Char: moxa, cleanup rx/tx

- cleanup types
- use tty_prepare_flip_string and io memcpys

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 51 insertions, 75 deletions

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index a64707623e47..797284fe5fce 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -224,7 +224,7 @@ static void MoxaPortLineCtrl(struct moxa_port *, int, int);
 static void MoxaPortFlowCtrl(struct moxa_port *, int, int, int, int, int);
 static int MoxaPortLineStatus(struct moxa_port *);
 static void MoxaPortFlushData(struct moxa_port *, int);
-static int MoxaPortWriteData(struct moxa_port *, unsigned char *, int);
+static int MoxaPortWriteData(struct moxa_port *, const unsigned char *, int);
 static int MoxaPortReadData(struct moxa_port *);
 static int MoxaPortTxQueue(struct moxa_port *);
 static int MoxaPortRxQueue(struct moxa_port *);
@@ -1165,7 +1165,7 @@ static int moxa_write(struct tty_struct *tty,
                 return 0;
 
         spin_lock_bh(&moxa_lock);
-        len = MoxaPortWriteData(ch, (unsigned char *) buf, count);
+        len = MoxaPortWriteData(ch, buf, count);
         spin_unlock_bh(&moxa_lock);
 
         /*********************************************
@@ -2030,15 +2030,13 @@ static int MoxaPortLineStatus(struct moxa_port *port)
         return val;
 }
 
-static int MoxaPortWriteData(struct moxa_port *port, unsigned char *buffer,
-                int len)
+static int MoxaPortWriteData(struct moxa_port *port,
+                const unsigned char *buffer, int len)
 {
-        int c, total, i;
-        ushort tail;
-        int cnt;
-        ushort head, tx_mask, spage, epage;
-        ushort pageno, pageofs, bufhead;
         void __iomem *baseAddr, *ofsAddr, *ofs;
+        unsigned int c, total;
+        u16 head, tail, tx_mask, spage, epage;
+        u16 pageno, pageofs, bufhead;
 
         ofsAddr = port->tableAddr;
         baseAddr = port->board->basemem;
@@ -2047,8 +2045,7 @@ static int MoxaPortWriteData(struct moxa_port *port, unsigned char *buffer,
         epage = readw(ofsAddr + EndPage_txb);
         tail = readw(ofsAddr + TXwptr);
         head = readw(ofsAddr + TXrptr);
-        c = (head > tail) ? (head - tail - 1)
-            : (head - tail + tx_mask);
+        c = (head > tail) ? (head - tail - 1) : (head - tail + tx_mask);
         if (c > len)
                 c = len;
         moxaLog.txcnt[port->tty->index] += c;
@@ -2063,46 +2060,42 @@ static int MoxaPortWriteData(struct moxa_port *port, unsigned char *buffer,
                                 len = tx_mask + 1 - tail;
                         len = (c > len) ? len : c;
                         ofs = baseAddr + DynPage_addr + bufhead + tail;
-                        for (i = 0; i < len; i++)
-                                writeb(*buffer++, ofs + i);
+                        memcpy_toio(ofs, buffer, len);
+                        buffer += len;
                         tail = (tail + len) & tx_mask;
                         c -= len;
                 }
-                writew(tail, ofsAddr + TXwptr);
         } else {
-                len = c;
                 pageno = spage + (tail >> 13);
                 pageofs = tail & Page_mask;
-                do {
-                        cnt = Page_size - pageofs;
-                        if (cnt > c)
-                                cnt = c;
-                        c -= cnt;
+                while (c > 0) {
+                        len = Page_size - pageofs;
+                        if (len > c)
+                                len = c;
                         writeb(pageno, baseAddr + Control_reg);
                         ofs = baseAddr + DynPage_addr + pageofs;
-                        for (i = 0; i < cnt; i++)
-                                writeb(*buffer++, ofs + i);
-                        if (c == 0) {
-                                writew((tail + len) & tx_mask, ofsAddr + TXwptr);
-                                break;
-                        }
+                        memcpy_toio(ofs, buffer, len);
+                        buffer += len;
                         if (++pageno == epage)
                                 pageno = spage;
                         pageofs = 0;
-                } while (1);
+                        c -= len;
+                }
+                tail = (tail + total) & tx_mask;
         }
+        writew(tail, ofsAddr + TXwptr);
         writeb(1, ofsAddr + CD180TXirq);        /* start to send */
-        return (total);
+        return total;
 }
 
 static int MoxaPortReadData(struct moxa_port *port)
 {
         struct tty_struct *tty = port->tty;
-        register ushort head, pageofs;
-        int i, count, cnt, len, total, remain;
-        ushort tail, rx_mask, spage, epage;
-        ushort pageno, bufhead;
+        unsigned char *dst;
         void __iomem *baseAddr, *ofsAddr, *ofs;
+        unsigned int count, len, total;
+        u16 tail, rx_mask, spage, epage;
+        u16 pageno, pageofs, bufhead, head;
 
         ofsAddr = port->tableAddr;
         baseAddr = port->board->basemem;
@@ -2111,101 +2104,84 @@ static int MoxaPortReadData(struct moxa_port *port)
         rx_mask = readw(ofsAddr + RX_mask);
         spage = readw(ofsAddr + Page_rxb);
         epage = readw(ofsAddr + EndPage_rxb);
-        count = (tail >= head) ? (tail - head)
-            : (tail - head + rx_mask + 1);
+        count = (tail >= head) ? (tail - head) : (tail - head + rx_mask + 1);
         if (count == 0)
                 return 0;
 
         total = count;
-        remain = count - total;
         moxaLog.rxcnt[tty->index] += total;
-        count = total;
         if (spage == epage) {
                 bufhead = readw(ofsAddr + Ofs_rxb);
                 writew(spage, baseAddr + Control_reg);
                 while (count > 0) {
-                        if (tail >= head)
-                                len = tail - head;
-                        else
-                                len = rx_mask + 1 - head;
-                        len = (count > len) ? len : count;
                         ofs = baseAddr + DynPage_addr + bufhead + head;
-                        for (i = 0; i < len; i++)
-                                tty_insert_flip_char(tty, readb(ofs + i), TTY_NORMAL);
+                        len = (tail >= head) ? (tail - head) :
+                                        (rx_mask + 1 - head);
+                        len = tty_prepare_flip_string(tty, &dst,
+                                        min(len, count));
+                        memcpy_fromio(dst, ofs, len);
                         head = (head + len) & rx_mask;
                         count -= len;
                 }
-                writew(head, ofsAddr + RXrptr);
         } else {
-                len = count;
                 pageno = spage + (head >> 13);
                 pageofs = head & Page_mask;
-                do {
-                        cnt = Page_size - pageofs;
-                        if (cnt > count)
-                                cnt = count;
-                        count -= cnt;
+                while (count > 0) {
                         writew(pageno, baseAddr + Control_reg);
                         ofs = baseAddr + DynPage_addr + pageofs;
-                        for (i = 0; i < cnt; i++)
-                                tty_insert_flip_char(tty, readb(ofs + i), TTY_NORMAL);
-                        if (count == 0) {
-                                writew((head + len) & rx_mask, ofsAddr + RXrptr);
-                                break;
-                        }
-                        if (++pageno == epage)
+                        len = tty_prepare_flip_string(tty, &dst,
+                                        min(Page_size - pageofs, count));
+                        memcpy_fromio(dst, ofs, len);
+
+                        count -= len;
+                        pageofs = (pageofs + len) & Page_mask;
+                        if (pageofs == 0 && ++pageno == epage)
                                 pageno = spage;
-                        pageofs = 0;
-                } while (1);
+                }
+                head = (head + total) & rx_mask;
         }
-        if ((readb(ofsAddr + FlagStat) & Xoff_state) && (remain < LowWater)) {
+        writew(head, ofsAddr + RXrptr);
+        if (readb(ofsAddr + FlagStat) & Xoff_state) {
                 moxaLowWaterChk = 1;
                 port->lowChkFlag = 1;
         }
-        return (total);
+        return total;
 }
 
 
 static int MoxaPortTxQueue(struct moxa_port *port)
 {
         void __iomem *ofsAddr = port->tableAddr;
-        ushort rptr, wptr, mask;
-        int len;
+        u16 rptr, wptr, mask;
 
         rptr = readw(ofsAddr + TXrptr);
         wptr = readw(ofsAddr + TXwptr);
         mask = readw(ofsAddr + TX_mask);
-        len = (wptr - rptr) & mask;
-        return (len);
+        return (wptr - rptr) & mask;
 }
 
 static int MoxaPortTxFree(struct moxa_port *port)
 {
         void __iomem *ofsAddr = port->tableAddr;
-        ushort rptr, wptr, mask;
-        int len;
+        u16 rptr, wptr, mask;
 
         rptr = readw(ofsAddr + TXrptr);
         wptr = readw(ofsAddr + TXwptr);
         mask = readw(ofsAddr + TX_mask);
-        len = mask - ((wptr - rptr) & mask);
-        return (len);
+        return mask - ((wptr - rptr) & mask);
 }
 
 static int MoxaPortRxQueue(struct moxa_port *port)
 {
         void __iomem *ofsAddr = port->tableAddr;
-        ushort rptr, wptr, mask;
-        int len;
+        u16 rptr, wptr, mask;
 
         rptr = readw(ofsAddr + RXrptr);
         wptr = readw(ofsAddr + RXwptr);
         mask = readw(ofsAddr + RX_mask);
-        len = (wptr - rptr) & mask;
-        return (len);
+        return (wptr - rptr) & mask;
 }
 
-
 static void MoxaPortTxDisable(struct moxa_port *port)
 {
         moxafunc(port->tableAddr, FC_SetXoffState, Magic_code);
diff --git a/drivers/char/moxa.h b/drivers/char/moxa.h
index 0b1650621a04..87d16ce57be7 100644
--- a/drivers/char/moxa.h
+++ b/drivers/char/moxa.h
@@ -217,7 +217,7 @@
 #define C320p32rx_mask  (C320p32rx_size - 1)
 #define C320p32tx_mask  (C320p32tx_size - 1)
 
-#define Page_size       0x2000
+#define Page_size       0x2000U
 #define Page_mask       (Page_size - 1)
 #define C218rx_spage    3
 #define C218tx_spage    4