habanalabs: perform accounting for active CS

This patch adds accounting for active CS. Active means that the CS was
submitted to the H/W queues and was not completed yet.

This is necessary to support suspend operation. Because the device will be
reset upon suspend, we can only suspend after all active CS have been
completed. Hence, we need to perform accounting on their number.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

drivers/misc/habanalabs/command_submission.c

@@ -179,6 +179,12 @@ static void cs_do_release(struct kref *ref)
 
 	/* We also need to update CI for internal queues */
 	if (cs->submitted) {
+		int cs_cnt = atomic_dec_return(&hdev->cs_active_cnt);
+
+		WARN_ONCE((cs_cnt < 0),
+			"hl%d: error in CS active cnt %d\n",
+			hdev->id, cs_cnt);
+
 		hl_int_hw_queue_update_ci(cs);
 
 		spin_lock(&hdev->hw_queues_mirror_lock);

drivers/misc/habanalabs/device.c

@@ -218,6 +218,7 @@ static int device_early_init(struct hl_device *hdev)
 	spin_lock_init(&hdev->hw_queues_mirror_lock);
 	atomic_set(&hdev->in_reset, 0);
 	atomic_set(&hdev->fd_open_cnt, 0);
+	atomic_set(&hdev->cs_active_cnt, 0);
 
 	return 0;
 

drivers/misc/habanalabs/habanalabs.h

@@ -1056,13 +1056,15 @@ struct hl_device_reset_work {
  * @cb_pool_lock: protects the CB pool.
  * @user_ctx: current user context executing.
  * @dram_used_mem: current DRAM memory consumption.
- * @in_reset: is device in reset flow.
- * @curr_pll_profile: current PLL profile.
- * @fd_open_cnt: number of open user processes.
  * @timeout_jiffies: device CS timeout value.
  * @max_power: the max power of the device, as configured by the sysadmin. This
  *             value is saved so in case of hard-reset, KMD will restore this
  *             value and update the F/W after the re-initialization
+ * @in_reset: is device in reset flow.
+ * @curr_pll_profile: current PLL profile.
+ * @fd_open_cnt: number of open user processes.
+ * @cs_active_cnt: number of active command submissions on this device (active
+ *                 means already in H/W queues)
  * @major: habanalabs KMD major.
  * @high_pll: high PLL profile frequency.
  * @soft_reset_cnt: number of soft reset since KMD loading.
@@ -1128,11 +1130,12 @@ struct hl_device {
 	struct hl_ctx			*user_ctx;
 
 	atomic64_t			dram_used_mem;
+	u64				timeout_jiffies;
+	u64				max_power;
 	atomic_t			in_reset;
 	atomic_t			curr_pll_profile;
 	atomic_t			fd_open_cnt;
-	u64				timeout_jiffies;
-	u64				max_power;
+	atomic_t			cs_active_cnt;
 	u32				major;
 	u32				high_pll;
 	u32				soft_reset_cnt;

drivers/misc/habanalabs/hw_queue.c

@@ -370,12 +370,13 @@ int hl_hw_queue_schedule_cs(struct hl_cs *cs)
 		spin_unlock(&hdev->hw_queues_mirror_lock);
 	}
 
-	list_for_each_entry_safe(job, tmp, &cs->job_list, cs_node) {
+	atomic_inc(&hdev->cs_active_cnt);
+
+	list_for_each_entry_safe(job, tmp, &cs->job_list, cs_node)
 		if (job->ext_queue)
 			ext_hw_queue_schedule_job(job);
 		else
 			int_hw_queue_schedule_job(job);
-	}
 
 	cs->submitted = true;