Merge tag 'v2.6.37' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / arch / arm / mach-ux500 / hotplug.c

diff --git a/arch/arm/mach-ux500/hotplug.c b/arch/arm/mach-ux500/hotplug.c
new file mode 100644 (file)
index 0000000..b782a03
--- /dev/null
+++ b/arch/arm/mach-ux500/hotplug.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) STMicroelectronics 2009
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ *     Based on ARM realview platform
+ *
+ * Author: Sundar Iyer <sundar.iyer@stericsson.com>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+#include <linux/completion.h>
+
+#include <asm/cacheflush.h>
+
+extern volatile int pen_release;
+
+static DECLARE_COMPLETION(cpu_killed);
+
+static inline void platform_do_lowpower(unsigned int cpu)
+{
+       flush_cache_all();
+
+       /* we put the platform to just WFI */
+       for (;;) {
+               __asm__ __volatile__("dsb\n\t" "wfi\n\t"
+                               : : : "memory");
+               if (pen_release == cpu) {
+                       /*
+                        * OK, proper wakeup, we're done
+                        */
+                       break;
+               }
+       }
+}
+
+int platform_cpu_kill(unsigned int cpu)
+{
+       return wait_for_completion_timeout(&cpu_killed, 5000);
+}
+
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+void platform_cpu_die(unsigned int cpu)
+{
+#ifdef DEBUG
+       unsigned int this_cpu = hard_smp_processor_id();
+
+       if (cpu != this_cpu) {
+               printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
+                          this_cpu, cpu);
+               BUG();
+       }
+#endif
+
+       printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
+       complete(&cpu_killed);
+
+       /* directly enter low power state, skipping secure registers */
+       platform_do_lowpower(cpu);
+}
+
+int platform_cpu_disable(unsigned int cpu)
+{
+       /*
+        * we don't allow CPU 0 to be shutdown (it is still too special
+        * e.g. clock tick interrupts)
+        */
+       return cpu == 0 ? -EPERM : 0;
+}