ARM: Enable selection of SMP operations at boot time

Add a new 'smp_init' hook to machine_desc so platforms can specify a
function to be used to setup smp ops instead of having a statically
defined value.  The hook must return true when smp_ops are initialized.
If false the static mdesc->smp_ops will be used by default.

Add the definition of "bool" by including the linux/types.h file to
asm/mach/arch.h and make it self-contained.
Signed-off-by: NJon Medhurst <tixy@linaro.org>
Signed-off-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm/include/asm/mach/arch.h

@@ -8,6 +8,8 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/types.h>
+
 #ifndef __ASSEMBLY__
 
 struct tag;
@@ -16,8 +18,10 @@ struct pt_regs;
 struct smp_operations;
 #ifdef CONFIG_SMP
 #define smp_ops(ops) (&(ops))
+#define smp_init_ops(ops) (&(ops))
 #else
 #define smp_ops(ops) (struct smp_operations *)NULL
+#define smp_init_ops(ops) (bool (*)(void))NULL
 #endif
 
 struct machine_desc {
@@ -41,6 +45,7 @@ struct machine_desc {
 	unsigned char		reserve_lp2 :1;	/* never has lp2	*/
 	char			restart_mode;	/* default restart mode	*/
 	struct smp_operations	*smp;		/* SMP operations	*/
+	bool			(*smp_init)(void);
 	void			(*fixup)(struct tag *, char **,
 					 struct meminfo *);
 	void			(*reserve)(void);/* reserve mem blocks	*/

arch/arm/kernel/setup.c

@@ -800,10 +800,12 @@ void __init setup_arch(char **cmdline_p)
 	psci_init();
 #ifdef CONFIG_SMP
 	if (is_smp()) {
-		if (psci_smp_available())
-			smp_set_ops(&psci_smp_ops);
-		else if (mdesc->smp)
-			smp_set_ops(mdesc->smp);
+		if (!mdesc->smp_init || !mdesc->smp_init()) {
+			if (psci_smp_available())
+				smp_set_ops(&psci_smp_ops);
+			else if (mdesc->smp)
+				smp_set_ops(mdesc->smp);
+		}
 		smp_init_cpus();
 	}
 #endif