[PATCH v4 4/4] ufs: core: Remove ufshcd_map_desc_id_to_length function

[Arthur Simchaev]

There shouldn't be any restriction of the descriptor size
(not the descriptor id for that matter) up to QUERY_DESC_MAX_SIZE.
According to the spec, the caller can use any descriptor size,
and it is up to the device to return the actual size.
Therefore there shouldn't be any sizes hardcoded in the kernel,
nor any need to cache it, hence ufshcd_map_desc_id_to_length function is redundant.
always read the descriptors with QUERY_DESC_MAX_SIZE size.

Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
Suggested-by: Bean Huo <beanhuo@xxxxxxxxxx>
Signed-off-by: Arthur Simchaev <Arthur.Simchaev@xxxxxxx>
---
 drivers/ufs/core/ufs_bsg.c     |  7 +------
 drivers/ufs/core/ufshcd-priv.h |  3 ---
 drivers/ufs/core/ufshcd.c      | 46 +++++++++++-------------------------------
 drivers/ufs/core/ufshpb.c      |  4 +---
 4 files changed, 14 insertions(+), 46 deletions(-)

diff --git a/drivers/ufs/core/ufs_bsg.c b/drivers/ufs/core/ufs_bsg.c
index b99e3f3..dc441ac 100644
--- a/drivers/ufs/core/ufs_bsg.c
+++ b/drivers/ufs/core/ufs_bsg.c
@@ -16,16 +16,11 @@ static int ufs_bsg_get_query_desc_size(struct ufs_hba *hba, int *desc_len,
 				       struct utp_upiu_query *qr)
 {
 	int desc_size = be16_to_cpu(qr->length);
-	int desc_id = qr->idn;
 
 	if (desc_size <= 0)
 		return -EINVAL;
 
-	ufshcd_map_desc_id_to_length(hba, desc_id, desc_len);
-	if (!*desc_len)
-		return -EINVAL;
-
-	*desc_len = min_t(int, *desc_len, desc_size);
+	*desc_len = min_t(int, QUERY_DESC_MAX_SIZE, desc_size);
 
 	return 0;
 }
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index a9e8e1f..c52e2f3 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -70,9 +70,6 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index,
 int ufshcd_hold(struct ufs_hba *hba, bool async);
 void ufshcd_release(struct ufs_hba *hba);
 
-void ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn desc_id,
-				  int *desc_length);
-
 int ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd);
 
 int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 617c4e0..7f89626 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3369,20 +3369,6 @@ int ufshcd_query_descriptor_retry(struct ufs_hba *hba,
 }
 
 /**
- * ufshcd_map_desc_id_to_length - map descriptor IDN to its length
- * @hba: Pointer to adapter instance
- * @desc_id: descriptor idn value
- * @desc_len: mapped desc length (out)
- */
-void ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn desc_id,
-				  int *desc_len)
-{
-	/*Always returns QUERY_DESC_MAX_SIZE*/
-	*desc_len = QUERY_DESC_MAX_SIZE;
-}
-EXPORT_SYMBOL(ufshcd_map_desc_id_to_length);
-
-/**
  * ufshcd_read_desc_param - read the specified descriptor parameter
  * @hba: Pointer to adapter instance
  * @desc_id: descriptor idn value
@@ -3402,26 +3388,13 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 {
 	int ret;
 	u8 *desc_buf;
-	int buff_len;
+	int buff_len = QUERY_DESC_MAX_SIZE;
 	bool is_kmalloc = true;
 
 	/* Safety check */
 	if (desc_id >= QUERY_DESC_IDN_MAX || !param_size)
 		return -EINVAL;
 
-	/* Get the length of descriptor */
-	ufshcd_map_desc_id_to_length(hba, desc_id, &buff_len);
-	if (!buff_len) {
-		dev_err(hba->dev, "%s: Failed to get desc length\n", __func__);
-		return -EINVAL;
-	}
-
-	if (param_offset >= buff_len) {
-		dev_err(hba->dev, "%s: Invalid offset 0x%x in descriptor IDN 0x%x, length 0x%x\n",
-			__func__, param_offset, desc_id, buff_len);
-		return -EINVAL;
-	}
-
 	/* Check whether we need temp memory */
 	if (param_offset != 0 || param_size < buff_len) {
 		desc_buf = kzalloc(buff_len, GFP_KERNEL);
@@ -3434,15 +3407,23 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 
 	/* Request for full descriptor */
 	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
-					desc_id, desc_index, 0,
-					desc_buf, &buff_len);
-
+					    desc_id, desc_index, 0,
+					    desc_buf, &buff_len);
 	if (ret) {
 		dev_err(hba->dev, "%s: Failed reading descriptor. desc_id %d, desc_index %d, param_offset %d, ret %d\n",
 			__func__, desc_id, desc_index, param_offset, ret);
 		goto out;
 	}
 
+	/* Update descriptor length */
+	buff_len = desc_buf[QUERY_DESC_LENGTH_OFFSET];
+
+	if (param_offset >= buff_len) {
+		dev_err(hba->dev, "%s: Invalid offset 0x%x in descriptor IDN 0x%x, length 0x%x\n",
+			__func__, param_offset, desc_id, buff_len);
+		return -EINVAL;
+	}
+
 	/* Sanity check */
 	if (desc_buf[QUERY_DESC_DESC_TYPE_OFFSET] != desc_id) {
 		dev_err(hba->dev, "%s: invalid desc_id %d in descriptor header\n",
@@ -3451,9 +3432,6 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 		goto out;
 	}
 
-	/* Update descriptor length */
-	buff_len = desc_buf[QUERY_DESC_LENGTH_OFFSET];
-
 	if (is_kmalloc) {
 		/* Make sure we don't copy more data than available */
 		if (param_offset >= buff_len)
diff --git a/drivers/ufs/core/ufshpb.c b/drivers/ufs/core/ufshpb.c
index be3fb24..19c9b5d 100644
--- a/drivers/ufs/core/ufshpb.c
+++ b/drivers/ufs/core/ufshpb.c
@@ -2382,12 +2382,10 @@ static int ufshpb_get_lu_info(struct ufs_hba *hba, int lun,
 {
 	u16 max_active_rgns;
 	u8 lu_enable;
-	int size;
+	int size = QUERY_DESC_MAX_SIZE;
 	int ret;
 	char desc_buf[QUERY_DESC_MAX_SIZE];
 
-	ufshcd_map_desc_id_to_length(hba, QUERY_DESC_IDN_UNIT, &size);
-
 	ufshcd_rpm_get_sync(hba);
 	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
 					    QUERY_DESC_IDN_UNIT, lun, 0,
-- 
2.7.4