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/*

 *  linux/arch/alpha/mm/init.c

 *

 *  Copyright (C) 1995  Linus Torvalds

 */

/* 2.3.x zone allocator, 1999 Andrea Arcangeli <andrea@suse.de> */

#include <linux/config.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/init.h>

#include <linux/bootmem.h> /* max_low_pfn */

#include <linux/vmalloc.h>

#ifdef CONFIG_BLK_DEV_INITRD

#include <linux/blk.h>

#endif

#include <asm/system.h>

#include <asm/uaccess.h>

#include <asm/pgtable.h>

#include <asm/pgalloc.h>

#include <asm/hwrpb.h>

#include <asm/dma.h>

#include <asm/mmu_context.h>

#include <asm/console.h>

#include <asm/tlb.h>

mmu_gather_t mmu_gathers[NR_CPUS];

unsigned long totalram_pages;

extern void die_if_kernel(char *,struct pt_regs *,long);

struct thread_struct original_pcb;

#ifndef CONFIG_SMP

struct pgtable_cache_struct quicklists;

#endif

pgd_t *

get_pgd_slow(void)

{

        pgd_t *ret, *init;

        ret = (pgd_t *)__get_free_page(GFP_KERNEL);

        init = pgd_offset(&init_mm, 0UL);

        if (ret) {

                clear_page(ret);

#ifdef CONFIG_ALPHA_LARGE_VMALLOC

                memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,

                        (PTRS_PER_PGD - USER_PTRS_PER_PGD - 1)*sizeof(pgd_t));

#else

                pgd_val(ret[PTRS_PER_PGD-2]) = pgd_val(init[PTRS_PER_PGD-2]);

#endif

                /* The last PGD entry is the VPTB self-map.  */

                pgd_val(ret[PTRS_PER_PGD-1])

                  = pte_val(mk_pte(virt_to_page(ret), PAGE_KERNEL));

        }

        return ret;

}

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) {

                                pmd_free_slow(pmd_alloc_one_fast(NULL, 0));

                                freed++;

                        }

                        if(pte_quicklist) {

                                pte_free_slow(pte_alloc_one_fast(NULL, 0));

                                freed++;

                        }

                } while(pgtable_cache_size > low);

        }

        return freed;

}

/*

 * BAD_PAGE is the page that is used for page faults when linux

 * is out-of-memory. Older versions of linux just did a

 * do_exit(), but using this instead means there is less risk

 * for a process dying in kernel mode, possibly leaving an inode

 * unused etc..

 *

 * BAD_PAGETABLE is the accompanying page-table: it is initialized

 * to point to BAD_PAGE entries.

 *

 * ZERO_PAGE is a special page that is used for zero-initialized

 * data and COW.

 */

pmd_t *

__bad_pagetable(void)

{

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

        return (pmd_t *) EMPTY_PGT;

}

pte_t

__bad_page(void)

{

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

        return pte_mkdirty(mk_pte(virt_to_page(EMPTY_PGE), PAGE_SHARED));

}

#ifndef CONFIG_DISCONTIGMEM

void

show_mem(void)

{

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

        long shared = 0, cached = 0;

        printk("\nMem-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 += atomic_read(&mem_map[i].count) - 1;

        }

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

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

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

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

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

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

        show_buffers();

}

#endif

static inline unsigned long

load_PCB(struct thread_struct * pcb)

{

        register unsigned long sp __asm__("$30");

        pcb->ksp = sp;

        return __reload_thread(pcb);

}

/* Set up initial PCB, VPTB, and other such nicities.  */

static inline void

switch_to_system_map(void)

{

        unsigned long newptbr;

        unsigned long original_pcb_ptr;

        /* Initialize the kernel's page tables.  Linux puts the vptb in

           the last slot of the L1 page table.  */

        memset(swapper_pg_dir, 0, PAGE_SIZE);

        newptbr = ((unsigned long) swapper_pg_dir - PAGE_OFFSET) >> PAGE_SHIFT;

        pgd_val(swapper_pg_dir[1023]) =

                (newptbr << 32) | pgprot_val(PAGE_KERNEL);

        /* Set the vptb.  This is often done by the bootloader, but

           shouldn't be required.  */

        if (hwrpb->vptb != 0xfffffffe00000000) {

                wrvptptr(0xfffffffe00000000);

                hwrpb->vptb = 0xfffffffe00000000;

                hwrpb_update_checksum(hwrpb);

        }

        /* Also set up the real kernel PCB while we're at it.  */

        init_task.thread.ptbr = newptbr;

        init_task.thread.pal_flags = 1; /* set FEN, clear everything else */

        init_task.thread.flags = 0;

        original_pcb_ptr = load_PCB(&init_task.thread);

        tbia();

        /* Save off the contents of the original PCB so that we can

           restore the original console's page tables for a clean reboot.

           Note that the PCB is supposed to be a physical address, but

           since KSEG values also happen to work, folks get confused.

           Check this here.  */

        if (original_pcb_ptr < PAGE_OFFSET) {

                original_pcb_ptr = (unsigned long)

                        phys_to_virt(original_pcb_ptr);

        }

        original_pcb = *(struct thread_struct *) original_pcb_ptr;

}

int callback_init_done;

void * __init

callback_init(void * kernel_end)

{

        struct crb_struct * crb;

        pgd_t *pgd;

        pmd_t *pmd;

        void *two_pages;

        /* Starting at the HWRPB, locate the CRB. */

        crb = (struct crb_struct *)((char *)hwrpb + hwrpb->crb_offset);

        if (alpha_using_srm) {

                /* Tell the console whither it is to be remapped. */

                if (srm_fixup(VMALLOC_START, (unsigned long)hwrpb))

                        __halt();               /* "We're boned."  --Bender */

                /* Edit the procedure descriptors for DISPATCH and FIXUP. */

                crb->dispatch_va = (struct procdesc_struct *)

                        (VMALLOC_START + (unsigned long)crb->dispatch_va

                         - crb->map[0].va);

                crb->fixup_va = (struct procdesc_struct *)

                        (VMALLOC_START + (unsigned long)crb->fixup_va

                         - crb->map[0].va);

        }

        switch_to_system_map();

        /* Allocate one PGD and one PMD.  In the case of SRM, we'll need

           these to actually remap the console.  There is an assumption

           here that only one of each is needed, and this allows for 8MB.

           On systems with larger consoles, additional pages will be

           allocated as needed during the mapping process.

           In the case of not SRM, but not CONFIG_ALPHA_LARGE_VMALLOC,

           we need to allocate the PGD we use for vmalloc before we start

           forking other tasks.  */

        two_pages = (void *)

          (((unsigned long)kernel_end + ~PAGE_MASK) & PAGE_MASK);

        kernel_end = two_pages + 2*PAGE_SIZE;

        memset(two_pages, 0, 2*PAGE_SIZE);

        pgd = pgd_offset_k(VMALLOC_START);

        pgd_set(pgd, (pmd_t *)two_pages);

        pmd = pmd_offset(pgd, VMALLOC_START);

        pmd_set(pmd, (pte_t *)(two_pages + PAGE_SIZE));

        if (alpha_using_srm) {

                static struct vm_struct console_remap_vm;

                unsigned long vaddr = VMALLOC_START;

                long i, j;

                /* Set up the third level PTEs and update the virtual

                   addresses of the CRB entries.  */

                for (i = 0; i < crb->map_entries; ++i) {

                        unsigned long paddr = crb->map[i].pa;

                        crb->map[i].va = vaddr;

                        for (j = 0; j < crb->map[i].count; ++j) {

                                /* Newer console's (especially on larger

                                   systems) may require more pages of

                                   PTEs. Grab additional pages as needed. */

                                if (pmd != pmd_offset(pgd, vaddr)) {

                                        memset(kernel_end, 0, PAGE_SIZE);

                                        pmd = pmd_offset(pgd, vaddr);

                                        pmd_set(pmd, (pte_t *)kernel_end);

                                        kernel_end += PAGE_SIZE;

                                }

                                set_pte(pte_offset(pmd, vaddr),

                                        mk_pte_phys(paddr, PAGE_KERNEL));

                                paddr += PAGE_SIZE;

                                vaddr += PAGE_SIZE;

                        }

                }

                /* Let vmalloc know that we've allocated some space.  */

                console_remap_vm.flags = VM_ALLOC;

                console_remap_vm.addr = VMALLOC_START;

                console_remap_vm.size = vaddr - VMALLOC_START;

                vmlist = &console_remap_vm;

        }

        callback_init_done = 1;

        return kernel_end;

}

#ifndef CONFIG_DISCONTIGMEM

/*

 * paging_init() sets up the memory map.

 */

void

paging_init(void)

{

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

        unsigned long dma_pfn, high_pfn;

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

        high_pfn = max_low_pfn;

        if (dma_pfn >= high_pfn)

                zones_size[ZONE_DMA] = high_pfn;

        else {

                zones_size[ZONE_DMA] = dma_pfn;

                zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;

        }

        /* Initialize mem_map[].  */

        free_area_init(zones_size);

        /* Initialize the kernel's ZERO_PGE. */

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

}

#endif /* CONFIG_DISCONTIGMEM */

#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)

void

srm_paging_stop (void)

{

        /* Move the vptb back to where the SRM console expects it.  */

        swapper_pg_dir[1] = swapper_pg_dir[1023];

        tbia();

        wrvptptr(0x200000000);

        hwrpb->vptb = 0x200000000;

        hwrpb_update_checksum(hwrpb);

        /* Reload the page tables that the console had in use.  */

        load_PCB(&original_pcb);

        tbia();

}

#endif

#ifndef CONFIG_DISCONTIGMEM

static void __init

printk_memory_info(void)

{

        unsigned long codesize, reservedpages, datasize, initsize, tmp;

        extern int page_is_ram(unsigned long) __init;

        extern char _text, _etext, _data, _edata;

        extern char __init_begin, __init_end;

        /* printk all informations */

        reservedpages = 0;

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

                /*

                 * Only count reserved RAM pages

                 */

                if (page_is_ram(tmp) && PageReserved(mem_map+tmp))

                        reservedpages++;

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

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

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

        printk("Memory: %luk/%luk available (%luk kernel code, %luk reserved, %luk data, %luk init)\n",

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

               max_mapnr << (PAGE_SHIFT-10),

               codesize >> 10,

               reservedpages << (PAGE_SHIFT-10),

               datasize >> 10,

               initsize >> 10);

}

void __init

mem_init(void)

{

        max_mapnr = num_physpages = max_low_pfn;

        totalram_pages += free_all_bootmem();

        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

        printk_memory_info();

}

#endif /* CONFIG_DISCONTIGMEM */

void

free_reserved_mem(void *start, void *end)

{

        void *__start = start;

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

                ClearPageReserved(virt_to_page(__start));

                set_page_count(virt_to_page(__start), 1);

                free_page((long)__start);

                totalram_pages++;

        }

}

void

free_initmem(void)

{

        extern char __init_begin, __init_end;

        free_reserved_mem(&__init_begin, &__init_end);

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

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

}

#ifdef CONFIG_BLK_DEV_INITRD

void

free_initrd_mem(unsigned long start, unsigned long end)

{

        free_reserved_mem((void *)start, (void *)end);

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

               (end - start) >> 10);

}

#endif

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 = 0;

        val->mem_unit = PAGE_SIZE;

}