proc tty: switch serial_core to ->proc_fops

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 36 insertions, 40 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 42f4e66fccaf..bf3c0e32a334 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -27,6 +27,8 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/console.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/serial_core.h>
 #include <linux/smp_lock.h>
 #include <linux/device.h>
@@ -1682,20 +1684,20 @@ static const char *uart_type(struct uart_port *port)
 
 #ifdef CONFIG_PROC_FS
 
-static int uart_line_info(char *buf, struct uart_driver *drv, int i)
+static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 {
         struct uart_state *state = drv->state + i;
         int pm_state;
         struct uart_port *port = state->port;
         char stat_buf[32];
         unsigned int status;
-        int mmio, ret;
+        int mmio;
 
         if (!port)
-                return 0;
+                return;
 
         mmio = port->iotype >= UPIO_MEM;
-        ret = sprintf(buf, "%d: uart:%s %s%08llX irq:%d",
+        seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
                         port->line, uart_type(port),
                         mmio ? "mmio:0x" : "port:",
                         mmio ? (unsigned long long)port->mapbase
@@ -1703,8 +1705,8 @@ static int uart_line_info(char *buf, struct uart_driver *drv, int i)
                         port->irq);
 
         if (port->type == PORT_UNKNOWN) {
-                strcat(buf, "\n");
-                return ret + 1;
+                seq_putc(m, '\n');
+                return;
         }
 
         if (capable(CAP_SYS_ADMIN)) {
@@ -1719,19 +1721,19 @@ static int uart_line_info(char *buf, struct uart_driver *drv, int i)
                         uart_change_pm(state, pm_state);
                 mutex_unlock(&state->mutex);
 
-                ret += sprintf(buf + ret, " tx:%d rx:%d",
+                seq_printf(m, " tx:%d rx:%d",
                                 port->icount.tx, port->icount.rx);
                 if (port->icount.frame)
-                        ret += sprintf(buf + ret, " fe:%d",
+                        seq_printf(m, " fe:%d",
                                 port->icount.frame);
                 if (port->icount.parity)
-                        ret += sprintf(buf + ret, " pe:%d",
+                        seq_printf(m, " pe:%d",
                                 port->icount.parity);
                 if (port->icount.brk)
-                        ret += sprintf(buf + ret, " brk:%d",
+                        seq_printf(m, " brk:%d",
                                 port->icount.brk);
                 if (port->icount.overrun)
-                        ret += sprintf(buf + ret, " oe:%d",
+                        seq_printf(m, " oe:%d",
                                 port->icount.overrun);
 
 #define INFOBIT(bit, str) \
@@ -1753,45 +1755,39 @@ static int uart_line_info(char *buf, struct uart_driver *drv, int i)
                 STATBIT(TIOCM_RNG, "|RI");
                 if (stat_buf[0])
                         stat_buf[0] = ' ';
-                strcat(stat_buf, "\n");
 
-                ret += sprintf(buf + ret, stat_buf);
-        } else {
-                strcat(buf, "\n");
-                ret++;
+                seq_puts(m, stat_buf);
         }
+        seq_putc(m, '\n');
 #undef STATBIT
 #undef INFOBIT
-        return ret;
 }
 
-static int uart_read_proc(char *page, char **start, off_t off,
-                          int count, int *eof, void *data)
+static int uart_proc_show(struct seq_file *m, void *v)
 {
-        struct tty_driver *ttydrv = data;
+        struct tty_driver *ttydrv = v;
         struct uart_driver *drv = ttydrv->driver_state;
-        int i, len = 0, l;
-        off_t begin = 0;
+        int i;
 
-        len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
+        seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
                         "", "", "");
-        for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
-                l = uart_line_info(page + len, drv, i);
-                len += l;
-                if (len + begin > off + count)
-                        goto done;
-                if (len + begin < off) {
-                        begin += len;
-                        len = 0;
-                }
-        }
-        *eof = 1;
- done:
-        if (off >= len + begin)
-                return 0;
-        *start = page + (off - begin);
-        return (count < begin + len - off) ? count : (begin + len - off);
+        for (i = 0; i < drv->nr; i++)
+                uart_line_info(m, drv, i);
+        return 0;
 }
+
+static int uart_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, uart_proc_show, PDE(inode)->data);
+}
+
+static const struct file_operations uart_proc_fops = {
+        .owner          = THIS_MODULE,
+        .open           = uart_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
 #endif
 
 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
@@ -2299,7 +2295,7 @@ static const struct tty_operations uart_ops = {
         .break_ctl      = uart_break_ctl,
         .wait_until_sent= uart_wait_until_sent,
 #ifdef CONFIG_PROC_FS
-        .read_proc      = uart_read_proc,
+        .proc_fops      = &uart_proc_fops,
 #endif
         .tiocmget       = uart_tiocmget,
         .tiocmset       = uart_tiocmset,