Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6

[mirror_ubuntu-disco-kernel.git] / arch / sparc / mm / init.c

/*  $Id: init.c,v 1.103 2001/11/19 19:03:08 davem Exp $
 *  linux/arch/sparc/mm/init.c
 *
 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1995 Eddie C. Dost (ecd@skynet.be)
 *  Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 *  Copyright (C) 2000 Anton Blanchard (anton@samba.org)
 */

#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 <asm/system.h>
#include <asm/vac-ops.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>

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

unsigned long *sparc_valid_addr_bitmap;

unsigned long phys_base;
unsigned long pfn_base;

unsigned long page_kernel;

struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
unsigned long sparc_unmapped_base;

struct pgtable_cache_struct pgt_quicklists;

/* References to section boundaries */
extern char __init_begin, __init_end, _start, _end, etext , edata;

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

unsigned long highstart_pfn, highend_pfn;

pte_t *kmap_pte;
pgprot_t kmap_prot;

#define kmap_get_fixmap_pte(vaddr) \
        pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))

void __init kmap_init(void)
{
        /* cache the first kmap pte */
        kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
        kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
}

void show_mem(void)
{
        printk("Mem-info:\n");
        show_free_areas();
        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());
#if 0 /* undefined pgtable_cache_size, pgd_cache_size */
        printk("%ld pages in page table cache\n",pgtable_cache_size);
#ifndef CONFIG_SMP
        if (sparc_cpu_model == sun4m || sparc_cpu_model == sun4d)
                printk("%ld entries in page dir cache\n",pgd_cache_size);
#endif  
#endif
}

void __init sparc_context_init(int numctx)
{
        int ctx;

        ctx_list_pool = __alloc_bootmem(numctx * sizeof(struct ctx_list), SMP_CACHE_BYTES, 0UL);

        for(ctx = 0; ctx < numctx; ctx++) {
                struct ctx_list *clist;

                clist = (ctx_list_pool + ctx);
                clist->ctx_number = ctx;
                clist->ctx_mm = NULL;
        }
        ctx_free.next = ctx_free.prev = &ctx_free;
        ctx_used.next = ctx_used.prev = &ctx_used;
        for(ctx = 0; ctx < numctx; ctx++)
                add_to_free_ctxlist(ctx_list_pool + ctx);
}

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;
}

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) {
                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);
                *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);
        *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);
        *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

        return max_pfn;
}

/*
 * check_pgt_cache
 *
 * This is called at the end of unmapping of VMA (zap_page_range),
 * to rescan the page cache for architecture specific things,
 * presumably something like sun4/sun4c PMEGs. Most architectures
 * define check_pgt_cache empty.
 *
 * We simply copy the 2.4 implementation for now.
 */
int pgt_cache_water[2] = { 25, 50 };

void check_pgt_cache(void)
{
        do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]);
}

/*
 * 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 sun4c_paging_init(void);
extern void srmmu_paging_init(void);
extern void device_scan(void);

pgprot_t PAGE_SHARED __read_mostly;
EXPORT_SYMBOL(PAGE_SHARED);

void __init paging_init(void)
{
        switch(sparc_cpu_model) {
        case sun4c:
        case sun4e:
        case sun4:
                sun4c_paging_init();
                sparc_unmapped_base = 0xe0000000;
                BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
                break;
        case sun4m:
        case sun4d:
                srmmu_paging_init();
                sparc_unmapped_base = 0x50000000;
                BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
                break;
        default:
                prom_printf("paging_init: Cannot init paging on this Sparc\n");
                prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
                prom_printf("paging_init: Halting...\n");
                prom_halt();
        };

        /* Initialize the protection map with non-constant, MMU dependent values. */
        protection_map[0] = PAGE_NONE;
        protection_map[1] = PAGE_READONLY;
        protection_map[2] = PAGE_COPY;
        protection_map[3] = PAGE_COPY;
        protection_map[4] = PAGE_READONLY;
        protection_map[5] = PAGE_READONLY;
        protection_map[6] = PAGE_COPY;
        protection_map[7] = PAGE_COPY;
        protection_map[8] = PAGE_NONE;
        protection_map[9] = PAGE_READONLY;
        protection_map[10] = PAGE_SHARED;
        protection_map[11] = PAGE_SHARED;
        protection_map[12] = PAGE_READONLY;
        protection_map[13] = PAGE_READONLY;
        protection_map[14] = PAGE_SHARED;
        protection_map[15] = PAGE_SHARED;
        btfixup();
        prom_build_devicetree();
        device_scan();
}

struct cache_palias *sparc_aliases;

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;
                }
        }
}

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 sparclinux@vger.kernel.org.\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",
               (unsigned long) 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;

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

                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: %dk freed\n", (&__init_end - &__init_begin) >> 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 = virt_to_page(start);

                ClearPageReserved(p);
                init_page_count(p);
                __free_page(p);
                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);
}