On 10-04-2024 03:45, Rodrigo Vivi wrote:
> So, the wedged mode can be selected per device at runtime,
> before the tests or before reproducing the issue.
>
> v2: - s/busted/wedged
>      - some locking consistency
>
> Cc: Lucas De Marchi<lucas.demarchi@intel.com>
> Cc: Alan Previn<alan.previn.teres.alexis@intel.com>
> Signed-off-by: Rodrigo Vivi<rodrigo.vivi@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_debugfs.c      | 56 ++++++++++++++++++++++++++++
>   drivers/gpu/drm/xe/xe_device.c       | 41 ++++++++++++++------
>   drivers/gpu/drm/xe/xe_device.h       |  4 +-
>   drivers/gpu/drm/xe/xe_device_types.h | 11 +++++-
>   drivers/gpu/drm/xe/xe_gt.c           |  2 +-
>   drivers/gpu/drm/xe/xe_guc.c          |  2 +-
>   drivers/gpu/drm/xe/xe_guc_ads.c      | 52 +++++++++++++++++++++++++-
>   drivers/gpu/drm/xe/xe_guc_ads.h      |  1 +
>   drivers/gpu/drm/xe/xe_guc_submit.c   | 28 +++++++-------
>   9 files changed, 163 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
> index 86150cafe0ff..6ff067ea5a8f 100644
> --- a/drivers/gpu/drm/xe/xe_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_debugfs.c
> @@ -12,6 +12,7 @@
>   #include "xe_bo.h"
>   #include "xe_device.h"
>   #include "xe_gt_debugfs.h"
> +#include "xe_guc_ads.h"
>   #include "xe_pm.h"
>   #include "xe_step.h"
>   
> @@ -106,6 +107,58 @@ static const struct file_operations forcewake_all_fops = {
>   	.release = forcewake_release,
>   };
>   
> +static ssize_t wedged_mode_show(struct file *f, char __user *ubuf,
> +				size_t size, loff_t *pos)
> +{
> +	struct xe_device *xe = file_inode(f)->i_private;
> +	char buf[32];
> +	int len = 0;
> +
> +	mutex_lock(&xe->wedged.lock);
> +	len = scnprintf(buf, sizeof(buf), "%d\n", xe->wedged.mode);
> +	mutex_unlock(&xe->wedged.lock);
> +
> +	return simple_read_from_buffer(ubuf, size, pos, buf, len);
> +}
> +
> +static ssize_t wedged_mode_set(struct file *f, const char __user *ubuf,
> +			       size_t size, loff_t *pos)
> +{
> +	struct xe_device *xe = file_inode(f)->i_private;
> +	struct xe_gt *gt;
> +	u32 wedged_mode;
> +	ssize_t ret;
> +	u8 id;
> +
> +	ret = kstrtouint_from_user(ubuf, size, 0, &wedged_mode);
> +	if (ret)
> +		return ret;
> +
> +	if (wedged_mode > 2)
> +		return -EINVAL;
> +
> +	mutex_lock(&xe->wedged.lock);
> +	xe->wedged.mode = wedged_mode;
> +	if (wedged_mode == 2) {



The transition of |xe->wedged.mode|from 2 to 1 indicates change in 
wedged state , yet the GUC policy still retains engine reset disabled, 
which seems incorrect. How about calling 
|xe_guc_ads_scheduler_policy_disable_reset|for both modes (1 and 2) ? 
For mode 1, this function will reset the GUC policies to default settings.

If we agree on calling above function unconditionally, it might be 
better to rename |xe_guc_ads_scheduler_policy_disable_reset|to a more 
suitable name, as for mode 1, it won't actually disable reset.

> +		for_each_gt(gt, xe, id) {
> +			ret = xe_guc_ads_scheduler_policy_disable_reset(&gt->uc.guc.ads);


Given this debugs, where users have the option to choose whether to 
disable engine reset before submission, is the modparam introduced in 
[PATCH 3/4] really necessary? This also ensures post rebind we have 
default policies.

> +			if (ret) {
> +				drm_err(&xe->drm, "Failed to update GuC ADS scheduler policy. GPU might still reset even on the wedged_mode=2\n");
> +				break;
> +			}
> +		}
> +	}
> +	mutex_unlock(&xe->wedged.lock);
> +
> +	return size;
> +}
> +
> +static const struct file_operations wedged_mode_fops = {
> +	.owner = THIS_MODULE,
> +	.read = wedged_mode_show,
> +	.write = wedged_mode_set,
> +};
> +
>   void xe_debugfs_register(struct xe_device *xe)
>   {
>   	struct ttm_device *bdev = &xe->ttm;
> @@ -123,6 +176,9 @@ void xe_debugfs_register(struct xe_device *xe)
>   	debugfs_create_file("forcewake_all", 0400, root, xe,
>   			    &forcewake_all_fops);
>   
> +	debugfs_create_file("wedged_mode", 0400, root, xe,
> +			    &wedged_mode_fops);
> +
>   	for (mem_type = XE_PL_VRAM0; mem_type <= XE_PL_VRAM1; ++mem_type) {
>   		man = ttm_manager_type(bdev, mem_type);
>   
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 7928a5470cee..949fca2f0400 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -445,6 +445,9 @@ int xe_device_probe_early(struct xe_device *xe)
>   	if (err)
>   		return err;
>   
> +	mutex_init(&xe->wedged.lock);
> +	xe->wedged.mode = xe_modparam.wedged_mode;
> +
>   	return 0;
>   }
>   
> @@ -787,26 +790,37 @@ u64 xe_device_uncanonicalize_addr(struct xe_device *xe, u64 address)
>   }
>   
>   /**
> - * xe_device_declare_wedged - Declare device wedged
> + * xe_device_hint_wedged - Get a hint and possibly declare device as wedged
>    * @xe: xe device instance
> + * @in_timeout_path: hint coming from a timeout path
>    *
> - * This is a final state that can only be cleared with a module
> + * The wedged state is a final on that can only be cleared with a module
>    * re-probe (unbind + bind).
>    * In this state every IOCTL will be blocked so the GT cannot be used.
> - * In general it will be called upon any critical error such as gt reset
> - * failure or guc loading failure.
> - * If xe.wedged module parameter is set to 2, this function will be called
> - * on every single execution timeout (a.k.a. GPU hang) right after devcoredump
> - * snapshot capture. In this mode, GT reset won't be attempted so the state of
> - * the issue is preserved for further debugging.
> + * In general device will be declared wedged only at critical
> + * error paths such as gt reset failure or guc loading failure.
> + * Hints are also expected from every single execution timeout (a.k.a. GPU hang)
> + * right after devcoredump snapshot capture. Then, device can be declared wedged
> + * if wedged_mode is set to 2. In this mode, GT reset won't be attempted so the
> + * state of the issue is preserved for further debugging.
> + *
> + * Return: True if device has been just declared wedged. False otherwise.
>    */
> -void xe_device_declare_wedged(struct xe_device *xe)
> +bool xe_device_hint_wedged(struct xe_device *xe, bool in_timeout_path)
>   {
> -	if (xe_modparam.wedged_mode == 0)
> -		return;
> +	bool ret = false;
> +
> +	mutex_lock(&xe->wedged.lock);
>   
> -	if (!atomic_xchg(&xe->wedged, 1)) {
> +	if (xe->wedged.mode == 0)
> +		goto out;
> +
> +	if (in_timeout_path && xe->wedged.mode != 2)
> +		goto out;
> +
> +	if (!atomic_xchg(&xe->wedged.flag, 1)) {
>   		xe->needs_flr_on_fini = true;
> +		ret = true;
>   		drm_err(&xe->drm,
>   			"CRITICAL: Xe has declared device %s as wedged.\n"
>   			"IOCTLs and executions are blocked until device is probed again with unbind and bind operations:\n"
> @@ -816,4 +830,7 @@ void xe_device_declare_wedged(struct xe_device *xe)
>   			dev_name(xe->drm.dev), dev_name(xe->drm.dev),
>   			dev_name(xe->drm.dev));
>   	}
> +out:
> +	mutex_unlock(&xe->wedged.lock);
> +	return ret;
>   }
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index 0fea5c18f76d..e3ea8a43e7f9 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -178,9 +178,9 @@ u64 xe_device_uncanonicalize_addr(struct xe_device *xe, u64 address);
>   
>   static inline bool xe_device_wedged(struct xe_device *xe)
>   {
> -	return atomic_read(&xe->wedged);
> +	return atomic_read(&xe->wedged.flag);
>   }
>   
> -void xe_device_declare_wedged(struct xe_device *xe);
> +bool xe_device_hint_wedged(struct xe_device *xe, bool in_timeout_path);
>   
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index b9ef60f21750..0da4787f1087 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -458,8 +458,15 @@ struct xe_device {
>   	/** @needs_flr_on_fini: requests function-reset on fini */
>   	bool needs_flr_on_fini;
>   
> -	/** @wedged: Xe device faced a critical error and is now blocked. */
> -	atomic_t wedged;
> +	/** @wedged: Struct to control Wedged States and mode */
> +	struct {
> +		/** @wedged.flag: Xe device faced a critical error and is now blocked. */
> +		atomic_t flag;
> +		/** @wedged.mode: Mode controlled by kernel parameter and debugfs */
> +		int mode;
> +		/** @wedged.lock: To protect @wedged.mode */
> +		struct mutex lock;
> +	} wedged;
>   
>   	/* private: */
>   
> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> index 0844081b88ef..da16f4273877 100644
> --- a/drivers/gpu/drm/xe/xe_gt.c
> +++ b/drivers/gpu/drm/xe/xe_gt.c
> @@ -688,7 +688,7 @@ static int gt_reset(struct xe_gt *gt)
>   err_fail:
>   	xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
>   
> -	xe_device_declare_wedged(gt_to_xe(gt));
> +	xe_device_hint_wedged(gt_to_xe(gt), false);
>   
>   	return err;
>   }
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index f1c3e338301d..ee7e0fa4815d 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -495,7 +495,7 @@ static void guc_wait_ucode(struct xe_guc *guc)
>   			xe_gt_err(gt, "GuC firmware exception. EIP: %#x\n",
>   				  xe_mmio_read32(gt, SOFT_SCRATCH(13)));
>   
> -		xe_device_declare_wedged(gt_to_xe(gt));
> +		xe_device_hint_wedged(gt_to_xe(gt), false);
>   	} else {
>   		xe_gt_dbg(gt, "GuC successfully loaded\n");
>   	}
> diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
> index dbd88ae20aa3..ad64d5a31239 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ads.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
> @@ -9,6 +9,7 @@
>   
>   #include <generated/xe_wa_oob.h>
>   
> +#include "abi/guc_actions_abi.h"
>   #include "regs/xe_engine_regs.h"
>   #include "regs/xe_gt_regs.h"
>   #include "regs/xe_guc_regs.h"
> @@ -16,11 +17,11 @@
>   #include "xe_gt.h"
>   #include "xe_gt_ccs_mode.h"
>   #include "xe_guc.h"
> +#include "xe_guc_ct.h"
>   #include "xe_hw_engine.h"
>   #include "xe_lrc.h"
>   #include "xe_map.h"
>   #include "xe_mmio.h"
> -#include "xe_module.h"
>   #include "xe_platform_types.h"
>   #include "xe_wa.h"
>   
> @@ -395,6 +396,7 @@ int xe_guc_ads_init_post_hwconfig(struct xe_guc_ads *ads)
>   
>   static void guc_policies_init(struct xe_guc_ads *ads)
>   {
> +	struct xe_device *xe = ads_to_xe(ads);
>   	u32 global_flags = 0;
>   
>   	ads_blob_write(ads, policies.dpc_promote_time,
> @@ -402,8 +404,10 @@ static void guc_policies_init(struct xe_guc_ads *ads)
>   	ads_blob_write(ads, policies.max_num_work_items,
>   		       GLOBAL_POLICY_MAX_NUM_WI);
>   
> -	if (xe_modparam.wedged_mode == 2)
> +	mutex_lock(&xe->wedged.lock);
> +	if (xe->wedged.mode == 2)
>   		global_flags |= GLOBAL_POLICY_DISABLE_ENGINE_RESET;
> +	mutex_unlock(&xe->wedged.lock);
>   
>   	ads_blob_write(ads, policies.global_flags, global_flags);
>   	ads_blob_write(ads, policies.is_valid, 1);
> @@ -760,3 +764,47 @@ void xe_guc_ads_populate_post_load(struct xe_guc_ads *ads)
>   {
>   	guc_populate_golden_lrc(ads);
>   }
> +
> +static int guc_ads_action_update_policies(struct xe_guc_ads *ads, u32 policy_offset)
> +{
> +	struct  xe_guc_ct *ct = &ads_to_guc(ads)->ct;
> +	u32 action[] = {
> +		XE_GUC_ACTION_GLOBAL_SCHED_POLICY_CHANGE,
> +		policy_offset
> +	};
> +
> +	return xe_guc_ct_send(ct, action, ARRAY_SIZE(action), 0, 0);
> +}
> +
> +int xe_guc_ads_scheduler_policy_disable_reset(struct xe_guc_ads *ads)
> +{
> +	struct xe_device *xe = ads_to_xe(ads);
> +	struct xe_gt *gt = ads_to_gt(ads);
> +	struct xe_tile *tile = gt_to_tile(gt);
> +	struct guc_policies *policies;
> +	struct xe_bo *bo;
> +	int ret = 0;
> +
> +	policies = kmalloc(sizeof(*policies), GFP_KERNEL);
> +	if (!policies)
> +		return -ENOMEM;
> +
> +	policies->dpc_promote_time = ads_blob_read(ads, policies.dpc_promote_time);
> +	policies->max_num_work_items = ads_blob_read(ads, policies.max_num_work_items);
> +	policies->is_valid = 1;
> +	if (xe->wedged.mode == 2)
> +		policies->global_flags |= GLOBAL_POLICY_DISABLE_ENGINE_RESET;
> +
> +	bo = xe_managed_bo_create_from_data(xe, tile, policies, sizeof(struct guc_policies),
> +					    XE_BO_FLAG_VRAM_IF_DGFX(tile) |
> +					    XE_BO_FLAG_GGTT);
> +	if (IS_ERR(bo)) {
> +		ret = PTR_ERR(bo);
> +		goto out;
> +	}
> +
> +	ret = guc_ads_action_update_policies(ads, xe_bo_ggtt_addr(bo));
> +out:
> +	kfree(policies);
> +	return ret;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_guc_ads.h b/drivers/gpu/drm/xe/xe_guc_ads.h
> index 138ef6267671..7c45c40fab34 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ads.h
> +++ b/drivers/gpu/drm/xe/xe_guc_ads.h
> @@ -13,5 +13,6 @@ int xe_guc_ads_init_post_hwconfig(struct xe_guc_ads *ads);
>   void xe_guc_ads_populate(struct xe_guc_ads *ads);
>   void xe_guc_ads_populate_minimal(struct xe_guc_ads *ads);
>   void xe_guc_ads_populate_post_load(struct xe_guc_ads *ads);
> +int xe_guc_ads_scheduler_policy_disable_reset(struct xe_guc_ads *ads);
>   
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> index 0bea17536659..7de97b90ad00 100644
> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> @@ -35,7 +35,6 @@
>   #include "xe_macros.h"
>   #include "xe_map.h"
>   #include "xe_mocs.h"
> -#include "xe_module.h"
>   #include "xe_ring_ops_types.h"
>   #include "xe_sched_job.h"
>   #include "xe_trace.h"
> @@ -868,26 +867,33 @@ static void xe_guc_exec_queue_trigger_cleanup(struct xe_exec_queue *q)
>   		xe_sched_tdr_queue_imm(&q->guc->sched);
>   }
>   
> -static void guc_submit_wedged(struct xe_guc *guc)
> +static bool guc_submit_hint_wedged(struct xe_guc *guc)
>   {
>   	struct xe_exec_queue *q;
>   	unsigned long index;
>   	int err;
>   
> -	xe_device_declare_wedged(guc_to_xe(guc));
> +	if (xe_device_wedged(guc_to_xe(guc)))
> +		return true;
> +
> +	if (!xe_device_hint_wedged(guc_to_xe(guc), true))
> +		return false;
> +
>   	xe_guc_submit_reset_prepare(guc);
>   	xe_guc_ct_stop(&guc->ct);
>   
>   	err = drmm_add_action_or_reset(&guc_to_xe(guc)->drm,
>   				       guc_submit_wedged_fini, guc);
>   	if (err)
> -		return;
> +		return true; /* Device is wedged anyway */
>   
>   	mutex_lock(&guc->submission_state.lock);
>   	xa_for_each(&guc->submission_state.exec_queue_lookup, index, q)
>   		if (xe_exec_queue_get_unless_zero(q))
>   			set_exec_queue_wedged(q);
>   	mutex_unlock(&guc->submission_state.lock);
> +
> +	return true;
>   }
>   
>   static void xe_guc_exec_queue_lr_cleanup(struct work_struct *w)
> @@ -898,15 +904,12 @@ static void xe_guc_exec_queue_lr_cleanup(struct work_struct *w)
>   	struct xe_guc *guc = exec_queue_to_guc(q);
>   	struct xe_device *xe = guc_to_xe(guc);
>   	struct xe_gpu_scheduler *sched = &ge->sched;
> -	bool wedged = xe_device_wedged(xe);
> +	bool wedged;
>   
>   	xe_assert(xe, xe_exec_queue_is_lr(q));
>   	trace_xe_exec_queue_lr_cleanup(q);
>   
> -	if (!wedged && xe_modparam.wedged_mode == 2) {
> -		guc_submit_wedged(exec_queue_to_guc(q));
> -		wedged = true;
> -	}
> +	wedged = guc_submit_hint_wedged(exec_queue_to_guc(q));
>   
>   	/* Kill the run_job / process_msg entry points */
>   	xe_sched_submission_stop(sched);
> @@ -957,7 +960,7 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>   	struct xe_device *xe = guc_to_xe(exec_queue_to_guc(q));
>   	int err = -ETIME;
>   	int i = 0;
> -	bool wedged = xe_device_wedged(xe);
> +	bool wedged;
>   
>   	/*
>   	 * TDR has fired before free job worker. Common if exec queue
> @@ -981,10 +984,7 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>   
>   	trace_xe_sched_job_timedout(job);
>   
> -	if (!wedged && xe_modparam.wedged_mode == 2) {
> -		guc_submit_wedged(exec_queue_to_guc(q));
> -		wedged = true;
> -	}
> +	wedged = guc_submit_hint_wedged(exec_queue_to_guc(q));
>   
>   	/* Kill the run_job entry point */
>   	xe_sched_submission_stop(sched);