[PATCH 5/7] char: xillybus: Integer arithmetic improvements

[Eli Billauer <eli.billauer@gmail.com>]

Choose unsigned integers instead of signed where natural, and also ensure
overflow wraps as expected.

Simplify an arithmetic expression too.

No functional change is expected, as the relevant variables normally never
reach values where this transition matters.

Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
---
 drivers/char/xillybus/xillybus_core.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/char/xillybus/xillybus_core.c b/drivers/char/xillybus/xillybus_core.c
index 7acebc1e6050..b264578b2572 100644
--- a/drivers/char/xillybus/xillybus_core.c
+++ b/drivers/char/xillybus/xillybus_core.c
@@ -343,7 +343,8 @@ static int xilly_map_single(struct xilly_endpoint *ep,
 static int xilly_get_dma_buffers(struct xilly_endpoint *ep,
 				 struct xilly_alloc_state *s,
 				 struct xilly_buffer **buffers,
-				 int bufnum, int bytebufsize)
+				 unsigned int bufnum,
+				 unsigned int bytebufsize)
 {
 	int i, rc;
 	dma_addr_t dma_addr;
@@ -431,8 +432,8 @@ static int xilly_setupchannels(struct xilly_endpoint *ep,
 	struct device *dev = ep->dev;
 	int i, entry, rc;
 	struct xilly_channel *channel;
-	int channelnum, bufnum, bufsize, format, is_writebuf;
-	int bytebufsize;
+	unsigned int channelnum, bufnum, bufsize, format, is_writebuf;
+	unsigned int bytebufsize;
 	int synchronous, allowpartial, exclusive_open, seekable;
 	int supports_nonempty;
 	int msg_buf_done = 0;
@@ -531,8 +532,7 @@ static int xilly_setupchannels(struct xilly_endpoint *ep,
 			channel->log2_element_size = ((format > 2) ?
 						      2 : format);
 
-			bytebufsize = bufsize *
-				(1 << channel->log2_element_size);
+			bytebufsize = bufsize << channel->log2_element_size;
 
 			buffers = devm_kcalloc(dev, bufnum,
 					       sizeof(struct xilly_buffer *),
@@ -589,7 +589,7 @@ static int xilly_setupchannels(struct xilly_endpoint *ep,
 static int xilly_scan_idt(struct xilly_endpoint *endpoint,
 			  struct xilly_idt_handle *idt_handle)
 {
-	int count = 0;
+	unsigned int count = 0;
 	unsigned char *idt = endpoint->channels[1]->wr_buffers[0]->addr;
 	unsigned char *end_of_idt = idt + endpoint->idtlen - 4;
 	unsigned char *scan;
-- 
2.34.1