Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit efeaed4d authored by Felix Kuehling's avatar Felix Kuehling Committed by Oded Gabbay
Browse files

drm/amdkfd: Reliably prevent reclaim-FS while holding DQM lock 



This is needed to prevent deadlocks when MMU notifiers run in
reclaim-FS context and take the DQM lock for userptr evictions.
Previously this was done by making all memory allocations under
DQM locks GFP_NOIO. This is error prone. Using
memalloc_nofs_save/restore will reliably affect all memory
allocations anywhere in the kernel while the DQM lock is held.

Signed-off-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarOded Gabbay <oded.gabbay@gmail.com>
parent 0337976f

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c

+43 −42
Original line number Diff line number Diff line
@@ -240,7 +240,7 @@ static int create_queue_nocpsch(struct device_queue_manager *dqm, 


	print_queue(q);



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	if (dqm->total_queue_count >= max_num_of_queues_per_device) {

		pr_warn("Can't create new usermode queue because %d queues were already created\n",
@@ -297,7 +297,7 @@ static int create_queue_nocpsch(struct device_queue_manager *dqm, 
			dqm->total_queue_count);



out_unlock:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -457,9 +457,9 @@ static int destroy_queue_nocpsch(struct device_queue_manager *dqm, 
{

	int retval;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	retval = destroy_queue_nocpsch_locked(dqm, qpd, q);

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	return retval;

}
@@ -471,7 +471,7 @@ static int update_queue(struct device_queue_manager *dqm, struct queue *q) 
	struct kfd_process_device *pdd;

	bool prev_active = false;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	pdd = kfd_get_process_device_data(q->device, q->process);

	if (!pdd) {

		retval = -ENODEV;
@@ -537,7 +537,7 @@ static int update_queue(struct device_queue_manager *dqm, struct queue *q) 
				       &q->properties, q->process->mm);



out_unlock:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -570,7 +570,7 @@ static int evict_process_queues_nocpsch(struct device_queue_manager *dqm, 
	struct kfd_process_device *pdd;

	int retval = 0;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	if (qpd->evicted++ > 0) /* already evicted, do nothing */

		goto out;
@@ -600,7 +600,7 @@ static int evict_process_queues_nocpsch(struct device_queue_manager *dqm, 
	}



out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -611,7 +611,7 @@ static int evict_process_queues_cpsch(struct device_queue_manager *dqm, 
	struct kfd_process_device *pdd;

	int retval = 0;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	if (qpd->evicted++ > 0) /* already evicted, do nothing */

		goto out;
@@ -633,7 +633,7 @@ static int evict_process_queues_cpsch(struct device_queue_manager *dqm, 
				KFD_UNMAP_QUEUES_FILTER_DYNAMIC_QUEUES, 0);



out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -650,7 +650,7 @@ static int restore_process_queues_nocpsch(struct device_queue_manager *dqm, 
	/* Retrieve PD base */

	pd_base = dqm->dev->kfd2kgd->get_process_page_dir(pdd->vm);



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	if (WARN_ON_ONCE(!qpd->evicted)) /* already restored, do nothing */

		goto out;

	if (qpd->evicted > 1) { /* ref count still > 0, decrement & quit */
@@ -695,7 +695,7 @@ static int restore_process_queues_nocpsch(struct device_queue_manager *dqm, 
	}

	qpd->evicted = 0;

out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -711,7 +711,7 @@ static int restore_process_queues_cpsch(struct device_queue_manager *dqm, 
	/* Retrieve PD base */

	pd_base = dqm->dev->kfd2kgd->get_process_page_dir(pdd->vm);



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	if (WARN_ON_ONCE(!qpd->evicted)) /* already restored, do nothing */

		goto out;

	if (qpd->evicted > 1) { /* ref count still > 0, decrement & quit */
@@ -739,7 +739,7 @@ static int restore_process_queues_cpsch(struct device_queue_manager *dqm, 
	if (!retval)

		qpd->evicted = 0;

out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -761,7 +761,7 @@ static int register_process(struct device_queue_manager *dqm, 
	/* Retrieve PD base */

	pd_base = dqm->dev->kfd2kgd->get_process_page_dir(pdd->vm);



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	list_add(&n->list, &dqm->queues);



	/* Update PD Base in QPD */
@@ -771,7 +771,7 @@ static int register_process(struct device_queue_manager *dqm, 


	dqm->processes_count++;



	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	return retval;

}
@@ -786,7 +786,7 @@ static int unregister_process(struct device_queue_manager *dqm, 
			list_empty(&qpd->queues_list) ? "empty" : "not empty");



	retval = 0;

	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	list_for_each_entry_safe(cur, next, &dqm->queues, list) {

		if (qpd == cur->qpd) {
@@ -799,7 +799,7 @@ static int unregister_process(struct device_queue_manager *dqm, 
	/* qpd not found in dqm list */

	retval = 1;

out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -838,7 +838,7 @@ static int initialize_nocpsch(struct device_queue_manager *dqm) 
	if (!dqm->allocated_queues)

		return -ENOMEM;



	mutex_init(&dqm->lock);

	mutex_init(&dqm->lock_hidden);

	INIT_LIST_HEAD(&dqm->queues);

	dqm->queue_count = dqm->next_pipe_to_allocate = 0;

	dqm->sdma_queue_count = 0;
@@ -867,7 +867,7 @@ static void uninitialize(struct device_queue_manager *dqm) 
	kfree(dqm->allocated_queues);

	for (i = 0 ; i < KFD_MQD_TYPE_MAX ; i++)

		kfree(dqm->mqds[i]);

	mutex_destroy(&dqm->lock);

	mutex_destroy(&dqm->lock_hidden);

	kfd_gtt_sa_free(dqm->dev, dqm->pipeline_mem);

}
@@ -1003,7 +1003,7 @@ static int initialize_cpsch(struct device_queue_manager *dqm) 
{

	pr_debug("num of pipes: %d\n", get_pipes_per_mec(dqm));



	mutex_init(&dqm->lock);

	mutex_init(&dqm->lock_hidden);

	INIT_LIST_HEAD(&dqm->queues);

	dqm->queue_count = dqm->processes_count = 0;

	dqm->sdma_queue_count = 0;
@@ -1041,9 +1041,9 @@ static int start_cpsch(struct device_queue_manager *dqm) 


	init_interrupts(dqm);



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	execute_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_DYNAMIC_QUEUES, 0);

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	return 0;

fail_allocate_vidmem:
@@ -1055,9 +1055,9 @@ static int start_cpsch(struct device_queue_manager *dqm) 


static int stop_cpsch(struct device_queue_manager *dqm)

{

	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	unmap_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES, 0);

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	kfd_gtt_sa_free(dqm->dev, dqm->fence_mem);

	pm_uninit(&dqm->packets);
@@ -1069,11 +1069,11 @@ static int create_kernel_queue_cpsch(struct device_queue_manager *dqm, 
					struct kernel_queue *kq,

					struct qcm_process_device *qpd)

{

	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	if (dqm->total_queue_count >= max_num_of_queues_per_device) {

		pr_warn("Can't create new kernel queue because %d queues were already created\n",

				dqm->total_queue_count);

		mutex_unlock(&dqm->lock);

		dqm_unlock(dqm);

		return -EPERM;

	}
@@ -1089,7 +1089,7 @@ static int create_kernel_queue_cpsch(struct device_queue_manager *dqm, 
	dqm->queue_count++;

	qpd->is_debug = true;

	execute_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_DYNAMIC_QUEUES, 0);

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	return 0;

}
@@ -1098,7 +1098,7 @@ static void destroy_kernel_queue_cpsch(struct device_queue_manager *dqm, 
					struct kernel_queue *kq,

					struct qcm_process_device *qpd)

{

	mutex_lock(&dqm->lock);

	dqm_lock(dqm);

	list_del(&kq->list);

	dqm->queue_count--;

	qpd->is_debug = false;
@@ -1110,7 +1110,7 @@ static void destroy_kernel_queue_cpsch(struct device_queue_manager *dqm, 
	dqm->total_queue_count--;

	pr_debug("Total of %d queues are accountable so far\n",

			dqm->total_queue_count);

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

}



static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
@@ -1121,7 +1121,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, 


	retval = 0;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	if (dqm->total_queue_count >= max_num_of_queues_per_device) {

		pr_warn("Can't create new usermode queue because %d queues were already created\n",
@@ -1188,7 +1188,7 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, 
	pr_debug("Total of %d queues are accountable so far\n",

			dqm->total_queue_count);



	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;



out_deallocate_doorbell:
@@ -1197,7 +1197,8 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, 
	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)

		deallocate_sdma_queue(dqm, q->sdma_id);

out_unlock:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	return retval;

}
@@ -1314,7 +1315,7 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm, 
	retval = 0;



	/* remove queue from list to prevent rescheduling after preemption */

	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	if (qpd->is_debug) {

		/*
@@ -1360,14 +1361,14 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm, 
	pr_debug("Total of %d queues are accountable so far\n",

			dqm->total_queue_count);



	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);



	return retval;



failed:

failed_try_destroy_debugged_queue:



	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -1391,7 +1392,7 @@ static bool set_cache_memory_policy(struct device_queue_manager *dqm, 
	if (!dqm->asic_ops.set_cache_memory_policy)

		return retval;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	if (alternate_aperture_size == 0) {

		/* base > limit disables APE1 */
@@ -1437,7 +1438,7 @@ static bool set_cache_memory_policy(struct device_queue_manager *dqm, 
		qpd->sh_mem_ape1_limit);



out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -1468,7 +1469,7 @@ static int process_termination_nocpsch(struct device_queue_manager *dqm, 
	struct device_process_node *cur, *next_dpn;

	int retval = 0;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	/* Clear all user mode queues */

	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
@@ -1489,7 +1490,7 @@ static int process_termination_nocpsch(struct device_queue_manager *dqm, 
		}

	}



	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}
@@ -1507,7 +1508,7 @@ static int process_termination_cpsch(struct device_queue_manager *dqm, 


	retval = 0;



	mutex_lock(&dqm->lock);

	dqm_lock(dqm);



	/* Clean all kernel queues */

	list_for_each_entry_safe(kq, kq_next, &qpd->priv_queue_list, list) {
@@ -1562,7 +1563,7 @@ static int process_termination_cpsch(struct device_queue_manager *dqm, 
	}



out:

	mutex_unlock(&dqm->lock);

	dqm_unlock(dqm);

	return retval;

}

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h

+19 −1
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ 


#include <linux/rwsem.h>

#include <linux/list.h>

#include <linux/mutex.h>

#include <linux/sched/mm.h>

#include "kfd_priv.h"

#include "kfd_mqd_manager.h"
@@ -173,8 +175,9 @@ struct device_queue_manager { 
	struct mqd_manager	*mqds[KFD_MQD_TYPE_MAX];

	struct packet_manager	packets;

	struct kfd_dev		*dev;

	struct mutex		lock;

	struct mutex		lock_hidden; /* use dqm_lock/unlock(dqm) */

	struct list_head	queues;

	unsigned int		saved_flags;

	unsigned int		processes_count;

	unsigned int		queue_count;

	unsigned int		sdma_queue_count;
@@ -219,4 +222,19 @@ get_sh_mem_bases_nybble_64(struct kfd_process_device *pdd) 
	return (pdd->lds_base >> 60) & 0x0E;

}



/* The DQM lock can be taken in MMU notifiers. Make sure no reclaim-FS

 * happens while holding this lock anywhere to prevent deadlocks when

 * an MMU notifier runs in reclaim-FS context.

 */

static inline void dqm_lock(struct device_queue_manager *dqm)

{

	mutex_lock(&dqm->lock_hidden);

	dqm->saved_flags = memalloc_nofs_save();

}

static inline void dqm_unlock(struct device_queue_manager *dqm)

{

	memalloc_nofs_restore(dqm->saved_flags);

	mutex_unlock(&dqm->lock_hidden);

}



#endif /* KFD_DEVICE_QUEUE_MANAGER_H_ */