ARM: tango: add HOTPLUG_CPU support

cpu_die() and cpu_kill() are implemented in firmware.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

diff --git a/arch/arm/mach-tango/platsmp.c b/arch/arm/mach-tango/platsmp.c
index a21f55e000d258c734535cbfc9df57744599887a..8380699d4fa3480392beb604400bd54f1312ff38 100644 (file)
--- a/arch/arm/mach-tango/platsmp.c
+++ b/arch/arm/mach-tango/platsmp.c
@@ -1,3 +1,4 @@
+#include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/smp.h>
 #include "smc.h"
@@ -9,8 +10,43 @@ static int tango_boot_secondary(unsigned int cpu, struct task_struct *idle)
        return 0;
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * cpu_kill() and cpu_die() run concurrently on different cores.
+ * Firmware will only "kill" a core once it has properly "died".
+ * Try a few times to kill a core before giving up, and sleep
+ * between tries to give that core enough time to die.
+ */
+static int tango_cpu_kill(unsigned int cpu)
+{
+       int i, err;
+
+       for (i = 0; i < 10; ++i) {
+               msleep(10);
+               err = tango_aux_core_kill(cpu);
+               if (!err)
+                       return true;
+       }
+
+       return false;
+}
+
+static void tango_cpu_die(unsigned int cpu)
+{
+       while (tango_aux_core_die(cpu) < 0)
+               cpu_relax();
+
+       panic("cpu %d failed to die\n", cpu);
+}
+#else
+#define tango_cpu_kill NULL
+#define tango_cpu_die  NULL
+#endif
+
 static const struct smp_operations tango_smp_ops __initconst = {
        .smp_boot_secondary     = tango_boot_secondary,
+       .cpu_kill               = tango_cpu_kill,
+       .cpu_die                = tango_cpu_die,
 };
 
 CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops);

diff --git a/arch/arm/mach-tango/smc.h b/arch/arm/mach-tango/smc.h
index 7a4af35cc390bd3acc29b3ce1d38c3f62feef304..3d31f984f44ce149ce0fc48e37f939dad64d0ceb 100644 (file)
--- a/arch/arm/mach-tango/smc.h
+++ b/arch/arm/mach-tango/smc.h
@@ -2,4 +2,6 @@ extern int tango_smc(unsigned int val, unsigned int service);
 
 #define tango_set_l2_control(val)      tango_smc(val, 0x102)
 #define tango_start_aux_core(val)      tango_smc(val, 0x104)
-#define tango_set_aux_boot_addr(val)   tango_smc((unsigned int)val, 0x105)
+#define tango_set_aux_boot_addr(val)   tango_smc(val, 0x105)
+#define tango_aux_core_die(val)                tango_smc(val, 0x121)
+#define tango_aux_core_kill(val)       tango_smc(val, 0x122)