V4L/DVB (8130): split dvb_ringbuffer dual-use functions

split the suckers into kernel-memory and user-memory versions,
annotate both properly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 53 insertions, 25 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_ringbuffer.c b/drivers/media/dvb/dvb-core/dvb_ringbuffer.c
index 872985b7912d..584bbd194dc8 100644
--- a/drivers/media/dvb/dvb-core/dvb_ringbuffer.c
+++ b/drivers/media/dvb/dvb-core/dvb_ringbuffer.c
@@ -107,35 +107,43 @@ void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf)
 	wake_up(&rbuf->queue);
 }
 
-
-
-ssize_t dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len, int usermem)
+ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, size_t len)
 {
 	size_t todo = len;
 	size_t split;
 
 	split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
 	if (split > 0) {
-		if (!usermem)
-			memcpy(buf, rbuf->data+rbuf->pread, split);
-		else
-			if (copy_to_user(buf, rbuf->data+rbuf->pread, split))
-				return -EFAULT;
+		if (copy_to_user(buf, rbuf->data+rbuf->pread, split))
+			return -EFAULT;
 		buf += split;
 		todo -= split;
 		rbuf->pread = 0;
 	}
-	if (!usermem)
-		memcpy(buf, rbuf->data+rbuf->pread, todo);
-	else
-		if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
-			return -EFAULT;
+	if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
+		return -EFAULT;
 
 	rbuf->pread = (rbuf->pread + todo) % rbuf->size;
 
 	return len;
 }
 
+void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len)
+{
+	size_t todo = len;
+	size_t split;
+
+	split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
+	if (split > 0) {
+		memcpy(buf, rbuf->data+rbuf->pread, split);
+		buf += split;
+		todo -= split;
+		rbuf->pread = 0;
+	}
+	memcpy(buf, rbuf->data+rbuf->pread, todo);
+
+	rbuf->pread = (rbuf->pread + todo) % rbuf->size;
+}
 
 
 ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t len)
@@ -171,8 +179,8 @@ ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, size_t le
 	return status;
 }
 
-ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
-				int offset, u8* buf, size_t len, int usermem)
+ssize_t dvb_ringbuffer_pkt_read_user(struct dvb_ringbuffer *rbuf, size_t idx,
+				int offset, u8 __user *buf, size_t len)
 {
 	size_t todo;
 	size_t split;
@@ -187,21 +195,40 @@ ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
 	todo = len;
 	split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
 	if (split > 0) {
-		if (!usermem)
-			memcpy(buf, rbuf->data+idx, split);
-		else
-			if (copy_to_user(buf, rbuf->data+idx, split))
-				return -EFAULT;
+		if (copy_to_user(buf, rbuf->data+idx, split))
+			return -EFAULT;
 		buf += split;
 		todo -= split;
 		idx = 0;
 	}
-	if (!usermem)
-		memcpy(buf, rbuf->data+idx, todo);
-	else
-		if (copy_to_user(buf, rbuf->data+idx, todo))
-			return -EFAULT;
+	if (copy_to_user(buf, rbuf->data+idx, todo))
+		return -EFAULT;
+
+	return len;
+}
 
+ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
+				int offset, u8* buf, size_t len)
+{
+	size_t todo;
+	size_t split;
+	size_t pktlen;
+
+	pktlen = rbuf->data[idx] << 8;
+	pktlen |= rbuf->data[(idx + 1) % rbuf->size];
+	if (offset > pktlen) return -EINVAL;
+	if ((offset + len) > pktlen) len = pktlen - offset;
+
+	idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
+	todo = len;
+	split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
+	if (split > 0) {
+		memcpy(buf, rbuf->data+idx, split);
+		buf += split;
+		todo -= split;
+		idx = 0;
+	}
+	memcpy(buf, rbuf->data+idx, todo);
 	return len;
 }
 
@@ -266,5 +293,6 @@ EXPORT_SYMBOL(dvb_ringbuffer_empty);
 EXPORT_SYMBOL(dvb_ringbuffer_free);
 EXPORT_SYMBOL(dvb_ringbuffer_avail);
 EXPORT_SYMBOL(dvb_ringbuffer_flush_spinlock_wakeup);
+EXPORT_SYMBOL(dvb_ringbuffer_read_user);
 EXPORT_SYMBOL(dvb_ringbuffer_read);
 EXPORT_SYMBOL(dvb_ringbuffer_write);