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authorMarc Gonzalez <marc_gonzalez@sigmadesigns.com>2016-06-29 14:21:42 +0200
committerOlof Johansson <olof@lixom.net>2016-07-05 20:57:13 -0700
commit222de7bfdf135e33f8708c6b287c888c8ff100cc (patch)
tree4cc13d209979e198edcf25b9b6ee74533efb043a /arch
parent06de15694bb0c9d6c27b1f33dbf8337f1985a59d (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-tango/platsmp.c36
-rw-r--r--arch/arm/mach-tango/smc.h4
2 files changed, 39 insertions, 1 deletions
diff --git a/arch/arm/mach-tango/platsmp.c b/arch/arm/mach-tango/platsmp.c
index a21f55e000d2..8380699d4fa3 100644
--- 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 7a4af35cc390..3d31f984f44c 100644
--- 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)