From: Martin Aberg <mab...@gaisler.com>
This commit updates the OCCAN driver locking mechanism:
1. Convert interrupt disable/enable to interrupt locks.
2. Make sure interrupt service routines use proper locking to deal with threads
running in parallel.
---
c/src/lib/libbsp/sparc/shared/can/occan.c | 55 +++++++++++++++++++++----------
1 file changed, 38 insertions(+), 17 deletions(-)
diff --git a/c/src/lib/libbsp/sparc/shared/can/occan.c
b/c/src/lib/libbsp/sparc/shared/can/occan.c
index 2f113c4..3245d8e 100644
--- a/c/src/lib/libbsp/sparc/shared/can/occan.c
+++ b/c/src/lib/libbsp/sparc/shared/can/occan.c
@@ -14,6 +14,7 @@
#include <string.h>
#include <bsp.h>
#include <rtems/bspIo.h> /* printk */
+#include <rtems/score/isrlock.h> /* spin-lock */
#include <drvmgr/drvmgr.h>
#include <drvmgr/ambapp_bus.h>
@@ -70,6 +71,16 @@ rtems_assoc_t errno_assoc[] = {
#define DBG(fmt, vargs...)
#endif
+/* Spin locks mapped via ISR lock: */
+#define SPIN_DECLARE(lock) ISR_LOCK_MEMBER(lock)
+#define SPIN_INIT(lock, name) _ISR_lock_Initialize(lock, name)
+#define SPIN_LOCK(lock, level) _ISR_lock_Acquire_inline(lock, &level)
+#define SPIN_LOCK_IRQ(lock, level) _ISR_lock_ISR_disable_and_acquire(lock,
&level)
+#define SPIN_UNLOCK(lock, level) _ISR_lock_Release_inline(lock, &level)
+#define SPIN_UNLOCK_IRQ(lock, level) _ISR_lock_Release_and_ISR_enable(lock,
&level)
+#define SPIN_IRQFLAGS(k) ISR_lock_Context k
+#define SPIN_ISR_IRQFLAGS(k) SPIN_IRQFLAGS(k)
+
/* fifo interface */
typedef struct {
int cnt;
@@ -203,6 +214,7 @@ typedef struct {
typedef struct {
struct drvmgr_dev *dev;
char devName[32];
+ SPIN_DECLARE(devlock);
/* hardware shortcuts */
pelican_regs *regs;
@@ -1165,7 +1177,8 @@ static rtems_device_driver
occan_initialize(rtems_device_major_number major, rte
return RTEMS_SUCCESSFUL;
}
-static rtems_device_driver occan_open(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg){
+static rtems_device_driver occan_open(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg)
+{
occan_priv *can;
struct drvmgr_dev *dev;
@@ -1179,7 +1192,7 @@ static rtems_device_driver
occan_open(rtems_device_major_number major, rtems_dev
can = (occan_priv *)dev->priv;
/* already opened? */
- rtems_semaphore_obtain(can->devsem,RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+ rtems_semaphore_obtain(can->devsem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
if ( can->open ){
rtems_semaphore_release(can->devsem);
return RTEMS_RESOURCE_IN_USE; /* EBUSY */
@@ -1187,6 +1200,8 @@ static rtems_device_driver
occan_open(rtems_device_major_number major, rtems_dev
can->open = 1;
rtems_semaphore_release(can->devsem);
+ SPIN_INIT(&can->devlock, can->devName);
+
/* allocate fifos */
can->rxfifo = occan_fifo_create(DEFAULT_RX_FIFO_LEN);
if ( !can->rxfifo ){
@@ -1253,12 +1268,13 @@ static rtems_device_driver
occan_close(rtems_device_major_number major, rtems_de
return RTEMS_SUCCESSFUL;
}
-static rtems_device_driver occan_read(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg){
+static rtems_device_driver occan_read(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg)
+{
occan_priv *can;
struct drvmgr_dev *dev;
rtems_libio_rw_args_t *rw_args=(rtems_libio_rw_args_t *) arg;
CANMsg *dstmsg, *srcmsg;
- rtems_interrupt_level oldLevel;
+ SPIN_IRQFLAGS(oldLevel);
int left;
if ( drvmgr_get_dev(&occan_drv_info.general, minor, &dev) ) {
@@ -1288,11 +1304,11 @@ static rtems_device_driver
occan_read(rtems_device_major_number major, rtems_dev
while (left >= sizeof(CANMsg) ){
/* turn off interrupts */
- rtems_interrupt_disable(oldLevel);
+ SPIN_LOCK_IRQ(&can->devlock, oldLevel);
/* A bus off interrupt may have occured after checking
can->started */
if ( can->status & (OCCAN_STATUS_ERR_BUSOFF|OCCAN_STATUS_RESET)
){
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
DBG("OCCAN: read is cancelled due to a BUS OFF
error\n\r");
rw_args->bytes_moved = rw_args->count-left;
return RTEMS_IO_ERROR; /* EIO */
@@ -1307,12 +1323,12 @@ static rtems_device_driver
occan_read(rtems_device_major_number major, rtems_dev
*/
if ( !can->rxblk || (left != rw_args->count) ){
/* turn on interrupts again */
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
break;
}
/* turn on interrupts again */
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
DBG("OCCAN: Waiting for RX int\n\r");
@@ -1339,7 +1355,7 @@ static rtems_device_driver
occan_read(rtems_device_major_number major, rtems_dev
occan_fifo_get(can->rxfifo);
/* turn on interrupts again */
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
/* increase pointers */
left -= sizeof(CANMsg);
@@ -1355,12 +1371,13 @@ static rtems_device_driver
occan_read(rtems_device_major_number major, rtems_dev
return RTEMS_SUCCESSFUL;
}
-static rtems_device_driver occan_write(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg){
+static rtems_device_driver occan_write(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg)
+{
occan_priv *can;
struct drvmgr_dev *dev;
rtems_libio_rw_args_t *rw_args=(rtems_libio_rw_args_t *) arg;
CANMsg *msg,*fifo_msg;
- rtems_interrupt_level oldLevel;
+ SPIN_IRQFLAGS(oldLevel);
int left;
DBG("OCCAN: Writing %d bytes from 0x%lx
(%d)\n\r",rw_args->count,rw_args->buffer,sizeof(CANMsg));
@@ -1389,11 +1406,11 @@ static rtems_device_driver
occan_write(rtems_device_major_number major, rtems_de
#endif
/* turn off interrupts */
- rtems_interrupt_disable(oldLevel);
+ SPIN_LOCK_IRQ(&can->devlock, oldLevel);
/* A bus off interrupt may have occured after checking can->started */
if ( can->status & (OCCAN_STATUS_ERR_BUSOFF|OCCAN_STATUS_RESET) ){
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
rw_args->bytes_moved = 0;
return RTEMS_IO_ERROR; /* EIO */
}
@@ -1445,7 +1462,7 @@ static rtems_device_driver
occan_write(rtems_device_major_number major, rtems_de
INT_OFF;
CHECK_IF_FIFO_EMPTY ==> SEND DIRECT VIA HW;
*/
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
DBG("OCCAN: Waiting for tx int\n\r");
@@ -1459,7 +1476,7 @@ static rtems_device_driver
occan_write(rtems_device_major_number major, rtems_de
return RTEMS_IO_ERROR; /* EIO */
}
- rtems_interrupt_disable(oldLevel);
+ SPIN_LOCK_IRQ(&can->devlock, oldLevel);
if ( occan_fifo_empty(can->txfifo) ){
if ( !pelican_send(can,msg) ) {
@@ -1496,7 +1513,7 @@ static rtems_device_driver
occan_write(rtems_device_major_number major, rtems_de
left-=sizeof(CANMsg);
}
- rtems_interrupt_enable(oldLevel);
+ SPIN_UNLOCK_IRQ(&can->devlock, oldLevel);
rw_args->bytes_moved = rw_args->count-left;
DBG("OCCAN: Sent %d\n\r",rw_args->bytes_moved);
@@ -1506,7 +1523,8 @@ static rtems_device_driver
occan_write(rtems_device_major_number major, rtems_de
return RTEMS_SUCCESSFUL;
}
-static rtems_device_driver occan_ioctl(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg){
+static rtems_device_driver occan_ioctl(rtems_device_major_number major,
rtems_device_minor_number minor, void *arg)
+{
int ret;
occan_speed_regs timing;
occan_priv *can;
@@ -1704,10 +1722,12 @@ void occan_interrupt(void *arg)
int signal_rx=0, signal_tx=0;
unsigned char tmp, errcode, arbcode;
int tx_error_cnt,rx_error_cnt;
+ SPIN_ISR_IRQFLAGS(irqflags);
if ( !can->started )
return; /* Spurious Interrupt, do nothing */
+ SPIN_LOCK(&can->devlock, irqflags);
while (1) {
iflags = READ_REG(can, &can->regs->intflags);
@@ -1942,6 +1962,7 @@ void occan_interrupt(void *arg)
can->stats.err_bus++;
}
}
+ SPIN_UNLOCK(&can->devlock, irqflags);
/* signal Binary semaphore, messages available! */
if ( signal_rx ){
--
2.7.4
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