/*
 *  linux/arch/arm/mm/init.c
 *
 *  Copyright (C) 1995-2002 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/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/ptrace.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 <asm/mach-types.h>
#include <asm/hardware.h>
#include <asm/setup.h>
#include <asm/tlb.h>

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

#define TABLE_SIZE      (2 * PTRS_PER_PTE * sizeof(pte_t))

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end;
extern unsigned long phys_initrd_start;
extern unsigned long phys_initrd_size;

/*
 * The sole use of this is to pass memory configuration
 * data from paging_init to mem_init.
 */
static struct meminfo meminfo __initdata = { 0, };

/*
 * empty_zero_page is a special page that is used for
 * zero-initialized data and COW.
 */
struct page *empty_zero_page;

void show_mem(void)
{
        int free = 0, total = 0, reserved = 0;
        int shared = 0, cached = 0, slab = 0, node;

        printk("Mem-info:\n");
        show_free_areas();
        printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));

        for_each_online_node(node) {
                struct page *page, *end;

                page = NODE_MEM_MAP(node);
                end  = page + NODE_DATA(node)->node_spanned_pages;

                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);
}

struct node_info {
        unsigned int start;
        unsigned int end;
        int bootmap_pages;
};

#define O_PFN_DOWN(x)   ((x) >> PAGE_SHIFT)
#define V_PFN_DOWN(x)   O_PFN_DOWN(__pa(x))

#define O_PFN_UP(x)     (PAGE_ALIGN(x) >> PAGE_SHIFT)
#define V_PFN_UP(x)     O_PFN_UP(__pa(x))

#define PFN_SIZE(x)     ((x) >> PAGE_SHIFT)
#define PFN_RANGE(s,e)  PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \
                                (((unsigned long)(s)) & PAGE_MASK))

/*
 * 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, bank, bootmap_pfn;

        start_pfn   = V_PFN_UP(&_end);
        bootmap_pfn = 0;

        for (bank = 0; bank < mi->nr_banks; bank ++) {
                unsigned int start, end;

                if (mi->bank[bank].node != node)
                        continue;

                start = O_PFN_UP(mi->bank[bank].start);
                end   = O_PFN_DOWN(mi->bank[bank].size +
                                   mi->bank[bank].start);

                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;
}

/*
 * Scan the memory info structure and pull out:
 *  - the end of memory
 *  - the number of nodes
 *  - the pfn range of each node
 *  - the number of bootmem bitmap pages
 */
static unsigned int __init
find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
{
        unsigned int i, bootmem_pages = 0, memend_pfn = 0;

        for (i = 0; i < MAX_NUMNODES; i++) {
                np[i].start = -1U;
                np[i].end = 0;
                np[i].bootmap_pages = 0;
        }

        for (i = 0; i < mi->nr_banks; i++) {
                unsigned long start, end;
                int node;

                if (mi->bank[i].size == 0) {
                        /*
                         * Mark this bank with an invalid node number
                         */
                        mi->bank[i].node = -1;
                        continue;
                }

                node = mi->bank[i].node;

                /*
                 * Make sure we haven't exceeded the maximum number of nodes
                 * that we have in this configuration.  If we have, we're in
                 * trouble.  (maybe we ought to limit, instead of bugging?)
                 */
                if (node >= MAX_NUMNODES)
                        BUG();
                node_set_online(node);

                /*
                 * Get the start and end pfns for this bank
                 */
                start = O_PFN_UP(mi->bank[i].start);
                end   = O_PFN_DOWN(mi->bank[i].start + mi->bank[i].size);

                if (np[node].start > start)
                        np[node].start = start;

                if (np[node].end < end)
                        np[node].end = end;

                if (memend_pfn < end)
                        memend_pfn = end;
        }

        /*
         * Calculate the number of pages we require to
         * store the bootmem bitmaps.
         */
        for_each_online_node(i) {
                if (np[i].end == 0)
                        continue;

                np[i].bootmap_pages = bootmem_bootmap_pages(np[i].end -
                                                            np[i].start);
                bootmem_pages += np[i].bootmap_pages;
        }

        high_memory = __va(memend_pfn << PAGE_SHIFT);

        /*
         * This doesn't seem to be used by the Linux memory
         * manager any more.  If we can get rid of it, we
         * also get rid of some of the stuff above as well.
         */
        max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);
        max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);

        return bootmem_pages;
}

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++) {
                        unsigned long bank_end;

                        bank_end = mi->bank[i].start + mi->bank[i].size;

                        if (mi->bank[i].start <= phys_initrd_start &&
                            end <= bank_end)
                                initrd_node = mi->bank[i].node;
                }
        }

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

        return initrd_node;
}

/*
 * Reserve the various regions of node 0
 */
static __init void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages)
{
        pg_data_t *pgdat = NODE_DATA(0);
        unsigned long res_size = 0;

        /*
         * Register the kernel text and data with bootmem.
         * Note that this can only be in node 0.
         */
#ifdef CONFIG_XIP_KERNEL
        reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
#else
        reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
#endif

        /*
         * Reserve the page tables.  These are already in use,
         * and can only be in node 0.
         */
        reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
                             PTRS_PER_PGD * sizeof(pgd_t));

        /*
         * And don't forget to reserve the allocator bitmap,
         * which will be freed later.
         */
        reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
                             bootmap_pages << PAGE_SHIFT);

        /*
         * Hmm... This should go elsewhere, but we really really need to
         * stop things allocating the low memory; ideally we need a better
         * implementation of GFP_DMA which does not assume that DMA-able
         * memory starts at zero.
         */
        if (machine_is_integrator() || machine_is_cintegrator())
                res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;

        /*
         * These should likewise go elsewhere.  They pre-reserve the
         * screen memory region at the start of main system memory.
         */
        if (machine_is_edb7211())
                res_size = 0x00020000;
        if (machine_is_p720t())
                res_size = 0x00014000;

#ifdef CONFIG_SA1111
        /*
         * Because of the SA1111 DMA bug, we want to preserve our
         * precious DMA-able memory...
         */
        res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
#endif
        if (res_size)
                reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
}

/*
 * Register all available RAM in this node with the bootmem allocator.
 */
static inline void free_bootmem_node_bank(int node, struct meminfo *mi)
{
        pg_data_t *pgdat = NODE_DATA(node);
        int bank;

        for (bank = 0; bank < mi->nr_banks; bank++)
                if (mi->bank[bank].node == node)
                        free_bootmem_node(pgdat, mi->bank[bank].start,
                                          mi->bank[bank].size);
}

/*
 * Initialise the bootmem allocator for all nodes.  This is called
 * early during the architecture specific initialisation.
 */
static void __init bootmem_init(struct meminfo *mi)
{
        struct node_info node_info[MAX_NUMNODES], *np = node_info;
        unsigned int bootmap_pages, bootmap_pfn, map_pg;
        int node, initrd_node;

        bootmap_pages = find_memend_and_nodes(mi, np);
        bootmap_pfn   = find_bootmap_pfn(0, mi, bootmap_pages);
        initrd_node   = check_initrd(mi);

        map_pg = bootmap_pfn;

        /*
         * Initialise the bootmem nodes.
         *
         * What we really want to do is:
         *
         *   unmap_all_regions_except_kernel();
         *   for_each_node_in_reverse_order(node) {
         *     map_node(node);
         *     allocate_bootmem_map(node);
         *     init_bootmem_node(node);
         *     free_bootmem_node(node);
         *   }
         *
         * but this is a 2.5-type change.  For now, we just set
         * the nodes up in reverse order.
         *
         * (we could also do with rolling bootmem_init and paging_init
         * into one generic "memory_init" type function).
         */
        np += num_online_nodes() - 1;
        for (node = num_online_nodes() - 1; node >= 0; node--, np--) {
                /*
                 * If there are no pages in this node, ignore it.
                 * Note that node 0 must always have some pages.
                 */
                if (np->end == 0 || !node_online(node)) {
                        if (node == 0)
                                BUG();
                        continue;
                }

                /*
                 * Initialise the bootmem allocator.
                 */
                init_bootmem_node(NODE_DATA(node), map_pg, np->start, np->end);
                free_bootmem_node_bank(node, mi);
                map_pg += np->bootmap_pages;

                /*
                 * If this is node 0, we need to reserve some areas ASAP -
                 * we may use bootmem on node 0 to setup the other nodes.
                 */
                if (node == 0)
                        reserve_node_zero(bootmap_pfn, bootmap_pages);
        }


#ifdef CONFIG_BLK_DEV_INITRD
        if (phys_initrd_size && initrd_node >= 0) {
                reserve_bootmem_node(NODE_DATA(initrd_node), phys_initrd_start,
                                     phys_initrd_size);
                initrd_start = __phys_to_virt(phys_initrd_start);
                initrd_end = initrd_start + phys_initrd_size;
        }
#endif

        BUG_ON(map_pg != bootmap_pfn + bootmap_pages);
}

/*
 * paging_init() sets up the page tables, initialises the zone memory
 * maps, and sets up the zero page, bad page and bad page tables.
 */
void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
{
        void *zero_page;
        int node;

        bootmem_init(mi);

        memcpy(&meminfo, mi, sizeof(meminfo));

        /*
         * allocate the zero page.  Note that we count on this going ok.
         */
        zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

        /*
         * initialise the page tables.
         */
        memtable_init(mi);
        if (mdesc->map_io)
                mdesc->map_io();
        flush_tlb_all();

        /*
         * initialise the zones within each node
         */
        for_each_online_node(node) {
                unsigned long zone_size[MAX_NR_ZONES];
                unsigned long zhole_size[MAX_NR_ZONES];
                struct bootmem_data *bdata;
                pg_data_t *pgdat;
                int i;

                /*
                 * Initialise the zone size information.
                 */
                for (i = 0; i < MAX_NR_ZONES; i++) {
                        zone_size[i]  = 0;
                        zhole_size[i] = 0;
                }

                pgdat = NODE_DATA(node);
                bdata = pgdat->bdata;

                /*
                 * 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] = bdata->node_low_pfn -
                                (bdata->node_boot_start >> PAGE_SHIFT);

                /*
                 * If this zone has zero size, skip it.
                 */
                if (!zone_size[0])
                        continue;

                /*
                 * For each bank in this node, calculate the size of the
                 * holes.  holes = node_size - sum(bank_sizes_in_node)
                 */
                zhole_size[0] = zone_size[0];
                for (i = 0; i < mi->nr_banks; i++) {
                        if (mi->bank[i].node != node)
                                continue;

                        zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT;
                }

                /*
                 * 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, pgdat, zone_size,
                                bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
        }

#ifndef CONFIG_DISCONTIGMEM
        mem_map = contig_page_data.node_mem_map;
#endif

        /*
         * finish off the bad pages once
         * the mem_map is initialised
         */
        memzero(zero_page, PAGE_SIZE);
        empty_zero_page = virt_to_page(zero_page);
        flush_dcache_page(empty_zero_page);
}

static inline void free_area(unsigned long addr, unsigned long end, char *s)
{
        unsigned int size = (end - addr) >> 10;

        for (; addr < end; addr += PAGE_SIZE) {
                struct page *page = virt_to_page(addr);
                ClearPageReserved(page);
                set_page_count(page, 1);
                free_page(addr);
                totalram_pages++;
        }

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

/*
 * 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 codepages, datapages, initpages;
        int i, node;

        codepages = &_etext - &_text;
        datapages = &_end - &__data_start;
        initpages = &__init_end - &__init_begin;

#ifndef CONFIG_DISCONTIGMEM
        max_mapnr   = virt_to_page(high_memory) - mem_map;
#endif

        /*
         * We may have non-contiguous memory.
         */
        if (meminfo.nr_banks != 1)
                create_memmap_holes(&meminfo);

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

                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 */
        free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL);
#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 += meminfo.bank[i].size >> PAGE_SHIFT;
                printk(" %ldMB", meminfo.bank[i].size >> 20);
        }

        printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
        printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
                "%dK data, %dK init)\n",
                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
                codepages >> 10, datapages >> 10, initpages >> 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)
{
        if (!machine_is_integrator() && !machine_is_cintegrator()) {
                free_area((unsigned long)(&__init_begin),
                          (unsigned long)(&__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)
                free_area(start, end, "initrd");
}

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

__setup("keepinitrd", keepinitrd_setup);
#endif