4 files changed, 113 insertions, 0 deletions

diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile
index b595d22134ec..1b25d92ebf22 100644
--- a/arch/arm/mach-zynq/Makefile
+++ b/arch/arm/mach-zynq/Makefile
@@ -4,4 +4,7 @@
 
 # Common support
 obj-y                           := common.o slcr.o
+CFLAGS_REMOVE_hotplug.o         =-march=armv6k
+CFLAGS_hotplug.o                =-Wa,-march=armv7-a -mcpu=cortex-a9
+obj-$(CONFIG_HOTPLUG_CPU)       += hotplug.o
 obj-$(CONFIG_SMP)               += headsmp.o platsmp.o
diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h
index fd308f8b18d9..fbbd0e21c404 100644
--- a/arch/arm/mach-zynq/common.h
+++ b/arch/arm/mach-zynq/common.h
@@ -34,4 +34,7 @@ extern struct smp_operations zynq_smp_ops __initdata;
 extern void __iomem *zynq_slcr_base;
 extern void __iomem *zynq_scu_base;
 
+/* Hotplug */
+extern void zynq_platform_cpu_die(unsigned int cpu);
+
 #endif
diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c
new file mode 100644
index 000000000000..c89672bd1de2
--- /dev/null
+++ b/arch/arm/mach-zynq/hotplug.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2012-2013 Xilinx
+ *
+ * based on linux/arch/arm/mach-realview/hotplug.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/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include "common.h"
+
+static inline void zynq_cpu_enter_lowpower(void)
+{
+        unsigned int v;
+
+        flush_cache_all();
+        asm volatile(
+        "       mcr     p15, 0, %1, c7, c5, 0\n"
+        "       dsb\n"
+        /*
+         * Turn off coherency
+         */
+        "       mrc     p15, 0, %0, c1, c0, 1\n"
+        "       bic     %0, %0, #0x40\n"
+        "       mcr     p15, 0, %0, c1, c0, 1\n"
+        "       mrc     p15, 0, %0, c1, c0, 0\n"
+        "       bic     %0, %0, %2\n"
+        "       mcr     p15, 0, %0, c1, c0, 0\n"
+          : "=&r" (v)
+          : "r" (0), "Ir" (CR_C)
+          : "cc");
+}
+
+static inline void zynq_cpu_leave_lowpower(void)
+{
+        unsigned int v;
+
+        asm volatile(
+        "       mrc     p15, 0, %0, c1, c0, 0\n"
+        "       orr     %0, %0, %1\n"
+        "       mcr     p15, 0, %0, c1, c0, 0\n"
+        "       mrc     p15, 0, %0, c1, c0, 1\n"
+        "       orr     %0, %0, #0x40\n"
+        "       mcr     p15, 0, %0, c1, c0, 1\n"
+          : "=&r" (v)
+          : "Ir" (CR_C)
+          : "cc");
+}
+
+static inline void zynq_platform_do_lowpower(unsigned int cpu, int *spurious)
+{
+        /*
+         * there is no power-control hardware on this platform, so all
+         * we can do is put the core into WFI; this is safe as the calling
+         * code will have already disabled interrupts
+         */
+        for (;;) {
+                dsb();
+                wfi();
+
+                /*
+                 * Getting here, means that we have come out of WFI without
+                 * having been woken up - this shouldn't happen
+                 *
+                 * Just note it happening - when we're woken, we can report
+                 * its occurrence.
+                 */
+                (*spurious)++;
+        }
+}
+
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+void zynq_platform_cpu_die(unsigned int cpu)
+{
+        int spurious = 0;
+
+        /*
+         * we're ready for shutdown now, so do it
+         */
+        zynq_cpu_enter_lowpower();
+        zynq_platform_do_lowpower(cpu, &spurious);
+
+        /*
+         * bring this CPU back into the world of cache
+         * coherency, and then restore interrupts
+         */
+        zynq_cpu_leave_lowpower();
+
+        if (spurious)
+                pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+}
diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
index cdfd888ca783..3072cbd7ec6f 100644
--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c
@@ -146,4 +146,7 @@ struct smp_operations zynq_smp_ops __initdata = {
         .smp_prepare_cpus       = zynq_smp_prepare_cpus,
         .smp_secondary_init     = zynq_secondary_init,
         .smp_boot_secondary     = zynq_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+        .cpu_die                = zynq_platform_cpu_die,
+#endif
 };