kexec does not disable the outer cache before disabling the inner
caches in cpu_proc_fin(). So L2 is enabled across the kexec jump. When
the new kernel enables chaches again, it randomly crashes.

Disabling L2 before calling cpu_proc_fin() cures the problem.

Add a disable function to the outer_cache_fns struct and call it
before calling cpu_proc_fin().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Index: linux-2.6/arch/arm/include/asm/outercache.h
===================================================================
--- linux-2.6.orig/arch/arm/include/asm/outercache.h
+++ linux-2.6/arch/arm/include/asm/outercache.h
@@ -28,6 +28,7 @@ struct outer_cache_fns {
 #ifdef CONFIG_OUTER_CACHE_SYNC
 	void (*sync)(void);
 #endif
+	void (*disable)(void);
 };
 
 #ifdef CONFIG_OUTER_CACHE
@@ -50,6 +51,12 @@ static inline void outer_flush_range(uns
 		outer_cache.flush_range(start, end);
 }
 
+static inline void outer_cache_disable(void)
+{
+	if (outer_cache.disable)
+		outer_cache.disable();
+}
+
 #else
 
 static inline void outer_inv_range(unsigned long start, unsigned long end)
@@ -58,6 +65,7 @@ static inline void outer_clean_range(uns
 { }
 static inline void outer_flush_range(unsigned long start, unsigned long end)
 { }
+static inline void outer_cache_disable(void) { }
 
 #endif
 
Index: linux-2.6/arch/arm/kernel/machine_kexec.c
===================================================================
--- linux-2.6.orig/arch/arm/kernel/machine_kexec.c
+++ linux-2.6/arch/arm/kernel/machine_kexec.c
@@ -74,6 +74,7 @@ void machine_kexec(struct kimage *image)
 			   (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
 	printk(KERN_INFO "Bye!\n");
 
+	outer_cache_disable();
 	cpu_proc_fin();
 	setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
 	cpu_reset(reboot_code_buffer_phys);