summaryrefslogtreecommitdiff
path: root/arch/arm/mach-sti/platsmp.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-sti/platsmp.c')
-rw-r--r--arch/arm/mach-sti/platsmp.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c
new file mode 100644
index 000000000..d4b624f8d
--- /dev/null
+++ b/arch/arm/mach-sti/platsmp.c
@@ -0,0 +1,116 @@
+/*
+ * arch/arm/mach-sti/platsmp.c
+ *
+ * Copyright (C) 2013 STMicroelectronics (R&D) Limited.
+ * http://www.st.com
+ *
+ * Cloned from linux/arch/arm/mach-vexpress/platsmp.c
+ *
+ * Copyright (C) 2002 ARM Ltd.
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#include "smp.h"
+
+static void write_pen_release(int val)
+{
+ pen_release = val;
+ smp_wmb();
+ sync_cache_w(&pen_release);
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void sti_secondary_init(unsigned int cpu)
+{
+ trace_hardirqs_off();
+
+ /*
+ * let the primary processor know we're out of the
+ * pen, then head off into the C entry point
+ */
+ write_pen_release(-1);
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+static int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ unsigned long timeout;
+
+ /*
+ * set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ spin_lock(&boot_lock);
+
+ /*
+ * The secondary processor is waiting to be released from
+ * the holding pen - release it, then wait for it to flag
+ * that it has been released by resetting pen_release.
+ *
+ * Note that "pen_release" is the hardware CPU ID, whereas
+ * "cpu" is Linux's internal ID.
+ */
+ write_pen_release(cpu_logical_map(cpu));
+
+ /*
+ * Send the secondary CPU a soft interrupt, thereby causing
+ * it to jump to the secondary entrypoint.
+ */
+ arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ smp_rmb();
+ if (pen_release == -1)
+ break;
+
+ udelay(10);
+ }
+
+ /*
+ * now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ spin_unlock(&boot_lock);
+
+ return pen_release != -1 ? -ENOSYS : 0;
+}
+
+static void __init sti_smp_prepare_cpus(unsigned int max_cpus)
+{
+ void __iomem *scu_base = NULL;
+ struct device_node *np = of_find_compatible_node(
+ NULL, NULL, "arm,cortex-a9-scu");
+ if (np) {
+ scu_base = of_iomap(np, 0);
+ scu_enable(scu_base);
+ of_node_put(np);
+ }
+}
+
+struct smp_operations __initdata sti_smp_ops = {
+ .smp_prepare_cpus = sti_smp_prepare_cpus,
+ .smp_secondary_init = sti_secondary_init,
+ .smp_boot_secondary = sti_boot_secondary,
+};