/*
 *  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/export.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <linux/of_fdt.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/memblock.h>

#include <asm/mach-types.h>
#include <asm/memblock.h>
#include <asm/prom.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/fixmap.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 int __init early_initrd(char *p)
{
        unsigned long start, size;
        char *endp;

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

                phys_initrd_start = start;
                phys_initrd_size = size;
        }
        return 0;
}
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);

#ifdef CONFIG_OF_FLATTREE
void __init early_init_dt_setup_initrd_arch(unsigned long start, unsigned long end)
{
        phys_initrd_start = start;
        phys_initrd_size = end - start;
}
#endif /* CONFIG_OF_FLATTREE */

/*
 * 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(unsigned int filter)
{
        int free = 0, total = 0, reserved = 0;
        int shared = 0, cached = 0, slab = 0, i;
        struct meminfo * mi = &meminfo;

        printk("Mem-info:\n");
        show_free_areas(filter);

        for_each_bank (i, mi) {
                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 = pfn_to_page(pfn1);
                end  = pfn_to_page(pfn2 - 1) + 1;

                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_limits(unsigned long *min, unsigned long *max_low,
                               unsigned long *max_high)
{
        struct meminfo *mi = &meminfo;
        int i;

        /* This assumes the meminfo array is properly sorted */
        *min = bank_pfn_start(&mi->bank[0]);
        for_each_bank (i, mi)
                if (mi->bank[i].highmem)
                                break;
        *max_low = bank_pfn_end(&mi->bank[i - 1]);
        *max_high = bank_pfn_end(&mi->bank[mi->nr_banks - 1]);
}

static void __init arm_bootmem_init(unsigned long start_pfn,
        unsigned long end_pfn)
{
        struct memblock_region *reg;
        unsigned int boot_pages;
        phys_addr_t bitmap;
        pg_data_t *pgdat;

        /*
         * Allocate the bootmem bitmap page.  This must be in a region
         * of memory which has already been mapped.
         */
        boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
        bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
                                __pfn_to_phys(end_pfn));

        /*
         * Initialise the bootmem allocator, handing the
         * memory banks over to bootmem.
         */
        node_set_online(0);
        pgdat = NODE_DATA(0);
        init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

        /* Free the lowmem regions from memblock into bootmem. */
        for_each_memblock(memory, reg) {
                unsigned long start = memblock_region_memory_base_pfn(reg);
                unsigned long end = memblock_region_memory_end_pfn(reg);

                if (end >= end_pfn)
                        end = end_pfn;
                if (start >= end)
                        break;

                free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
        }

        /* Reserve the lowmem memblock reserved regions in bootmem. */
        for_each_memblock(reserved, reg) {
                unsigned long start = memblock_region_reserved_base_pfn(reg);
                unsigned long end = memblock_region_reserved_end_pfn(reg);

                if (end >= end_pfn)
                        end = end_pfn;
                if (start >= end)
                        break;

                reserve_bootmem(__pfn_to_phys(start),
                                (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
        }
}

#ifdef CONFIG_ZONE_DMA

unsigned long arm_dma_zone_size __read_mostly;
EXPORT_SYMBOL(arm_dma_zone_size);

/*
 * The DMA mask corresponding to the maximum bus address allocatable
 * using GFP_DMA.  The default here places no restriction on DMA
 * allocations.  This must be the smallest DMA mask in the system,
 * so a successful GFP_DMA allocation will always satisfy this.
 */
u32 arm_dma_limit;

static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
        unsigned long dma_size)
{
        if (size[0] <= dma_size)
                return;

        size[ZONE_NORMAL] = size[0] - dma_size;
        size[ZONE_DMA] = dma_size;
        hole[ZONE_NORMAL] = hole[0];
        hole[ZONE_DMA] = 0;
}
#endif

static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
        unsigned long max_high)
{
        unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
        struct memblock_region *reg;

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

        /*
         * The memory size 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

        /*
         * Calculate the size of the holes.
         *  holes = node_size - sum(bank_sizes)
         */
        memcpy(zhole_size, zone_size, sizeof(zhole_size));
        for_each_memblock(memory, reg) {
                unsigned long start = memblock_region_memory_base_pfn(reg);
                unsigned long end = memblock_region_memory_end_pfn(reg);

                if (start < max_low) {
                        unsigned long low_end = min(end, max_low);
                        zhole_size[0] -= low_end - start;
                }
#ifdef CONFIG_HIGHMEM
                if (end > max_low) {
                        unsigned long high_start = max(start, max_low);
                        zhole_size[ZONE_HIGHMEM] -= end - high_start;
                }
#endif
        }

#ifdef CONFIG_ZONE_DMA
        /*
         * Adjust the sizes according to any special requirements for
         * this machine type.
         */
        if (arm_dma_zone_size) {
                arm_adjust_dma_zone(zone_size, zhole_size,
                        arm_dma_zone_size >> PAGE_SHIFT);
                arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
        } else
                arm_dma_limit = 0xffffffff;
#endif

        free_area_init_node(0, zone_size, min, zhole_size);
}

#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
        return memblock_is_memory(__pfn_to_phys(pfn));
}
EXPORT_SYMBOL(pfn_valid);
#endif

#ifndef CONFIG_SPARSEMEM
static void __init arm_memory_present(void)
{
}
#else
static void __init arm_memory_present(void)
{
        struct memblock_region *reg;

        for_each_memblock(memory, reg)
                memory_present(0, memblock_region_memory_base_pfn(reg),
                               memblock_region_memory_end_pfn(reg));
}
#endif

static bool arm_memblock_steal_permitted = true;

phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
{
        phys_addr_t phys;

        BUG_ON(!arm_memblock_steal_permitted);

        phys = memblock_alloc(size, align);
        memblock_free(phys, size);
        memblock_remove(phys, size);

        return phys;
}

void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
{
        int i;

        for (i = 0; i < mi->nr_banks; i++)
                memblock_add(mi->bank[i].start, mi->bank[i].size);

        /* Register the kernel text, kernel data and initrd with memblock. */
#ifdef CONFIG_XIP_KERNEL
        memblock_reserve(__pa(_sdata), _end - _sdata);
#else
        memblock_reserve(__pa(_stext), _end - _stext);
#endif
#ifdef CONFIG_BLK_DEV_INITRD
        if (phys_initrd_size &&
            !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
                pr_err("INITRD: 0x%08lx+0x%08lx is not a memory region - disabling initrd\n",
                       phys_initrd_start, phys_initrd_size);
                phys_initrd_start = phys_initrd_size = 0;
        }
        if (phys_initrd_size &&
            memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
                pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region - disabling initrd\n",
                       phys_initrd_start, phys_initrd_size);
                phys_initrd_start = phys_initrd_size = 0;
        }
        if (phys_initrd_size) {
                memblock_reserve(phys_initrd_start, phys_initrd_size);

                /* Now convert initrd to virtual addresses */
                initrd_start = __phys_to_virt(phys_initrd_start);
                initrd_end = initrd_start + phys_initrd_size;
        }
#endif

        arm_mm_memblock_reserve();
        arm_dt_memblock_reserve();

        /* reserve any platform specific memblock areas */
        if (mdesc->reserve)
                mdesc->reserve();

        arm_memblock_steal_permitted = false;
        memblock_allow_resize();
        memblock_dump_all();
}

void __init bootmem_init(void)
{
        unsigned long min, max_low, max_high;

        max_low = max_high = 0;

        find_limits(&min, &max_low, &max_high);

        arm_bootmem_init(min, max_low);

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

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

        /*
         * Now free the memory - free_area_init_node needs
         * the sparse mem_map arrays initialized by sparse_init()
         * for memmap_init_zone(), otherwise all PFNs are invalid.
         */
        arm_bootmem_free(min, max_low, max_high);

        /*
         * 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;
}

/*
 * Poison init memory with an undefined instruction (ARM) or a branch to an
 * undefined instruction (Thumb).
 */
static inline void poison_init_mem(void *s, size_t count)
{
        u32 *p = (u32 *)s;
        for (; count != 0; count -= 4)
                *p++ = 0xe7fddef0;
}

static inline void
free_memmap(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 - 1) + 1;

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

        /*
         * If there are free pages between these,
         * free the section of the memmap array.
         */
        if (pg < pgend)
                free_bootmem(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(struct meminfo *mi)
{
        unsigned long bank_start, prev_bank_end = 0;
        unsigned int i;

        /*
         * This relies on each bank being in address order.
         * The banks are sorted previously in bootmem_init().
         */
        for_each_bank(i, mi) {
                struct membank *bank = &mi->bank[i];

                bank_start = bank_pfn_start(bank);

#ifdef CONFIG_SPARSEMEM
                /*
                 * Take care not to free memmap entries that don't exist
                 * due to SPARSEMEM sections which aren't present.
                 */
                bank_start = min(bank_start,
                                 ALIGN(prev_bank_end, PAGES_PER_SECTION));
#else
                /*
                 * Align down here since the VM subsystem insists that the
                 * memmap entries are valid from the bank start aligned to
                 * MAX_ORDER_NR_PAGES.
                 */
                bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES);
#endif
                /*
                 * 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(prev_bank_end, bank_start);

                /*
                 * Align up here since the VM subsystem insists that the
                 * memmap entries are valid from the bank end aligned to
                 * MAX_ORDER_NR_PAGES.
                 */
                prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
        }

#ifdef CONFIG_SPARSEMEM
        if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
                free_memmap(prev_bank_end,
                            ALIGN(prev_bank_end, PAGES_PER_SECTION));
#endif
}

static void __init free_highpages(void)
{
#ifdef CONFIG_HIGHMEM
        unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
        struct memblock_region *mem, *res;

        /* set highmem page free */
        for_each_memblock(memory, mem) {
                unsigned long start = memblock_region_memory_base_pfn(mem);
                unsigned long end = memblock_region_memory_end_pfn(mem);

                /* Ignore complete lowmem entries */
                if (end <= max_low)
                        continue;

                /* Truncate partial highmem entries */
                if (start < max_low)
                        start = max_low;

                /* Find and exclude any reserved regions */
                for_each_memblock(reserved, res) {
                        unsigned long res_start, res_end;

                        res_start = memblock_region_reserved_base_pfn(res);
                        res_end = memblock_region_reserved_end_pfn(res);

                        if (res_end < start)
                                continue;
                        if (res_start < start)
                                res_start = start;
                        if (res_start > end)
                                res_start = end;
                        if (res_end > end)
                                res_end = end;
                        if (res_start != start)
                                totalhigh_pages += free_area(start, res_start,
                                                             NULL);
                        start = res_end;
                        if (start == end)
                                break;
                }

                /* And now free anything which remains */
                if (start < end)
                        totalhigh_pages += free_area(start, end, NULL);
        }
        totalram_pages += totalhigh_pages;
#endif
}

/*
 * 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 long reserved_pages, free_pages;
        struct memblock_region *reg;
        int i;
#ifdef CONFIG_HAVE_TCM
        /* These pointers are filled in on TCM detection */
        extern u32 dtcm_end;
        extern u32 itcm_end;
#endif

        max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;

        /* this will put all unused low memory onto the freelists */
        free_unused_memmap(&meminfo);

        totalram_pages += free_all_bootmem();

#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

        free_highpages();

        reserved_pages = free_pages = 0;

        for_each_bank(i, &meminfo) {
                struct membank *bank = &meminfo.bank[i];
                unsigned int pfn1, pfn2;
                struct page *page, *end;

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

                page = pfn_to_page(pfn1);
                end  = pfn_to_page(pfn2 - 1) + 1;

                do {
                        if (PageReserved(page))
                                reserved_pages++;
                        else if (!page_count(page))
                                free_pages++;
                        page++;
                } while (page < end);
        }

        /*
         * 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_each_memblock(memory, reg) {
                unsigned long pages = memblock_region_memory_end_pfn(reg) -
                        memblock_region_memory_base_pfn(reg);
                num_physpages += pages;
                printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
        }
        printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));

        printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
                nr_free_pages() << (PAGE_SHIFT-10),
                free_pages << (PAGE_SHIFT-10),
                reserved_pages << (PAGE_SHIFT-10),
                totalhigh_pages << (PAGE_SHIFT-10));

#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)

        printk(KERN_NOTICE "Virtual kernel memory layout:\n"
                        "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#ifdef CONFIG_HAVE_TCM
                        "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                        "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#endif
                        "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                        "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
                        "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#ifdef CONFIG_HIGHMEM
                        "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#endif
#ifdef CONFIG_MODULES
                        "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#endif
                        "      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
                        "      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
                        "      .data : 0x%p" " - 0x%p" "   (%4d kB)\n"
                        "       .bss : 0x%p" " - 0x%p" "   (%4d kB)\n",

                        MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
                                (PAGE_SIZE)),
#ifdef CONFIG_HAVE_TCM
                        MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
                        MLK(ITCM_OFFSET, (unsigned long) itcm_end),
#endif
                        MLK(FIXADDR_START, FIXADDR_TOP),
                        MLM(VMALLOC_START, VMALLOC_END),
                        MLM(PAGE_OFFSET, (unsigned long)high_memory),
#ifdef CONFIG_HIGHMEM
                        MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
                                (PAGE_SIZE)),
#endif
#ifdef CONFIG_MODULES
                        MLM(MODULES_VADDR, MODULES_END),
#endif

                        MLK_ROUNDUP(_text, _etext),
                        MLK_ROUNDUP(__init_begin, __init_end),
                        MLK_ROUNDUP(_sdata, _edata),
                        MLK_ROUNDUP(__bss_start, __bss_stop));

#undef MLK
#undef MLM
#undef MLK_ROUNDUP

        /*
         * Check boundaries twice: Some fundamental inconsistencies can
         * be detected at build time already.
         */
#ifdef CONFIG_MMU
        BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
        BUG_ON(TASK_SIZE                                > MODULES_VADDR);
#endif

#ifdef CONFIG_HIGHMEM
        BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
        BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
#endif

        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;

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

        poison_init_mem(__init_begin, __init_end - __init_begin);
        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) {
                poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
                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