[PATCH 27/27] alpha, smpboot: Use generic SMP booting infrastructure

From: Srivatsa S. Bhat
Date: Fri Jun 01 2012 - 05:17:19 EST


Convert alpha to use the generic framework to boot secondary CPUs.

Notes:
1. The secondary cpu was being set in the cpu_online_mask way too early.
Postpone it.

2. The original code was enabling interrupts before calling
wait_boot_cpu_to_stop(). Instead postpone the enabling of interrupts
to after the cpu_online_mask is set.

Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Mike Frysinger <vapier@xxxxxxxxxx>
Cc: linux-alpha@xxxxxxxxxxxxxxx
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---

arch/alpha/kernel/smp.c | 27 +++++++++++++++------------
1 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index 35ddc02..2547431 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -28,6 +28,7 @@
#include <linux/profile.h>
#include <linux/bitops.h>
#include <linux/cpu.h>
+#include <linux/smpboot.h>

#include <asm/hwrpb.h>
#include <asm/ptrace.h>
@@ -119,13 +120,17 @@ wait_boot_cpu_to_stop(int cpuid)
void __cpuinit
smp_callin(void)
{
- int cpuid = hard_smp_processor_id();
+ smpboot_start_secondary(NULL);
+}
+
+void __cpuinit __cpu_pre_starting(void *unused)
+{
+ unsigned int cpuid = hard_smp_processor_id();

if (cpu_online(cpuid)) {
printk("??, cpu 0x%x already present??\n", cpuid);
BUG();
}
- set_cpu_online(cpuid, true);

/* Turn on machine checks. */
wrmces(7);
@@ -145,15 +150,16 @@ smp_callin(void)
/* All kernel threads share the same mm context. */
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
+}

- /* inform the notifiers about the new cpu */
- notify_cpu_starting(cpuid);
-
- /* Must have completely accurate bogos. */
- local_irq_enable();
+void __cpuinit __cpu_pre_online(void *unused)
+{
+ unsigned int cpuid = hard_smp_processor_id();

- /* Wait boot CPU to stop with irq enabled before running
- calibrate_delay. */
+ /*
+ * Wait boot CPU to stop with irq disabled before running
+ * calibrate_delay.
+ */
wait_boot_cpu_to_stop(cpuid);
mb();
calibrate_delay();
@@ -165,9 +171,6 @@ smp_callin(void)

DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
cpuid, current, current->active_mm));
-
- /* Do nothing. */
- cpu_idle();
}

/* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/