Commit bea9a56a authored by Felix Kuehling's avatar Felix Kuehling Committed by Alex Deucher
Browse files

drm/amdkfd: Handle restart of kfd_ioctl_wait_events 



When kfd_ioctl_wait_events needs to restart due to a signal, we need to
update the timeout to account for the time already elapsed. We also need
to undo auto_reset of events that have signaled already, so that the
restarted ioctl will be able to count those signals again.

This fixes infinite hangs when kfd_ioctl_wait_events is interrupted by a
signal.

Signed-off-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Reviewed-and-tested-by: default avatarXiaogang Chen <Xiaogang.Chen@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent c4c10a68

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

+1 −1
Original line number Diff line number Diff line
@@ -874,7 +874,7 @@ static int kfd_ioctl_wait_events(struct file *filp, struct kfd_process *p, 
	err = kfd_wait_on_events(p, args->num_events,

			(void __user *)args->events_ptr,

			(args->wait_for_all != 0),

			args->timeout, &args->wait_result);

			&args->timeout, &args->wait_result);



	return err;

}

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

+12 −12
Original line number Diff line number Diff line
@@ -894,7 +894,8 @@ static long user_timeout_to_jiffies(uint32_t user_timeout_ms) 
	return msecs_to_jiffies(user_timeout_ms) + 1;

}



static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters)

static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters,

			 bool undo_auto_reset)

{

	uint32_t i;
@@ -903,6 +904,9 @@ static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters) 
			spin_lock(&waiters[i].event->lock);

			remove_wait_queue(&waiters[i].event->wq,

					  &waiters[i].wait);

			if (undo_auto_reset && waiters[i].activated &&

			    waiters[i].event && waiters[i].event->auto_reset)

				set_event(waiters[i].event);

			spin_unlock(&waiters[i].event->lock);

		}
@@ -911,7 +915,7 @@ static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters) 


int kfd_wait_on_events(struct kfd_process *p,

		       uint32_t num_events, void __user *data,

		       bool all, uint32_t user_timeout_ms,

		       bool all, uint32_t *user_timeout_ms,

		       uint32_t *wait_result)

{

	struct kfd_event_data __user *events =
@@ -920,7 +924,7 @@ int kfd_wait_on_events(struct kfd_process *p, 
	int ret = 0;



	struct kfd_event_waiter *event_waiters = NULL;

	long timeout = user_timeout_to_jiffies(user_timeout_ms);

	long timeout = user_timeout_to_jiffies(*user_timeout_ms);



	event_waiters = alloc_event_waiters(num_events);

	if (!event_waiters) {
@@ -970,15 +974,11 @@ int kfd_wait_on_events(struct kfd_process *p, 
		}



		if (signal_pending(current)) {

			/*

			 * This is wrong when a nonzero, non-infinite timeout

			 * is specified. We need to use

			 * ERESTARTSYS_RESTARTBLOCK, but struct restart_block

			 * contains a union with data for each user and it's

			 * in generic kernel code that I don't want to

			 * touch yet.

			 */

			ret = -ERESTARTSYS;

			if (*user_timeout_ms != KFD_EVENT_TIMEOUT_IMMEDIATE &&

			    *user_timeout_ms != KFD_EVENT_TIMEOUT_INFINITE)

				*user_timeout_ms = jiffies_to_msecs(

					max(0l, timeout-1));

			break;

		}
@@ -1019,7 +1019,7 @@ int kfd_wait_on_events(struct kfd_process *p, 
					       event_waiters, events);



out_unlock:

	free_waiters(num_events, event_waiters);

	free_waiters(num_events, event_waiters, ret == -ERESTARTSYS);

	mutex_unlock(&p->event_mutex);

out:

	if (ret)

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

+1 −1
Original line number Diff line number Diff line
@@ -1317,7 +1317,7 @@ void kfd_event_free_process(struct kfd_process *p); 
int kfd_event_mmap(struct kfd_process *process, struct vm_area_struct *vma);

int kfd_wait_on_events(struct kfd_process *p,

		       uint32_t num_events, void __user *data,

		       bool all, uint32_t user_timeout_ms,

		       bool all, uint32_t *user_timeout_ms,

		       uint32_t *wait_result);

void kfd_signal_event_interrupt(u32 pasid, uint32_t partial_id,

				uint32_t valid_id_bits);