/*
 * 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/mm.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/nodemask.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/pfn.h>
#include <linux/swap.h>

#include <asm/e820.h>
#include <asm/setup.h>
#include <asm/mmzone.h>
#include <bios_ebda.h>

struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
EXPORT_SYMBOL(node_data);
bootmem_data_t node0_bdata;

/*
 * numa interface - we expect the numa architecture specific code to have
 *                  populated the following initialisation.
 *
 * 1) node_online_map  - the map of all nodes configured (online) in the system
 * 2) node_start_pfn   - the starting page frame number for a node
 * 3) node_end_pfn     - the ending page fram number for a node
 */
unsigned long node_start_pfn[MAX_NUMNODES] __read_mostly;
unsigned long node_end_pfn[MAX_NUMNODES] __read_mostly;


#ifdef CONFIG_DISCONTIGMEM
/*
 * 4) physnode_map     - the mapping between a pfn and owning 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] __read_mostly = { [0 ... (MAX_ELEMENTS - 1)] = -1};
EXPORT_SYMBOL(physnode_map);

void memory_present(int nid, unsigned long start, unsigned long end)
{
        unsigned long pfn;

        printk(KERN_INFO "Node: %d, start_pfn: %ld, end_pfn: %ld\n",
                        nid, start, end);
        printk(KERN_DEBUG "  Setting physnode_map array to node %d for pfns:\n", nid);
        printk(KERN_DEBUG "  ");
        for (pfn = start; pfn < end; pfn += PAGES_PER_ELEMENT) {
                physnode_map[pfn / PAGES_PER_ELEMENT] = nid;
                printk("%ld ", pfn);
        }
        printk("\n");
}

unsigned long node_memmap_size_bytes(int nid, unsigned long start_pfn,
                                              unsigned long end_pfn)
{
        unsigned long nr_pages = end_pfn - start_pfn;

        if (!nr_pages)
                return 0;

        return (nr_pages + 1) * sizeof(struct page);
}
#endif

extern unsigned long find_max_low_pfn(void);
extern void add_one_highpage_init(struct page *, int, int);
extern unsigned long highend_pfn, highstart_pfn;

#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);

void *node_remap_end_vaddr[MAX_NUMNODES];
void *node_remap_alloc_vaddr[MAX_NUMNODES];
static unsigned long kva_start_pfn;
static unsigned long kva_pages;
/*
 * 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;
        memory_present(0, 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;
        BUG_ON(node_start_pfn[nid] > node_end_pfn[nid]);
}

/* 
 * 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_has_online_mem(nid))
                NODE_DATA(nid) = (pg_data_t *)node_remap_start_vaddr[nid];
        else {
                NODE_DATA(nid) = (pg_data_t *)(pfn_to_kaddr(min_low_pfn));
                min_low_pfn += PFN_UP(sizeof(pg_data_t));
        }
}

void *alloc_remap(int nid, unsigned long size)
{
        void *allocation = node_remap_alloc_vaddr[nid];

        size = ALIGN(size, L1_CACHE_BYTES);

        if (!allocation || (allocation + size) >= node_remap_end_vaddr[nid])
                return 0;

        node_remap_alloc_vaddr[nid] += size;
        memset(allocation, 0, size);

        return allocation;
}

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

        for_each_online_node(node) {
                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;
        unsigned long pfn;

        for_each_online_node(nid) {
                unsigned old_end_pfn = node_end_pfn[nid];

                /*
                 * The acpi/srat node info can show hot-add memroy zones
                 * where memory could be added but not currently present.
                 */
                if (node_start_pfn[nid] > max_pfn)
                        continue;
                if (node_end_pfn[nid] > max_pfn)
                        node_end_pfn[nid] = max_pfn;

                /* ensure the remap includes space for the pgdat. */
                size = node_remap_size[nid] + 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;

                /*
                 * Validate the region we are allocating only contains valid
                 * pages.
                 */
                for (pfn = node_end_pfn[nid] - size;
                     pfn < node_end_pfn[nid]; pfn++)
                        if (!page_is_ram(pfn))
                                break;

                if (pfn != node_end_pfn[nid])
                        size = 0;

                printk("Reserving %ld pages of KVA for lmem_map of node %d\n",
                                size, nid);
                node_remap_size[nid] = size;
                node_remap_offset[nid] = reserve_pages;
                reserve_pages += size;
                printk("Shrinking node %d from %ld pages to %ld pages\n",
                        nid, node_end_pfn[nid], node_end_pfn[nid] - size);

                if (node_end_pfn[nid] & (PTRS_PER_PTE-1)) {
                        /*
                         * Align node_end_pfn[] and node_remap_start_pfn[] to
                         * pmd boundary. remap_numa_kva will barf otherwise.
                         */
                        printk("Shrinking node %d further by %ld pages for proper alignment\n",
                                nid, node_end_pfn[nid] & (PTRS_PER_PTE-1));
                        size +=  node_end_pfn[nid] & (PTRS_PER_PTE-1);
                }

                node_end_pfn[nid] -= size;
                node_remap_start_pfn[nid] = node_end_pfn[nid];
                shrink_active_range(nid, old_end_pfn, node_end_pfn[nid]);
        }
        printk("Reserving total of %ld pages for numa KVA remap\n",
                        reserve_pages);
        return reserve_pages;
}

extern void setup_bootmem_allocator(void);
unsigned long __init setup_memory(void)
{
        int nid;
        unsigned long system_start_pfn, system_max_low_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.
         */
        find_max_pfn();
        get_memcfg_numa();

        kva_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);

        kva_start_pfn = find_max_low_pfn() - kva_pages;

#ifdef CONFIG_BLK_DEV_INITRD
        /* Numa kva area is below the initrd */
        if (LOADER_TYPE && INITRD_START)
                kva_start_pfn = PFN_DOWN(INITRD_START)  - kva_pages;
#endif
        kva_start_pfn -= kva_start_pfn & (PTRS_PER_PTE-1);

        system_max_low_pfn = max_low_pfn = find_max_low_pfn();
        printk("kva_start_pfn ~ %ld find_max_low_pfn() ~ %ld\n",
                kva_start_pfn, max_low_pfn);
        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));
        num_physpages = highend_pfn;
        high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
#else
        num_physpages = system_max_low_pfn;
        high_memory = (void *) __va(system_max_low_pfn * PAGE_SIZE - 1) + 1;
#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(
                                kva_start_pfn + node_remap_offset[nid]);
                /* Init the node remap allocator */
                node_remap_end_vaddr[nid] = node_remap_start_vaddr[nid] +
                        (node_remap_size[nid] * PAGE_SIZE);
                node_remap_alloc_vaddr[nid] = node_remap_start_vaddr[nid] +
                        ALIGN(sizeof(pg_data_t), PAGE_SIZE);

                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
                           + node_remap_offset[nid] + node_remap_size[nid]));
        }
        printk("High memory starts at vaddr %08lx\n",
                        (ulong) pfn_to_kaddr(highstart_pfn));
        for_each_online_node(nid)
                find_max_pfn_node(nid);

        memset(NODE_DATA(0), 0, sizeof(struct pglist_data));
        NODE_DATA(0)->bdata = &node0_bdata;
        setup_bootmem_allocator();
        return max_low_pfn;
}

void __init numa_kva_reserve(void)
{
        reserve_bootmem(PFN_PHYS(kva_start_pfn),PFN_PHYS(kva_pages));
}

void __init zone_sizes_init(void)
{
        int nid;
        unsigned long max_zone_pfns[MAX_NR_ZONES];
        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
        max_zone_pfns[ZONE_DMA] =
                virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
        max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
#endif

        /* If SRAT has not registered memory, register it now */
        if (find_max_pfn_with_active_regions() == 0) {
                for_each_online_node(nid) {
                        if (node_has_online_mem(nid))
                                add_active_range(nid, node_start_pfn[nid],
                                                        node_end_pfn[nid]);
                }
        }

        free_area_init_nodes(max_zone_pfns);
        return;
}

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

        for_each_zone(zone) {
                unsigned long node_pfn, zone_start_pfn, zone_end_pfn;

                if (!is_highmem(zone))
                        continue;

                zone_start_pfn = zone->zone_start_pfn;
                zone_end_pfn = zone_start_pfn + zone->spanned_pages;

                printk("Initializing %s for node %d (%08lx:%08lx)\n",
                                zone->name, zone_to_nid(zone),
                                zone_start_pfn, zone_end_pfn);

                for (node_pfn = zone_start_pfn; node_pfn < zone_end_pfn; node_pfn++) {
                        if (!pfn_valid(node_pfn))
                                continue;
                        page = pfn_to_page(node_pfn);
                        add_one_highpage_init(page, node_pfn, bad_ppro);
                }
        }
        totalram_pages += totalhigh_pages;
#endif
}

#ifdef CONFIG_MEMORY_HOTPLUG
int paddr_to_nid(u64 addr)
{
        int nid;
        unsigned long pfn = PFN_DOWN(addr);

        for_each_node(nid)
                if (node_start_pfn[nid] <= pfn &&
                    pfn < node_end_pfn[nid])
                        return nid;

        return -1;
}

/*
 * This function is used to ask node id BEFORE memmap and mem_section's
 * initialization (pfn_to_nid() can't be used yet).
 * If _PXM is not defined on ACPI's DSDT, node id must be found by this.
 */
int memory_add_physaddr_to_nid(u64 addr)
{
        int nid = paddr_to_nid(addr);
        return (nid >= 0) ? nid : 0;
}

EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif