init_32.c

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/*
 *  linux/arch/sparc/mm/init.c
 *
 *  Copyright (C) 1995 David S. Miller ([email protected])
 *  Copyright (C) 1995 Eddie C. Dost ([email protected])
 *  Copyright (C) 1998 Jakub Jelinek ([email protected])
 *  Copyright (C) 2000 Anton Blanchard ([email protected])
 */

#include <linux/module.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/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/initrd.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/pagemap.h>
#include <linux/poison.h>
#include <linux/gfp.h>

#include <asm/sections.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/vaddrs.h>
#include <asm/pgalloc.h>    /* bug in asm-generic/tlb.h: check_pgt_cache */
#include <asm/tlb.h>
#include <asm/prom.h>
#include <asm/leon.h>

unsigned long *sparc_valid_addr_bitmap;
EXPORT_SYMBOL(sparc_valid_addr_bitmap);

unsigned long phys_base;
EXPORT_SYMBOL(phys_base);

unsigned long pfn_base;
EXPORT_SYMBOL(pfn_base);

struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];

/* Initial ramdisk setup */
extern unsigned int sparc_ramdisk_image;
extern unsigned int sparc_ramdisk_size;

unsigned long highstart_pfn, highend_pfn;

void show_mem(unsigned int filter)
{
    printk("Mem-info:\n");
    show_free_areas(filter);
    printk("Free swap:       %6ldkB\n",
           nr_swap_pages << (PAGE_SHIFT-10));
    printk("%ld pages of RAM\n", totalram_pages);
    printk("%ld free pages\n", nr_free_pages());
}


extern unsigned long cmdline_memory_size;
unsigned long last_valid_pfn;

unsigned long calc_highpages(void)
{
    int i;
    int nr = 0;

    for (i = 0; sp_banks[i].num_bytes != 0; i++) {
        unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
        unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;

        if (end_pfn <= max_low_pfn)
            continue;

        if (start_pfn < max_low_pfn)
            start_pfn = max_low_pfn;

        nr += end_pfn - start_pfn;
    }

    return nr;
}

static unsigned long calc_max_low_pfn(void)
{
    int i;
    unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
    unsigned long curr_pfn, last_pfn;

    last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
    for (i = 1; sp_banks[i].num_bytes != 0; i++) {
        curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;

        if (curr_pfn >= tmp) {
            if (last_pfn < tmp)
                tmp = last_pfn;
            break;
        }

        last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
    }

    return tmp;
}

unsigned long __init bootmem_init(unsigned long *pages_avail)
{
    unsigned long bootmap_size, start_pfn;
    unsigned long end_of_phys_memory = 0UL;
    unsigned long bootmap_pfn, bytes_avail, size;
    int i;

    bytes_avail = 0UL;
    for (i = 0; sp_banks[i].num_bytes != 0; i++) {
        end_of_phys_memory = sp_banks[i].base_addr +
            sp_banks[i].num_bytes;
        bytes_avail += sp_banks[i].num_bytes;
        if (cmdline_memory_size) {
            if (bytes_avail > cmdline_memory_size) {
                unsigned long slack = bytes_avail - cmdline_memory_size;

                bytes_avail -= slack;
                end_of_phys_memory -= slack;

                sp_banks[i].num_bytes -= slack;
                if (sp_banks[i].num_bytes == 0) {
                    sp_banks[i].base_addr = 0xdeadbeef;
                } else {
                    sp_banks[i+1].num_bytes = 0;
                    sp_banks[i+1].base_addr = 0xdeadbeef;
                }
                break;
            }
        }
    }

    /* Start with page aligned address of last symbol in kernel
     * image.  
     */
    start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));

    /* Now shift down to get the real physical page frame number. */
    start_pfn >>= PAGE_SHIFT;

    bootmap_pfn = start_pfn;

    max_pfn = end_of_phys_memory >> PAGE_SHIFT;

    max_low_pfn = max_pfn;
    highstart_pfn = highend_pfn = max_pfn;

    if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
        highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
        max_low_pfn = calc_max_low_pfn();
        printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
            calc_highpages() >> (20 - PAGE_SHIFT));
    }

#ifdef CONFIG_BLK_DEV_INITRD
    /* Now have to check initial ramdisk, so that bootmap does not overwrite it */
    if (sparc_ramdisk_image) {
        if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
            sparc_ramdisk_image -= KERNBASE;
        initrd_start = sparc_ramdisk_image + phys_base;
        initrd_end = initrd_start + sparc_ramdisk_size;
        if (initrd_end > end_of_phys_memory) {
            printk(KERN_CRIT "initrd extends beyond end of memory "
                             "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
                   initrd_end, end_of_phys_memory);
            initrd_start = 0;
        }
        if (initrd_start) {
            if (initrd_start >= (start_pfn << PAGE_SHIFT) &&
                initrd_start < (start_pfn << PAGE_SHIFT) + 2 * PAGE_SIZE)
                bootmap_pfn = PAGE_ALIGN (initrd_end) >> PAGE_SHIFT;
        }
    }
#endif  
    /* Initialize the boot-time allocator. */
    bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn, pfn_base,
                     max_low_pfn);

    /* Now register the available physical memory with the
     * allocator.
     */
    *pages_avail = 0;
    for (i = 0; sp_banks[i].num_bytes != 0; i++) {
        unsigned long curr_pfn, last_pfn;

        curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
        if (curr_pfn >= max_low_pfn)
            break;

        last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
        if (last_pfn > max_low_pfn)
            last_pfn = max_low_pfn;

        /*
         * .. finally, did all the rounding and playing
         * around just make the area go away?
         */
        if (last_pfn <= curr_pfn)
            continue;

        size = (last_pfn - curr_pfn) << PAGE_SHIFT;
        *pages_avail += last_pfn - curr_pfn;

        free_bootmem(sp_banks[i].base_addr, size);
    }

#ifdef CONFIG_BLK_DEV_INITRD
    if (initrd_start) {
        /* Reserve the initrd image area. */
        size = initrd_end - initrd_start;
        reserve_bootmem(initrd_start, size, BOOTMEM_DEFAULT);
        *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

        initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
        initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;        
    }
#endif
    /* Reserve the kernel text/data/bss. */
    size = (start_pfn << PAGE_SHIFT) - phys_base;
    reserve_bootmem(phys_base, size, BOOTMEM_DEFAULT);
    *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

    /* Reserve the bootmem map.   We do not account for it
     * in pages_avail because we will release that memory
     * in free_all_bootmem.
     */
    size = bootmap_size;
    reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size, BOOTMEM_DEFAULT);
    *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

    return max_pfn;
}

/*
 * paging_init() sets up the page tables: We call the MMU specific
 * init routine based upon the Sun model type on the Sparc.
 *
 */
extern void srmmu_paging_init(void);
extern void device_scan(void);

void __init paging_init(void)
{
    srmmu_paging_init();
    prom_build_devicetree();
    of_fill_in_cpu_data();
    device_scan();
}

static void __init taint_real_pages(void)
{
    int i;

    for (i = 0; sp_banks[i].num_bytes; i++) {
        unsigned long start, end;

        start = sp_banks[i].base_addr;
        end = start + sp_banks[i].num_bytes;

        while (start < end) {
            set_bit(start >> 20, sparc_valid_addr_bitmap);
            start += PAGE_SIZE;
        }
    }
}

static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
{
    unsigned long tmp;

#ifdef CONFIG_DEBUG_HIGHMEM
    printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
#endif

    for (tmp = start_pfn; tmp < end_pfn; tmp++) {
        struct page *page = pfn_to_page(tmp);

        ClearPageReserved(page);
        init_page_count(page);
        __free_page(page);
        totalhigh_pages++;
    }
}

void __init mem_init(void)
{
    int codepages = 0;
    int datapages = 0;
    int initpages = 0; 
    int reservedpages = 0;
    int i;

    if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
        prom_printf("BUG: fixmap and pkmap areas overlap\n");
        prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
               PKMAP_BASE,
               (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
               FIXADDR_START);
        prom_printf("Please mail [email protected].\n");
        prom_halt();
    }


    /* Saves us work later. */
    memset((void *)&empty_zero_page, 0, PAGE_SIZE);

    i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
    i += 1;
    sparc_valid_addr_bitmap = (unsigned long *)
        __alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);

    if (sparc_valid_addr_bitmap == NULL) {
        prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
        prom_halt();
    }
    memset(sparc_valid_addr_bitmap, 0, i << 2);

    taint_real_pages();

    max_mapnr = last_valid_pfn - pfn_base;
    high_memory = __va(max_low_pfn << PAGE_SHIFT);

    totalram_pages = free_all_bootmem();

    for (i = 0; sp_banks[i].num_bytes != 0; i++) {
        unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
        unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;

        num_physpages += sp_banks[i].num_bytes >> PAGE_SHIFT;

        if (end_pfn <= highstart_pfn)
            continue;

        if (start_pfn < highstart_pfn)
            start_pfn = highstart_pfn;

        map_high_region(start_pfn, end_pfn);
    }
    
    totalram_pages += totalhigh_pages;

    codepages = (((unsigned long) &_etext) - ((unsigned long)&_start));
    codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
    datapages = (((unsigned long) &_edata) - ((unsigned long)&_etext));
    datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
    initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
    initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;

    /* Ignore memory holes for the purpose of counting reserved pages */
    for (i=0; i < max_low_pfn; i++)
        if (test_bit(i >> (20 - PAGE_SHIFT), sparc_valid_addr_bitmap)
            && PageReserved(pfn_to_page(i)))
            reservedpages++;

    printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
           nr_free_pages() << (PAGE_SHIFT-10),
           num_physpages << (PAGE_SHIFT - 10),
           codepages << (PAGE_SHIFT-10),
           reservedpages << (PAGE_SHIFT - 10),
           datapages << (PAGE_SHIFT-10), 
           initpages << (PAGE_SHIFT-10),
           totalhigh_pages << (PAGE_SHIFT-10));
}

void free_initmem (void)
{
    unsigned long addr;
    unsigned long freed;

    addr = (unsigned long)(&__init_begin);
    freed = (unsigned long)(&__init_end) - addr;
    for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
        struct page *p;

        memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
        p = virt_to_page(addr);

        ClearPageReserved(p);
        init_page_count(p);
        __free_page(p);
        totalram_pages++;
        num_physpages++;
    }
    printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
        freed >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
    if (start < end)
        printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
            (end - start) >> 10);
    for (; start < end; start += PAGE_SIZE) {
        struct page *p;

        memset((void *)start, POISON_FREE_INITMEM, PAGE_SIZE);
        p = virt_to_page(start);

        ClearPageReserved(p);
        init_page_count(p);
        __free_page(p);
        totalram_pages++;
        num_physpages++;
    }
}
#endif

void sparc_flush_page_to_ram(struct page *page)
{
    unsigned long vaddr = (unsigned long)page_address(page);

    if (vaddr)
        __flush_page_to_ram(vaddr);
}
EXPORT_SYMBOL(sparc_flush_page_to_ram);