scsi: ufs: Split ufshcd_probe_hba() based on its called flow

This patch has two major non-functionality changes:

1. Take scanning host if-statement out from ufshcd_probe_hba(), and move
into a new added function ufshcd_add_lus().  In this new function
ufshcd_add_lus(), the main functionalitis include: ICC initialization, add
well-known LUs, devfreq initialization, UFS bsg probe and scsi host
scan. The reason for this change is that these functionalities only being
called during booting stage flow ufshcd_init()->ufshcd_async_scan(). In the
processes of error handling and power management ufshcd_suspend(),
ufshcd_resume(), ufshcd_probe_hba() being called, but these functionalitis
above metioned are not hit.

2. Move context of initialization of parameters associated with the UFS
device to a new added function ufshcd_device_params_init().  The reason of
this change is that all of these parameters are used by driver, but only
need to be initialized once when booting. Combine them into an integral
function, make them easier maintain.

Link: https://lore.kernel.org/r/20200120130820.1737-4-huobean@gmail.comReviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -246,7 +246,7 @@ static int ufshcd_reset_and_restore(struct ufs_hba *hba);
 static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd);
 static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
 static void ufshcd_hba_exit(struct ufs_hba *hba);
-static int ufshcd_probe_hba(struct ufs_hba *hba);
+static int ufshcd_probe_hba(struct ufs_hba *hba, bool async);
 static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 				 bool skip_ref_clk);
 static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
@@ -6310,7 +6310,7 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 		goto out;
 
 	/* Establish the link again and restore the device */
-	err = ufshcd_probe_hba(hba);
+	err = ufshcd_probe_hba(hba, false);
 
 	if (!err && (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL))
 		err = -EIO;
@@ -6938,13 +6938,83 @@ static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba)
 	return err;
 }
 
+static int ufshcd_device_params_init(struct ufs_hba *hba)
+{
+	bool flag;
+	int ret;
+
+	/* Init check for device descriptor sizes */
+	ufshcd_init_desc_sizes(hba);
+
+	/* Check and apply UFS device quirks */
+	ret = ufs_get_device_desc(hba);
+	if (ret) {
+		dev_err(hba->dev, "%s: Failed getting device info. err = %d\n",
+			__func__, ret);
+		goto out;
+	}
+
+	ufs_fixup_device_setup(hba);
+
+	/* Clear any previous UFS device information */
+	memset(&hba->dev_info, 0, sizeof(hba->dev_info));
+	if (!ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,
+			QUERY_FLAG_IDN_PWR_ON_WPE, &flag))
+		hba->dev_info.f_power_on_wp_en = flag;
+
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_add_lus - probe and add UFS logical units
+ * @hba: per-adapter instance
+ */
+static int ufshcd_add_lus(struct ufs_hba *hba)
+{
+	int ret;
+
+	if (!hba->is_init_prefetch)
+		ufshcd_init_icc_levels(hba);
+
+	/* Add required well known logical units to scsi mid layer */
+	ret = ufshcd_scsi_add_wlus(hba);
+	if (ret)
+		goto out;
+
+	/* Initialize devfreq after UFS device is detected */
+	if (ufshcd_is_clkscaling_supported(hba)) {
+		memcpy(&hba->clk_scaling.saved_pwr_info.info,
+			&hba->pwr_info,
+			sizeof(struct ufs_pa_layer_attr));
+		hba->clk_scaling.saved_pwr_info.is_valid = true;
+		if (!hba->devfreq) {
+			ret = ufshcd_devfreq_init(hba);
+			if (ret)
+				goto out;
+		}
+
+		hba->clk_scaling.is_allowed = true;
+	}
+
+	ufs_bsg_probe(hba);
+	scsi_scan_host(hba->host);
+	pm_runtime_put_sync(hba->dev);
+
+	if (!hba->is_init_prefetch)
+		hba->is_init_prefetch = true;
+out:
+	return ret;
+}
+
 /**
  * ufshcd_probe_hba - probe hba to detect device and initialize
  * @hba: per-adapter instance
+ * @async: asynchronous execution or not
  *
  * Execute link-startup and verify device initialization
  */
-static int ufshcd_probe_hba(struct ufs_hba *hba)
+static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
 {
 	int ret;
 	ktime_t start = ktime_get();
@@ -6963,25 +7033,26 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* UniPro link is active now */
 	ufshcd_set_link_active(hba);
 
+	/* Verify device initialization by sending NOP OUT UPIU */
 	ret = ufshcd_verify_dev_init(hba);
 	if (ret)
 		goto out;
 
+	/* Initiate UFS initialization, and waiting until completion */
 	ret = ufshcd_complete_dev_init(hba);
 	if (ret)
 		goto out;
 
-	/* Init check for device descriptor sizes */
-	ufshcd_init_desc_sizes(hba);
-
-	ret = ufs_get_device_desc(hba);
-	if (ret) {
-		dev_err(hba->dev, "%s: Failed getting device info. err = %d\n",
-			__func__, ret);
-		goto out;
+	/*
+	 * Initialize UFS device parameters used by driver, these
+	 * parameters are associated with UFS descriptors.
+	 */
+	if (async) {
+		ret = ufshcd_device_params_init(hba);
+		if (ret)
+			goto out;
 	}
 
-	ufs_fixup_device_setup(hba);
 	ufshcd_tune_unipro_params(hba);
 
 	/* UFS device is also active now */
@@ -7014,60 +7085,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 	/* Enable Auto-Hibernate if configured */
 	ufshcd_auto_hibern8_enable(hba);
 
-	/*
-	 * If we are in error handling context or in power management callbacks
-	 * context, no need to scan the host
-	 */
-	if (!ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress) {
-		bool flag;
-
-		/* clear any previous UFS device information */
-		memset(&hba->dev_info, 0, sizeof(hba->dev_info));
-		if (!ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,
-				QUERY_FLAG_IDN_PWR_ON_WPE, &flag))
-			hba->dev_info.f_power_on_wp_en = flag;
-
-		if (!hba->is_init_prefetch)
-			ufshcd_init_icc_levels(hba);
-
-		/* Add required well known logical units to scsi mid layer */
-		ret = ufshcd_scsi_add_wlus(hba);
-		if (ret)
-			goto out;
-
-		/* Initialize devfreq after UFS device is detected */
-		if (ufshcd_is_clkscaling_supported(hba)) {
-			memcpy(&hba->clk_scaling.saved_pwr_info.info,
-				&hba->pwr_info,
-				sizeof(struct ufs_pa_layer_attr));
-			hba->clk_scaling.saved_pwr_info.is_valid = true;
-			if (!hba->devfreq) {
-				ret = ufshcd_devfreq_init(hba);
-				if (ret)
-					goto out;
-			}
-			hba->clk_scaling.is_allowed = true;
-		}
-
-		ufs_bsg_probe(hba);
-
-		scsi_scan_host(hba->host);
-		pm_runtime_put_sync(hba->dev);
-	}
-
-	if (!hba->is_init_prefetch)
-		hba->is_init_prefetch = true;
-
 out:
-	/*
-	 * If we failed to initialize the device or the device is not
-	 * present, turn off the power/clocks etc.
-	 */
-	if (ret && !ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress) {
-		pm_runtime_put_sync(hba->dev);
-		ufshcd_exit_clk_scaling(hba);
-		ufshcd_hba_exit(hba);
-	}
 
 	trace_ufshcd_init(dev_name(hba->dev), ret,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
@@ -7083,8 +7101,25 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 static void ufshcd_async_scan(void *data, async_cookie_t cookie)
 {
 	struct ufs_hba *hba = (struct ufs_hba *)data;
+	int ret;
 
-	ufshcd_probe_hba(hba);
+	/* Initialize hba, detect and initialize UFS device */
+	ret = ufshcd_probe_hba(hba, true);
+	if (ret)
+		goto out;
+
+	/* Probe and add UFS logical units  */
+	ret = ufshcd_add_lus(hba);
+out:
+	/*
+	 * If we failed to initialize the device or the device is not
+	 * present, turn off the power/clocks etc.
+	 */
+	if (ret) {
+		pm_runtime_put_sync(hba->dev);
+		ufshcd_exit_clk_scaling(hba);
+		ufshcd_hba_exit(hba);
+	}
 }
 
 static const struct attribute_group *ufshcd_driver_groups[] = {