Re: [PATCH][2.5][10/18] smp_call_function_on_cpu - ppc

From: Zwane Mwaikambo (zwane@holomorphy.com)
Date: Thu Jan 23 2003 - 10:11:16 EST


On Thu, 23 Jan 2003, Paul Mackerras wrote:

> Zwane Mwaikambo writes:
>
> > + if (num_cpus == 0 || )
> > + return -EINVAL;
>
> Doesn't look to me like this will even compile. :(

Oops...

Index: linux-2.5.59/arch/ppc/kernel/smp.c
===================================================================
RCS file: /build/cvsroot/linux-2.5.59/arch/ppc/kernel/smp.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 smp.c
--- linux-2.5.59/arch/ppc/kernel/smp.c 17 Jan 2003 11:14:47 -0000 1.1.1.1
+++ linux-2.5.59/arch/ppc/kernel/smp.c 23 Jan 2003 15:09:09 -0000
@@ -165,7 +165,7 @@
 
 void smp_send_stop(void)
 {
- smp_call_function(stop_this_cpu, NULL, 1, 0);
+ smp_call_function(stop_this_cpu, NULL, 0);
 }
 
 /*
@@ -188,13 +188,10 @@
  * in the system.
  */
 
-int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
- int wait)
 /*
  * [SUMMARY] Run a function on all other CPUs.
  * <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.
  * [RETURNS] 0 on success, else a negative status code. Does not return until
  * remote CPUs are nearly ready to execute <<func>> or are or have executed.
@@ -202,6 +199,8 @@
  * You must not call this function with disabled interrupts or from a
  * hardware interrupt handler or from a bottom half handler.
  */
+
+int smp_call_function(void (*func) (void *info), void *info, int wait)
 {
         /* FIXME: get cpu lock with hotplug cpus, or change this to
            bitmask. --RR */
@@ -263,6 +262,85 @@
 
  out:
         spin_unlock(&call_lock);
+ return ret;
+}
+
+/*
+ * 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.
+ * @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.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+
+static int smp_call_function_on_cpu(void (*func) (void *info), void *info,
+ int wait, unsigned long mask)
+{
+ struct call_data_struct data;
+ int ret = -1;
+ int timeout;
+ int i, cpu, num_cpus = hweight32(mask);
+
+ if (num_cpus == 0)
+ return -EINVAL;
+
+ cpu = get_cpu();
+ if ((1UL << cpu) & mask) {
+ put_cpu_no_resched();
+ return -EINVAL;
+ }
+
+ data.func = func;
+ data.info = info;
+ atomic_set(&data.started, 0);
+ data.wait = wait;
+ if (wait)
+ atomic_set(&data.finished, 0);
+
+ spin_lock(&call_lock);
+ call_data = &data;
+ /* Send a message to all other CPUs and wait for them to respond */
+ for (i = 0; i < NR_CPUS; i++) {
+ if (cpu_online(i) && ((1UL << i) & mask))
+ smp_message_pass(i, PPC_MSG_CALL_FUNCTION, 0, 0);
+ }
+
+ /* Wait for response */
+ timeout = 1000000;
+ while (atomic_read(&data.started) != num_cpus) {
+ if (--timeout == 0) {
+ printk("smp_call_function on cpu %d: other cpus not responding (%d)\n",
+ cpu, atomic_read(&data.started));
+ goto out;
+ }
+ barrier();
+ udelay(1);
+ }
+
+ if (wait) {
+ timeout = 1000000;
+ while (atomic_read(&data.finished) != num_cpus) {
+ if (--timeout == 0) {
+ printk("smp_call_function on cpu %d: other cpus not finishing (%d/%d)\n",
+ cpu, atomic_read(&data.finished), atomic_read(&data.started));
+ goto out;
+ }
+ barrier();
+ udelay(1);
+ }
+ }
+ ret = 0;
+
+ out:
+ spin_unlock(&call_lock);
+ pu_cpu_no_resched();
         return ret;
 }
 

-- 
function.linuxpower.ca

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