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/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 1994 - 2000 by Ralf Baechle

 * Copyright (C) 1999, 2000 by Silicon Graphics

 */

#include <linux/config.h>

#include <linux/init.h>

#include <linux/signal.h>

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/string.h>

#include <linux/types.h>

#include <linux/pagemap.h>

#include <linux/ptrace.h>

#include <linux/mman.h>

#include <linux/mm.h>

#include <linux/bootmem.h>

#include <linux/highmem.h>

#include <linux/swap.h>

#include <linux/swapctl.h>

#ifdef CONFIG_BLK_DEV_INITRD

#include <linux/blk.h>

#endif

#include <asm/bootinfo.h>

#include <asm/cachectl.h>

#include <asm/dma.h>

#include <asm/system.h>

#include <asm/pgtable.h>

#include <asm/pgalloc.h>

#include <asm/mmu_context.h>

#include <asm/tlb.h>

#include <asm/cpu.h>

mmu_gather_t mmu_gathers[NR_CPUS];

unsigned long totalram_pages;

void pgd_init(unsigned long page)

{

        unsigned long *p, *end;

        p = (unsigned long *) page;

        end = p + PTRS_PER_PGD;

        while (p < end) {

                p[0] = (unsigned long) invalid_pmd_table;

                p[1] = (unsigned long) invalid_pmd_table;

                p[2] = (unsigned long) invalid_pmd_table;

                p[3] = (unsigned long) invalid_pmd_table;

                p[4] = (unsigned long) invalid_pmd_table;

                p[5] = (unsigned long) invalid_pmd_table;

                p[6] = (unsigned long) invalid_pmd_table;

                p[7] = (unsigned long) invalid_pmd_table;

                p += 8;

        }

}

pgd_t *get_pgd_slow(void)

{

        pgd_t *ret, *init;

        ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ORDER);

        if (ret) {

                init = pgd_offset(&init_mm, 0);

                pgd_init((unsigned long)ret);

                memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,

                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));

        }

        return ret;

}

void pmd_init(unsigned long addr, unsigned long pagetable)

{

        unsigned long *p, *end;

        p = (unsigned long *) addr;

        end = p + PTRS_PER_PMD;

        while (p < end) {

                p[0] = (unsigned long)pagetable;

                p[1] = (unsigned long)pagetable;

                p[2] = (unsigned long)pagetable;

                p[3] = (unsigned long)pagetable;

                p[4] = (unsigned long)pagetable;

                p[5] = (unsigned long)pagetable;

                p[6] = (unsigned long)pagetable;

                p[7] = (unsigned long)pagetable;

                p += 8;

        }

}

int do_check_pgt_cache(int low, int high)

{

        int freed = 0;

        if (pgtable_cache_size > high) {

                do {

                        if (pgd_quicklist)

                                free_pgd_slow(get_pgd_fast()), freed++;

                        if (pmd_quicklist)

                                free_pmd_slow(get_pmd_fast()), freed++;

                        if (pte_quicklist)

                                free_pte_slow(get_pte_fast()), freed++;

                } while (pgtable_cache_size > low);

        }

        return freed;

}

/*

 * We have up to 8 empty zeroed pages so we can map one of the right colour

 * when needed.  This is necessary only on R4000 / R4400 SC and MC versions

 * where we have to avoid VCED / VECI exceptions for good performance at

 * any price.  Since page is never written to after the initialization we

 * don't have to care about aliases on other CPUs.

 */

unsigned long empty_zero_page, zero_page_mask;

unsigned long setup_zero_pages(void)

{

        unsigned long order, size;

        struct page *page;

        if (cpu_has_vce)

                order = 3;

        else

                order = 0;

        empty_zero_page = __get_free_pages(GFP_KERNEL, order);

        if (!empty_zero_page)

                panic("Oh boy, that early out of memory?");

        page = virt_to_page(empty_zero_page);

        while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {

                set_bit(PG_reserved, &page->flags);

                set_page_count(page, 0);

                page++;

        }

        size = PAGE_SIZE << order;

        zero_page_mask = (size - 1) & PAGE_MASK;

        memset((void *)empty_zero_page, 0, size);

        return 1UL << order;

}

void show_mem(void)

{

        int i, free = 0, total = 0, reserved = 0;

        int shared = 0, cached = 0;

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

        show_free_areas();

        printk("Free swap:       %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10));

        i = max_mapnr;

        while (i-- > 0) {

                total++;

                if (PageReserved(mem_map+i))

                        reserved++;

                else if (PageSwapCache(mem_map+i))

                        cached++;

                else if (!page_count(mem_map + i))

                        free++;

                else

                        shared += page_count(mem_map + i) - 1;

        }

        printk("%d pages of RAM\n", total);

        printk("%d reserved pages\n", reserved);

        printk("%d pages shared\n", shared);

        printk("%d pages swap cached\n",cached);

        printk("%ld pages in page table cache\n", pgtable_cache_size);

        printk("%d free pages\n", free);

        show_buffers();

}

#ifndef CONFIG_DISCONTIGMEM

/* References to section boundaries */

extern char _stext, _etext, _fdata, _edata;

extern char __init_begin, __init_end;

void __init paging_init(void)

{

        pmd_t *pmd = kpmdtbl;

        pte_t *pte = kptbl;

        unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};

        unsigned long max_dma, low;

        int i;

        /* Initialize the entire pgd.  */

        pgd_init((unsigned long)swapper_pg_dir);

        pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);

        memset((void *)invalid_pte_table, 0, sizeof(pte_t) * PTRS_PER_PTE);

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

        low = max_low_pfn;

#ifdef CONFIG_ISA

        if (low < max_dma)

                zones_size[ZONE_DMA] = low;

        else {

                zones_size[ZONE_DMA] = max_dma;

                zones_size[ZONE_NORMAL] = low - max_dma;

        }

#else

        zones_size[ZONE_DMA] = low;

#endif

        free_area_init(zones_size);

        memset((void *)kptbl, 0, PAGE_SIZE << PGD_ORDER);

        memset((void *)kpmdtbl, 0, PAGE_SIZE);

        pgd_set(swapper_pg_dir, kpmdtbl);

        for (i = 0; i < (1 << PGD_ORDER); pmd++,i++,pte+=PTRS_PER_PTE)

                pmd_val(*pmd) = (unsigned long)pte;

}

//extern int page_is_ram(unsigned long pagenr);

#define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)

#define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)

static inline int page_is_ram(unsigned long pagenr)

{

        int i;

        for (i = 0; i < boot_mem_map.nr_map; i++) {

                unsigned long addr, end;

                if (boot_mem_map.map[i].type != BOOT_MEM_RAM)

                        /* not usable memory */

                        continue;

                addr = PFN_UP(boot_mem_map.map[i].addr);

                end = PFN_DOWN(boot_mem_map.map[i].addr +

                               boot_mem_map.map[i].size);

                if (pagenr >= addr && pagenr < end)

                        return 1;

        }

        return 0;

}

void __init mem_init(void)

{

        unsigned long codesize, reservedpages, datasize, initsize;

        unsigned long tmp, ram;

        max_mapnr = num_mappedpages = num_physpages = max_low_pfn;

        high_memory = (void *) __va(max_mapnr << PAGE_SHIFT);

        totalram_pages += free_all_bootmem();

        totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */

        reservedpages = ram = 0;

        for (tmp = 0; tmp < max_low_pfn; tmp++)

                if (page_is_ram(tmp)) {

                        ram++;

                        if (PageReserved(mem_map+tmp))

                                reservedpages++;

                }

        codesize =  (unsigned long) &_etext - (unsigned long) &_stext;

        datasize =  (unsigned long) &_edata - (unsigned long) &_fdata;

        initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;

        printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "

               "%ldk reserved, %ldk data, %ldk init)\n",

               (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),

               ram << (PAGE_SHIFT-10),

               codesize >> 10,

               reservedpages << (PAGE_SHIFT-10),

               datasize >> 10,

               initsize >> 10);

}

#endif /* !CONFIG_DISCONTIGMEM */

#ifdef CONFIG_BLK_DEV_INITRD

void free_initrd_mem(unsigned long start, unsigned long end)

{

        /* Switch from KSEG0 to XKPHYS addresses */

        start = (unsigned long)phys_to_virt(CPHYSADDR(start));

        end = (unsigned long)phys_to_virt(CPHYSADDR(end));

        if (start < end)

                printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",

                       (end - start) >> 10);

        for (; start < end; start += PAGE_SIZE) {

                ClearPageReserved(virt_to_page(start));

                set_page_count(virt_to_page(start), 1);

                free_page(start);

                totalram_pages++;

        }

}

#endif

extern char __init_begin, __init_end;

extern void prom_free_prom_memory(void) __init;

void

free_initmem(void)

{

        unsigned long addr, page;

        prom_free_prom_memory();

        addr = (unsigned long)(&__init_begin);

        while (addr < (unsigned long)&__init_end) {

                page = PAGE_OFFSET | CPHYSADDR(addr);

                ClearPageReserved(virt_to_page(page));

                set_page_count(virt_to_page(page), 1);

                free_page(page);

                totalram_pages++;

                addr += PAGE_SIZE;

        }

        printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",

               (&__init_end - &__init_begin) >> 10);

}

void

si_meminfo(struct sysinfo *val)

{

        val->totalram = totalram_pages;

        val->sharedram = 0;

        val->freeram = nr_free_pages();

        val->bufferram = atomic_read(&buffermem_pages);

        val->totalhigh = 0;

        val->freehigh = nr_free_highpages();

        val->mem_unit = PAGE_SIZE;

        return;

}