/*
 * Written by: Patricia Gaughen <gone@us.ibm.com>, IBM Corporation
 * August 2002: added remote node KVA remap - Martin J. Bligh 
 *
 * Copyright (C) 2002, IBM Corp.
 *
 * All rights reserved.          
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/nodemask.h>
#include <asm/e820.h>
#include <asm/setup.h>
#include <asm/mmzone.h>
#include <bios_ebda.h>

struct pglist_data *node_data[MAX_NUMNODES];
bootmem_data_t node0_bdata;

/*
 * numa interface - we expect the numa architecture specfic code to have
 *                  populated the following initialisation.
 *
 * 1) node_online_map  - the map of all nodes configured (online) in the system
 * 2) physnode_map     - the mapping between a pfn and owning node
 * 3) node_start_pfn   - the starting page frame number for a node
 * 3) node_end_pfn     - the ending page fram number for a node
 */

/*
 * physnode_map keeps track of the physical memory layout of a generic
 * numa node on a 256Mb break (each element of the array will
 * represent 256Mb of memory and will be marked by the node id.  so,
 * if the first gig is on node 0, and the second gig is on node 1
 * physnode_map will contain:
 *
 *     physnode_map[0-3] = 0;
 *     physnode_map[4-7] = 1;
 *     physnode_map[8- ] = -1;
 */
s8 physnode_map[MAX_ELEMENTS] = { [0 ... (MAX_ELEMENTS - 1)] = -1};

unsigned long node_start_pfn[MAX_NUMNODES];
unsigned long node_end_pfn[MAX_NUMNODES];

extern unsigned long find_max_low_pfn(void);
extern void find_max_pfn(void);
extern void one_highpage_init(struct page *, int, int);

extern struct e820map e820;
extern unsigned long init_pg_tables_end;
extern unsigned long highend_pfn, highstart_pfn;
extern unsigned long max_low_pfn;
extern unsigned long totalram_pages;
extern unsigned long totalhigh_pages;

#define LARGE_PAGE_BYTES (PTRS_PER_PTE * PAGE_SIZE)

unsigned long node_remap_start_pfn[MAX_NUMNODES];
unsigned long node_remap_size[MAX_NUMNODES];
unsigned long node_remap_offset[MAX_NUMNODES];
void *node_remap_start_vaddr[MAX_NUMNODES];
void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);

/*
 * FLAT - support for basic PC memory model with discontig enabled, essentially
 *        a single node with all available processors in it with a flat
 *        memory map.
 */
int __init get_memcfg_numa_flat(void)
{
        printk("NUMA - single node, flat memory mode\n");

        /* Run the memory configuration and find the top of memory. */
        find_max_pfn();
        node_start_pfn[0] = 0;
        node_end_pfn[0] = max_pfn;

        /* Indicate there is one node available. */
        nodes_clear(node_online_map);
        node_set_online(0);
        return 1;
}

/*
 * Find the highest page frame number we have available for the node
 */
static void __init find_max_pfn_node(int nid)
{
        if (node_end_pfn[nid] > max_pfn)
                node_end_pfn[nid] = max_pfn;
        /*
         * if a user has given mem=XXXX, then we need to make sure 
         * that the node _starts_ before that, too, not just ends
         */
        if (node_start_pfn[nid] > max_pfn)
                node_start_pfn[nid] = max_pfn;
        if (node_start_pfn[nid] > node_end_pfn[nid])
                BUG();
}

/* 
 * Allocate memory for the pg_data_t for this node via a crude pre-bootmem
 * method.  For node zero take this from the bottom of memory, for
 * subsequent nodes place them at node_remap_start_vaddr which contains
 * node local data in physically node local memory.  See setup_memory()
 * for details.
 */
static void __init allocate_pgdat(int nid)
{
        if (nid)
                NODE_DATA(nid) = (pg_data_t *)node_remap_start_vaddr[nid];
        else {
                NODE_DATA(nid) = (pg_data_t *)(__va(min_low_pfn << PAGE_SHIFT));
                min_low_pfn += PFN_UP(sizeof(pg_data_t));
                memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
        }
}

/*
 * Register fully available low RAM pages with the bootmem allocator.
 */
static void __init register_bootmem_low_pages(unsigned long system_max_low_pfn)
{
        int i;

        for (i = 0; i < e820.nr_map; i++) {
                unsigned long curr_pfn, last_pfn, size;
                /*
                 * Reserve usable low memory
                 */
                if (e820.map[i].type != E820_RAM)
                        continue;
                /*
                 * We are rounding up the start address of usable memory:
                 */
                curr_pfn = PFN_UP(e820.map[i].addr);
                if (curr_pfn >= system_max_low_pfn)
                        continue;
                /*
                 * ... and at the end of the usable range downwards:
                 */
                last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);

                if (last_pfn > system_max_low_pfn)
                        last_pfn = system_max_low_pfn;

                /*
                 * .. finally, did all the rounding and playing
                 * around just make the area go away?
                 */
                if (last_pfn <= curr_pfn)
                        continue;

                size = last_pfn - curr_pfn;
                free_bootmem_node(NODE_DATA(0), PFN_PHYS(curr_pfn), PFN_PHYS(size));
        }
}

void __init remap_numa_kva(void)
{
        void *vaddr;
        unsigned long pfn;
        int node;

        for_each_online_node(node) {
                if (node == 0)
                        continue;
                for (pfn=0; pfn < node_remap_size[node]; pfn += PTRS_PER_PTE) {
                        vaddr = node_remap_start_vaddr[node]+(pfn<<PAGE_SHIFT);
                        set_pmd_pfn((ulong) vaddr, 
                                node_remap_start_pfn[node] + pfn, 
                                PAGE_KERNEL_LARGE);
                }
        }
}

static unsigned long calculate_numa_remap_pages(void)
{
        int nid;
        unsigned long size, reserve_pages = 0;

        for_each_online_node(nid) {
                if (nid == 0)
                        continue;
                /* calculate the size of the mem_map needed in bytes */
                size = (node_end_pfn[nid] - node_start_pfn[nid] + 1) 
                        * sizeof(struct page) + sizeof(pg_data_t);
                /* convert size to large (pmd size) pages, rounding up */
                size = (size + LARGE_PAGE_BYTES - 1) / LARGE_PAGE_BYTES;
                /* now the roundup is correct, convert to PAGE_SIZE pages */
                size = size * PTRS_PER_PTE;
                printk("Reserving %ld pages of KVA for lmem_map of node %d\n",
                                size, nid);
                node_remap_size[nid] = size;
                reserve_pages += size;
                node_remap_offset[nid] = reserve_pages;
                printk("Shrinking node %d from %ld pages to %ld pages\n",
                        nid, node_end_pfn[nid], node_end_pfn[nid] - size);
                node_end_pfn[nid] -= size;
                node_remap_start_pfn[nid] = node_end_pfn[nid];
        }
        printk("Reserving total of %ld pages for numa KVA remap\n",
                        reserve_pages);
        return reserve_pages;
}

/*
 * workaround for Dell systems that neglect to reserve EBDA
 */
static void __init reserve_ebda_region_node(void)
{
        unsigned int addr;
        addr = get_bios_ebda();
        if (addr)
                reserve_bootmem_node(NODE_DATA(0), addr, PAGE_SIZE);
}

unsigned long __init setup_memory(void)
{
        int nid;
        unsigned long bootmap_size, system_start_pfn, system_max_low_pfn;
        unsigned long reserve_pages, pfn;

        /*
         * When mapping a NUMA machine we allocate the node_mem_map arrays
         * from node local memory.  They are then mapped directly into KVA
         * between zone normal and vmalloc space.  Calculate the size of
         * this space and use it to adjust the boundry between ZONE_NORMAL
         * and ZONE_HIGHMEM.
         */
        get_memcfg_numa();

        /* Fill in the physnode_map */
        for_each_online_node(nid) {
                printk("Node: %d, start_pfn: %ld, end_pfn: %ld\n",
                                nid, node_start_pfn[nid], node_end_pfn[nid]);
                printk("  Setting physnode_map array to node %d for pfns:\n  ",
                                nid);
                for (pfn = node_start_pfn[nid]; pfn < node_end_pfn[nid];
                                        pfn += PAGES_PER_ELEMENT) {
                        physnode_map[pfn / PAGES_PER_ELEMENT] = nid;
                        printk("%ld ", pfn);
                }
                printk("\n");
        }

        reserve_pages = calculate_numa_remap_pages();

        /* partially used pages are not usable - thus round upwards */
        system_start_pfn = min_low_pfn = PFN_UP(init_pg_tables_end);

        find_max_pfn();
        system_max_low_pfn = max_low_pfn = find_max_low_pfn() - reserve_pages;
        printk("reserve_pages = %ld find_max_low_pfn() ~ %ld\n",
                        reserve_pages, max_low_pfn + reserve_pages);
        printk("max_pfn = %ld\n", max_pfn);
#ifdef CONFIG_HIGHMEM
        highstart_pfn = highend_pfn = max_pfn;
        if (max_pfn > system_max_low_pfn)
                highstart_pfn = system_max_low_pfn;
        printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
               pages_to_mb(highend_pfn - highstart_pfn));
#endif
        printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
                        pages_to_mb(system_max_low_pfn));
        printk("min_low_pfn = %ld, max_low_pfn = %ld, highstart_pfn = %ld\n", 
                        min_low_pfn, max_low_pfn, highstart_pfn);

        printk("Low memory ends at vaddr %08lx\n",
                        (ulong) pfn_to_kaddr(max_low_pfn));
        for_each_online_node(nid) {
                node_remap_start_vaddr[nid] = pfn_to_kaddr(
                        (highstart_pfn + reserve_pages) - node_remap_offset[nid]);
                allocate_pgdat(nid);
                printk ("node %d will remap to vaddr %08lx - %08lx\n", nid,
                        (ulong) node_remap_start_vaddr[nid],
                        (ulong) pfn_to_kaddr(highstart_pfn + reserve_pages
                            - node_remap_offset[nid] + node_remap_size[nid]));
        }
        printk("High memory starts at vaddr %08lx\n",
                        (ulong) pfn_to_kaddr(highstart_pfn));
        vmalloc_earlyreserve = reserve_pages * PAGE_SIZE;
        for_each_online_node(nid)
                find_max_pfn_node(nid);

        NODE_DATA(0)->bdata = &node0_bdata;

        /*
         * Initialize the boot-time allocator (with low memory only):
         */
        bootmap_size = init_bootmem_node(NODE_DATA(0), min_low_pfn, 0, system_max_low_pfn);

        register_bootmem_low_pages(system_max_low_pfn);

        /*
         * Reserve the bootmem bitmap itself as well. We do this in two
         * steps (first step was init_bootmem()) because this catches
         * the (very unlikely) case of us accidentally initializing the
         * bootmem allocator with an invalid RAM area.
         */
        reserve_bootmem_node(NODE_DATA(0), HIGH_MEMORY, (PFN_PHYS(min_low_pfn) +
                 bootmap_size + PAGE_SIZE-1) - (HIGH_MEMORY));

        /*
         * reserve physical page 0 - it's a special BIOS page on many boxes,
         * enabling clean reboots, SMP operation, laptop functions.
         */
        reserve_bootmem_node(NODE_DATA(0), 0, PAGE_SIZE);

        /*
         * But first pinch a few for the stack/trampoline stuff
         * FIXME: Don't need the extra page at 4K, but need to fix
         * trampoline before removing it. (see the GDT stuff)
         */
        reserve_bootmem_node(NODE_DATA(0), PAGE_SIZE, PAGE_SIZE);

        /* reserve EBDA region, it's a 4K region */
        reserve_ebda_region_node();

#ifdef CONFIG_ACPI_SLEEP
        /*
         * Reserve low memory region for sleep support.
         */
        acpi_reserve_bootmem();
#endif

        /*
         * Find and reserve possible boot-time SMP configuration:
         */
        find_smp_config();

#ifdef CONFIG_BLK_DEV_INITRD
        if (LOADER_TYPE && INITRD_START) {
                if (INITRD_START + INITRD_SIZE <= (system_max_low_pfn << PAGE_SHIFT)) {
                        reserve_bootmem_node(NODE_DATA(0), INITRD_START, INITRD_SIZE);
                        initrd_start =
                                INITRD_START ? INITRD_START + PAGE_OFFSET : 0;
                        initrd_end = initrd_start+INITRD_SIZE;
                }
                else {
                        printk(KERN_ERR "initrd extends beyond end of memory "
                            "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
                            INITRD_START + INITRD_SIZE,
                            system_max_low_pfn << PAGE_SHIFT);
                        initrd_start = 0;
                }
        }
#endif
        return system_max_low_pfn;
}

void __init zone_sizes_init(void)
{
        int nid;

        /*
         * Insert nodes into pgdat_list backward so they appear in order.
         * Clobber node 0's links and NULL out pgdat_list before starting.
         */
        pgdat_list = NULL;
        for (nid = MAX_NUMNODES - 1; nid >= 0; nid--) {
                if (!node_online(nid))
                        continue;
                if (nid)
                        memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
                NODE_DATA(nid)->pgdat_next = pgdat_list;
                pgdat_list = NODE_DATA(nid);
        }

        for_each_online_node(nid) {
                unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
                unsigned long *zholes_size;
                unsigned int max_dma;

                unsigned long low = max_low_pfn;
                unsigned long start = node_start_pfn[nid];
                unsigned long high = node_end_pfn[nid];

                max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;

                if (start > low) {
#ifdef CONFIG_HIGHMEM
                        BUG_ON(start > high);
                        zones_size[ZONE_HIGHMEM] = high - start;
#endif
                } else {
                        if (low < max_dma)
                                zones_size[ZONE_DMA] = low;
                        else {
                                BUG_ON(max_dma > low);
                                BUG_ON(low > high);
                                zones_size[ZONE_DMA] = max_dma;
                                zones_size[ZONE_NORMAL] = low - max_dma;
#ifdef CONFIG_HIGHMEM
                                zones_size[ZONE_HIGHMEM] = high - low;
#endif
                        }
                }
                zholes_size = get_zholes_size(nid);
                /*
                 * We let the lmem_map for node 0 be allocated from the
                 * normal bootmem allocator, but other nodes come from the
                 * remapped KVA area - mbligh
                 */
                if (!nid)
                        free_area_init_node(nid, NODE_DATA(nid),
                                        zones_size, start, zholes_size);
                else {
                        unsigned long lmem_map;
                        lmem_map = (unsigned long)node_remap_start_vaddr[nid];
                        lmem_map += sizeof(pg_data_t) + PAGE_SIZE - 1;
                        lmem_map &= PAGE_MASK;
                        NODE_DATA(nid)->node_mem_map = (struct page *)lmem_map;
                        free_area_init_node(nid, NODE_DATA(nid), zones_size,
                                start, zholes_size);
                }
        }
        return;
}

void __init set_highmem_pages_init(int bad_ppro) 
{
#ifdef CONFIG_HIGHMEM
        struct zone *zone;

        for_each_zone(zone) {
                unsigned long node_pfn, node_high_size, zone_start_pfn;
                struct page * zone_mem_map;
                
                if (!is_highmem(zone))
                        continue;

                printk("Initializing %s for node %d\n", zone->name,
                        zone->zone_pgdat->node_id);

                node_high_size = zone->spanned_pages;
                zone_mem_map = zone->zone_mem_map;
                zone_start_pfn = zone->zone_start_pfn;

                for (node_pfn = 0; node_pfn < node_high_size; node_pfn++) {
                        one_highpage_init((struct page *)(zone_mem_map + node_pfn),
                                          zone_start_pfn + node_pfn, bad_ppro);
                }
        }
        totalram_pages += totalhigh_pages;
#endif
}

void __init set_max_mapnr_init(void)
{
#ifdef CONFIG_HIGHMEM
        num_physpages = highend_pfn;
#else
        num_physpages = max_low_pfn;
#endif
}