ARM: vexpress/realview: consolidate immitation CPU hotplug

The only difference between the hotplug implementation for Realview
and Versatile Express are the bit in the auxiliary control register
to disable coherency.  Combine the two implentations accounting for
that difference.

Rename the functions to try to discourage cargo-cult copying of this
code.

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

4 files changed, 7 insertions, 111 deletions

diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile
index 51c35e2b737a..3651a1ed0f2b 100644
--- a/arch/arm/mach-vexpress/Makefile
+++ b/arch/arm/mach-vexpress/Makefile
@@ -15,6 +15,5 @@ obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM)	+= tc2_pm.o
 CFLAGS_tc2_pm.o                         += -march=armv7-a
 CFLAGS_REMOVE_tc2_pm.o                  = -pg
 obj-$(CONFIG_SMP)                       += platsmp.o
-obj-$(CONFIG_HOTPLUG_CPU)               += hotplug.o
 
 obj-$(CONFIG_ARCH_MPS2)                 += v2m-mps2.o
diff --git a/arch/arm/mach-vexpress/core.h b/arch/arm/mach-vexpress/core.h
index a162ab46ee02..f4a7519084f1 100644
--- a/arch/arm/mach-vexpress/core.h
+++ b/arch/arm/mach-vexpress/core.h
@@ -1,5 +1,3 @@
 bool vexpress_smp_init_ops(void);
 
 extern const struct smp_operations vexpress_smp_dt_ops;
-
-extern void vexpress_cpu_die(unsigned int cpu);
diff --git a/arch/arm/mach-vexpress/hotplug.c b/arch/arm/mach-vexpress/hotplug.c
deleted file mode 100644
index d8f1a05f5e87..000000000000
--- a/arch/arm/mach-vexpress/hotplug.c
+++ /dev/null
@@ -1,108 +0,0 @@
-/*
- *  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/smp_plat.h>
-#include <asm/cp15.h>
-
-#include "core.h"
-
-static inline void cpu_enter_lowpower(void)
-{
-        unsigned int v;
-
-        asm volatile(
-                "mcr    p15, 0, %1, c7, c5, 0\n"
-        "       mcr     p15, 0, %1, c7, c10, 4\n"
-        /*
-         * Turn off coherency
-         */
-        "       mrc     p15, 0, %0, c1, c0, 1\n"
-        "       bic     %0, %0, %3\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), "Ir" (0x40)
-          : "cc");
-}
-
-static inline void 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, %2\n"
-        "       mcr     p15, 0, %0, c1, c0, 1\n"
-          : "=&r" (v)
-          : "Ir" (CR_C), "Ir" (0x40)
-          : "cc");
-}
-
-static inline void 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 (;;) {
-                wfi();
-
-                if (pen_release == cpu_logical_map(cpu)) {
-                        /*
-                         * OK, proper wakeup, we're done
-                         */
-                        break;
-                }
-
-                /*
-                 * 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 vexpress_cpu_die(unsigned int cpu)
-{
-        int spurious = 0;
-
-        /*
-         * we're ready for shutdown now, so do it
-         */
-        cpu_enter_lowpower();
-        platform_do_lowpower(cpu, &spurious);
-
-        /*
-         * bring this CPU back into the world of cache
-         * coherency, and then restore interrupts
-         */
-        cpu_leave_lowpower();
-
-        if (spurious)
-                pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
-}
diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index 742499bac6d0..af0113be5970 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -82,6 +82,13 @@ static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
         vexpress_flags_set(__pa_symbol(versatile_secondary_startup));
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+static void vexpress_cpu_die(unsigned int cpu)
+{
+        versatile_immitation_cpu_die(cpu, 0x40);
+}
+#endif
+
 const struct smp_operations vexpress_smp_dt_ops __initconst = {
         .smp_prepare_cpus       = vexpress_smp_dt_prepare_cpus,
         .smp_secondary_init     = versatile_secondary_init,