init: provide a generic free_initmem implementation

Patch series "provide a generic free_initmem implementation", v2.

Many architectures implement free_initmem() in exactly the same or very
similar way: they wrap the call to free_initmem_default() with sometimes
different 'poison' parameter.

These patches switch those architectures to use a generic implementation
that does free_initmem_default(POISON_FREE_INITMEM).

This was inspired by Christoph's patches for free_initrd_mem [1] and I
shamelessly copied changelog entries from his patches :)

[1] https://lore.kernel.org/lkml/[e-mail]/

This patch (of 2):

For most architectures free_initmem just a wrapper for the same
free_initmem_default(-1) call. Provide that as a generic implementation
marked __weak.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Mike Rapoport <[e-mail]>
Reviewed-by: Andrew Morton <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: Richard Kuo <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/alpha/mm/init.c

···
 	memblock_free_all();
 	mem_init_print_info(NULL);
 }
-
-void
-free_initmem(void)
-{
-	free_initmem_default(-1);
-}

arch/arc/mm/init.c

···
 	memblock_free_all();
 	mem_init_print_info(NULL);
 }
-
-/*
- * free_initmem: Free all the __init memory.
- */
-void __ref free_initmem(void)
-{
-	free_initmem_default(-1);
-}

arch/c6x/mm/init.c

···
 
 	mem_init_print_info(NULL);
 }
-
-void __init free_initmem(void)
-{
-	free_initmem_default(-1);
-}

arch/h8300/mm/init.c

···
 
 	mem_init_print_info(NULL);
 }
-
-void
-free_initmem(void)
-{
-	free_initmem_default(-1);
-}

arch/microblaze/mm/init.c

···
 	paging_init();
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 void __init mem_init(void)
 {
 	high_memory = (void *)__va(memory_start + lowmem_size - 1);

arch/nds32/mm/init.c

···
 	return;
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 void __set_fixmap(enum fixed_addresses idx,
 			       phys_addr_t phys, pgprot_t flags)
 {

arch/nios2/mm/init.c

···
 	flush_tlb_all();
 }
 
-void __ref free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 #define __page_aligned(order) __aligned(PAGE_SIZE << (order))
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);

arch/openrisc/mm/init.c

···
 	mem_init_done = 1;
 	return;
 }
-
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}

arch/sh/mm/init.c

···
 	mem_init_done = 1;
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 #ifdef CONFIG_MEMORY_HOTPLUG
 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
 		bool want_memblock)

arch/unicore32/mm/init.c

···
 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 	}
 }
-
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}

arch/xtensa/mm/init.c

···
 }
 #endif
 
-void free_initmem(void)
-{
-	free_initmem_default(-1);
-}
-
 static void __init parse_memmap_one(char *p)
 {
 	char *oldp;

init/main.c

···
 }
 #endif
 
+void __weak free_initmem(void)
+{
+	free_initmem_default(-1);
+}
+
 static int __ref kernel_init(void *unused)
 {
 	int ret;