[PATCH 2/3] scsi: ufs: initialize max_lu_supported while booting

[Bean Huo <huobean@xxxxxxxxx>]

From: Bean Huo <beanhuo@xxxxxxxxxx>

This patch is to add a new function ufshcd_init_device_param() for
initialization of  UFS device related parameters which are used by
driver. In this version patch, there is only dev_info.max_lu_supported
being initialized.

Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
---
 drivers/scsi/ufs/ufshcd.c | 47 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 1b97f2dc0b63..a297fe55e36a 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3158,6 +3158,11 @@ static int ufshcd_read_device_desc(struct ufs_hba *hba, u8 *buf, u32 size)
 	return ufshcd_read_desc(hba, QUERY_DESC_IDN_DEVICE, 0, buf, size);
 }
 
+static int ufshcd_read_geometry_desc(struct ufs_hba *hba, u8 *buf, u32 size)
+{
+	return ufshcd_read_desc(hba, QUERY_DESC_IDN_GEOMETRY, 0, buf, size);
+}
+
 /**
  * struct uc_string_id - unicode string
  *
@@ -6827,6 +6832,37 @@ static void ufshcd_clear_dbg_ufs_stats(struct ufs_hba *hba)
 	hba->req_abort_count = 0;
 }
 
+static int ufshcd_init_device_param(struct ufs_hba *hba)
+{
+	int err;
+	size_t buff_len;
+	u8 *desc_buf;
+
+	buff_len = QUERY_DESC_MAX_SIZE;
+	desc_buf = kmalloc(buff_len, GFP_KERNEL);
+	if (!desc_buf) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = ufshcd_read_geometry_desc(hba, desc_buf,
+			hba->desc_size.geom_desc);
+	if (err) {
+		dev_err(hba->dev, "%s: Failed reading Geometry Desc. err = %d\n",
+			__func__, err);
+		goto out;
+	}
+
+	if (desc_buf[GEOMETRY_DESC_PARAM_MAX_NUM_LUN] == 1)
+		hba->dev_info.max_lu_supported = 32;
+	else if (desc_buf[GEOMETRY_DESC_PARAM_MAX_NUM_LUN] == 0)
+		hba->dev_info.max_lu_supported = 8;
+
+out:
+	kfree(desc_buf);
+	return err;
+}
+
 static void ufshcd_init_desc_sizes(struct ufs_hba *hba)
 {
 	int err;
@@ -7016,13 +7052,22 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 
 	/*
 	 * If we are in error handling context or in power management callbacks
-	 * context, no need to scan the host
+	 * context, no need to scan the host and to reinitialize the parameters
 	 */
 	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));
+		/* Init parameters according to UFS relevant descriptors */
+		ret = ufshcd_init_device_param(hba);
+		if (ret) {
+			dev_err(hba->dev,
+				"%s: Init of device param failed. err = %d\n",
+				__func__, ret);
+			goto out;
+		}
+
 		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;
-- 
2.17.1