sys/src/vmsbootmem.c

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// _Id: vmsbootmem.c,v 1.11 2006-03-09 10:47:59 roart Exp $
// _Locker:  $

// Author. Roar Thronæs.
// Modified Linux source file, 2001-2004. Based on bootmem.c.

/*
 *  linux/mm/bootmem.c
 *
 *  Copyright (C) 1999 Ingo Molnar
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *
 *  simple boot-time physical memory area allocator and
 *  free memory collector. It's used to deal with reserved
 *  system memory and memory holes as well.
 */

#include <linux/config.h>
#include <linux/mm.h>
#include <linux/kernel_stat.h>
#include <linux/swap.h>
#include <linux/swapctl.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <asm/dma.h>

#include <system_data_cells.h>

#undef OLDINT
#define OLDINT

#ifdef __x86_64__
#undef OLDINT
#endif

/*
 * Access to this subsystem has to be serialized externally. (this is
 * true for the boot process anyway)
 */
unsigned long max_low_pfn;
unsigned long min_low_pfn;

/* return the number of _pages_ that will be allocated for the boot bitmap */
unsigned long __init bootmem_bootmap_pages (unsigned long pages)
{
        unsigned long mapsize;

        mapsize = (pages+7)/8;
        mapsize = (mapsize + ~PAGE_MASK) & PAGE_MASK;
        mapsize >>= PAGE_SHIFT;

        return mapsize;
}

/*
 * Called once to set up the allocator itself.
 */
static unsigned long __init init_bootmem_core (pg_data_t *pgdat,
        unsigned long mapstart, unsigned long start, unsigned long end)
{
        bootmem_data_t *bdata = pgdat->bdata;
        unsigned long mapsize = ((end - start)+7)/8;

        pgdat->node_next = pgdat_list;
        pgdat_list = pgdat;

        mapsize = (mapsize + (sizeof(long) - 1UL)) & ~(sizeof(long) - 1UL);
        bdata->node_bootmem_map = phys_to_virt(mapstart << PAGE_SHIFT);
        bdata->node_boot_start = (start << PAGE_SHIFT);
        bdata->node_low_pfn = end;

        /*
         * Initially all pages are reserved - setup_arch() has to
         * register free RAM areas explicitly.
         */
        memset(bdata->node_bootmem_map, 0xff, mapsize);

        return mapsize;
}

/*
 * Marks a particular physical memory range as unallocatable. Usable RAM
 * might be used for boot-time allocations - or it might get added
 * to the free page pool later on.
 */
static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size)
{
        unsigned long i;
        /*
         * round up, partially reserved pages are considered
         * fully reserved.
         */
        unsigned long sidx = (addr - bdata->node_boot_start)/PAGE_SIZE;
        unsigned long eidx = (addr + size - bdata->node_boot_start + 
                                                        PAGE_SIZE-1)/PAGE_SIZE;
        unsigned long end = (addr + size + PAGE_SIZE-1)/PAGE_SIZE;

        if (!size) BUG();

        if (sidx < 0)
                BUG();
        if (eidx < 0)
                BUG();
        if (sidx >= eidx)
                BUG();
        if ((addr >> PAGE_SHIFT) >= bdata->node_low_pfn)
                BUG();
        if (end > bdata->node_low_pfn)
                BUG();
        for (i = sidx; i < eidx; i++)
                if (test_and_set_bit(i, bdata->node_bootmem_map))
                        printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
}

static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size)
{
        unsigned long i;
        unsigned long start;
        /*
         * round down end of usable mem, partially free pages are
         * considered reserved.
         */
        unsigned long sidx;
        unsigned long eidx = (addr + size - bdata->node_boot_start)/PAGE_SIZE;
        unsigned long end = (addr + size)/PAGE_SIZE;

        if (!size) BUG();
        if (end > bdata->node_low_pfn)
                BUG();

        /*
         * Round up the beginning of the address.
         */
        start = (addr + PAGE_SIZE-1) / PAGE_SIZE;
        sidx = start - (bdata->node_boot_start/PAGE_SIZE);

        for (i = sidx; i < eidx; i++) {
                if (!test_and_clear_bit(i, bdata->node_bootmem_map))
                        BUG();
        }
}

/*
 * We 'merge' subsequent allocations to save space. We might 'lose'
 * some fraction of a page if allocations cannot be satisfied due to
 * size constraints on boxes where there is physical RAM space
 * fragmentation - in these cases * (mostly large memory boxes) this
 * is not a problem.
 *
 * On low memory boxes we get it right in 100% of the cases.
 */

/*
 * alignment has to be a power of 2 value.
 */
static void * __init __alloc_bootmem_core (bootmem_data_t *bdata, 
        unsigned long size, unsigned long align, unsigned long goal)
{
        unsigned long i, start = 0;
        void *ret;
        unsigned long offset, remaining_size;
        unsigned long areasize, preferred, incr;
        unsigned long eidx = bdata->node_low_pfn - (bdata->node_boot_start >>
                                                        PAGE_SHIFT);

        if (!size) BUG();

        if (align & (align-1))
                BUG();

        offset = 0;
        if (align &&
            (bdata->node_boot_start & (align - 1UL)) != 0)
                offset = (align - (bdata->node_boot_start & (align - 1UL)));
        offset >>= PAGE_SHIFT;

        /*
         * We try to allocate bootmem pages above 'goal'
         * first, then we try to allocate lower pages.
         */
        if (goal && (goal >= bdata->node_boot_start) && 
                        ((goal >> PAGE_SHIFT) < bdata->node_low_pfn)) {
                preferred = goal - bdata->node_boot_start;
        } else
                preferred = 0;

        preferred = ((preferred + align - 1) & ~(align - 1)) >> PAGE_SHIFT;
        preferred += offset;
        areasize = (size+PAGE_SIZE-1)/PAGE_SIZE;
        incr = align >> PAGE_SHIFT ? : 1;

restart_scan:
        for (i = preferred; i < eidx; i += incr) {
                unsigned long j;
                if (test_bit(i, bdata->node_bootmem_map))
                        continue;
                for (j = i + 1; j < i + areasize; ++j) {
                        if (j >= eidx)
                                goto fail_block;
                        if (test_bit (j, bdata->node_bootmem_map))
                                goto fail_block;
                }
                start = i;
                goto found;
        fail_block:;
        }
        if (preferred) {
                preferred = offset;
                goto restart_scan;
        }
        return NULL;
found:
        if (start >= eidx)
                BUG();

        /*
         * Is the next page of the previous allocation-end the start
         * of this allocation's buffer? If yes then we can 'merge'
         * the previous partial page with this allocation.
         */
        if (align <= PAGE_SIZE
            && bdata->last_offset && bdata->last_pos+1 == start) {
                offset = (bdata->last_offset+align-1) & ~(align-1);
                if (offset > PAGE_SIZE)
                        BUG();
                remaining_size = PAGE_SIZE-offset;
                if (size < remaining_size) {
                        areasize = 0;
                        // last_pos unchanged
                        bdata->last_offset = offset+size;
                        ret = phys_to_virt(bdata->last_pos*PAGE_SIZE + offset +
                                                bdata->node_boot_start);
                } else {
                        remaining_size = size - remaining_size;
                        areasize = (remaining_size+PAGE_SIZE-1)/PAGE_SIZE;
                        ret = phys_to_virt(bdata->last_pos*PAGE_SIZE + offset +
                                                bdata->node_boot_start);
                        bdata->last_pos = start+areasize-1;
                        bdata->last_offset = remaining_size;
                }
                bdata->last_offset &= ~PAGE_MASK;
        } else {
                bdata->last_pos = start + areasize - 1;
                bdata->last_offset = size & ~PAGE_MASK;
                ret = phys_to_virt(start * PAGE_SIZE + bdata->node_boot_start);
        }
        /*
         * Reserve the area now:
         */
        for (i = start; i < start+areasize; i++)
                if (test_and_set_bit(i, bdata->node_bootmem_map))
                        BUG();
        memset(ret, 0, size);
        printk("alloc_bootmem_core %x %x\n",ret,size);
        return ret;
}

int in_free_all_bootmem_core=0;

static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
{
        struct page *page = pgdat->node_mem_map;
        bootmem_data_t *bdata = pgdat->bdata;
        unsigned long i, count, total = 0;
        unsigned long idx;
        struct page * prev;

        in_free_all_bootmem_core=1;

        if (!bdata->node_bootmem_map) BUG();

        count = 0;
        idx = bdata->node_low_pfn - (bdata->node_boot_start >> PAGE_SHIFT);
        for (i = 0; i < idx; i++, page++) {
                if (!test_bit(i, bdata->node_bootmem_map)) {
                        count++;
                        ClearPageReserved(page);
                        set_page_count(page, 1);
                        __free_page(page);
                }
        }
        total += count;

        /*
         * Now free the allocator bitmap itself, it's not
         * needed anymore:
         */
        page = virt_to_page(bdata->node_bootmem_map);
        count = 0;
        for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
                count++;
                ClearPageReserved(page);
                set_page_count(page, 1);
                __free_page(page);
        }
        total += count;
        bdata->node_bootmem_map = NULL;

        prev = 0;
#ifndef OLDINT
        int previ = 0;
#endif
        page = pgdat->node_mem_map;
        page++;
        for (i = 1; i < idx; i++, page++) { // skip physical 0
          if (!PageReserved(page)) {
            sch_gl_freecnt++;
            if (prev) {
#ifdef OLDINT
              prev->pfn_l_flink=page;
#else
              prev->pfn_l_flink=i; // was: page;
#endif
            } else {
#ifdef OLDINT
              pfn_al_head[PFN$C_FREPAGLST]=page;
#else
              pfn_al_head[PFN$C_FREPAGLST]=i; // was: page;
#endif
            }
            {
#ifdef OLDINT
              unsigned long * prev2=&page->pfn_l_flink;
#else
              unsigned int * prev2=&page->pfn_l_flink;
#endif
              prev2++;
#ifdef OLDINT
              *prev2=prev; 
#else
              *prev2=previ; // was: prev; 
#endif
              // sick compiler
              // it optimized away page->pfn_l_blink=prev
              // or interpreted as flink
            }
#ifdef OLDINT
            prev=page;
#else
            prev=page;
            previ=i;
#endif
            page->pfn_v_loc=PFN$C_FREPAGLST;
            page->pfn_v_pagtyp=PFN$C_SYSTEM;
          }
        }
        prev->pfn_l_flink=0;
#ifdef OLDINT
        pfn_al_tail[PFN$C_FREPAGLST]=prev;
#else
        pfn_al_tail[PFN$C_FREPAGLST]=i; // was: prev;
#endif
if (0) {
  int k,l,m[24];
  l=pfn_al_head[0];
  for(k=0;k<24;k++) {
    printk("%lx ",l);
    m[k]=mem_map[l].pfn_l_blink;
    l=mem_map[l].pfn_l_flink;
  }
  printk("\n");
  l=pfn_al_head[0];
  for(k=0;k<24;k++) {
    printk("%lx ",m[k]);
  }
  printk("\n");
 }

        pfn_al_head[PFN$C_MFYPAGLST]=0;
        pfn_al_tail[PFN$C_MFYPAGLST]=0;
        pfn_al_head[PFN$C_BADPAGLST]=0;
        pfn_al_tail[PFN$C_BADPAGLST]=0;

        in_free_all_bootmem_core=0;

        return total;
}

unsigned long __init init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn)
{
        return(init_bootmem_core(pgdat, freepfn, startpfn, endpfn));
}

void __init reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size)
{
        reserve_bootmem_core(pgdat->bdata, physaddr, size);
}

void __init free_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size)
{
        return(free_bootmem_core(pgdat->bdata, physaddr, size));
}

unsigned long __init free_all_bootmem_node (pg_data_t *pgdat)
{
        return(free_all_bootmem_core(pgdat));
}

unsigned long __init init_bootmem (unsigned long start, unsigned long pages)
{
        max_low_pfn = pages;
        min_low_pfn = start;
        return(init_bootmem_core(&contig_page_data, start, 0, pages));
}

void __init reserve_bootmem (unsigned long addr, unsigned long size)
{
        reserve_bootmem_core(contig_page_data.bdata, addr, size);
}

void __init free_bootmem (unsigned long addr, unsigned long size)
{
        return(free_bootmem_core(contig_page_data.bdata, addr, size));
}

unsigned long __init free_all_bootmem (void)
{
        return(free_all_bootmem_core(&contig_page_data));
}

void * __init __alloc_bootmem (unsigned long size, unsigned long align, unsigned long goal)
{
        pg_data_t *pgdat = pgdat_list;
        void *ptr;

        while (pgdat) {
                if ((ptr = __alloc_bootmem_core(pgdat->bdata, size,
                                                align, goal)))
                        return(ptr);
                pgdat = pgdat->node_next;
        }
        /*
         * Whoops, we cannot satisfy the allocation request.
         */
        printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
        panic("Out of memory");
        return NULL;
}

void * __init __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal)
{
        void *ptr;

        ptr = __alloc_bootmem_core(pgdat->bdata, size, align, goal);
        if (ptr)
                return (ptr);

        /*
         * Whoops, we cannot satisfy the allocation request.
         */
        printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
        panic("Out of memory");
        return NULL;
}

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