[PATCH] ieee1394: nodemgr: switch to kthread api, replace reset semaphore
Convert nodemgr's host thread from kernel_thread to kthread and its
sleep/restart mechanism from a counting semaphore to a schedule()/
wake_up_process() scheme.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c
index 04b62ec..2e6dc59 100644
--- a/drivers/ieee1394/nodemgr.c
+++ b/drivers/ieee1394/nodemgr.c
@@ -12,8 +12,8 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/slab.h>
-#include <linux/completion.h>
#include <linux/delay.h>
+#include <linux/kthread.h>
#include <linux/moduleparam.h>
#include <asm/atomic.h>
@@ -163,11 +163,7 @@
struct host_info {
struct hpsb_host *host;
struct list_head list;
- struct completion exited;
- struct semaphore reset_sem;
- int pid;
- char daemon_name[15];
- int kill_me;
+ struct task_struct *thread;
};
static int nodemgr_bus_match(struct device * dev, struct device_driver * drv);
@@ -1477,9 +1473,8 @@
/* If we had a bus reset while we were scanning the bus, it is
* possible that we did not probe all nodes. In that case, we
* skip the clean up for now, since we could remove nodes that
- * were still on the bus. The bus reset increased hi->reset_sem,
- * so there's a bus scan pending which will do the clean up
- * eventually.
+ * were still on the bus. Another bus scan is pending which will
+ * do the clean up eventually.
*
* Now let's tell the bus to rescan our devices. This may seem
* like overhead, but the driver-model core will only scan a
@@ -1607,41 +1602,37 @@
{
struct host_info *hi = (struct host_info *)__hi;
struct hpsb_host *host = hi->host;
- int reset_cycles = 0;
-
- /* No userlevel access needed */
- daemonize(hi->daemon_name);
+ unsigned int g, generation = get_hpsb_generation(host) - 1;
+ int i, reset_cycles = 0;
/* Setup our device-model entries */
nodemgr_create_host_dev_files(host);
- /* Sit and wait for a signal to probe the nodes on the bus. This
- * happens when we get a bus reset. */
- while (1) {
- unsigned int generation = 0;
- int i;
+ for (;;) {
+ /* Sleep until next bus reset */
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (get_hpsb_generation(host) == generation)
+ schedule();
+ __set_current_state(TASK_RUNNING);
- if (down_interruptible(&hi->reset_sem) ||
- down_interruptible(&nodemgr_serialize)) {
+ /* Thread may have been woken up to freeze or to exit */
+ if (try_to_freeze())
+ continue;
+ if (kthread_should_stop())
+ goto exit;
+
+ if (down_interruptible(&nodemgr_serialize)) {
if (try_to_freeze())
continue;
- printk("NodeMgr: received unexpected signal?!\n" );
- break;
- }
-
- if (hi->kill_me) {
- up(&nodemgr_serialize);
- break;
+ goto exit;
}
/* Pause for 1/4 second in 1/16 second intervals,
* to make sure things settle down. */
+ g = get_hpsb_generation(host);
for (i = 0; i < 4 ; i++) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (msleep_interruptible(63)) {
- up(&nodemgr_serialize);
- goto caught_signal;
- }
+ if (msleep_interruptible(63) || kthread_should_stop())
+ goto unlock_exit;
/* Now get the generation in which the node ID's we collect
* are valid. During the bus scan we will use this generation
@@ -1652,14 +1643,8 @@
/* If we get a reset before we are done waiting, then
* start the the waiting over again */
- while (!down_trylock(&hi->reset_sem))
- i = 0;
-
- /* Check the kill_me again */
- if (hi->kill_me) {
- up(&nodemgr_serialize);
- goto caught_signal;
- }
+ if (generation != g)
+ g = generation, i = 0;
}
if (!nodemgr_check_irm_capability(host, reset_cycles) ||
@@ -1685,11 +1670,11 @@
up(&nodemgr_serialize);
}
-
-caught_signal:
+unlock_exit:
+ up(&nodemgr_serialize);
+exit:
HPSB_VERBOSE("NodeMgr: Exiting thread");
-
- complete_and_exit(&hi->exited, 0);
+ return 0;
}
int nodemgr_for_each_host(void *__data, int (*cb)(struct hpsb_host *, void *))
@@ -1749,41 +1734,27 @@
struct host_info *hi;
hi = hpsb_create_hostinfo(&nodemgr_highlevel, host, sizeof(*hi));
-
if (!hi) {
- HPSB_ERR ("NodeMgr: out of memory in add host");
+ HPSB_ERR("NodeMgr: out of memory in add host");
return;
}
-
hi->host = host;
- init_completion(&hi->exited);
- sema_init(&hi->reset_sem, 0);
-
- sprintf(hi->daemon_name, "knodemgrd_%d", host->id);
-
- hi->pid = kernel_thread(nodemgr_host_thread, hi, CLONE_KERNEL);
-
- if (hi->pid < 0) {
- HPSB_ERR ("NodeMgr: failed to start %s thread for %s",
- hi->daemon_name, host->driver->name);
+ hi->thread = kthread_run(nodemgr_host_thread, hi, "knodemgrd_%d",
+ host->id);
+ if (IS_ERR(hi->thread)) {
+ HPSB_ERR("NodeMgr: cannot start thread for host %d", host->id);
hpsb_destroy_hostinfo(&nodemgr_highlevel, host);
- return;
}
-
- return;
}
static void nodemgr_host_reset(struct hpsb_host *host)
{
struct host_info *hi = hpsb_get_hostinfo(&nodemgr_highlevel, host);
- if (hi != NULL) {
- HPSB_VERBOSE("NodeMgr: Processing host reset for %s", hi->daemon_name);
- up(&hi->reset_sem);
- } else
- HPSB_ERR ("NodeMgr: could not process reset of unused host");
-
- return;
+ if (hi) {
+ HPSB_VERBOSE("NodeMgr: Processing reset for host %d", host->id);
+ wake_up_process(hi->thread);
+ }
}
static void nodemgr_remove_host(struct hpsb_host *host)
@@ -1791,18 +1762,9 @@
struct host_info *hi = hpsb_get_hostinfo(&nodemgr_highlevel, host);
if (hi) {
- if (hi->pid >= 0) {
- hi->kill_me = 1;
- mb();
- up(&hi->reset_sem);
- wait_for_completion(&hi->exited);
- nodemgr_remove_host_dev(&host->device);
- }
- } else
- HPSB_ERR("NodeMgr: host %s does not exist, cannot remove",
- host->driver->name);
-
- return;
+ kthread_stop(hi->thread);
+ nodemgr_remove_host_dev(&host->device);
+ }
}
static struct hpsb_highlevel nodemgr_highlevel = {