soc: qcom: fix QMI encoding/decoding for basic elements

Extend the QMI byte encoding and decoding logic to support multiple basic
data type sizes (u8, u16, u32, u64) using differnet macros for each type.
Ensure correct handling of data sizes and proper byte order conversion on
big-endian platforms by consistently applying these macros during encoding
and decoding of basic elements.

Signed-off-by: Alexander Wilhelm <alexander.wilhelm@westermo.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251119104008.3505152-3-alexander.wilhelm@westermo.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: alewi-westermo

drivers/soc/qcom/qmi_encdec.c

@@ -23,18 +23,60 @@
 	*p_length |= ((u8)*p_src) << 8; \
 } while (0)
 
-#define QMI_ENCDEC_ENCODE_N_BYTES(p_dst, p_src, size) \
+#define QMI_ENCDEC_ENCODE_U8(p_dst, p_src) \
 do { \
-	memcpy(p_dst, p_src, size); \
-	p_dst = (u8 *)p_dst + size; \
-	p_src = (u8 *)p_src + size; \
+	memcpy(p_dst, p_src, sizeof(u8)); \
+	p_dst = (u8 *)p_dst + sizeof(u8); \
+	p_src = (u8 *)p_src + sizeof(u8); \
 } while (0)
 
-#define QMI_ENCDEC_DECODE_N_BYTES(p_dst, p_src, size) \
+#define QMI_ENCDEC_ENCODE_U16(p_dst, p_src) \
 do { \
-	memcpy(p_dst, p_src, size); \
-	p_dst = (u8 *)p_dst + size; \
-	p_src = (u8 *)p_src + size; \
+	*(__le16 *)p_dst = __cpu_to_le16(*(u16 *)p_src); \
+	p_dst = (u8 *)p_dst + sizeof(u16); \
+	p_src = (u8 *)p_src + sizeof(u16); \
+} while (0)
+
+#define QMI_ENCDEC_ENCODE_U32(p_dst, p_src) \
+do { \
+	*(__le32 *)p_dst = __cpu_to_le32(*(u32 *)p_src); \
+	p_dst = (u8 *)p_dst + sizeof(u32); \
+	p_src = (u8 *)p_src + sizeof(u32); \
+} while (0)
+
+#define QMI_ENCDEC_ENCODE_U64(p_dst, p_src) \
+do { \
+	*(__le64 *)p_dst = __cpu_to_le64(*(u64 *)p_src); \
+	p_dst = (u8 *)p_dst + sizeof(u64); \
+	p_src = (u8 *)p_src + sizeof(u64); \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_U8(p_dst, p_src) \
+do { \
+	memcpy(p_dst, p_src, sizeof(u8)); \
+	p_dst = (u8 *)p_dst + sizeof(u8); \
+	p_src = (u8 *)p_src + sizeof(u8); \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_U16(p_dst, p_src) \
+do { \
+	*(u16 *)p_dst = __le16_to_cpu(*(__le16 *)p_src); \
+	p_dst = (u8 *)p_dst + sizeof(u16); \
+	p_src = (u8 *)p_src + sizeof(u16); \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_U32(p_dst, p_src) \
+do { \
+	*(u32 *)p_dst = __le32_to_cpu(*(__le32 *)p_src); \
+	p_dst = (u8 *)p_dst + sizeof(u32); \
+	p_src = (u8 *)p_src + sizeof(u32); \
+} while (0)
+
+#define QMI_ENCDEC_DECODE_U64(p_dst, p_src) \
+do { \
+	*(u64 *)p_dst = __le64_to_cpu(*(__le64 *)p_src); \
+	p_dst = (u8 *)p_dst + sizeof(u64); \
+	p_src = (u8 *)p_src + sizeof(u64); \
 } while (0)
 
 #define UPDATE_ENCODE_VARIABLES(temp_si, buf_dst, \
@@ -161,15 +203,33 @@ static int qmi_calc_min_msg_len(const struct qmi_elem_info *ei_array,
  * of primary data type which include u8 - u64 or similar. This
  * function returns the number of bytes of encoded information.
  *
- * Return: The number of bytes of encoded information.
+ * Return: The number of bytes of encoded information on success or negative
+ * errno on error.
  */
 static int qmi_encode_basic_elem(void *buf_dst, const void *buf_src,
 				 u32 elem_len, u32 elem_size)
 {
 	u32 i, rc = 0;
 
 	for (i = 0; i < elem_len; i++) {
-		QMI_ENCDEC_ENCODE_N_BYTES(buf_dst, buf_src, elem_size);
+		switch (elem_size) {
+		case sizeof(u8):
+			QMI_ENCDEC_ENCODE_U8(buf_dst, buf_src);
+			break;
+		case sizeof(u16):
+			QMI_ENCDEC_ENCODE_U16(buf_dst, buf_src);
+			break;
+		case sizeof(u32):
+			QMI_ENCDEC_ENCODE_U32(buf_dst, buf_src);
+			break;
+		case sizeof(u64):
+			QMI_ENCDEC_ENCODE_U64(buf_dst, buf_src);
+			break;
+		default:
+			pr_err("%s: Unrecognized element size\n", __func__);
+			return -EINVAL;
+		}
+
 		rc += elem_size;
 	}
 
@@ -456,15 +516,33 @@ static int qmi_encode(const struct qmi_elem_info *ei_array, void *out_buf,
  * of primary data type which include u8 - u64 or similar. This
  * function returns the number of bytes of decoded information.
  *
- * Return: The total size of the decoded data elements, in bytes.
+ * Return: The total size of the decoded data elements, in bytes, on success or
+ * negative errno on error.
  */
 static int qmi_decode_basic_elem(void *buf_dst, const void *buf_src,
 				 u32 elem_len, u32 elem_size)
 {
 	u32 i, rc = 0;
 
 	for (i = 0; i < elem_len; i++) {
-		QMI_ENCDEC_DECODE_N_BYTES(buf_dst, buf_src, elem_size);
+		switch (elem_size) {
+		case sizeof(u8):
+			QMI_ENCDEC_DECODE_U8(buf_dst, buf_src);
+			break;
+		case sizeof(u16):
+			QMI_ENCDEC_DECODE_U16(buf_dst, buf_src);
+			break;
+		case sizeof(u32):
+			QMI_ENCDEC_DECODE_U32(buf_dst, buf_src);
+			break;
+		case sizeof(u64):
+			QMI_ENCDEC_DECODE_U64(buf_dst, buf_src);
+			break;
+		default:
+			pr_err("%s: Unrecognized element size\n", __func__);
+			return -EINVAL;
+		}
+
 		rc += elem_size;
 	}