* [PATCH] drivers/char/riscom8.c: cli/sti removal
@ 2003-07-30 17:47 Felipe W Damasio
2003-07-30 19:05 ` Francois Romieu
0 siblings, 1 reply; 2+ messages in thread
From: Felipe W Damasio @ 2003-07-30 17:47 UTC (permalink / raw)
To: torvalds, akpm, alan; +Cc: linux-kernel
[-- Attachment #1: Type: text/plain, Size: 272 bytes --]
Hi,
Since Dmitry Gorodchanin doesn't have a valid email, I'm sending this
directly here.
This patch, against 2.6-test2, replaces {save|restore}_flags and cli
with lock spinlocks on the RISCom/8 multiport serial driver.
Please consider applying.
Thanks,
Felipe
[-- Attachment #2: riscom8-cli_sti_removal.patch --]
[-- Type: text/plain, Size: 10375 bytes --]
--- linux-2.6.0-test2/drivers/char/riscom8.c.orig Wed Jul 30 14:39:11 2003
+++ linux-2.6.0-test2/drivers/char/riscom8.c Wed Jul 30 14:42:44 2003
@@ -29,6 +29,9 @@
* ChangeLog:
* Arnaldo Carvalho de Melo <acme@conectiva.com.br> - 27-Jun-2001
* - get rid of check_region and several cleanups
+ *
+ * Felipe Damasio <felipewd@terra.com.br> - 30-Jul-2003
+ * - Fixed SMP support by removing {save|restore}_flags, cli/sti
*/
#include <linux/module.h>
@@ -45,6 +48,7 @@
#include <linux/fcntl.h>
#include <linux/major.h>
#include <linux/init.h>
+#include <linux/spinlock.h>
#include <asm/uaccess.h>
@@ -88,6 +92,8 @@
static unsigned char * tmp_buf;
static DECLARE_MUTEX(tmp_buf_sem);
+static spinlock_t rc_lock = SPIN_LOCK_UNLOCKED;
+
static unsigned long baud_table[] = {
0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
9600, 19200, 38400, 57600, 76800, 0,
@@ -237,13 +243,13 @@
{
unsigned long flags;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
rc_out(bp, RC_CTOUT, 0); /* Clear timeout */
rc_wait_CCR(bp); /* Wait for CCR ready */
rc_out(bp, CD180_CCR, CCR_HARDRESET); /* Reset CD180 chip */
- sti();
+ spin_unlock_irqsave(&rc_lock, flags);
rc_long_delay(HZ/20); /* Delay 0.05 sec */
- cli();
+ spin_lock_irqsave(&rc_lock, flags);
rc_out(bp, CD180_GIVR, RC_ID); /* Set ID for this chip */
rc_out(bp, CD180_GICR, 0); /* Clear all bits */
rc_out(bp, CD180_PILR1, RC_ACK_MINT); /* Prio for modem intr */
@@ -253,8 +259,8 @@
/* Setting up prescaler. We need 4 ticks per 1 ms */
rc_out(bp, CD180_PPRH, (RC_OSCFREQ/(1000000/RISCOM_TPS)) >> 8);
rc_out(bp, CD180_PPRL, (RC_OSCFREQ/(1000000/RISCOM_TPS)) & 0xff);
-
- restore_flags(flags);
+
+ spin_unlock_irqsave(&rc_lock, flags);
}
/* Main probing routine, also sets irq. */
@@ -875,7 +881,7 @@
port->xmit_buf = (unsigned char *) tmp;
}
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
if (port->tty)
clear_bit(TTY_IO_ERROR, &port->tty->flags);
@@ -886,8 +892,8 @@
port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
rc_change_speed(bp, port);
port->flags |= ASYNC_INITIALIZED;
-
- restore_flags(flags);
+
+ spin_unlock_irqsave(&rc_lock, flags);
return 0;
}
@@ -998,19 +1004,19 @@
*/
retval = 0;
add_wait_queue(&port->open_wait, &wait);
- cli();
+ spin_lock(&rc_lock);
if (!tty_hung_up_p(filp))
port->count--;
- sti();
+ spin_unlock(&rc_lock);
port->blocked_open++;
while (1) {
- cli();
+ spin_lock(&rc_lock);
rc_out(bp, CD180_CAR, port_No(port));
CD = rc_in(bp, CD180_MSVR) & MSVR_CD;
rc_out(bp, CD180_MSVR, MSVR_RTS);
bp->DTR &= ~(1u << port_No(port));
rc_out(bp, RC_DTR, bp->DTR);
- sti();
+ spin_unlock(&rc_lock);
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(port->flags & ASYNC_INITIALIZED)) {
@@ -1084,7 +1090,7 @@
if (!port || rc_paranoia_check(port, tty->name, "close"))
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
if (tty_hung_up_p(filp))
goto out;
@@ -1153,7 +1159,7 @@
}
port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
wake_up_interruptible(&port->close_wait);
-out: restore_flags(flags);
+out: spin_unlock_irqsave(&rc_lock, flags);
}
static int rc_write(struct tty_struct * tty, int from_user,
@@ -1172,30 +1178,31 @@
if (!tty || !port->xmit_buf || !tmp_buf)
return 0;
- save_flags(flags);
if (from_user) {
down(&tmp_buf_sem);
while (1) {
- cli();
+ spin_lock_irqsave(&rc_lock, flags);
c = MIN(count, MIN(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
SERIAL_XMIT_SIZE - port->xmit_head));
- if (c <= 0)
+ if (c <= 0){
+ spin_unlock_irqsave(&rc_lock, flags);
break;
+ }
c -= copy_from_user(tmp_buf, buf, c);
if (!c) {
if (!total)
total = -EFAULT;
+ spin_unlock_irqsave(&rc_lock, flags);
break;
}
- cli();
c = MIN(c, MIN(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
SERIAL_XMIT_SIZE - port->xmit_head));
memcpy(port->xmit_buf + port->xmit_head, tmp_buf, c);
port->xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
port->xmit_cnt += c;
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
buf += c;
count -= c;
@@ -1204,18 +1211,18 @@
up(&tmp_buf_sem);
} else {
while (1) {
- cli();
+ spin_lock_irqsave(&rc_lock, flags);
c = MIN(count, MIN(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
SERIAL_XMIT_SIZE - port->xmit_head));
if (c <= 0) {
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
break;
}
memcpy(port->xmit_buf + port->xmit_head, buf, c);
port->xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
port->xmit_cnt += c;
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
buf += c;
count -= c;
@@ -1223,14 +1230,14 @@
}
}
- cli();
+ spin_lock_irqsave(&rc_lock, flags);
if (port->xmit_cnt && !tty->stopped && !tty->hw_stopped &&
!(port->IER & IER_TXRDY)) {
port->IER |= IER_TXRDY;
rc_out(bp, CD180_CAR, port_No(port));
rc_out(bp, CD180_IER, port->IER);
}
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
return total;
}
@@ -1246,7 +1253,7 @@
if (!tty || !port->xmit_buf)
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1)
goto out;
@@ -1254,7 +1261,7 @@
port->xmit_buf[port->xmit_head++] = ch;
port->xmit_head &= SERIAL_XMIT_SIZE - 1;
port->xmit_cnt++;
-out: restore_flags(flags);
+out: spin_unlock_irqsave(&rc_lock, flags);
}
static void rc_flush_chars(struct tty_struct * tty)
@@ -1269,11 +1276,11 @@
!port->xmit_buf)
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
port->IER |= IER_TXRDY;
rc_out(port_Board(port), CD180_CAR, port_No(port));
rc_out(port_Board(port), CD180_IER, port->IER);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
static int rc_write_room(struct tty_struct * tty)
@@ -1308,9 +1315,9 @@
if (rc_paranoia_check(port, tty->name, "rc_flush_buffer"))
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
wake_up_interruptible(&tty->write_wait);
if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
@@ -1326,11 +1333,11 @@
unsigned long flags;
bp = port_Board(port);
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
rc_out(bp, CD180_CAR, port_No(port));
status = rc_in(bp, CD180_MSVR);
result = rc_in(bp, RC_RI) & (1u << port_No(port)) ? 0 : TIOCM_RNG;
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
result |= ((status & MSVR_RTS) ? TIOCM_RTS : 0)
| ((status & MSVR_DTR) ? TIOCM_DTR : 0)
| ((status & MSVR_CD) ? TIOCM_CAR : 0)
@@ -1370,11 +1377,11 @@
default:
return -EINVAL;
}
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
rc_out(bp, CD180_CAR, port_No(port));
rc_out(bp, CD180_MSVR, port->MSVR);
rc_out(bp, RC_DTR, bp->DTR);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
return 0;
}
@@ -1383,7 +1390,7 @@
struct riscom_board *bp = port_Board(port);
unsigned long flags;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
port->break_length = RISCOM_TPS / HZ * length;
port->COR2 |= COR2_ETC;
port->IER |= IER_TXRDY;
@@ -1393,7 +1400,7 @@
rc_wait_CCR(bp);
rc_out(bp, CD180_CCR, CCR_CORCHG2);
rc_wait_CCR(bp);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
static inline int rc_set_serial_info(struct riscom_port * port,
@@ -1436,9 +1443,9 @@
port->closing_wait = tmp.closing_wait;
}
if (change_speed) {
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
rc_change_speed(bp, port);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
return 0;
}
@@ -1524,7 +1531,7 @@
bp = port_Board(port);
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
port->MSVR &= ~MSVR_RTS;
rc_out(bp, CD180_CAR, port_No(port));
if (I_IXOFF(tty)) {
@@ -1533,7 +1540,7 @@
rc_wait_CCR(bp);
}
rc_out(bp, CD180_MSVR, port->MSVR);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
static void rc_unthrottle(struct tty_struct * tty)
@@ -1547,7 +1554,7 @@
bp = port_Board(port);
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
port->MSVR |= MSVR_RTS;
rc_out(bp, CD180_CAR, port_No(port));
if (I_IXOFF(tty)) {
@@ -1556,7 +1563,7 @@
rc_wait_CCR(bp);
}
rc_out(bp, CD180_MSVR, port->MSVR);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
static void rc_stop(struct tty_struct * tty)
@@ -1570,11 +1577,11 @@
bp = port_Board(port);
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
port->IER &= ~IER_TXRDY;
rc_out(bp, CD180_CAR, port_No(port));
rc_out(bp, CD180_IER, port->IER);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
static void rc_start(struct tty_struct * tty)
@@ -1588,13 +1595,13 @@
bp = port_Board(port);
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
if (port->xmit_cnt && port->xmit_buf && !(port->IER & IER_TXRDY)) {
port->IER |= IER_TXRDY;
rc_out(bp, CD180_CAR, port_No(port));
rc_out(bp, CD180_IER, port->IER);
}
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
/*
@@ -1646,9 +1653,9 @@
tty->termios->c_iflag == old_termios->c_iflag)
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&rc_lock, flags);
rc_change_speed(port_Board(port), port);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
if ((old_termios->c_cflag & CRTSCTS) &&
!(tty->termios->c_cflag & CRTSCTS)) {
@@ -1751,13 +1758,12 @@
{
unsigned long flags;
- save_flags(flags);
- cli();
+ spin_lock_irqsave(&rc_lock, flags);
remove_bh(RISCOM8_BH);
free_page((unsigned long)tmp_buf);
tty_unregister_driver(riscom_driver);
put_tty_driver(riscom_driver);
- restore_flags(flags);
+ spin_unlock_irqsave(&rc_lock, flags);
}
#ifndef MODULE
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] drivers/char/riscom8.c: cli/sti removal
2003-07-30 17:47 [PATCH] drivers/char/riscom8.c: cli/sti removal Felipe W Damasio
@ 2003-07-30 19:05 ` Francois Romieu
0 siblings, 0 replies; 2+ messages in thread
From: Francois Romieu @ 2003-07-30 19:05 UTC (permalink / raw)
To: Felipe W Damasio; +Cc: torvalds, akpm, alan, linux-kernel
Felipe W Damasio <felipewd@terra.com.br> :
[cli+restore/spinlock conversioni for riscom8]
> --- linux-2.6.0-test2/drivers/char/riscom8.c.orig Wed Jul 30 14:39:11 2003
> +++ linux-2.6.0-test2/drivers/char/riscom8.c Wed Jul 30 14:42:44 2003
[...]
> @@ -1084,7 +1090,7 @@
> if (!port || rc_paranoia_check(port, tty->name, "close"))
> return;
>
> - save_flags(flags); cli();
> + spin_lock_irqsave(&rc_lock, flags);
> if (tty_hung_up_p(filp))
> goto out;
>
1111 tty->closing = 1;
1112 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1113 tty_wait_until_sent(tty, port->closing_wait);
^^^^^^^^^^^^^^^^^^^ -> may sleep
[...]
1132 while(port->IER & IER_TXEMPTY) {
1133 current->state = TASK_INTERRUPTIBLE;
1134 schedule_timeout(port->timeout);
^^^^^^^^^^^^^^^^ -> <blink>BOOM</blink>
If you haven't read Documentation/DocBook/kernel-locking.tmpl, please give
it a try. If you have, well, double-check your code.
Regards
--
Ueimor
^ permalink raw reply [flat|nested] 2+ messages in thread
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2003-07-30 19:05 ` Francois Romieu
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