powerpc/85xx: kexec for SMP 85xx BookE systems

Adds support for kexec on 85xx machines for the BookE platform.
Including support for SMP machines

Based off work from Maxim Uvarov <muvarov@mvista.com>
Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/Kconfig

@@ -352,7 +352,7 @@ config ARCH_ENABLE_MEMORY_HOTREMOVE
 
 config KEXEC
 	bool "kexec system call (EXPERIMENTAL)"
-	depends on (PPC_BOOK3S || (FSL_BOOKE && !SMP)) && EXPERIMENTAL
+	depends on (PPC_BOOK3S || FSL_BOOKE) && EXPERIMENTAL
 	help
 	  kexec is a system call that implements the ability to shutdown your
 	  current kernel, and to start another kernel.  It is like a reboot
@@ -369,8 +369,8 @@ config KEXEC
 
 config CRASH_DUMP
 	bool "Build a kdump crash kernel"
-	depends on PPC64 || 6xx
-	select RELOCATABLE if PPC64
+	depends on PPC64 || 6xx || FSL_BOOKE
+	select RELOCATABLE if PPC64 || FSL_BOOKE
 	help
 	  Build a kernel suitable for use as a kdump capture kernel.
 	  The same kernel binary can be used as production kernel and dump
@@ -898,7 +898,7 @@ config KERNEL_START_BOOL
 config KERNEL_START
 	hex "Virtual address of kernel base" if KERNEL_START_BOOL
 	default PAGE_OFFSET if PAGE_OFFSET_BOOL
-	default "0xc2000000" if CRASH_DUMP
+	default "0xc2000000" if CRASH_DUMP && !RELOCATABLE
 	default "0xc0000000"
 
 config PHYSICAL_START_BOOL
@@ -911,7 +911,7 @@ config PHYSICAL_START_BOOL
 
 config PHYSICAL_START
 	hex "Physical address where the kernel is loaded" if PHYSICAL_START_BOOL
-	default "0x02000000" if PPC_STD_MMU && CRASH_DUMP
+	default "0x02000000" if PPC_STD_MMU && CRASH_DUMP && !RELOCATABLE
 	default "0x00000000"
 
 config PHYSICAL_ALIGN

arch/powerpc/platforms/85xx/smp.c

@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/of.h>
+#include <linux/kexec.h>
 
 #include <asm/machdep.h>
 #include <asm/pgtable.h>
@@ -24,6 +25,7 @@
 #include <asm/dbell.h>
 
 #include <sysdev/fsl_soc.h>
+#include <sysdev/mpic.h>
 
 extern void __early_start(void);
 
@@ -105,8 +107,64 @@ smp_85xx_setup_cpu(int cpu_nr)
 
 struct smp_ops_t smp_85xx_ops = {
 	.kick_cpu = smp_85xx_kick_cpu,
+#ifdef CONFIG_KEXEC
+	.give_timebase	= smp_generic_give_timebase,
+	.take_timebase	= smp_generic_take_timebase,
+#endif
 };
 
+#ifdef CONFIG_KEXEC
+static int kexec_down_cpus = 0;
+
+void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
+{
+	mpic_teardown_this_cpu(1);
+
+	/* When crashing, this gets called on all CPU's we only
+	 * take down the non-boot cpus */
+	if (smp_processor_id() != boot_cpuid)
+	{
+		local_irq_disable();
+		kexec_down_cpus++;
+
+		while (1);
+	}
+}
+
+static void mpc85xx_smp_kexec_down(void *arg)
+{
+	if (ppc_md.kexec_cpu_down)
+		ppc_md.kexec_cpu_down(0,1);
+}
+
+static void mpc85xx_smp_machine_kexec(struct kimage *image)
+{
+	int timeout = 2000;
+	int i;
+
+	set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
+
+	smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);
+
+	while ( (kexec_down_cpus != (num_online_cpus() - 1)) &&
+		( timeout > 0 ) )
+	{
+		timeout--;
+	}
+
+	if ( !timeout )
+		printk(KERN_ERR "Unable to bring down secondary cpu(s)");
+
+	for (i = 0; i < num_present_cpus(); i++)
+	{
+		if ( i == smp_processor_id() ) continue;
+		mpic_reset_core(i);
+	}
+
+	default_machine_kexec(image);
+}
+#endif /* CONFIG_KEXEC */
+
 void __init mpc85xx_smp_init(void)
 {
 	struct device_node *np;
@@ -124,4 +182,9 @@ void __init mpc85xx_smp_init(void)
 	BUG_ON(!smp_85xx_ops.message_pass);
 
 	smp_ops = &smp_85xx_ops;
+
+#ifdef CONFIG_KEXEC
+	ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
+	ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
+#endif
 }