[POWERPC] Limit range of __init_ref_ok somewhat

This patch introduces zalloc_maybe_bootmem and uses it so that we don't
have to mark a whole (largish) routine as __init_ref_ok.

Signed-off-by: Stephen Rothwell <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

arch/powerpc/kernel/irq.c

···
 	return h->of_node != NULL && h->of_node == np;
 }
 
-__init_refok struct irq_host *irq_alloc_host(struct device_node *of_node,
+struct irq_host *irq_alloc_host(struct device_node *of_node,
 				unsigned int revmap_type,
 				unsigned int revmap_arg,
 				struct irq_host_ops *ops,
···
 	/* Allocate structure and revmap table if using linear mapping */
 	if (revmap_type == IRQ_HOST_MAP_LINEAR)
 		size += revmap_arg * sizeof(unsigned int);
-	if (mem_init_done)
-		host = kzalloc(size, GFP_KERNEL);
-	else {
-		host = alloc_bootmem(size);
-		if (host)
-			memset(host, 0, size);
-	}
+	host = zalloc_maybe_bootmem(size, GFP_KERNEL);
 	if (host == NULL)
 		return NULL;
 

arch/powerpc/lib/alloc.c

···
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/bootmem.h>
+#include <linux/string.h>
 
 #include <asm/system.h>
 
···
 		return kmalloc(size, mask);
 	else
 		return alloc_bootmem(size);
+}
+
+void * __init_refok zalloc_maybe_bootmem(size_t size, gfp_t mask)
+{
+	void *p;
+
+	if (mem_init_done)
+		p = kzalloc(size, mask);
+	else {
+		p = alloc_bootmem(size);
+		if (p)
+			memset(p, 0, size);
+	}
+	return p;
 }

include/asm-powerpc/system.h

···
 extern unsigned long klimit;
 
 extern void *alloc_maybe_bootmem(size_t size, gfp_t mask);
+extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask);
 
 extern int powersave_nap;	/* set if nap mode can be used in idle loop */