// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/array_size.h>
#include <linux/sort.h>
#include <linux/printk.h>
#include <linux/memblock.h>
#include <linux/numa.h>
#include <linux/numa_memblks.h>

#include <asm/numa.h>

int numa_distance_cnt;
static u8 *numa_distance;

nodemask_t numa_nodes_parsed __initdata;

static struct numa_meminfo numa_meminfo __initdata_or_meminfo;
static struct numa_meminfo numa_reserved_meminfo __initdata_or_meminfo;

/*
 * 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_free(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;

        /* 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]);

        numa_distance = memblock_alloc(size, PAGE_SIZE);
        if (!numa_distance) {
                pr_warn("Warning: can't allocate distance table!\n");
                /* don't retry until explicitly reset */
                numa_distance = (void *)1LU;
                return -ENOMEM;
        }

        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;
        pr_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 or lower than zero
 * 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 ||
                        from < 0 || to < 0) {
                pr_warn_once("Warning: node ids are 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("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);

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_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
                        nid, start, end - 1);
                return 0;
        }

        if (mi->nr_blks >= NR_NODE_MEMBLKS) {
                pr_err("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_move_tail_memblk - Move a numa_memblk from one numa_meminfo to another
 * @dst: numa_meminfo to append block to
 * @idx: Index of memblk to remove
 * @src: numa_meminfo to remove memblk from
 */
static void __init numa_move_tail_memblk(struct numa_meminfo *dst, int idx,
                                         struct numa_meminfo *src)
{
        dst->blk[dst->nr_blks++] = src->blk[idx];
        numa_remove_memblk_from(idx, src);
}

/**
 * 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);
}

/**
 * numa_add_reserved_memblk - Add one numa_memblk to numa_reserved_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 numa_reserved_meminfo.
 *
 * Usage Case: numa_cleanup_meminfo() reconciles all numa_memblk instances
 * against memblock_type information and moves any that intersect reserved
 * ranges to numa_reserved_meminfo. However, when that information is known
 * ahead of time, we use numa_add_reserved_memblk() to add the numa_memblk
 * to numa_reserved_meminfo directly.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int __init numa_add_reserved_memblk(int nid, u64 start, u64 end)
{
        return numa_add_memblk_to(nid, start, end, &numa_reserved_meminfo);
}

/**
 * numa_cleanup_meminfo - Cleanup a numa_meminfo
 * @mi: numa_meminfo to clean up
 *
 * Sanitize @mi by merging and removing unnecessary 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 = memblock_start_of_DRAM();
        const u64 high = memblock_end_of_DRAM();
        int i, j, k;

        /* first, trim all entries */
        for (i = 0; i < mi->nr_blks; i++) {
                struct numa_memblk *bi = &mi->blk[i];

                /* move / save reserved memory ranges */
                if (!memblock_overlaps_region(&memblock.memory,
                                        bi->start, bi->end - bi->start)) {
                        numa_move_tail_memblk(&numa_reserved_meminfo, i--, mi);
                        continue;
                }

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

                /* preserve info for non-RAM areas above 'max_pfn': */
                if (bi->end > high) {
                        numa_add_memblk_to(bi->nid, high, bi->end,
                                           &numa_reserved_meminfo);
                        bi->end = high;
                }

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

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

                for (j = i + 1; j < mi->nr_blks; j++) {
                        struct numa_memblk *bj = &mi->blk[j];
                        u64 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("node %d [mem %#010Lx-%#010Lx] overlaps with node %d [mem %#010Lx-%#010Lx]\n",
                                               bi->nid, bi->start, bi->end - 1,
                                               bj->nid, bj->start, bj->end - 1);
                                        return -EINVAL;
                                }
                                pr_warn("Warning: node %d [mem %#010Lx-%#010Lx] overlaps with itself [mem %#010Lx-%#010Lx]\n",
                                        bi->nid, bi->start, bi->end - 1,
                                        bj->start, bj->end - 1);
                        }

                        /*
                         * 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 = min(bi->start, bj->start);
                        end = max(bi->end, bj->end);
                        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;
                        pr_info("NUMA: Node %d [mem %#010Lx-%#010Lx] + [mem %#010Lx-%#010Lx] -> [mem %#010Lx-%#010Lx]\n",
                               bi->nid, bi->start, bi->end - 1, bj->start,
                               bj->end - 1, start, end - 1);
                        bi->start = start;
                        bi->end = end;
                        numa_remove_memblk_from(j--, mi);
                }
        }

        /* clear unused ones */
        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;
}

/*
 * Mark all currently memblock-reserved physical memory (which covers the
 * kernel's own memory ranges) as hot-unswappable.
 */
static void __init numa_clear_kernel_node_hotplug(void)
{
        nodemask_t reserved_nodemask = NODE_MASK_NONE;
        struct memblock_region *mb_region;
        int i;

        /*
         * We have to do some preprocessing of memblock regions, to
         * make them suitable for reservation.
         *
         * At this time, all memory regions reserved by memblock are
         * used by the kernel, but those regions are not split up
         * along node boundaries yet, and don't necessarily have their
         * node ID set yet either.
         *
         * So iterate over all parsed memory blocks and use those ranges to
         * set the nid in memblock.reserved.  This will split up the
         * memblock regions along node boundaries and will set the node IDs
         * as well.
         */
        for (i = 0; i < numa_meminfo.nr_blks; i++) {
                struct numa_memblk *mb = numa_meminfo.blk + i;
                int ret;

                ret = memblock_set_node(mb->start, mb->end - mb->start,
                                        &memblock.reserved, mb->nid);
                WARN_ON_ONCE(ret);
        }

        /*
         * Now go over all reserved memblock regions, to construct a
         * node mask of all kernel reserved memory areas.
         *
         * [ Note, when booting with mem=nn[kMG] or in a kdump kernel,
         *   numa_meminfo might not include all memblock.reserved
         *   memory ranges, because quirks such as trim_snb_memory()
         *   reserve specific pages for Sandy Bridge graphics. ]
         */
        for_each_reserved_mem_region(mb_region) {
                int nid = memblock_get_region_node(mb_region);

                if (numa_valid_node(nid))
                        node_set(nid, reserved_nodemask);
        }

        /*
         * Finally, clear the MEMBLOCK_HOTPLUG flag for all memory
         * belonging to the reserved node mask.
         *
         * Note that this will include memory regions that reside
         * on nodes that contain kernel memory - entire nodes
         * become hot-unpluggable:
         */
        for (i = 0; i < numa_meminfo.nr_blks; i++) {
                struct numa_memblk *mb = numa_meminfo.blk + i;

                if (!node_isset(mb->nid, reserved_nodemask))
                        continue;

                memblock_clear_hotplug(mb->start, mb->end - mb->start);
        }
}

static int __init numa_register_meminfo(struct numa_meminfo *mi)
{
        int i;

        /* 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++) {
                struct numa_memblk *mb = &mi->blk[i];

                memblock_set_node(mb->start, mb->end - mb->start,
                                  &memblock.memory, mb->nid);
        }

        /*
         * At very early time, the kernel have to use some memory such as
         * loading the kernel image. We cannot prevent this anyway. So any
         * node the kernel resides in should be un-hotpluggable.
         *
         * And when we come here, alloc node data won't fail.
         */
        numa_clear_kernel_node_hotplug();

        /*
         * If sections array is gonna be used for pfn -> nid mapping, check
         * whether its granularity is fine enough.
         */
        if (IS_ENABLED(NODE_NOT_IN_PAGE_FLAGS)) {
                unsigned long pfn_align = node_map_pfn_alignment();

                if (pfn_align && pfn_align < PAGES_PER_SECTION) {
                        unsigned long node_align_mb = PFN_PHYS(pfn_align) / SZ_1M;

                        unsigned long sect_align_mb = PFN_PHYS(PAGES_PER_SECTION) / SZ_1M;

                        pr_warn("Node alignment %luMB < min %luMB, rejecting NUMA config\n",
                                node_align_mb, sect_align_mb);
                        return -EINVAL;
                }
        }

        return 0;
}

int __init numa_memblks_init(int (*init_func)(void),
                             bool memblock_force_top_down)
{
        phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
        int ret;

        nodes_clear(numa_nodes_parsed);
        nodes_clear(node_possible_map);
        nodes_clear(node_online_map);
        memset(&numa_meminfo, 0, sizeof(numa_meminfo));
        WARN_ON(memblock_set_node(0, max_addr, &memblock.memory, NUMA_NO_NODE));
        WARN_ON(memblock_set_node(0, max_addr, &memblock.reserved,
                                  NUMA_NO_NODE));
        /* In case that parsing SRAT failed. */
        WARN_ON(memblock_clear_hotplug(0, max_addr));
        numa_reset_distance();

        ret = init_func();
        if (ret < 0)
                return ret;

        /*
         * We reset memblock back to the top-down direction
         * here because if we configured ACPI_NUMA, we have
         * parsed SRAT in init_func(). It is ok to have the
         * reset here even if we didn't configure ACPI_NUMA
         * or acpi numa init fails and fallbacks to dummy
         * numa init.
         */
        if (memblock_force_top_down)
                memblock_set_bottom_up(false);

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

        numa_emulation(&numa_meminfo, numa_distance_cnt);

        return numa_register_meminfo(&numa_meminfo);
}

static int __init cmp_memblk(const void *a, const void *b)
{
        const struct numa_memblk *ma = *(const struct numa_memblk **)a;
        const struct numa_memblk *mb = *(const struct numa_memblk **)b;

        return (ma->start > mb->start) - (ma->start < mb->start);
}

static struct numa_memblk *numa_memblk_list[NR_NODE_MEMBLKS] __initdata;

/**
 * numa_fill_memblks - Fill gaps in numa_meminfo memblks
 * @start: address to begin fill
 * @end: address to end fill
 *
 * Find and extend numa_meminfo memblks to cover the physical
 * address range @start-@end
 *
 * RETURNS:
 * 0              : Success
 * NUMA_NO_MEMBLK : No memblks exist in address range @start-@end
 */

int __init numa_fill_memblks(u64 start, u64 end)
{
        struct numa_memblk **blk = &numa_memblk_list[0];
        struct numa_meminfo *mi = &numa_meminfo;
        int count = 0;
        u64 prev_end;

        /*
         * Create a list of pointers to numa_meminfo memblks that
         * overlap start, end. The list is used to make in-place
         * changes that fill out the numa_meminfo memblks.
         */
        for (int i = 0; i < mi->nr_blks; i++) {
                struct numa_memblk *bi = &mi->blk[i];

                if (memblock_addrs_overlap(start, end - start, bi->start,
                                           bi->end - bi->start)) {
                        blk[count] = &mi->blk[i];
                        count++;
                }
        }
        if (!count)
                return NUMA_NO_MEMBLK;

        /* Sort the list of pointers in memblk->start order */
        sort(&blk[0], count, sizeof(blk[0]), cmp_memblk, NULL);

        /* Make sure the first/last memblks include start/end */
        blk[0]->start = min(blk[0]->start, start);
        blk[count - 1]->end = max(blk[count - 1]->end, end);

        /*
         * Fill any gaps by tracking the previous memblks
         * end address and backfilling to it if needed.
         */
        prev_end = blk[0]->end;
        for (int i = 1; i < count; i++) {
                struct numa_memblk *curr = blk[i];

                if (prev_end >= curr->start) {
                        if (prev_end < curr->end)
                                prev_end = curr->end;
                } else {
                        curr->start = prev_end;
                        prev_end = curr->end;
                }
        }
        return 0;
}

#ifdef CONFIG_NUMA_KEEP_MEMINFO
static int meminfo_to_nid(struct numa_meminfo *mi, u64 start)
{
        int i;

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

int phys_to_target_node(u64 start)
{
        int nid = meminfo_to_nid(&numa_meminfo, start);
        int reserved_nid = meminfo_to_nid(&numa_reserved_meminfo, start);

        /*
         * Prefer online nodes unless the address is also described
         * by reserved ranges, in which case use the reserved nid.
         */
        if (nid != NUMA_NO_NODE && reserved_nid == NUMA_NO_NODE)
                return nid;

        return reserved_nid;
}
EXPORT_SYMBOL_GPL(phys_to_target_node);

int memory_add_physaddr_to_nid(u64 start)
{
        int nid = meminfo_to_nid(&numa_meminfo, start);

        if (nid == NUMA_NO_NODE)
                nid = numa_meminfo.blk[0].nid;
        return nid;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);

#endif /* CONFIG_NUMA_KEEP_MEMINFO */