> index c846e98ec6ab..005db8ab9622 100644
> --- a/drivers/gpu/drm/xe/xe_ras.c
> +++ b/drivers/gpu/drm/xe/xe_ras.c
> @@ -9,6 +9,11 @@
>   #include "xe_ras_types.h"
>   #include "xe_sysctrl.h"
>   #include "xe_sysctrl_event_types.h"
> +#include "xe_sysctrl_mailbox.h"
> +#include "xe_sysctrl_mailbox_types.h"
> +
> +#define CORE_COMPUTE_UNCORR_TYPE	GENMASK(26, 25)
> +#define  GLOBAL_UNCORR_ERROR		2
>   
>   /* Severity of detected errors  */
>   enum xe_ras_severity {
> @@ -66,6 +71,24 @@ static inline const char *comp_to_str(u8 component)
>   	return xe_ras_components[component];
>   }
>   
> +static enum xe_ras_recovery_action handle_core_compute_errors(struct xe_ras_error_array *arr)
> +{
> +	struct xe_ras_compute_error *error_info = (void *)arr->details;
> +	u8 uncorr_type;
> +
nit: Static check needed.
> +	uncorr_type = FIELD_GET(CORE_COMPUTE_UNCORR_TYPE, error_info->log_header);
> +
> +	/* Request a reset if error is global */
> +	if (uncorr_type == GLOBAL_UNCORR_ERROR)
> +		return XE_RAS_RECOVERY_ACTION_RESET;
> +
> +	/*
> +	 * No action needed for other errors.
> +	 * Local errors are recovered using an engine reset by GuC.
> +	 */
> +	return XE_RAS_RECOVERY_ACTION_RECOVERED;
> +}
> +
>   void xe_ras_counter_threshold_crossed(struct xe_device *xe,
>   				      struct xe_sysctrl_event_response *response)
>   {
> @@ -92,6 +115,93 @@ void xe_ras_counter_threshold_crossed(struct xe_device *xe,
>   	}
>   }
>   
> +/**
> + * xe_ras_process_errors() - Process and contain hardware errors
> + * @xe: xe device instance
> + *
> + * Get error details from system controller and return recovery
> + * method. Called only from PCI error handling.
> + *
> + * Returns: recovery action to be taken
> + */
> +enum xe_ras_recovery_action xe_ras_process_errors(struct xe_device *xe)
> +{
> +	struct xe_sysctrl_mailbox_command command = {0};
> +	struct xe_ras_get_soc_error response;
Zero initialization required.
> +	enum xe_ras_recovery_action final_action;
> +	u32 remaining = XE_SYSCTRL_FLOOD_LIMIT;
> +	size_t rlen;
> +	int ret;
> +
> +	if (!xe->info.has_sysctrl)
> +		return XE_RAS_RECOVERY_ACTION_RESET;
> +
> +	/* Default action */
> +	final_action = XE_RAS_RECOVERY_ACTION_RECOVERED;
> +
> +	xe_sysctrl_create_command(&command, XE_SYSCTRL_GROUP_GFSP, XE_SYSCTRL_CMD_GET_SOC_ERROR,
> +				  NULL, 0, &response, sizeof(response));
> +
> +	do {
> +		memset(&response, 0, sizeof(response));
> +
> +		ret = xe_sysctrl_send_command(&xe->sc, &command, &rlen);
> +		if (ret) {
> +			xe_err(xe, "sysctrl: failed to get soc error %d\n", ret);
> +			goto err;
> +		}
> +
> +		if (rlen != sizeof(response)) {
> +			xe_err(xe, "sysctrl: unexpected get soc error response length %zu (expected %zu)\n",
> +			       rlen, sizeof(response));
> +			goto err;
> +		}
> +
> +		/* Report if number of errors exceeds the maximum errors supported */
> +		if (response.num_errors > XE_RAS_NUM_ERROR_ARR)
> +			xe_err(xe, "sysctrl: number of errors received %d out of bound (%d)\n",
> +			       response.num_errors, XE_RAS_NUM_ERROR_ARR);
> +
> +		for (int i = 0; i < response.num_errors && i < XE_RAS_NUM_ERROR_ARR; i++) {
> +			struct xe_ras_error_array *arr = &response.arr[i];
> +			enum xe_ras_recovery_action action;
> +			u8 component, severity;
> +
> +			component = arr->counter.common.component;
> +			severity = arr->counter.common.severity;
> +
> +			xe_err(xe, "[RAS]: %s %s detected\n", comp_to_str(component),
> +			       sev_to_str(severity));
> +
> +			switch (component) {
> +			case XE_RAS_COMP_CORE_COMPUTE:
> +				action = handle_core_compute_errors(arr);
> +				break;
> +			default:
> +				/* For any other component, reset */
> +				action = XE_RAS_RECOVERY_ACTION_RESET;
> +				break;
> +			}
> +
> +			/* Process and log all errors and then trigger highest recovery action */
> +			if (action > final_action)
> +				final_action = action;
> +		}
> +
> +		/* Treat flooding as an system controller error */
> +		if (!--remaining) {
> +			xe_err(xe, "[RAS]: sysctrl: get soc error response flooding\n");
> +			return XE_RAS_RECOVERY_ACTION_RESET;

We can use goto err.

With minor changes

Reviewed-by: Mallesh Koujalagi <mallesh.koujalagi@intel.com>

> +		}
> +
> +	} while (response.additional_errors);
> +
> +	return final_action;
> +
> +err:
> +	return XE_RAS_RECOVERY_ACTION_RESET;
> +}
> +
>   static struct pci_dev *find_usp_dev(struct pci_dev *pdev)
>   {
>   	struct pci_dev *vsp;
> diff --git a/drivers/gpu/drm/xe/xe_ras.h b/drivers/gpu/drm/xe/xe_ras.h
> index 8acfd0ffe48e..8d106c708ff1 100644
> --- a/drivers/gpu/drm/xe/xe_ras.h
> +++ b/drivers/gpu/drm/xe/xe_ras.h
> @@ -6,11 +6,14 @@
>   #ifndef _XE_RAS_H_
>   #define _XE_RAS_H_
>   
> +#include "xe_ras_types.h"
> +
>   struct xe_device;
>   struct xe_sysctrl_event_response;
>   
>   void xe_ras_counter_threshold_crossed(struct xe_device *xe,
>   				      struct xe_sysctrl_event_response *response);
>   void xe_ras_init(struct xe_device *xe);
> +enum xe_ras_recovery_action xe_ras_process_errors(struct xe_device *xe);
>   
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_ras_types.h b/drivers/gpu/drm/xe/xe_ras_types.h
> index 4e63c67f806a..3ffd7baa7a8c 100644
> --- a/drivers/gpu/drm/xe/xe_ras_types.h
> +++ b/drivers/gpu/drm/xe/xe_ras_types.h
> @@ -8,8 +8,27 @@
>   
>   #include <linux/types.h>
>   
> +#define XE_RAS_NUM_ERROR_ARR			3
>   #define XE_RAS_NUM_COUNTERS			16
>   
> +/**
> + * enum xe_ras_recovery_action - RAS recovery actions
> + *
> + * @XE_RAS_RECOVERY_ACTION_RECOVERED: Error recovered
> + * @XE_RAS_RECOVERY_ACTION_RESET: Requires reset
> + * @XE_RAS_RECOVERY_ACTION_DISCONNECT: Requires disconnect
> + * @XE_RAS_RECOVERY_ACTION_MAX: Max action value
> + *
> + * This enum defines the possible recovery actions that can be taken in response
> + * to RAS errors.
> + */
> +enum xe_ras_recovery_action {
> +	XE_RAS_RECOVERY_ACTION_RECOVERED = 0,
> +	XE_RAS_RECOVERY_ACTION_RESET,
> +	XE_RAS_RECOVERY_ACTION_DISCONNECT,
> +	XE_RAS_RECOVERY_ACTION_MAX
> +};
> +
>   /**
>    * struct xe_ras_error_common - Error fields that are common across all products
>    */
> @@ -70,4 +89,40 @@ struct xe_ras_threshold_crossed {
>   	struct xe_ras_error_class counters[XE_RAS_NUM_COUNTERS];
>   } __packed;
>   
> +/**
> + * struct xe_ras_error_array - Details of the error types
> + */
> +struct xe_ras_error_array {
> +	/** @counter_value: Counter value of the returned error */
> +	u32 counter_value;
> +	/** @counter: Error counter */
> +	struct xe_ras_error_class counter;
> +	/** @timestamp: Timestamp */
> +	u64 timestamp;
> +	/** @details: Error details specific to the counter */
> +	u32 details[XE_RAS_NUM_COUNTERS];
> +} __packed;
> +
> +/**
> + * struct xe_ras_get_soc_error - Response from get soc error command
> + */
> +struct xe_ras_get_soc_error {
> +	/** @num_errors: Number of errors reported in this response */
> +	u8 num_errors;
> +	/** @additional_errors: Indicates if the errors are pending */
> +	u8 additional_errors;
> +	/** @arr: Array of up to 3 errors */
> +	struct xe_ras_error_array arr[XE_RAS_NUM_ERROR_ARR];
> +} __packed;
> +
> +/**
> + * struct xe_ras_compute_error - Error details of Core Compute error
> + */
> +struct xe_ras_compute_error {
> +	/** @log_header: Error Source and type */
> +	u32 log_header;
> +	/** @reserved: Reserved */
> +	u32 reserved[15];
> +} __packed;
> +
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_sysctrl_mailbox.c b/drivers/gpu/drm/xe/xe_sysctrl_mailbox.c
> index 3caa9f15875f..f49d8dabcf73 100644
> --- a/drivers/gpu/drm/xe/xe_sysctrl_mailbox.c
> +++ b/drivers/gpu/drm/xe/xe_sysctrl_mailbox.c
> @@ -307,6 +307,34 @@ void xe_sysctrl_mailbox_init(struct xe_sysctrl *sc)
>   	sc->phase_bit = (ctrl_reg & SYSCTRL_FRAME_PHASE) ? 1 : 0;
>   }
>   
> +/**
> + * xe_sysctrl_create_command() - Create System controller command structure
> + * @command: Sysctrl command structure
> + * @group_id: Command group ID
> + * @cmd_id: Command ID
> + * @request: Pointer to request buffer (can be NULL)
> + * @request_len: Size of request buffer
> + * @response: Pointer to response buffer
> + * @response_len: Size of response buffer
> + *
> + * Helper function to create sysctrl command to be sent via xe_sysctrl_send_command()
> + */
> +void xe_sysctrl_create_command(struct xe_sysctrl_mailbox_command *command, u8 group_id, u8 cmd_id,
> +			       void *request, size_t request_len, void *response,
> +			       size_t response_len)
> +{
> +	struct xe_sysctrl_app_msg_hdr header = {0};
> +
> +	header.data = FIELD_PREP(APP_HDR_GROUP_ID_MASK, group_id) |
> +		      FIELD_PREP(APP_HDR_COMMAND_MASK, cmd_id);
> +
> +	command->header = header;
> +	command->data_in = request;
> +	command->data_in_len = request_len;
> +	command->data_out = response;
> +	command->data_out_len = response_len;
> +}
> +
>   /**
>    * xe_sysctrl_send_command() - Send mailbox command to System Controller
>    * @sc: System Controller instance
> diff --git a/drivers/gpu/drm/xe/xe_sysctrl_mailbox.h b/drivers/gpu/drm/xe/xe_sysctrl_mailbox.h
> index f67e9234de48..0ba841b0be1b 100644
> --- a/drivers/gpu/drm/xe/xe_sysctrl_mailbox.h
> +++ b/drivers/gpu/drm/xe/xe_sysctrl_mailbox.h
> @@ -27,5 +27,7 @@ void xe_sysctrl_mailbox_init(struct xe_sysctrl *sc);
>   int xe_sysctrl_send_command(struct xe_sysctrl *sc,
>   			    struct xe_sysctrl_mailbox_command *cmd,
>   			    size_t *rdata_len);
> -
> +void xe_sysctrl_create_command(struct xe_sysctrl_mailbox_command *command, u8 group_id, u8 cmd_id,
> +			       void *request, size_t request_len, void *response,
> +			       size_t response_len);
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> index faa973986c0d..93ff0d481d74 100644
> --- a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> +++ b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> @@ -22,9 +22,11 @@ enum xe_sysctrl_group {
>   /**
>    * enum xe_sysctrl_gfsp_cmd - Commands supported by GFSP group
>    *
> + * @XE_SYSCTRL_CMD_GET_SOC_ERROR: Retrieve basic error information
>    * @XE_SYSCTRL_CMD_GET_PENDING_EVENT: Retrieve pending event
>    */
>   enum xe_sysctrl_gfsp_cmd {
> +	XE_SYSCTRL_CMD_GET_SOC_ERROR		= 0x01,
>   	XE_SYSCTRL_CMD_GET_PENDING_EVENT	= 0x07,
>   };
>