numa.c

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/*
 *  linux/arch/alpha/mm/numa.c
 *
 *  DISCONTIGMEM NUMA alpha support.
 *
 *  Copyright (C) 2001 Andrea Arcangeli <[email protected]> SuSE
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/swap.h>
#include <linux/initrd.h>
#include <linux/pfn.h>
#include <linux/module.h>

#include <asm/hwrpb.h>
#include <asm/pgalloc.h>

pg_data_t node_data[MAX_NUMNODES];
EXPORT_SYMBOL(node_data);

#undef DEBUG_DISCONTIG
#ifdef DEBUG_DISCONTIG
#define DBGDCONT(args...) printk(args)
#else
#define DBGDCONT(args...)
#endif

#define for_each_mem_cluster(memdesc, _cluster, i)      \
    for ((_cluster) = (memdesc)->cluster, (i) = 0;      \
         (i) < (memdesc)->numclusters; (i)++, (_cluster)++)

static void __init show_mem_layout(void)
{
    struct memclust_struct * cluster;
    struct memdesc_struct * memdesc;
    int i;

    /* Find free clusters, and init and free the bootmem accordingly.  */
    memdesc = (struct memdesc_struct *)
      (hwrpb->mddt_offset + (unsigned long) hwrpb);

    printk("Raw memory layout:\n");
    for_each_mem_cluster(memdesc, cluster, i) {
        printk(" memcluster %2d, usage %1lx, start %8lu, end %8lu\n",
               i, cluster->usage, cluster->start_pfn,
               cluster->start_pfn + cluster->numpages);
    }
}

static void __init
setup_memory_node(int nid, void *kernel_end)
{
    extern unsigned long mem_size_limit;
    struct memclust_struct * cluster;
    struct memdesc_struct * memdesc;
    unsigned long start_kernel_pfn, end_kernel_pfn;
    unsigned long bootmap_size, bootmap_pages, bootmap_start;
    unsigned long start, end;
    unsigned long node_pfn_start, node_pfn_end;
    unsigned long node_min_pfn, node_max_pfn;
    int i;
    unsigned long node_datasz = PFN_UP(sizeof(pg_data_t));
    int show_init = 0;

    /* Find the bounds of current node */
    node_pfn_start = (node_mem_start(nid)) >> PAGE_SHIFT;
    node_pfn_end = node_pfn_start + (node_mem_size(nid) >> PAGE_SHIFT);
    
    /* Find free clusters, and init and free the bootmem accordingly.  */
    memdesc = (struct memdesc_struct *)
      (hwrpb->mddt_offset + (unsigned long) hwrpb);

    /* find the bounds of this node (node_min_pfn/node_max_pfn) */
    node_min_pfn = ~0UL;
    node_max_pfn = 0UL;
    for_each_mem_cluster(memdesc, cluster, i) {
        /* Bit 0 is console/PALcode reserved.  Bit 1 is
           non-volatile memory -- we might want to mark
           this for later.  */
        if (cluster->usage & 3)
            continue;

        start = cluster->start_pfn;
        end = start + cluster->numpages;

        if (start >= node_pfn_end || end <= node_pfn_start)
            continue;

        if (!show_init) {
            show_init = 1;
            printk("Initializing bootmem allocator on Node ID %d\n", nid);
        }
        printk(" memcluster %2d, usage %1lx, start %8lu, end %8lu\n",
               i, cluster->usage, cluster->start_pfn,
               cluster->start_pfn + cluster->numpages);

        if (start < node_pfn_start)
            start = node_pfn_start;
        if (end > node_pfn_end)
            end = node_pfn_end;

        if (start < node_min_pfn)
            node_min_pfn = start;
        if (end > node_max_pfn)
            node_max_pfn = end;
    }

    if (mem_size_limit && node_max_pfn > mem_size_limit) {
        static int msg_shown = 0;
        if (!msg_shown) {
            msg_shown = 1;
            printk("setup: forcing memory size to %ldK (from %ldK).\n",
                   mem_size_limit << (PAGE_SHIFT - 10),
                   node_max_pfn    << (PAGE_SHIFT - 10));
        }
        node_max_pfn = mem_size_limit;
    }

    if (node_min_pfn >= node_max_pfn)
        return;

    /* Update global {min,max}_low_pfn from node information. */
    if (node_min_pfn < min_low_pfn)
        min_low_pfn = node_min_pfn;
    if (node_max_pfn > max_low_pfn)
        max_pfn = max_low_pfn = node_max_pfn;

    num_physpages += node_max_pfn - node_min_pfn;

#if 0 /* we'll try this one again in a little while */
    /* Cute trick to make sure our local node data is on local memory */
    node_data[nid] = (pg_data_t *)(__va(node_min_pfn << PAGE_SHIFT));
#endif
    /* Quasi-mark the pg_data_t as in-use */
    node_min_pfn += node_datasz;
    if (node_min_pfn >= node_max_pfn) {
        printk(" not enough mem to reserve NODE_DATA");
        return;
    }
    NODE_DATA(nid)->bdata = &bootmem_node_data[nid];

    printk(" Detected node memory:   start %8lu, end %8lu\n",
           node_min_pfn, node_max_pfn);

    DBGDCONT(" DISCONTIG: node_data[%d]   is at 0x%p\n", nid, NODE_DATA(nid));
    DBGDCONT(" DISCONTIG: NODE_DATA(%d)->bdata is at 0x%p\n", nid, NODE_DATA(nid)->bdata);

    /* Find the bounds of kernel memory.  */
    start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
    end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
    bootmap_start = -1;

    if (!nid && (node_max_pfn < end_kernel_pfn || node_min_pfn > start_kernel_pfn))
        panic("kernel loaded out of ram");

    /* Zone start phys-addr must be 2^(MAX_ORDER-1) aligned.
       Note that we round this down, not up - node memory
       has much larger alignment than 8Mb, so it's safe. */
    node_min_pfn &= ~((1UL << (MAX_ORDER-1))-1);

    /* We need to know how many physically contiguous pages
       we'll need for the bootmap.  */
    bootmap_pages = bootmem_bootmap_pages(node_max_pfn-node_min_pfn);

    /* Now find a good region where to allocate the bootmap.  */
    for_each_mem_cluster(memdesc, cluster, i) {
        if (cluster->usage & 3)
            continue;

        start = cluster->start_pfn;
        end = start + cluster->numpages;

        if (start >= node_max_pfn || end <= node_min_pfn)
            continue;

        if (end > node_max_pfn)
            end = node_max_pfn;
        if (start < node_min_pfn)
            start = node_min_pfn;

        if (start < start_kernel_pfn) {
            if (end > end_kernel_pfn
                && end - end_kernel_pfn >= bootmap_pages) {
                bootmap_start = end_kernel_pfn;
                break;
            } else if (end > start_kernel_pfn)
                end = start_kernel_pfn;
        } else if (start < end_kernel_pfn)
            start = end_kernel_pfn;
        if (end - start >= bootmap_pages) {
            bootmap_start = start;
            break;
        }
    }

    if (bootmap_start == -1)
        panic("couldn't find a contiguous place for the bootmap");

    /* Allocate the bootmap and mark the whole MM as reserved.  */
    bootmap_size = init_bootmem_node(NODE_DATA(nid), bootmap_start,
                     node_min_pfn, node_max_pfn);
    DBGDCONT(" bootmap_start %lu, bootmap_size %lu, bootmap_pages %lu\n",
         bootmap_start, bootmap_size, bootmap_pages);

    /* Mark the free regions.  */
    for_each_mem_cluster(memdesc, cluster, i) {
        if (cluster->usage & 3)
            continue;

        start = cluster->start_pfn;
        end = cluster->start_pfn + cluster->numpages;

        if (start >= node_max_pfn || end <= node_min_pfn)
            continue;

        if (end > node_max_pfn)
            end = node_max_pfn;
        if (start < node_min_pfn)
            start = node_min_pfn;

        if (start < start_kernel_pfn) {
            if (end > end_kernel_pfn) {
                free_bootmem_node(NODE_DATA(nid), PFN_PHYS(start),
                         (PFN_PHYS(start_kernel_pfn)
                          - PFN_PHYS(start)));
                printk(" freeing pages %ld:%ld\n",
                       start, start_kernel_pfn);
                start = end_kernel_pfn;
            } else if (end > start_kernel_pfn)
                end = start_kernel_pfn;
        } else if (start < end_kernel_pfn)
            start = end_kernel_pfn;
        if (start >= end)
            continue;

        free_bootmem_node(NODE_DATA(nid), PFN_PHYS(start), PFN_PHYS(end) - PFN_PHYS(start));
        printk(" freeing pages %ld:%ld\n", start, end);
    }

    /* Reserve the bootmap memory.  */
    reserve_bootmem_node(NODE_DATA(nid), PFN_PHYS(bootmap_start),
            bootmap_size, BOOTMEM_DEFAULT);
    printk(" reserving pages %ld:%ld\n", bootmap_start, bootmap_start+PFN_UP(bootmap_size));

    node_set_online(nid);
}

void __init
setup_memory(void *kernel_end)
{
    int nid;

    show_mem_layout();

    nodes_clear(node_online_map);

    min_low_pfn = ~0UL;
    max_low_pfn = 0UL;
    for (nid = 0; nid < MAX_NUMNODES; nid++)
        setup_memory_node(nid, kernel_end);

#ifdef CONFIG_BLK_DEV_INITRD
    initrd_start = INITRD_START;
    if (initrd_start) {
        extern void *move_initrd(unsigned long);

        initrd_end = initrd_start+INITRD_SIZE;
        printk("Initial ramdisk at: 0x%p (%lu bytes)\n",
               (void *) initrd_start, INITRD_SIZE);

        if ((void *)initrd_end > phys_to_virt(PFN_PHYS(max_low_pfn))) {
            if (!move_initrd(PFN_PHYS(max_low_pfn)))
                printk("initrd extends beyond end of memory "
                       "(0x%08lx > 0x%p)\ndisabling initrd\n",
                       initrd_end,
                       phys_to_virt(PFN_PHYS(max_low_pfn)));
        } else {
            nid = kvaddr_to_nid(initrd_start);
            reserve_bootmem_node(NODE_DATA(nid),
                         virt_to_phys((void *)initrd_start),
                         INITRD_SIZE, BOOTMEM_DEFAULT);
        }
    }
#endif /* CONFIG_BLK_DEV_INITRD */
}

void __init paging_init(void)
{
    unsigned int    nid;
    unsigned long   zones_size[MAX_NR_ZONES] = {0, };
    unsigned long   dma_local_pfn;

    /*
     * The old global MAX_DMA_ADDRESS per-arch API doesn't fit
     * in the NUMA model, for now we convert it to a pfn and
     * we interpret this pfn as a local per-node information.
     * This issue isn't very important since none of these machines
     * have legacy ISA slots anyways.
     */
    dma_local_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;

    for_each_online_node(nid) {
        bootmem_data_t *bdata = &bootmem_node_data[nid];
        unsigned long start_pfn = bdata->node_min_pfn;
        unsigned long end_pfn = bdata->node_low_pfn;

        if (dma_local_pfn >= end_pfn - start_pfn)
            zones_size[ZONE_DMA] = end_pfn - start_pfn;
        else {
            zones_size[ZONE_DMA] = dma_local_pfn;
            zones_size[ZONE_NORMAL] = (end_pfn - start_pfn) - dma_local_pfn;
        }
        node_set_state(nid, N_NORMAL_MEMORY);
        free_area_init_node(nid, zones_size, start_pfn, NULL);
    }

    /* Initialize the kernel's ZERO_PGE. */
    memset((void *)ZERO_PGE, 0, PAGE_SIZE);
}

void __init mem_init(void)
{
    unsigned long codesize, reservedpages, datasize, initsize, pfn;
    extern int page_is_ram(unsigned long) __init;
    extern char _text, _etext, _data, _edata;
    extern char __init_begin, __init_end;
    unsigned long nid, i;
    high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);

    reservedpages = 0;
    for_each_online_node(nid) {
        /*
         * This will free up the bootmem, ie, slot 0 memory
         */
        totalram_pages += free_all_bootmem_node(NODE_DATA(nid));

        pfn = NODE_DATA(nid)->node_start_pfn;
        for (i = 0; i < node_spanned_pages(nid); i++, pfn++)
            if (page_is_ram(pfn) &&
                PageReserved(nid_page_nr(nid, i)))
                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",
           nr_free_pages() << (PAGE_SHIFT-10),
           num_physpages << (PAGE_SHIFT-10),
           codesize >> 10,
           reservedpages << (PAGE_SHIFT-10),
           datasize >> 10,
           initsize >> 10);
#if 0
    mem_stress();
#endif
}