arc: remove support for DISCONTIGMEM

DISCONTIGMEM was replaced by FLATMEM with freeing of the unused memory map
in v5.11.

Remove the support for DISCONTIGMEM entirely.

Link: https://lkml.kernel.org/r/20210608091316.3622-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: rppt

arch/arc/Kconfig

@@ -62,10 +62,6 @@ config SCHED_OMIT_FRAME_POINTER
 config GENERIC_CSUM
 	def_bool y
 
-config ARCH_DISCONTIGMEM_ENABLE
-	def_bool n
-	depends on BROKEN
-
 config ARCH_FLATMEM_ENABLE
 	def_bool y
 
@@ -344,15 +340,6 @@ config ARC_HUGEPAGE_16M
 
 endchoice
 
-config NODES_SHIFT
-	int "Maximum NUMA Nodes (as a power of 2)"
-	default "0" if !DISCONTIGMEM
-	default "1" if DISCONTIGMEM
-	depends on NEED_MULTIPLE_NODES
-	help
-	  Accessing memory beyond 1GB (with or w/o PAE) requires 2 memory
-	  zones.
-
 config ARC_COMPACT_IRQ_LEVELS
 	depends on ISA_ARCOMPACT
 	bool "Setup Timer IRQ as high Priority"

arch/arc/include/asm/mmzone.h

@@ -32,11 +32,6 @@ unsigned long arch_pfn_offset;
 EXPORT_SYMBOL(arch_pfn_offset);
 #endif
 
-#ifdef CONFIG_DISCONTIGMEM
-struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
-EXPORT_SYMBOL(node_data);
-#endif
-
 long __init arc_get_mem_sz(void)
 {
 	return low_mem_sz;
@@ -147,9 +142,6 @@ void __init setup_arch_memory(void)
 	 * to the hole is freed and ARC specific version of pfn_valid()
 	 * handles the hole in the memory map.
 	 */
-#ifdef CONFIG_DISCONTIGMEM
-	node_set_online(1);
-#endif
 
 	min_high_pfn = PFN_DOWN(high_mem_start);
 	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);