alpha: remove DISCONTIGMEM and NUMA

Patch series "Remove DISCONTIGMEM memory model", v3.

SPARSEMEM memory model was supposed to entirely replace DISCONTIGMEM a
(long) while ago.  The last architectures that used DISCONTIGMEM were
updated to use other memory models in v5.11 and it is about the time to
entirely remove DISCONTIGMEM from the kernel.

This set removes DISCONTIGMEM from alpha, arc and m68k, simplifies memory
model selection in mm/Kconfig and replaces usage of redundant
CONFIG_NEED_MULTIPLE_NODES and CONFIG_FLAT_NODE_MEM_MAP with CONFIG_NUMA
and CONFIG_FLATMEM respectively.

I've also removed NUMA support on alpha that was BROKEN for more than 15
years.

There were also minor updates all over arch/ to remove mentions of
DISCONTIGMEM in comments and #ifdefs.

This patch (of 9):

NUMA is marked broken on alpha for more than 15 years and DISCONTIGMEM was
replaced with SPARSEMEM in v5.11.

Remove both NUMA and DISCONTIGMEM support from alpha.

Link: https://lkml.kernel.org/r/20210608091316.3622-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210608091316.3622-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.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>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 0 insertions, 228 deletions

diff --git a/arch/alpha/mm/Makefile b/arch/alpha/mm/Makefile
index 08ac6612edad..bd770302eb82 100644
--- a/arch/alpha/mm/Makefile
+++ b/arch/alpha/mm/Makefile
@@ -6,5 +6,3 @@
 ccflags-y := -Werror
 
 obj-y	:= init.o fault.o
-
-obj-$(CONFIG_DISCONTIGMEM) += numa.o
diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index a97650a618f1..f6114d03357c 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -235,8 +235,6 @@ callback_init(void * kernel_end)
 	return kernel_end;
 }
 
-
-#ifndef CONFIG_DISCONTIGMEM
 /*
  * paging_init() sets up the memory map.
  */
@@ -257,7 +255,6 @@ void __init paging_init(void)
 	/* Initialize the kernel's ZERO_PGE. */
 	memset((void *)ZERO_PGE, 0, PAGE_SIZE);
 }
-#endif /* CONFIG_DISCONTIGMEM */
 
 #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)
 void
diff --git a/arch/alpha/mm/numa.c b/arch/alpha/mm/numa.c
deleted file mode 100644
index 0636e254a22f..000000000000
--- a/arch/alpha/mm/numa.c
+++ /dev/null
@@ -1,223 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- *  linux/arch/alpha/mm/numa.c
- *
- *  DISCONTIGMEM NUMA alpha support.
- *
- *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
- */
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/memblock.h>
-#include <linux/swap.h>
-#include <linux/initrd.h>
-#include <linux/pfn.h>
-#include <linux/module.h>
-
-#include <asm/hwrpb.h>
-#include <asm/sections.h>
-
-pg_data_t node_data[MAX_NUMNODES];
-EXPORT_SYMBOL(node_data);
-
-#undef DEBUG_DISCONTIG
-#ifdef DEBUG_DISCONTIG
-#define DBGDCONT(args...) printk(args)
-#else
-#define DBGDCONT(args...)
-#endif
-
-#define for_each_mem_cluster(memdesc, _cluster, i)		\
-	for ((_cluster) = (memdesc)->cluster, (i) = 0;		\
-	     (i) < (memdesc)->numclusters; (i)++, (_cluster)++)
-
-static void __init show_mem_layout(void)
-{
-	struct memclust_struct * cluster;
-	struct memdesc_struct * memdesc;
-	int i;
-
-	/* Find free clusters, and init and free the bootmem accordingly.  */
-	memdesc = (struct memdesc_struct *)
-	  (hwrpb->mddt_offset + (unsigned long) hwrpb);
-
-	printk("Raw memory layout:\n");
-	for_each_mem_cluster(memdesc, cluster, i) {
-		printk(" memcluster %2d, usage %1lx, start %8lu, end %8lu\n",
-		       i, cluster->usage, cluster->start_pfn,
-		       cluster->start_pfn + cluster->numpages);
-	}
-}
-
-static void __init
-setup_memory_node(int nid, void *kernel_end)
-{
-	extern unsigned long mem_size_limit;
-	struct memclust_struct * cluster;
-	struct memdesc_struct * memdesc;
-	unsigned long start_kernel_pfn, end_kernel_pfn;
-	unsigned long start, end;
-	unsigned long node_pfn_start, node_pfn_end;
-	unsigned long node_min_pfn, node_max_pfn;
-	int i;
-	int show_init = 0;
-
-	/* Find the bounds of current node */
-	node_pfn_start = (node_mem_start(nid)) >> PAGE_SHIFT;
-	node_pfn_end = node_pfn_start + (node_mem_size(nid) >> PAGE_SHIFT);
-	
-	/* Find free clusters, and init and free the bootmem accordingly.  */
-	memdesc = (struct memdesc_struct *)
-	  (hwrpb->mddt_offset + (unsigned long) hwrpb);
-
-	/* find the bounds of this node (node_min_pfn/node_max_pfn) */
-	node_min_pfn = ~0UL;
-	node_max_pfn = 0UL;
-	for_each_mem_cluster(memdesc, cluster, i) {
-		/* Bit 0 is console/PALcode reserved.  Bit 1 is
-		   non-volatile memory -- we might want to mark
-		   this for later.  */
-		if (cluster->usage & 3)
-			continue;
-
-		start = cluster->start_pfn;
-		end = start + cluster->numpages;
-
-		if (start >= node_pfn_end || end <= node_pfn_start)
-			continue;
-
-		if (!show_init) {
-			show_init = 1;
-			printk("Initializing bootmem allocator on Node ID %d\n", nid);
-		}
-		printk(" memcluster %2d, usage %1lx, start %8lu, end %8lu\n",
-		       i, cluster->usage, cluster->start_pfn,
-		       cluster->start_pfn + cluster->numpages);
-
-		if (start < node_pfn_start)
-			start = node_pfn_start;
-		if (end > node_pfn_end)
-			end = node_pfn_end;
-
-		if (start < node_min_pfn)
-			node_min_pfn = start;
-		if (end > node_max_pfn)
-			node_max_pfn = end;
-	}
-
-	if (mem_size_limit && node_max_pfn > mem_size_limit) {
-		static int msg_shown = 0;
-		if (!msg_shown) {
-			msg_shown = 1;
-			printk("setup: forcing memory size to %ldK (from %ldK).\n",
-			       mem_size_limit << (PAGE_SHIFT - 10),
-			       node_max_pfn    << (PAGE_SHIFT - 10));
-		}
-		node_max_pfn = mem_size_limit;
-	}
-
-	if (node_min_pfn >= node_max_pfn)
-		return;
-
-	/* Update global {min,max}_low_pfn from node information. */
-	if (node_min_pfn < min_low_pfn)
-		min_low_pfn = node_min_pfn;
-	if (node_max_pfn > max_low_pfn)
-		max_pfn = max_low_pfn = node_max_pfn;
-
-#if 0 /* we'll try this one again in a little while */
-	/* Cute trick to make sure our local node data is on local memory */
-	node_data[nid] = (pg_data_t *)(__va(node_min_pfn << PAGE_SHIFT));
-#endif
-	printk(" Detected node memory:   start %8lu, end %8lu\n",
-	       node_min_pfn, node_max_pfn);
-
-	DBGDCONT(" DISCONTIG: node_data[%d]   is at 0x%p\n", nid, NODE_DATA(nid));
-
-	/* Find the bounds of kernel memory.  */
-	start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
-	end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
-
-	if (!nid && (node_max_pfn < end_kernel_pfn || node_min_pfn > start_kernel_pfn))
-		panic("kernel loaded out of ram");
-
-	memblock_add_node(PFN_PHYS(node_min_pfn),
-			  (node_max_pfn - node_min_pfn) << PAGE_SHIFT, nid);
-
-	/* Zone start phys-addr must be 2^(MAX_ORDER-1) aligned.
-	   Note that we round this down, not up - node memory
-	   has much larger alignment than 8Mb, so it's safe. */
-	node_min_pfn &= ~((1UL << (MAX_ORDER-1))-1);
-
-	NODE_DATA(nid)->node_start_pfn = node_min_pfn;
-	NODE_DATA(nid)->node_present_pages = node_max_pfn - node_min_pfn;
-
-	node_set_online(nid);
-}
-
-void __init
-setup_memory(void *kernel_end)
-{
-	unsigned long kernel_size;
-	int nid;
-
-	show_mem_layout();
-
-	nodes_clear(node_online_map);
-
-	min_low_pfn = ~0UL;
-	max_low_pfn = 0UL;
-	for (nid = 0; nid < MAX_NUMNODES; nid++)
-		setup_memory_node(nid, kernel_end);
-
-	kernel_size = virt_to_phys(kernel_end) - KERNEL_START_PHYS;
-	memblock_reserve(KERNEL_START_PHYS, kernel_size);
-
-#ifdef CONFIG_BLK_DEV_INITRD
-	initrd_start = INITRD_START;
-	if (initrd_start) {
-		extern void *move_initrd(unsigned long);
-
-		initrd_end = initrd_start+INITRD_SIZE;
-		printk("Initial ramdisk at: 0x%p (%lu bytes)\n",
-		       (void *) initrd_start, INITRD_SIZE);
-
-		if ((void *)initrd_end > phys_to_virt(PFN_PHYS(max_low_pfn))) {
-			if (!move_initrd(PFN_PHYS(max_low_pfn)))
-				printk("initrd extends beyond end of memory "
-				       "(0x%08lx > 0x%p)\ndisabling initrd\n",
-				       initrd_end,
-				       phys_to_virt(PFN_PHYS(max_low_pfn)));
-		} else {
-			nid = kvaddr_to_nid(initrd_start);
-			memblock_reserve(virt_to_phys((void *)initrd_start),
-					 INITRD_SIZE);
-		}
-	}
-#endif /* CONFIG_BLK_DEV_INITRD */
-}
-
-void __init paging_init(void)
-{
-	unsigned long   max_zone_pfn[MAX_NR_ZONES] = {0, };
-	unsigned long	dma_local_pfn;
-
-	/*
-	 * The old global MAX_DMA_ADDRESS per-arch API doesn't fit
-	 * in the NUMA model, for now we convert it to a pfn and
-	 * we interpret this pfn as a local per-node information.
-	 * This issue isn't very important since none of these machines
-	 * have legacy ISA slots anyways.
-	 */
-	dma_local_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
-
-	max_zone_pfn[ZONE_DMA] = dma_local_pfn;
-	max_zone_pfn[ZONE_NORMAL] = max_pfn;
-
-	free_area_init(max_zone_pfn);
-
-	/* Initialize the kernel's ZERO_PGE. */
-	memset((void *)ZERO_PGE, 0, PAGE_SIZE);
-}