/*
 * Generic VM initialization for x86-64 NUMA setups.
 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/mmzone.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/nodemask.h>
#include <linux/sched.h>
#include <linux/acpi.h>

#include <asm/e820.h>
#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/acpi.h>
#include <asm/amd_nb.h>

#include "numa_internal.h"

struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
EXPORT_SYMBOL(node_data);

static struct numa_meminfo numa_meminfo
#ifndef CONFIG_MEMORY_HOTPLUG
__initdata
#endif
;

static int numa_distance_cnt;
static u8 *numa_distance;

static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
				     struct numa_meminfo *mi)
{
	/* ignore zero length blks */
	if (start == end)
		return 0;

	/* whine about and ignore invalid blks */
	if (start > end || nid < 0 || nid >= MAX_NUMNODES) {
		pr_warning("NUMA: Warning: invalid memblk node %d (%Lx-%Lx)\n",
			   nid, start, end);
		return 0;
	}

	if (mi->nr_blks >= NR_NODE_MEMBLKS) {
		pr_err("NUMA: too many memblk ranges\n");
		return -EINVAL;
	}

	mi->blk[mi->nr_blks].start = start;
	mi->blk[mi->nr_blks].end = end;
	mi->blk[mi->nr_blks].nid = nid;
	mi->nr_blks++;
	return 0;
}

/**
 * numa_remove_memblk_from - Remove one numa_memblk from a numa_meminfo
 * @idx: Index of memblk to remove
 * @mi: numa_meminfo to remove memblk from
 *
 * Remove @idx'th numa_memblk from @mi by shifting @mi->blk[] and
 * decrementing @mi->nr_blks.
 */
void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi)
{
	mi->nr_blks--;
	memmove(&mi->blk[idx], &mi->blk[idx + 1],
		(mi->nr_blks - idx) * sizeof(mi->blk[0]));
}

/**
 * numa_add_memblk - Add one numa_memblk to numa_meminfo
 * @nid: NUMA node ID of the new memblk
 * @start: Start address of the new memblk
 * @end: End address of the new memblk
 *
 * Add a new memblk to the default numa_meminfo.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int __init numa_add_memblk(int nid, u64 start, u64 end)
{
	return numa_add_memblk_to(nid, start, end, &numa_meminfo);
}

/* Initialize bootmem allocator for a node */
static void __init
setup_node_bootmem(int nid, unsigned long start, unsigned long end)
{
	const u64 nd_low = (u64)MAX_DMA_PFN << PAGE_SHIFT;
	const u64 nd_high = (u64)max_pfn_mapped << PAGE_SHIFT;
	const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
	unsigned long nd_pa;
	int tnid;

	/*
	 * Don't confuse VM with a node that doesn't have the
	 * minimum amount of memory:
	 */
	if (end && (end - start) < NODE_MIN_SIZE)
		return;

	start = roundup(start, ZONE_ALIGN);

	printk(KERN_INFO "Initmem setup node %d %016lx-%016lx\n",
	       nid, start, end);

	/*
	 * Try to allocate node data on local node and then fall back to
	 * all nodes.  Never allocate in DMA zone.
	 */
	nd_pa = memblock_x86_find_in_range_node(nid, nd_low, nd_high,
						nd_size, SMP_CACHE_BYTES);
	if (nd_pa == MEMBLOCK_ERROR)
		nd_pa = memblock_find_in_range(nd_low, nd_high,
					       nd_size, SMP_CACHE_BYTES);
	if (nd_pa == MEMBLOCK_ERROR) {
		pr_err("Cannot find %lu bytes in node %d\n", nd_size, nid);
		return;
	}
	memblock_x86_reserve_range(nd_pa, nd_pa + nd_size, "NODE_DATA");

	/* report and initialize */
	printk(KERN_INFO "  NODE_DATA [%016lx - %016lx]\n",
	       nd_pa, nd_pa + nd_size - 1);
	tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
	if (tnid != nid)
		printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nid, tnid);

	node_data[nid] = __va(nd_pa);
	memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
	NODE_DATA(nid)->node_id = nid;
	NODE_DATA(nid)->node_start_pfn = start >> PAGE_SHIFT;
	NODE_DATA(nid)->node_spanned_pages = (end - start) >> PAGE_SHIFT;

	node_set_online(nid);
}

/**
 * numa_cleanup_meminfo - Cleanup a numa_meminfo
 * @mi: numa_meminfo to clean up
 *
 * Sanitize @mi by merging and removing unncessary memblks.  Also check for
 * conflicts and clear unused memblks.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int __init numa_cleanup_meminfo(struct numa_meminfo *mi)
{
	const u64 low = 0;
	const u64 high = (u64)max_pfn << PAGE_SHIFT;
	int i, j, k;

	for (i = 0; i < mi->nr_blks; i++) {
		struct numa_memblk *bi = &mi->blk[i];

		/* make sure all blocks are inside the limits */
		bi->start = max(bi->start, low);
		bi->end = min(bi->end, high);

		/* and there's no empty block */
		if (bi->start >= bi->end) {
			numa_remove_memblk_from(i--, mi);
			continue;
		}

		for (j = i + 1; j < mi->nr_blks; j++) {
			struct numa_memblk *bj = &mi->blk[j];
			unsigned long start, end;

			/*
			 * See whether there are overlapping blocks.  Whine
			 * about but allow overlaps of the same nid.  They
			 * will be merged below.
			 */
			if (bi->end > bj->start && bi->start < bj->end) {
				if (bi->nid != bj->nid) {
					pr_err("NUMA: node %d (%Lx-%Lx) overlaps with node %d (%Lx-%Lx)\n",
					       bi->nid, bi->start, bi->end,
					       bj->nid, bj->start, bj->end);
					return -EINVAL;
				}
				pr_warning("NUMA: Warning: node %d (%Lx-%Lx) overlaps with itself (%Lx-%Lx)\n",
					   bi->nid, bi->start, bi->end,
					   bj->start, bj->end);
			}

			/*
			 * Join together blocks on the same node, holes
			 * between which don't overlap with memory on other
			 * nodes.
			 */
			if (bi->nid != bj->nid)
				continue;
			start = max(min(bi->start, bj->start), low);
			end = min(max(bi->end, bj->end), high);
			for (k = 0; k < mi->nr_blks; k++) {
				struct numa_memblk *bk = &mi->blk[k];

				if (bi->nid == bk->nid)
					continue;
				if (start < bk->end && end > bk->start)
					break;
			}
			if (k < mi->nr_blks)
				continue;
			printk(KERN_INFO "NUMA: Node %d [%Lx,%Lx) + [%Lx,%Lx) -> [%lx,%lx)\n",
			       bi->nid, bi->start, bi->end, bj->start, bj->end,
			       start, end);
			bi->start = start;
			bi->end = end;
			numa_remove_memblk_from(j--, mi);
		}
	}

	for (i = mi->nr_blks; i < ARRAY_SIZE(mi->blk); i++) {
		mi->blk[i].start = mi->blk[i].end = 0;
		mi->blk[i].nid = NUMA_NO_NODE;
	}

	return 0;
}

/*
 * Set nodes, which have memory in @mi, in *@nodemask.
 */
static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask,
					      const struct numa_meminfo *mi)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(mi->blk); i++)
		if (mi->blk[i].start != mi->blk[i].end &&
		    mi->blk[i].nid != NUMA_NO_NODE)
			node_set(mi->blk[i].nid, *nodemask);
}

/**
 * numa_reset_distance - Reset NUMA distance table
 *
 * The current table is freed.  The next numa_set_distance() call will
 * create a new one.
 */
void __init numa_reset_distance(void)
{
	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);

	/* numa_distance could be 1LU marking allocation failure, test cnt */
	if (numa_distance_cnt)
		memblock_x86_free_range(__pa(numa_distance),
					__pa(numa_distance) + size);
	numa_distance_cnt = 0;
	numa_distance = NULL;	/* enable table creation */
}

static int __init numa_alloc_distance(void)
{
	nodemask_t nodes_parsed;
	size_t size;
	int i, j, cnt = 0;
	u64 phys;

	/* size the new table and allocate it */
	nodes_parsed = numa_nodes_parsed;
	numa_nodemask_from_meminfo(&nodes_parsed, &numa_meminfo);

	for_each_node_mask(i, nodes_parsed)
		cnt = i;
	cnt++;
	size = cnt * cnt * sizeof(numa_distance[0]);

	phys = memblock_find_in_range(0, (u64)max_pfn_mapped << PAGE_SHIFT,
				      size, PAGE_SIZE);
	if (phys == MEMBLOCK_ERROR) {
		pr_warning("NUMA: Warning: can't allocate distance table!\n");
		/* don't retry until explicitly reset */
		numa_distance = (void *)1LU;
		return -ENOMEM;
	}
	memblock_x86_reserve_range(phys, phys + size, "NUMA DIST");

	numa_distance = __va(phys);
	numa_distance_cnt = cnt;

	/* fill with the default distances */
	for (i = 0; i < cnt; i++)
		for (j = 0; j < cnt; j++)
			numa_distance[i * cnt + j] = i == j ?
				LOCAL_DISTANCE : REMOTE_DISTANCE;
	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);

	return 0;
}

/**
 * numa_set_distance - Set NUMA distance from one NUMA to another
 * @from: the 'from' node to set distance
 * @to: the 'to'  node to set distance
 * @distance: NUMA distance
 *
 * Set the distance from node @from to @to to @distance.  If distance table
 * doesn't exist, one which is large enough to accommodate all the currently
 * known nodes will be created.
 *
 * If such table cannot be allocated, a warning is printed and further
 * calls are ignored until the distance table is reset with
 * numa_reset_distance().
 *
 * If @from or @to is higher than the highest known node at the time of
 * table creation or @distance doesn't make sense, the call is ignored.
 * This is to allow simplification of specific NUMA config implementations.
 */
void __init numa_set_distance(int from, int to, int distance)
{
	if (!numa_distance && numa_alloc_distance() < 0)
		return;

	if (from >= numa_distance_cnt || to >= numa_distance_cnt) {
		printk_once(KERN_DEBUG "NUMA: Debug: distance out of bound, from=%d to=%d distance=%d\n",
			    from, to, distance);
		return;
	}

	if ((u8)distance != distance ||
	    (from == to && distance != LOCAL_DISTANCE)) {
		pr_warn_once("NUMA: Warning: invalid distance parameter, from=%d to=%d distance=%d\n",
			     from, to, distance);
		return;
	}

	numa_distance[from * numa_distance_cnt + to] = distance;
}

int __node_distance(int from, int to)
{
	if (from >= numa_distance_cnt || to >= numa_distance_cnt)
		return from == to ? LOCAL_DISTANCE : REMOTE_DISTANCE;
	return numa_distance[from * numa_distance_cnt + to];
}
EXPORT_SYMBOL(__node_distance);

/*
 * Sanity check to catch more bad NUMA configurations (they are amazingly
 * common).  Make sure the nodes cover all memory.
 */
static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
{
	unsigned long numaram, e820ram;
	int i;

	numaram = 0;
	for (i = 0; i < mi->nr_blks; i++) {
		unsigned long s = mi->blk[i].start >> PAGE_SHIFT;
		unsigned long e = mi->blk[i].end >> PAGE_SHIFT;
		numaram += e - s;
		numaram -= __absent_pages_in_range(mi->blk[i].nid, s, e);
		if ((long)numaram < 0)
			numaram = 0;
	}

	e820ram = max_pfn - (memblock_x86_hole_size(0,
					max_pfn << PAGE_SHIFT) >> PAGE_SHIFT);
	/* We seem to lose 3 pages somewhere. Allow 1M of slack. */
	if ((long)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
		printk(KERN_ERR "NUMA: nodes only cover %luMB of your %luMB e820 RAM. Not used.\n",
		       (numaram << PAGE_SHIFT) >> 20,
		       (e820ram << PAGE_SHIFT) >> 20);
		return false;
	}
	return true;
}

static int __init numa_register_memblks(struct numa_meminfo *mi)
{
	int i, nid;

	/* Account for nodes with cpus and no memory */
	node_possible_map = numa_nodes_parsed;
	numa_nodemask_from_meminfo(&node_possible_map, mi);
	if (WARN_ON(nodes_empty(node_possible_map)))
		return -EINVAL;

	for (i = 0; i < mi->nr_blks; i++)
		memblock_x86_register_active_regions(mi->blk[i].nid,
					mi->blk[i].start >> PAGE_SHIFT,
					mi->blk[i].end >> PAGE_SHIFT);

	/* for out of order entries */
	sort_node_map();
	if (!numa_meminfo_cover_memory(mi))
		return -EINVAL;

	/* Finally register nodes. */
	for_each_node_mask(nid, node_possible_map) {
		u64 start = (u64)max_pfn << PAGE_SHIFT;
		u64 end = 0;

		for (i = 0; i < mi->nr_blks; i++) {
			if (nid != mi->blk[i].nid)
				continue;
			start = min(mi->blk[i].start, start);
			end = max(mi->blk[i].end, end);
		}

		if (start < end)
			setup_node_bootmem(nid, start, end);
	}

	return 0;
}

/**
 * dummy_numma_init - Fallback dummy NUMA init
 *
 * Used if there's no underlying NUMA architecture, NUMA initialization
 * fails, or NUMA is disabled on the command line.
 *
 * Must online at least one node and add memory blocks that cover all
 * allowed memory.  This function must not fail.
 */
static int __init dummy_numa_init(void)
{
	printk(KERN_INFO "%s\n",
	       numa_off ? "NUMA turned off" : "No NUMA configuration found");
	printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
	       0LU, max_pfn << PAGE_SHIFT);

	node_set(0, numa_nodes_parsed);
	numa_add_memblk(0, 0, (u64)max_pfn << PAGE_SHIFT);

	return 0;
}

static int __init numa_init(int (*init_func)(void))
{
	int i;
	int ret;

	for (i = 0; i < MAX_LOCAL_APIC; i++)
		set_apicid_to_node(i, NUMA_NO_NODE);

	nodes_clear(numa_nodes_parsed);
	nodes_clear(node_possible_map);
	nodes_clear(node_online_map);
	memset(&numa_meminfo, 0, sizeof(numa_meminfo));
	remove_all_active_ranges();
	numa_reset_distance();

	ret = init_func();
	if (ret < 0)
		return ret;
	ret = numa_cleanup_meminfo(&numa_meminfo);
	if (ret < 0)
		return ret;

	numa_emulation(&numa_meminfo, numa_distance_cnt);

	ret = numa_register_memblks(&numa_meminfo);
	if (ret < 0)
		return ret;

	for (i = 0; i < nr_cpu_ids; i++) {
		int nid = early_cpu_to_node(i);

		if (nid == NUMA_NO_NODE)
			continue;
		if (!node_online(nid))
			numa_clear_node(i);
	}
	numa_init_array();
	return 0;
}

void __init initmem_init(void)
{
	if (!numa_off) {
#ifdef CONFIG_ACPI_NUMA
		if (!numa_init(x86_acpi_numa_init))
			return;
#endif
#ifdef CONFIG_AMD_NUMA
		if (!numa_init(amd_numa_init))
			return;
#endif
	}

	numa_init(dummy_numa_init);
}

unsigned long __init numa_free_all_bootmem(void)
{
	unsigned long pages = 0;
	int i;

	for_each_online_node(i)
		pages += free_all_bootmem_node(NODE_DATA(i));

	pages += free_all_memory_core_early(MAX_NUMNODES);

	return pages;
}

#ifdef CONFIG_MEMORY_HOTPLUG
int memory_add_physaddr_to_nid(u64 start)
{
	struct numa_meminfo *mi = &numa_meminfo;
	int nid = mi->blk[0].nid;
	int i;

	for (i = 0; i < mi->nr_blks; i++)
		if (mi->blk[i].start <= start && mi->blk[i].end > start)
			nid = mi->blk[i].nid;
	return nid;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif