[POWERPC] Fix interrupt distribution in ppc970
In some of the PPC970 based systems, interrupt would be distributed to
offline cpus also even when booted with "maxcpus=1". So check whether
cpu online map and cpu present map are equal or not. If they are equal
default_distrib_server is used as interrupt server otherwise boot cpu
(default_server) used as interrupt server.
In addition to this, if an interrupt is assigned to a specific cpu (ie
smp affinity) and if that cpu is not online, the earlier code used to
return the default_distrib_server as interrupt server. This
introduces an additional parameter to the get_irq function, called
strict_check. Based on this parameter, if the cpu is not online
either default_distrib_server or -1 is returned.
Signed-off-by: Mohan Kumar M <mohan@in.ibm.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index f1df942..5bd90a7 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -156,9 +156,9 @@
#ifdef CONFIG_SMP
-static int get_irq_server(unsigned int virq)
+static int get_irq_server(unsigned int virq, unsigned int strict_check)
{
- unsigned int server;
+ int server;
/* For the moment only implement delivery to all cpus or one cpu */
cpumask_t cpumask = irq_desc[virq].affinity;
cpumask_t tmp = CPU_MASK_NONE;
@@ -166,22 +166,25 @@
if (!distribute_irqs)
return default_server;
- if (cpus_equal(cpumask, CPU_MASK_ALL)) {
- server = default_distrib_server;
- } else {
+ if (!cpus_equal(cpumask, CPU_MASK_ALL)) {
cpus_and(tmp, cpu_online_map, cpumask);
- if (cpus_empty(tmp))
- server = default_distrib_server;
- else
- server = get_hard_smp_processor_id(first_cpu(tmp));
+ server = first_cpu(tmp);
+
+ if (server < NR_CPUS)
+ return get_hard_smp_processor_id(server);
+
+ if (strict_check)
+ return -1;
}
- return server;
+ if (cpus_equal(cpu_online_map, cpu_present_map))
+ return default_distrib_server;
+ return default_server;
}
#else
-static int get_irq_server(unsigned int virq)
+static int get_irq_server(unsigned int virq, unsigned int strict_check)
{
return default_server;
}
@@ -192,7 +195,7 @@
{
unsigned int irq;
int call_status;
- unsigned int server;
+ int server;
pr_debug("xics: unmask virq %d\n", virq);
@@ -201,7 +204,7 @@
if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
return;
- server = get_irq_server(virq);
+ server = get_irq_server(virq, 0);
call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server,
DEFAULT_PRIORITY);
@@ -398,8 +401,7 @@
unsigned int irq;
int status;
int xics_status[2];
- unsigned long newmask;
- cpumask_t tmp = CPU_MASK_NONE;
+ int irq_server;
irq = (unsigned int)irq_map[virq].hwirq;
if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
@@ -413,18 +415,21 @@
return;
}
- /* For the moment only implement delivery to all cpus or one cpu */
- if (cpus_equal(cpumask, CPU_MASK_ALL)) {
- newmask = default_distrib_server;
- } else {
- cpus_and(tmp, cpu_online_map, cpumask);
- if (cpus_empty(tmp))
- return;
- newmask = get_hard_smp_processor_id(first_cpu(tmp));
+ /*
+ * For the moment only implement delivery to all cpus or one cpu.
+ * Get current irq_server for the given irq
+ */
+ irq_server = get_irq_server(irq, 1);
+ if (irq_server == -1) {
+ char cpulist[128];
+ cpumask_scnprintf(cpulist, sizeof(cpulist), cpumask);
+ printk(KERN_WARNING "xics_set_affinity: No online cpus in "
+ "the mask %s for irq %d\n", cpulist, virq);
+ return;
}
status = rtas_call(ibm_set_xive, 3, 1, NULL,
- irq, newmask, xics_status[1]);
+ irq, irq_server, xics_status[1]);
if (status) {
printk(KERN_ERR "xics_set_affinity: irq=%u ibm,set-xive "