HV:change the return type of sbuf_get and sbuf_put

Because of the return type inconsistent,change the
sbuf return type to uint32_t to fix it,and make the
pre-condition to check the parameter whether is NULL.

V1->V2:
  1.add () to bool expression
  2.add pre-assumption to sbuf_get and sbuf_put

Tracked-On: #861
Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: Shawnshh

hypervisor/debug/logmsg.c

@@ -174,7 +174,7 @@ void do_logmsg(uint32_t severity, const char *fmt, ...)
 void print_logmsg_buffer(uint16_t pcpu_id)
 {
 	char buffer[LOG_ENTRY_SIZE + 1];
-	int read_cnt;
+	uint32_t read_cnt;
 	struct shared_buf **sbuf;
 	int is_earlylog = 0;
 	uint64_t rflags;
@@ -203,13 +203,13 @@ void print_logmsg_buffer(uint16_t pcpu_id)
 		uint32_t idx;
 		(void)memset(buffer, 0U, LOG_ENTRY_SIZE + 1U);
 
-		if (*sbuf == NULL) {
+		if ((*sbuf == NULL) || (buffer == NULL)) {
 			return;
 		}
 
 		read_cnt = sbuf_get(*sbuf, (uint8_t *)buffer);
 
-		if (read_cnt <= 0) {
+		if (read_cnt == 0U) {
 			return;
 		}
 
@@ -220,5 +220,5 @@ void print_logmsg_buffer(uint16_t pcpu_id)
 		spinlock_irqsave_obtain(&(logmsg.lock), &rflags);
 		printf("%s\n\r", buffer);
 		spinlock_irqrestore_release(&(logmsg.lock), rflags);
-	} while (read_cnt > 0);
+	} while (read_cnt > 0U);
 }

hypervisor/debug/sbuf.c

@@ -82,14 +82,10 @@ void sbuf_free(struct shared_buf *sbuf)
 	free(sbuf);
 }
 
-int sbuf_get(struct shared_buf *sbuf, uint8_t *data)
+uint32_t sbuf_get(struct shared_buf *sbuf, uint8_t *data)
 {
 	const void *from;
 
-	if ((sbuf == NULL) || (data == NULL)) {
-		return -EINVAL;
-	}
-
 	if (sbuf_is_empty(sbuf)) {
 		/* no data available */
 		return 0;
@@ -122,16 +118,12 @@ int sbuf_get(struct shared_buf *sbuf, uint8_t *data)
  * negative:	failed.
  */
 
-int sbuf_put(struct shared_buf *sbuf, uint8_t *data)
+uint32_t sbuf_put(struct shared_buf *sbuf, uint8_t *data)
 {
 	void *to;
 	uint32_t next_tail;
 	bool trigger_overwrite = false;
 
-	if ((sbuf == NULL) || (data == NULL)) {
-		return -EINVAL;
-	}
-
 	next_tail = sbuf_next_ptr(sbuf->tail, sbuf->ele_size, sbuf->size);
 	/* if this write would trigger overrun */
 	if (next_tail == sbuf->head) {

hypervisor/include/debug/sbuf.h

@@ -74,8 +74,16 @@ static inline void sbuf_add_flags(struct shared_buf *sbuf, uint64_t flags)
 
 struct shared_buf *sbuf_allocate(uint32_t ele_num, uint32_t ele_size);
 void sbuf_free(struct shared_buf *sbuf);
-int sbuf_get(struct shared_buf *sbuf, uint8_t *data);
-int sbuf_put(struct shared_buf *sbuf, uint8_t *data);
+/**
+ *@pre sbuf != NULL
+ *@pre data != NULL
+ */
+uint32_t sbuf_get(struct shared_buf *sbuf, uint8_t *data);
+/**
+ *@pre sbuf != NULL
+ *@pre data != NULL
+ */
+uint32_t sbuf_put(struct shared_buf *sbuf, uint8_t *data);
 int sbuf_share_setup(uint16_t pcpu_id, uint32_t sbuf_id, uint64_t *hva);
 
 #else /* HV_DEBUG */