[PATCH 76/83] hsa/radeon: Check oversubscription before destroying runlist

[Oded Gabbay <oded.gabbay@gmail.com>]

This patch fixes a bug when using the mode of CP hardware
scheduling without oversubscription.

The bug was that the oversubscription check was performed
_after_ the current runlist was destroyed, which caused
the current HSA application to stop working.

This patch moves the oversubscription check before the call
to destroy the current runlist. If there is oversubscription,
the function prints an error to dmesg and simply exits.

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
---
 drivers/gpu/hsa/radeon/kfd_packet_manager.c        | 3 ---
 drivers/gpu/hsa/radeon/kfd_process_queue_manager.c | 9 +++++++++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/hsa/radeon/kfd_packet_manager.c b/drivers/gpu/hsa/radeon/kfd_packet_manager.c
index 5cd23b0..0aef907 100644
--- a/drivers/gpu/hsa/radeon/kfd_packet_manager.c
+++ b/drivers/gpu/hsa/radeon/kfd_packet_manager.c
@@ -88,9 +88,6 @@ static int pm_allocate_runlist_ib(struct packet_manager *pm, unsigned int **rl_b
 	BUG_ON(is_over_subscription == NULL);
 
 	pm_calc_rlib_size(pm, rl_buffer_size, is_over_subscription);
-	if (*is_over_subscription &&
-			sched_policy == KFD_SCHED_POLICY_HWS_NO_OVERSUBSCRIPTION)
-		return -EFAULT;
 
 	retval = radeon_kfd_vidmem_alloc_map(pm->dqm->dev, &pm->ib_buffer_obj, (void **)rl_buffer,
 					     rl_gpu_buffer, ALIGN(*rl_buffer_size, PAGE_SIZE));
diff --git a/drivers/gpu/hsa/radeon/kfd_process_queue_manager.c b/drivers/gpu/hsa/radeon/kfd_process_queue_manager.c
index 5d7c46d..97b3cc6 100644
--- a/drivers/gpu/hsa/radeon/kfd_process_queue_manager.c
+++ b/drivers/gpu/hsa/radeon/kfd_process_queue_manager.c
@@ -174,6 +174,15 @@ int pqm_create_queue(struct process_queue_manager *pqm,
 
 	switch (type) {
 	case KFD_QUEUE_TYPE_COMPUTE:
+		/* check if there is over subscription */
+		if ((sched_policy == KFD_SCHED_POLICY_HWS_NO_OVERSUBSCRIPTION) &&
+		((dev->dqm->processes_count >= VMID_PER_DEVICE) ||
+		(dev->dqm->queue_count >= PIPE_PER_ME_CP_SCHEDULING * QUEUES_PER_PIPE))) {
+			pr_err("kfd: over-subscription is not allowed in radeon_kfd.sched_policy == 1\n");
+			retval = -EPERM;
+			goto err_create_queue;
+		}
+
 		retval = create_cp_queue(pqm, dev, &q, &q_properties, f, *qid);
 		if (retval != 0)
 			goto err_create_queue;
-- 
1.9.1