path: root/target/linux/cns3xxx/patches-3.0/049-cns3xxx_smp_support.patch

--- a/arch/arm/mach-cns3xxx/Makefile
+++ b/arch/arm/mach-cns3xxx/Makefile
@@ -1,3 +1,6 @@
 obj-$(CONFIG_ARCH_CNS3XXX)		+= core.o pm.o devices.o
 obj-$(CONFIG_PCI)			+= pcie.o
 obj-$(CONFIG_MACH_CNS3420VB)		+= cns3420vb.o
+obj-$(CONFIG_SMP)			+= platsmp.o headsmp.o
+obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o
+obj-$(CONFIG_LOCAL_TIMERS)		+= localtimer.o
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/headsmp.S
@@ -0,0 +1,43 @@
+/*
+ *  linux/arch/arm/mach-cns3xxx/headsmp.S
+ *
+ *  Copyright (c) 2003 ARM Limited
+ *  Copyright 2011 Gateworks Corporation
+ *		   Chris Lang <clang@gateworks.com
+ *
+ *  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/linkage.h>
+#include <linux/init.h>
+
+	__INIT
+
+/*
+ * CNS3XXX specific entry point for secondary CPUs.  This
+ * provides a "holding pen" into which all secondary cores are held
+ * until we're ready for them to initialise.
+ */
+ENTRY(cns3xxx_secondary_startup)
+	mrc	p15, 0, r0, c0, c0, 5
+	and	r0, r0, #15
+	adr	r4, 1f
+	ldmia	r4, {r5, r6}
+	sub	r4, r4, r5
+	add	r6, r6, r4
+pen:	ldr	r7, [r6]
+	cmp	r7, r0
+	bne	pen
+
+	/*
+	 * we've been released from the holding pen: secondary_stack
+	 * should now contain the SVC stack for this core
+	 */
+	b	secondary_startup
+
+	.align
+1:	.long	.
+	.long	pen_release
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/hotplug.c
@@ -0,0 +1,131 @@
+/*
+ *  linux/arch/arm/mach-cns3xxx/hotplug.c
+ *
+ *  Copyright (C) 2002 ARM Ltd.
+ *  Copyright 2011 Gateworks Corporation
+ *		   Chris Lang <clang@gateworks.com>
+ *
+ *  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>
+
+extern volatile int pen_release;
+
+static inline void cpu_enter_lowpower(void)
+{
+	unsigned int v;
+
+	flush_cache_all();
+	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 (;;) {
+		/*
+		 * here's the WFI
+		 */
+		asm(".word	0xe320f003\n"
+		    :
+		    :
+		    : "memory", "cc");
+
+		if (pen_release == 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)++;
+	}
+}
+
+int platform_cpu_kill(unsigned int cpu)
+{
+	return 1;
+}
+
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+void platform_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);
+}
+
+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;
+}
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/localtimer.c
@@ -0,0 +1,29 @@
+/*
+ *  linux/arch/arm/mach-cns3xxx/localtimer.c
+ *
+ *  Copyright (C) 2002 ARM Ltd.
+ *  Copyright 2011 Gateworks Corporation
+ *		   Chris Lang <clang@gateworks.com>
+ *
+ *  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/init.h>
+#include <linux/smp.h>
+#include <linux/clockchips.h>
+
+#include <asm/smp_twd.h>
+#include <asm/localtimer.h>
+#include <mach/irqs.h>
+
+/*
+ * Setup the local clock events for a CPU.
+ */
+void __cpuinit local_timer_setup(struct clock_event_device *evt)
+{
+	evt->irq = IRQ_LOCALTIMER;
+	twd_timer_setup(evt);
+}
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/platsmp.c
@@ -0,0 +1,168 @@
+/*
+ *  linux/arch/arm/mach-cns3xxx/platsmp.c
+ *
+ *  Copyright (C) 2002 ARM Ltd.
+ *  Copyright 2011 Gateworks Corporation
+ *		   Chris Lang <clang@gateworks.com>
+ *
+ *  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/init.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_scu.h>
+#include <asm/unified.h>
+#include <mach/hardware.h>
+#include <mach/cns3xxx.h>
+
+#include "core.h"
+
+extern void cns3xxx_secondary_startup(void);
+
+/*
+ * control for which core is the next to come out of the secondary
+ * boot "holding pen"
+ */
+volatile int __cpuinitdata pen_release = -1;
+
+/*
+ * Write pen_release in a way that is guaranteed to be visible to all
+ * observers, irrespective of whether they're taking part in coherency
+ * or not.  This is necessary for the hotplug code to work reliably.
+ */
+static void __cpuinit write_pen_release(int val)
+{
+	pen_release = val;
+	smp_wmb();
+	__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
+	outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
+}
+
+static void __iomem *scu_base_addr(void)
+{
+	return (void __iomem *)(CNS3XXX_TC11MP_SCU_BASE_VIRT);
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+void __cpuinit platform_secondary_init(unsigned int cpu)
+{
+	/*
+	 * if any interrupts are already enabled for the primary
+	 * core (e.g. timer irq), then they will not have been enabled
+	 * for us: do so
+	 */
+	gic_secondary_init(0);
+
+	/*
+	 * let the primary processor know we're out of the
+	 * pen, then head off into the C entry point
+	 */
+	write_pen_release(-1);
+
+	/*
+	 * Synchronise with the boot thread.
+	 */
+	spin_lock(&boot_lock);
+	spin_unlock(&boot_lock);
+}
+
+int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	unsigned long timeout;
+
+	/*
+	 * Set synchronisation state between this boot processor
+	 * and the secondary one
+	 */
+	spin_lock(&boot_lock);
+
+	/*
+	 * This is really belt and braces; we hold unintended secondary
+	 * CPUs in the holding pen until we're ready for them.  However,
+	 * since we haven't sent them a soft interrupt, they shouldn't
+	 * be there.
+	 */
+	write_pen_release(cpu);
+
+	/*
+	 * Send the secondary CPU a soft interrupt, thereby causing
+	 * the boot monitor to read the system wide flags register,
+	 * and branch to the address found there.
+	 */
+	smp_cross_call(cpumask_of(cpu), 1);
+
+	timeout = jiffies + (1 * HZ);
+	while (time_before(jiffies, timeout)) {
+		smp_rmb();
+		if (pen_release == -1)
+			break;
+
+		udelay(10);
+	}
+
+	/*
+	 * now the secondary core is starting up let it run its
+	 * calibrations, then wait for it to finish
+	 */
+	spin_unlock(&boot_lock);
+
+	return pen_release != -1 ? -ENOSYS : 0;
+}
+
+/*
+ * Initialise the CPU possible map early - this describes the CPUs
+ * which may be present or become present in the system.
+ */
+void __init smp_init_cpus(void)
+{
+	void __iomem *scu_base = scu_base_addr();
+	unsigned int i, ncores;
+
+	ncores = scu_base ? scu_get_core_count(scu_base) : 1;
+
+	/* sanity check */
+	if (ncores > NR_CPUS) {
+		printk(KERN_WARNING
+		       "cns3xxx: no. of cores (%d) greater than configured "
+		       "maximum of %d - clipping\n",
+		       ncores, NR_CPUS);
+		ncores = NR_CPUS;
+	}
+
+	for (i = 0; i < ncores; i++)
+		set_cpu_possible(i, true);
+}
+
+void __init platform_smp_prepare_cpus(unsigned int max_cpus)
+{
+	int i;
+
+	/*
+	 * Initialise the present map, which describes the set of CPUs
+	 * actually populated at the present time.
+	 */
+	for (i = 0; i < max_cpus; i++)
+		set_cpu_present(i, true);
+
+	scu_enable(scu_base_addr());
+
+	/*
+	 * Write the address of secondary startup into the
+	 * system-wide flags register. The boot monitor waits
+	 * until it receives a soft interrupt, and then the
+	 * secondary CPU branches to this address.
+	 */
+	__raw_writel(virt_to_phys(cns3xxx_secondary_startup),
+			(void __iomem *)(0xFFF07000 + 0x0600));
+}
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/include/mach/smp.h
@@ -0,0 +1,13 @@
+#ifndef __MACH_SMP_H
+#define __MACH_SMP_H
+
+#include <asm/hardware/gic.h>
+
+/*
+ * We use IRQ1 as the IPI
+ */
+static inline void smp_cross_call(const struct cpumask *mask, int ipi)
+{
+	gic_raise_softirq(mask, ipi);
+}
+#endif
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1311,7 +1311,7 @@ config SMP
 	depends on REALVIEW_EB_ARM11MP || REALVIEW_EB_A9MP || \
 		 MACH_REALVIEW_PB11MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || \
 		 ARCH_EXYNOS4 || ARCH_TEGRA || ARCH_U8500 || ARCH_VEXPRESS_CA9X4 || \
-		 ARCH_MSM_SCORPIONMP || ARCH_SHMOBILE
+		 ARCH_MSM_SCORPIONMP || ARCH_SHMOBILE || ARCH_CNS3XXX
 	select USE_GENERIC_SMP_HELPERS
 	select HAVE_ARM_SCU if !ARCH_MSM_SCORPIONMP
 	help