// 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/pgalloc.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 bootmap_size, bootmap_pages, bootmap_start;
        unsigned long start, end;
        unsigned long node_pfn_start, node_pfn_end;
        unsigned long node_min_pfn, node_max_pfn;
        int i;
        unsigned long node_datasz = PFN_UP(sizeof(pg_data_t));
        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
        /* Quasi-mark the pg_data_t as in-use */
        node_min_pfn += node_datasz;
        if (node_min_pfn >= node_max_pfn) {
                printk(" not enough mem to reserve NODE_DATA");
                return;
        }
        NODE_DATA(nid)->bdata = &bootmem_node_data[nid];

        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));
        DBGDCONT(" DISCONTIG: NODE_DATA(%d)->bdata is at 0x%p\n", nid, NODE_DATA(nid)->bdata);

        /* Find the bounds of kernel memory.  */
        start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
        end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
        bootmap_start = -1;

        if (!nid && (node_max_pfn < end_kernel_pfn || node_min_pfn > start_kernel_pfn))
                panic("kernel loaded out of ram");

        /* 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);

        /* We need to know how many physically contiguous pages
           we'll need for the bootmap.  */
        bootmap_pages = bootmem_bootmap_pages(node_max_pfn-node_min_pfn);

        /* Now find a good region where to allocate the bootmap.  */
        for_each_mem_cluster(memdesc, cluster, i) {
                if (cluster->usage & 3)
                        continue;

                start = cluster->start_pfn;
                end = start + cluster->numpages;

                if (start >= node_max_pfn || end <= node_min_pfn)
                        continue;

                if (end > node_max_pfn)
                        end = node_max_pfn;
                if (start < node_min_pfn)
                        start = node_min_pfn;

                if (start < start_kernel_pfn) {
                        if (end > end_kernel_pfn
                            && end - end_kernel_pfn >= bootmap_pages) {
                                bootmap_start = end_kernel_pfn;
                                break;
                        } else if (end > start_kernel_pfn)
                                end = start_kernel_pfn;
                } else if (start < end_kernel_pfn)
                        start = end_kernel_pfn;
                if (end - start >= bootmap_pages) {
                        bootmap_start = start;
                        break;
                }
        }

        if (bootmap_start == -1)
                panic("couldn't find a contiguous place for the bootmap");

        /* Allocate the bootmap and mark the whole MM as reserved.  */
        bootmap_size = init_bootmem_node(NODE_DATA(nid), bootmap_start,
                                         node_min_pfn, node_max_pfn);
        DBGDCONT(" bootmap_start %lu, bootmap_size %lu, bootmap_pages %lu\n",
                 bootmap_start, bootmap_size, bootmap_pages);

        /* Mark the free regions.  */
        for_each_mem_cluster(memdesc, cluster, i) {
                if (cluster->usage & 3)
                        continue;

                start = cluster->start_pfn;
                end = cluster->start_pfn + cluster->numpages;

                if (start >= node_max_pfn || end <= node_min_pfn)
                        continue;

                if (end > node_max_pfn)
                        end = node_max_pfn;
                if (start < node_min_pfn)
                        start = node_min_pfn;

                if (start < start_kernel_pfn) {
                        if (end > end_kernel_pfn) {
                                free_bootmem_node(NODE_DATA(nid), PFN_PHYS(start),
                                             (PFN_PHYS(start_kernel_pfn)
                                              - PFN_PHYS(start)));
                                printk(" freeing pages %ld:%ld\n",
                                       start, start_kernel_pfn);
                                start = end_kernel_pfn;
                        } else if (end > start_kernel_pfn)
                                end = start_kernel_pfn;
                } else if (start < end_kernel_pfn)
                        start = end_kernel_pfn;
                if (start >= end)
                        continue;

                free_bootmem_node(NODE_DATA(nid), PFN_PHYS(start), PFN_PHYS(end) - PFN_PHYS(start));
                printk(" freeing pages %ld:%ld\n", start, end);
        }

        /* Reserve the bootmap memory.  */
        reserve_bootmem_node(NODE_DATA(nid), PFN_PHYS(bootmap_start),
                        bootmap_size, BOOTMEM_DEFAULT);
        printk(" reserving pages %ld:%ld\n", bootmap_start, bootmap_start+PFN_UP(bootmap_size));

        node_set_online(nid);
}

void __init
setup_memory(void *kernel_end)
{
        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);

#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);
                        reserve_bootmem_node(NODE_DATA(nid),
                                             virt_to_phys((void *)initrd_start),
                                             INITRD_SIZE, BOOTMEM_DEFAULT);
                }
        }
#endif /* CONFIG_BLK_DEV_INITRD */
}

void __init paging_init(void)
{
        unsigned int    nid;
        unsigned long   zones_size[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;

        for_each_online_node(nid) {
                bootmem_data_t *bdata = &bootmem_node_data[nid];
                unsigned long start_pfn = bdata->node_min_pfn;
                unsigned long end_pfn = bdata->node_low_pfn;

                if (dma_local_pfn >= end_pfn - start_pfn)
                        zones_size[ZONE_DMA] = end_pfn - start_pfn;
                else {
                        zones_size[ZONE_DMA] = dma_local_pfn;
                        zones_size[ZONE_NORMAL] = (end_pfn - start_pfn) - dma_local_pfn;
                }
                node_set_state(nid, N_NORMAL_MEMORY);
                free_area_init_node(nid, zones_size, start_pfn, NULL);
        }

        /* Initialize the kernel's ZERO_PGE. */
        memset((void *)ZERO_PGE, 0, PAGE_SIZE);
}