mm: remove CONFIG_HAVE_MEMBLOCK

All architecures use memblock for early memory management. There is no need
for the CONFIG_HAVE_MEMBLOCK configuration option.

[rppt@linux.vnet.ibm.com: of/fdt: fixup #ifdefs]
  Link: http://lkml.kernel.org/r/20180919103457.GA20545@rapoport-lnx
[rppt@linux.vnet.ibm.com: csky: fixups after bootmem removal]
  Link: http://lkml.kernel.org/r/20180926112744.GC4628@rapoport-lnx
[rppt@linux.vnet.ibm.com: remove stale #else and the code it protects]
  Link: http://lkml.kernel.org/r/1538067825-24835-1-git-send-email-rppt@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1536927045-23536-4-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/Kconfig

@@ -127,9 +127,6 @@ config SPARSEMEM_VMEMMAP
 	 pfn_to_page and page_to_pfn operations.  This is the most
 	 efficient option when sufficient kernel resources are available.
 
-config HAVE_MEMBLOCK
-	bool
-
 config HAVE_MEMBLOCK_NODE_MAP
 	bool
 
@@ -478,7 +475,7 @@ config FRONTSWAP
 
 config CMA
 	bool "Contiguous Memory Allocator"
-	depends on HAVE_MEMBLOCK && MMU
+	depends on MMU
 	select MIGRATION
 	select MEMORY_ISOLATION
 	help

mm/Makefile

@@ -43,11 +43,11 @@ obj-y			:= filemap.o mempool.o oom_kill.o fadvise.o \
 
 obj-y += init-mm.o
 obj-y += nobootmem.o
+obj-y += memblock.o
 
 ifdef CONFIG_MMU
 	obj-$(CONFIG_ADVISE_SYSCALLS)	+= madvise.o
 endif
-obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
 
 obj-$(CONFIG_SWAP)	+= page_io.o swap_state.o swapfile.o swap_slots.o
 obj-$(CONFIG_FRONTSWAP)	+= frontswap.o

mm/nobootmem.c

@@ -23,10 +23,6 @@
 
 #include "internal.h"
 
-#ifndef CONFIG_HAVE_MEMBLOCK
-#error CONFIG_HAVE_MEMBLOCK not defined
-#endif
-
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 struct pglist_data __refdata contig_page_data;
 EXPORT_SYMBOL(contig_page_data);

mm/page_alloc.c

@@ -6508,8 +6508,7 @@ void __init free_area_init_node(int nid, unsigned long *zones_size,
 	free_area_init_core(pgdat);
 }
 
-#if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP)
-
+#if !defined(CONFIG_FLAT_NODE_MEM_MAP)
 /*
  * Zero all valid struct pages in range [spfn, epfn), return number of struct
  * pages zeroed
@@ -6569,7 +6568,7 @@ void __init zero_resv_unavail(void)
 	if (pgcnt)
 		pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt);
 }
-#endif /* CONFIG_HAVE_MEMBLOCK && !CONFIG_FLAT_NODE_MEM_MAP */
+#endif /* !CONFIG_FLAT_NODE_MEM_MAP */
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP