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Subject[PATCH][2.5] smp_call_function_on_cpu for PARISC
This patch adds an smp_call_function which accepts a cpu bitmask instead 
of only doing a broadcast. One thing though, where is hweight64 on parisc?

Zwane

Index: linux-2.5.58-cpu_hotplug/arch/parisc/kernel/smp.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.58/arch/parisc/kernel/smp.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smp.c
--- linux-2.5.58-cpu_hotplug/arch/parisc/kernel/smp.c 14 Jan 2003 07:00:30 -0000 1.1.1.1
+++ linux-2.5.58-cpu_hotplug/arch/parisc/kernel/smp.c 17 Jan 2003 09:47:58 -0000
@@ -371,7 +371,89 @@
return 0;
}

+/*
+ * smp_call_function_on_cpu - Runs func on all processors in the mask
+ *
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @nonatomic: currently unused.
+ * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ * @mask The bitmask of CPUs to call the function
+ *
+ * Returns 0 on success, else a negative status code. Does not return until
+ * remote CPUs are nearly ready to execute func or have executed it.
+ *
+ */

+int
+smp_call_function_on_cpu (void (*func) (void *info), void *info, int retry, int wait,
+ unsigned long mask)
+{
+ struct smp_call_struct data;
+ long timeout;
+ static spinlock_t lock = SPIN_LOCK_UNLOCKED;
+ int num_cpus = hweight32(mask), cpu, i, ret;
+
+ cpu = get_cpu();
+ if ((1UL << cpu) & mask) {
+ ret = -EINVAL
+ goto out;
+ }
+
+ data.func = func;
+ data.info = info;
+ data.wait = wait;
+ atomic_set(&data.unstarted_count, num_cpus);
+ atomic_set(&data.unfinished_count, num_cpus);
+
+ if (retry) {
+ spin_lock (&lock);
+ while (smp_call_function_data != 0)
+ barrier();
+ }
+ else {
+ spin_lock (&lock);
+ if (smp_call_function_data) {
+ spin_unlock (&lock);
+ ret = -EBUSY;
+ goto out;
+ }
+ }
+
+ smp_call_function_data = &data;
+ spin_unlock (&lock);
+
+ /* Send a message to the target CPUs and wait */
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_online(i) || !(mask & (1UL << i)))
+ continue;
+ send_IPI_single(i, IPI_CALL_FUNC);
+ }
+
+ /* Wait for response */
+ timeout = jiffies + HZ;
+ while ( (atomic_read (&data.unstarted_count) > 0) &&
+ time_before (jiffies, timeout) )
+ barrier ();
+
+ /* We either got one or timed out. Release the lock */
+
+ mb();
+ smp_call_function_data = NULL;
+ if (atomic_read (&data.unstarted_count) > 0) {
+ printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d)\n",
+ cpu);
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+
+ while (wait && atomic_read (&data.unfinished_count) > 0)
+ barrier ();
+ ret = 0;
+out:
+ put_cpu_no_resched();
+ return ret;
+}

/*
* Setup routine for controlling SMP activation
--
function.linuxpower.ca


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