/*
 *  linux/arch/arm/mm/init.c
 *
 *  Copyright (C) 1995-2005 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <linux/sort.h>
#include <linux/highmem.h>

#include <asm/mach-types.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>

#include "mm.h"

static unsigned long phys_initrd_start __initdata = 0;
static unsigned long phys_initrd_size __initdata = 0;

static void __init early_initrd(char **p)
{
        unsigned long start, size;

        start = memparse(*p, p);
        if (**p == ',') {
                size = memparse((*p) + 1, p);

                phys_initrd_start = start;
                phys_initrd_size = size;
        }
}
__early_param("initrd=", early_initrd);

static int __init parse_tag_initrd(const struct tag *tag)
{
        printk(KERN_WARNING "ATAG_INITRD is deprecated; "
                "please update your bootloader.\n");
        phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
        phys_initrd_size = tag->u.initrd.size;
        return 0;
}

__tagtable(ATAG_INITRD, parse_tag_initrd);

static int __init parse_tag_initrd2(const struct tag *tag)
{
        phys_initrd_start = tag->u.initrd.start;
        phys_initrd_size = tag->u.initrd.size;
        return 0;
}

__tagtable(ATAG_INITRD2, parse_tag_initrd2);

/*
 * This keeps memory configuration data used by a couple memory
 * initialization functions, as well as show_mem() for the skipping
 * of holes in the memory map.  It is populated by arm_add_memory().
 */
struct meminfo meminfo;

void show_mem(void)
{
        int free = 0, total = 0, reserved = 0;
        int shared = 0, cached = 0, slab = 0, node, i;
        struct meminfo * mi = &meminfo;

        printk("Mem-info:\n");
        show_free_areas();
        for_each_online_node(node) {
                pg_data_t *n = NODE_DATA(node);
                struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;

                for_each_nodebank (i,mi,node) {
                        struct membank *bank = &mi->bank[i];
                        unsigned int pfn1, pfn2;
                        struct page *page, *end;

                        pfn1 = bank_pfn_start(bank);
                        pfn2 = bank_pfn_end(bank);

                        page = map + pfn1;
                        end  = map + pfn2;

                        do {
                                total++;
                                if (PageReserved(page))
                                        reserved++;
                                else if (PageSwapCache(page))
                                        cached++;
                                else if (PageSlab(page))
                                        slab++;
                                else if (!page_count(page))
                                        free++;
                                else
                                        shared += page_count(page) - 1;
                                page++;
                        } while (page < end);
                }
        }

        printk("%d pages of RAM\n", total);
        printk("%d free pages\n", free);
        printk("%d reserved pages\n", reserved);
        printk("%d slab pages\n", slab);
        printk("%d pages shared\n", shared);
        printk("%d pages swap cached\n", cached);
}

static void __init find_node_limits(int node, struct meminfo *mi,
        unsigned long *min, unsigned long *max_low, unsigned long *max_high)
{
        int i;

        *min = -1UL;
        *max_low = *max_high = 0;

        for_each_nodebank(i, mi, node) {
                struct membank *bank = &mi->bank[i];
                unsigned long start, end;

                start = bank_pfn_start(bank);
                end = bank_pfn_end(bank);

                if (*min > start)
                        *min = start;
                if (*max_high < end)
                        *max_high = end;
                if (bank->highmem)
                        continue;
                if (*max_low < end)
                        *max_low = end;
        }
}

/*
 * FIXME: We really want to avoid allocating the bootmap bitmap
 * over the top of the initrd.  Hopefully, this is located towards
 * the start of a bank, so if we allocate the bootmap bitmap at
 * the end, we won't clash.
 */
static unsigned int __init
find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
{
        unsigned int start_pfn, i, bootmap_pfn;

        start_pfn   = PAGE_ALIGN(__pa(_end)) >> PAGE_SHIFT;
        bootmap_pfn = 0;

        for_each_nodebank(i, mi, node) {
                struct membank *bank = &mi->bank[i];
                unsigned int start, end;

                start = bank_pfn_start(bank);
                end   = bank_pfn_end(bank);

                if (end < start_pfn)
                        continue;

                if (start < start_pfn)
                        start = start_pfn;

                if (end <= start)
                        continue;

                if (end - start >= bootmap_pages) {
                        bootmap_pfn = start;
                        break;
                }
        }

        if (bootmap_pfn == 0)
                BUG();

        return bootmap_pfn;
}

static int __init check_initrd(struct meminfo *mi)
{
        int initrd_node = -2;
#ifdef CONFIG_BLK_DEV_INITRD
        unsigned long end = phys_initrd_start + phys_initrd_size;

        /*
         * Make sure that the initrd is within a valid area of
         * memory.
         */
        if (phys_initrd_size) {
                unsigned int i;

                initrd_node = -1;

                for (i = 0; i < mi->nr_banks; i++) {
                        struct membank *bank = &mi->bank[i];
                        if (bank_phys_start(bank) <= phys_initrd_start &&
                            end <= bank_phys_end(bank))
                                initrd_node = bank->node;
                }
        }

        if (initrd_node == -1) {
                printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
                       "physical memory - disabling initrd\n",
                       phys_initrd_start, phys_initrd_size);
                phys_initrd_start = phys_initrd_size = 0;
        }
#endif

        return initrd_node;
}

static inline void map_memory_bank(struct membank *bank)
{
#ifdef CONFIG_MMU
        struct map_desc map;

        map.pfn = bank_pfn_start(bank);
        map.virtual = __phys_to_virt(bank_phys_start(bank));
        map.length = bank_phys_size(bank);
        map.type = MT_MEMORY;

        create_mapping(&map);
#endif
}

static void __init bootmem_init_node(int node, struct meminfo *mi,
        unsigned long start_pfn, unsigned long end_pfn)
{
        unsigned long boot_pfn;
        unsigned int boot_pages;
        pg_data_t *pgdat;
        int i;

        /*
         * Map the memory banks for this node.
         */
        for_each_nodebank(i, mi, node) {
                struct membank *bank = &mi->bank[i];

                if (!bank->highmem)
                        map_memory_bank(bank);
        }

        /*
         * Allocate the bootmem bitmap page.
         */
        boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
        boot_pfn = find_bootmap_pfn(node, mi, boot_pages);

        /*
         * Initialise the bootmem allocator for this node, handing the
         * memory banks over to bootmem.
         */
        node_set_online(node);
        pgdat = NODE_DATA(node);
        init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);

        for_each_nodebank(i, mi, node) {
                struct membank *bank = &mi->bank[i];
                if (!bank->highmem)
                        free_bootmem_node(pgdat, bank_phys_start(bank), bank_phys_size(bank));
        }

        /*
         * Reserve the bootmem bitmap for this node.
         */
        reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
                             boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
}

static void __init bootmem_reserve_initrd(int node)
{
#ifdef CONFIG_BLK_DEV_INITRD
        pg_data_t *pgdat = NODE_DATA(node);
        int res;

        res = reserve_bootmem_node(pgdat, phys_initrd_start,
                             phys_initrd_size, BOOTMEM_EXCLUSIVE);

        if (res == 0) {
                initrd_start = __phys_to_virt(phys_initrd_start);
                initrd_end = initrd_start + phys_initrd_size;
        } else {
                printk(KERN_ERR
                        "INITRD: 0x%08lx+0x%08lx overlaps in-use "
                        "memory region - disabling initrd\n",
                        phys_initrd_start, phys_initrd_size);
        }
#endif
}

static void __init bootmem_free_node(int node, struct meminfo *mi)
{
        unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
        unsigned long min, max_low, max_high;
        int i;

        find_node_limits(node, mi, &min, &max_low, &max_high);

        /*
         * initialise the zones within this node.
         */
        memset(zone_size, 0, sizeof(zone_size));

        /*
         * The size of this node has already been determined.  If we need
         * to do anything fancy with the allocation of this memory to the
         * zones, now is the time to do it.
         */
        zone_size[0] = max_low - min;
#ifdef CONFIG_HIGHMEM
        zone_size[ZONE_HIGHMEM] = max_high - max_low;
#endif

        /*
         * For each bank in this node, calculate the size of the holes.
         *  holes = node_size - sum(bank_sizes_in_node)
         */
        memcpy(zhole_size, zone_size, sizeof(zhole_size));
        for_each_nodebank(i, mi, node) {
                int idx = 0;
#ifdef CONFIG_HIGHMEM
                if (mi->bank[i].highmem)
                        idx = ZONE_HIGHMEM;
#endif
                zhole_size[idx] -= bank_pfn_size(&mi->bank[i]);
        }

        /*
         * Adjust the sizes according to any special requirements for
         * this machine type.
         */
        arch_adjust_zones(node, zone_size, zhole_size);

        free_area_init_node(node, zone_size, min, zhole_size);
}

#ifndef CONFIG_SPARSEMEM
int pfn_valid(unsigned long pfn)
{
        struct meminfo *mi = &meminfo;
        unsigned int left = 0, right = mi->nr_banks;

        do {
                unsigned int mid = (right + left) / 2;
                struct membank *bank = &mi->bank[mid];

                if (pfn < bank_pfn_start(bank))
                        right = mid;
                else if (pfn >= bank_pfn_end(bank))
                        left = mid + 1;
                else
                        return 1;
        } while (left < right);
        return 0;
}
EXPORT_SYMBOL(pfn_valid);

static void arm_memory_present(struct meminfo *mi, int node)
{
}
#else
static void arm_memory_present(struct meminfo *mi, int node)
{
        int i;
        for_each_nodebank(i, mi, node) {
                struct membank *bank = &mi->bank[i];
                memory_present(node, bank_pfn_start(bank), bank_pfn_end(bank));
        }
}
#endif

static int __init meminfo_cmp(const void *_a, const void *_b)
{
        const struct membank *a = _a, *b = _b;
        long cmp = bank_pfn_start(a) - bank_pfn_start(b);
        return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
}

void __init bootmem_init(void)
{
        struct meminfo *mi = &meminfo;
        unsigned long min, max_low, max_high;
        int node, initrd_node;

        sort(&mi->bank, mi->nr_banks, sizeof(mi->bank[0]), meminfo_cmp, NULL);

        /*
         * Locate which node contains the ramdisk image, if any.
         */
        initrd_node = check_initrd(mi);

        max_low = max_high = 0;

        /*
         * Run through each node initialising the bootmem allocator.
         */
        for_each_node(node) {
                unsigned long node_low, node_high;

                find_node_limits(node, mi, &min, &node_low, &node_high);

                if (node_low > max_low)
                        max_low = node_low;
                if (node_high > max_high)
                        max_high = node_high;

                /*
                 * If there is no memory in this node, ignore it.
                 * (We can't have nodes which have no lowmem)
                 */
                if (node_low == 0)
                        continue;

                bootmem_init_node(node, mi, min, node_low);

                /*
                 * Reserve any special node zero regions.
                 */
                if (node == 0)
                        reserve_node_zero(NODE_DATA(node));

                /*
                 * If the initrd is in this node, reserve its memory.
                 */
                if (node == initrd_node)
                        bootmem_reserve_initrd(node);

                /*
                 * Sparsemem tries to allocate bootmem in memory_present(),
                 * so must be done after the fixed reservations
                 */
                arm_memory_present(mi, node);
        }

        /*
         * sparse_init() needs the bootmem allocator up and running.
         */
        sparse_init();

        /*
         * Now free memory in each node - free_area_init_node needs
         * the sparse mem_map arrays initialized by sparse_init()
         * for memmap_init_zone(), otherwise all PFNs are invalid.
         */
        for_each_node(node)
                bootmem_free_node(node, mi);

        high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;

        /*
         * This doesn't seem to be used by the Linux memory manager any
         * more, but is used by ll_rw_block.  If we can get rid of it, we
         * also get rid of some of the stuff above as well.
         *
         * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
         * the system, not the maximum PFN.
         */
        max_low_pfn = max_low - PHYS_PFN_OFFSET;
        max_pfn = max_high - PHYS_PFN_OFFSET;
}

static inline int free_area(unsigned long pfn, unsigned long end, char *s)
{
        unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);

        for (; pfn < end; pfn++) {
                struct page *page = pfn_to_page(pfn);
                ClearPageReserved(page);
                init_page_count(page);
                __free_page(page);
                pages++;
        }

        if (size && s)
                printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);

        return pages;
}

static inline void
free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn)
{
        struct page *start_pg, *end_pg;
        unsigned long pg, pgend;

        /*
         * Convert start_pfn/end_pfn to a struct page pointer.
         */
        start_pg = pfn_to_page(start_pfn - 1) + 1;
        end_pg = pfn_to_page(end_pfn);

        /*
         * Convert to physical addresses, and
         * round start upwards and end downwards.
         */
        pg = PAGE_ALIGN(__pa(start_pg));
        pgend = __pa(end_pg) & PAGE_MASK;

        /*
         * If there are free pages between these,
         * free the section of the memmap array.
         */
        if (pg < pgend)
                free_bootmem_node(NODE_DATA(node), pg, pgend - pg);
}

/*
 * The mem_map array can get very big.  Free the unused area of the memory map.
 */
static void __init free_unused_memmap_node(int node, struct meminfo *mi)
{
        unsigned long bank_start, prev_bank_end = 0;
        unsigned int i;

        /*
         * [FIXME] This relies on each bank being in address order.  This
         * may not be the case, especially if the user has provided the
         * information on the command line.
         */
        for_each_nodebank(i, mi, node) {
                struct membank *bank = &mi->bank[i];

                bank_start = bank_pfn_start(bank);
                if (bank_start < prev_bank_end) {
                        printk(KERN_ERR "MEM: unordered memory banks.  "
                                "Not freeing memmap.\n");
                        break;
                }

                /*
                 * If we had a previous bank, and there is a space
                 * between the current bank and the previous, free it.
                 */
                if (prev_bank_end && prev_bank_end != bank_start)
                        free_memmap(node, prev_bank_end, bank_start);

                prev_bank_end = bank_pfn_end(bank);
        }
}

/*
 * mem_init() marks the free areas in the mem_map and tells us how much
 * memory is free.  This is done after various parts of the system have
 * claimed their memory after the kernel image.
 */
void __init mem_init(void)
{
        unsigned int codesize, datasize, initsize;
        int i, node;

#ifndef CONFIG_DISCONTIGMEM
        max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
#endif

        /* this will put all unused low memory onto the freelists */
        for_each_online_node(node) {
                pg_data_t *pgdat = NODE_DATA(node);

                free_unused_memmap_node(node, &meminfo);

                if (pgdat->node_spanned_pages != 0)
                        totalram_pages += free_all_bootmem_node(pgdat);
        }

#ifdef CONFIG_SA1111
        /* now that our DMA memory is actually so designated, we can free it */
        totalram_pages += free_area(PHYS_PFN_OFFSET,
                                    __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
#endif

#ifdef CONFIG_HIGHMEM
        /* set highmem page free */
        for_each_online_node(node) {
                for_each_nodebank (i, &meminfo, node) {
                        unsigned long start = bank_pfn_start(&meminfo.bank[i]);
                        unsigned long end = bank_pfn_end(&meminfo.bank[i]);
                        if (start >= max_low_pfn + PHYS_PFN_OFFSET)
                                totalhigh_pages += free_area(start, end, NULL);
                }
        }
        totalram_pages += totalhigh_pages;
#endif

        /*
         * Since our memory may not be contiguous, calculate the
         * real number of pages we have in this system
         */
        printk(KERN_INFO "Memory:");
        num_physpages = 0;
        for (i = 0; i < meminfo.nr_banks; i++) {
                num_physpages += bank_pfn_size(&meminfo.bank[i]);
                printk(" %ldMB", bank_phys_size(&meminfo.bank[i]) >> 20);
        }
        printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));

        codesize = _etext - _text;
        datasize = _end - _data;
        initsize = __init_end - __init_begin;

        printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
                "%dK data, %dK init, %luK highmem)\n",
                nr_free_pages() << (PAGE_SHIFT-10), codesize >> 10,
                datasize >> 10, initsize >> 10,
                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));

        if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
                extern int sysctl_overcommit_memory;
                /*
                 * On a machine this small we won't get
                 * anywhere without overcommit, so turn
                 * it on by default.
                 */
                sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
        }
}

void free_initmem(void)
{
#ifdef CONFIG_HAVE_TCM
        extern char *__tcm_start, *__tcm_end;

        totalram_pages += free_area(__phys_to_pfn(__pa(__tcm_start)),
                                    __phys_to_pfn(__pa(__tcm_end)),
                                    "TCM link");
#endif

        if (!machine_is_integrator() && !machine_is_cintegrator())
                totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
                                            __phys_to_pfn(__pa(__init_end)),
                                            "init");
}

#ifdef CONFIG_BLK_DEV_INITRD

static int keep_initrd;

void free_initrd_mem(unsigned long start, unsigned long end)
{
        if (!keep_initrd)
                totalram_pages += free_area(__phys_to_pfn(__pa(start)),
                                            __phys_to_pfn(__pa(end)),
                                            "initrd");
}

static int __init keepinitrd_setup(char *__unused)
{
        keep_initrd = 1;
        return 1;
}

__setup("keepinitrd", keepinitrd_setup);
#endif