[ARM] mem_init(): make highmem pages available for use
[safe/jmp/linux-2.6] / arch / arm / mm / init.c
index 41156c5..8277802 100644 (file)
 /*
  *  linux/arch/arm/mm/init.c
  *
- *  Copyright (C) 1995-2002 Russell King
+ *  Copyright (C) 1995-2005 Russell King
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-#include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
-#include <linux/ptrace.h>
 #include <linux/swap.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/mman.h>
 #include <linux/nodemask.h>
 #include <linux/initrd.h>
+#include <linux/highmem.h>
 
 #include <asm/mach-types.h>
-#include <asm/hardware.h>
+#include <asm/sections.h>
 #include <asm/setup.h>
+#include <asm/sizes.h>
 #include <asm/tlb.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
 
-#define TABLE_SIZE     (2 * PTRS_PER_PTE * sizeof(pte_t))
+#include "mm.h"
 
-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+static unsigned long phys_initrd_start __initdata = 0;
+static unsigned long phys_initrd_size __initdata = 0;
 
-extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
-extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end;
-extern unsigned long phys_initrd_start;
-extern unsigned long phys_initrd_size;
+static void __init early_initrd(char **p)
+{
+       unsigned long start, size;
 
-/*
- * The sole use of this is to pass memory configuration
- * data from paging_init to mem_init.
- */
-static struct meminfo meminfo __initdata = { 0, };
+       start = memparse(*p, p);
+       if (**p == ',') {
+               size = memparse((*p) + 1, p);
+
+               phys_initrd_start = start;
+               phys_initrd_size = size;
+       }
+}
+__early_param("initrd=", early_initrd);
+
+static int __init parse_tag_initrd(const struct tag *tag)
+{
+       printk(KERN_WARNING "ATAG_INITRD is deprecated; "
+               "please update your bootloader.\n");
+       phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
+       phys_initrd_size = tag->u.initrd.size;
+       return 0;
+}
+
+__tagtable(ATAG_INITRD, parse_tag_initrd);
+
+static int __init parse_tag_initrd2(const struct tag *tag)
+{
+       phys_initrd_start = tag->u.initrd.start;
+       phys_initrd_size = tag->u.initrd.size;
+       return 0;
+}
+
+__tagtable(ATAG_INITRD2, parse_tag_initrd2);
 
 /*
- * empty_zero_page is a special page that is used for
- * zero-initialized data and COW.
+ * This keeps memory configuration data used by a couple memory
+ * initialization functions, as well as show_mem() for the skipping
+ * of holes in the memory map.  It is populated by arm_add_memory().
  */
-struct page *empty_zero_page;
+struct meminfo meminfo;
 
 void show_mem(void)
 {
        int free = 0, total = 0, reserved = 0;
-       int shared = 0, cached = 0, slab = 0, node;
+       int shared = 0, cached = 0, slab = 0, node, i;
+       struct meminfo * mi = &meminfo;
 
        printk("Mem-info:\n");
        show_free_areas();
-       printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
-
        for_each_online_node(node) {
-               struct page *page, *end;
-
-               page = NODE_MEM_MAP(node);
-               end  = page + NODE_DATA(node)->node_spanned_pages;
-
-               do {
-                       total++;
-                       if (PageReserved(page))
-                               reserved++;
-                       else if (PageSwapCache(page))
-                               cached++;
-                       else if (PageSlab(page))
-                               slab++;
-                       else if (!page_count(page))
-                               free++;
-                       else
-                               shared += page_count(page) - 1;
-                       page++;
-               } while (page < end);
+               pg_data_t *n = NODE_DATA(node);
+               struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;
+
+               for_each_nodebank (i,mi,node) {
+                       struct membank *bank = &mi->bank[i];
+                       unsigned int pfn1, pfn2;
+                       struct page *page, *end;
+
+                       pfn1 = bank_pfn_start(bank);
+                       pfn2 = bank_pfn_end(bank);
+
+                       page = map + pfn1;
+                       end  = map + pfn2;
+
+                       do {
+                               total++;
+                               if (PageReserved(page))
+                                       reserved++;
+                               else if (PageSwapCache(page))
+                                       cached++;
+                               else if (PageSlab(page))
+                                       slab++;
+                               else if (!page_count(page))
+                                       free++;
+                               else
+                                       shared += page_count(page) - 1;
+                               page++;
+                       } while (page < end);
+               }
        }
 
        printk("%d pages of RAM\n", total);
@@ -86,22 +120,6 @@ void show_mem(void)
        printk("%d pages swap cached\n", cached);
 }
 
-struct node_info {
-       unsigned int start;
-       unsigned int end;
-       int bootmap_pages;
-};
-
-#define O_PFN_DOWN(x)  ((x) >> PAGE_SHIFT)
-#define V_PFN_DOWN(x)  O_PFN_DOWN(__pa(x))
-
-#define O_PFN_UP(x)    (PAGE_ALIGN(x) >> PAGE_SHIFT)
-#define V_PFN_UP(x)    O_PFN_UP(__pa(x))
-
-#define PFN_SIZE(x)    ((x) >> PAGE_SHIFT)
-#define PFN_RANGE(s,e) PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \
-                               (((unsigned long)(s)) & PAGE_MASK))
-
 /*
  * FIXME: We really want to avoid allocating the bootmap bitmap
  * over the top of the initrd.  Hopefully, this is located towards
@@ -111,20 +129,17 @@ struct node_info {
 static unsigned int __init
 find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
 {
-       unsigned int start_pfn, bank, bootmap_pfn;
+       unsigned int start_pfn, i, bootmap_pfn;
 
-       start_pfn   = V_PFN_UP(&_end);
+       start_pfn   = PAGE_ALIGN(__pa(_end)) >> PAGE_SHIFT;
        bootmap_pfn = 0;
 
-       for (bank = 0; bank < mi->nr_banks; bank ++) {
+       for_each_nodebank(i, mi, node) {
+               struct membank *bank = &mi->bank[i];
                unsigned int start, end;
 
-               if (mi->bank[bank].node != node)
-                       continue;
-
-               start = O_PFN_UP(mi->bank[bank].start);
-               end   = O_PFN_DOWN(mi->bank[bank].size +
-                                  mi->bank[bank].start);
+               start = bank_pfn_start(bank);
+               end   = bank_pfn_end(bank);
 
                if (end < start_pfn)
                        continue;
@@ -147,89 +162,6 @@ find_bootmap_pfn(int node, struct meminfo *mi, unsigned int bootmap_pages)
        return bootmap_pfn;
 }
 
-/*
- * Scan the memory info structure and pull out:
- *  - the end of memory
- *  - the number of nodes
- *  - the pfn range of each node
- *  - the number of bootmem bitmap pages
- */
-static unsigned int __init
-find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
-{
-       unsigned int i, bootmem_pages = 0, memend_pfn = 0;
-
-       for (i = 0; i < MAX_NUMNODES; i++) {
-               np[i].start = -1U;
-               np[i].end = 0;
-               np[i].bootmap_pages = 0;
-       }
-
-       for (i = 0; i < mi->nr_banks; i++) {
-               unsigned long start, end;
-               int node;
-
-               if (mi->bank[i].size == 0) {
-                       /*
-                        * Mark this bank with an invalid node number
-                        */
-                       mi->bank[i].node = -1;
-                       continue;
-               }
-
-               node = mi->bank[i].node;
-
-               /*
-                * Make sure we haven't exceeded the maximum number of nodes
-                * that we have in this configuration.  If we have, we're in
-                * trouble.  (maybe we ought to limit, instead of bugging?)
-                */
-               if (node >= MAX_NUMNODES)
-                       BUG();
-               node_set_online(node);
-
-               /*
-                * Get the start and end pfns for this bank
-                */
-               start = O_PFN_UP(mi->bank[i].start);
-               end   = O_PFN_DOWN(mi->bank[i].start + mi->bank[i].size);
-
-               if (np[node].start > start)
-                       np[node].start = start;
-
-               if (np[node].end < end)
-                       np[node].end = end;
-
-               if (memend_pfn < end)
-                       memend_pfn = end;
-       }
-
-       /*
-        * Calculate the number of pages we require to
-        * store the bootmem bitmaps.
-        */
-       for_each_online_node(i) {
-               if (np[i].end == 0)
-                       continue;
-
-               np[i].bootmap_pages = bootmem_bootmap_pages(np[i].end -
-                                                           np[i].start);
-               bootmem_pages += np[i].bootmap_pages;
-       }
-
-       high_memory = __va(memend_pfn << PAGE_SHIFT);
-
-       /*
-        * This doesn't seem to be used by the Linux memory
-        * manager any more.  If we can get rid of it, we
-        * also get rid of some of the stuff above as well.
-        */
-       max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);
-       max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET);
-
-       return bootmem_pages;
-}
-
 static int __init check_initrd(struct meminfo *mi)
 {
        int initrd_node = -2;
@@ -246,20 +178,17 @@ static int __init check_initrd(struct meminfo *mi)
                initrd_node = -1;
 
                for (i = 0; i < mi->nr_banks; i++) {
-                       unsigned long bank_end;
-
-                       bank_end = mi->bank[i].start + mi->bank[i].size;
-
-                       if (mi->bank[i].start <= phys_initrd_start &&
-                           end <= bank_end)
-                               initrd_node = mi->bank[i].node;
+                       struct membank *bank = &mi->bank[i];
+                       if (bank_phys_start(bank) <= phys_initrd_start &&
+                           end <= bank_phys_end(bank))
+                               initrd_node = bank->node;
                }
        }
 
        if (initrd_node == -1) {
-               printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond "
+               printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
                       "physical memory - disabling initrd\n",
-                      phys_initrd_start, end);
+                      phys_initrd_start, phys_initrd_size);
                phys_initrd_start = phys_initrd_size = 0;
        }
 #endif
@@ -267,263 +196,283 @@ static int __init check_initrd(struct meminfo *mi)
        return initrd_node;
 }
 
-/*
- * Reserve the various regions of node 0
- */
-static __init void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages)
+static inline void map_memory_bank(struct membank *bank)
 {
-       pg_data_t *pgdat = NODE_DATA(0);
-       unsigned long res_size = 0;
+#ifdef CONFIG_MMU
+       struct map_desc map;
 
-       /*
-        * Register the kernel text and data with bootmem.
-        * Note that this can only be in node 0.
-        */
-#ifdef CONFIG_XIP_KERNEL
-       reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
-#else
-       reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
+       map.pfn = bank_pfn_start(bank);
+       map.virtual = __phys_to_virt(bank_phys_start(bank));
+       map.length = bank_phys_size(bank);
+       map.type = MT_MEMORY;
+
+       create_mapping(&map);
 #endif
+}
+
+static unsigned long __init bootmem_init_node(int node, struct meminfo *mi)
+{
+       unsigned long start_pfn, end_pfn, boot_pfn;
+       unsigned int boot_pages;
+       pg_data_t *pgdat;
+       int i;
+
+       start_pfn = -1UL;
+       end_pfn = 0;
 
        /*
-        * Reserve the page tables.  These are already in use,
-        * and can only be in node 0.
+        * Calculate the pfn range, and map the memory banks for this node.
         */
-       reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
-                            PTRS_PER_PGD * sizeof(pgd_t));
+       for_each_nodebank(i, mi, node) {
+               struct membank *bank = &mi->bank[i];
+               unsigned long start, end;
+
+               start = bank_pfn_start(bank);
+               end = bank_pfn_end(bank);
+
+               if (start_pfn > start)
+                       start_pfn = start;
+               if (end_pfn < end)
+                       end_pfn = end;
+
+               map_memory_bank(bank);
+       }
 
        /*
-        * And don't forget to reserve the allocator bitmap,
-        * which will be freed later.
+        * If there is no memory in this node, ignore it.
         */
-       reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
-                            bootmap_pages << PAGE_SHIFT);
+       if (end_pfn == 0)
+               return end_pfn;
 
        /*
-        * Hmm... This should go elsewhere, but we really really need to
-        * stop things allocating the low memory; ideally we need a better
-        * implementation of GFP_DMA which does not assume that DMA-able
-        * memory starts at zero.
+        * Allocate the bootmem bitmap page.
         */
-       if (machine_is_integrator() || machine_is_cintegrator())
-               res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
+       boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
+       boot_pfn = find_bootmap_pfn(node, mi, boot_pages);
 
        /*
-        * These should likewise go elsewhere.  They pre-reserve the
-        * screen memory region at the start of main system memory.
+        * Initialise the bootmem allocator for this node, handing the
+        * memory banks over to bootmem.
         */
-       if (machine_is_edb7211())
-               res_size = 0x00020000;
-       if (machine_is_p720t())
-               res_size = 0x00014000;
+       node_set_online(node);
+       pgdat = NODE_DATA(node);
+       init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);
+
+       for_each_nodebank(i, mi, node) {
+               struct membank *bank = &mi->bank[i];
+               free_bootmem_node(pgdat, bank_phys_start(bank), bank_phys_size(bank));
+               memory_present(node, bank_pfn_start(bank), bank_pfn_end(bank));
+       }
 
-#ifdef CONFIG_SA1111
        /*
-        * Because of the SA1111 DMA bug, we want to preserve our
-        * precious DMA-able memory...
+        * Reserve the bootmem bitmap for this node.
         */
-       res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
-#endif
-       if (res_size)
-               reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
-}
-
-/*
- * Register all available RAM in this node with the bootmem allocator.
- */
-static inline void free_bootmem_node_bank(int node, struct meminfo *mi)
-{
-       pg_data_t *pgdat = NODE_DATA(node);
-       int bank;
+       reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
+                            boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
 
-       for (bank = 0; bank < mi->nr_banks; bank++)
-               if (mi->bank[bank].node == node)
-                       free_bootmem_node(pgdat, mi->bank[bank].start,
-                                         mi->bank[bank].size);
+       return end_pfn;
 }
 
-/*
- * Initialise the bootmem allocator for all nodes.  This is called
- * early during the architecture specific initialisation.
- */
-static void __init bootmem_init(struct meminfo *mi)
+static void __init bootmem_reserve_initrd(int node)
 {
-       struct node_info node_info[MAX_NUMNODES], *np = node_info;
-       unsigned int bootmap_pages, bootmap_pfn, map_pg;
-       int node, initrd_node;
-
-       bootmap_pages = find_memend_and_nodes(mi, np);
-       bootmap_pfn   = find_bootmap_pfn(0, mi, bootmap_pages);
-       initrd_node   = check_initrd(mi);
-
-       map_pg = bootmap_pfn;
-
-       /*
-        * Initialise the bootmem nodes.
-        *
-        * What we really want to do is:
-        *
-        *   unmap_all_regions_except_kernel();
-        *   for_each_node_in_reverse_order(node) {
-        *     map_node(node);
-        *     allocate_bootmem_map(node);
-        *     init_bootmem_node(node);
-        *     free_bootmem_node(node);
-        *   }
-        *
-        * but this is a 2.5-type change.  For now, we just set
-        * the nodes up in reverse order.
-        *
-        * (we could also do with rolling bootmem_init and paging_init
-        * into one generic "memory_init" type function).
-        */
-       np += num_online_nodes() - 1;
-       for (node = num_online_nodes() - 1; node >= 0; node--, np--) {
-               /*
-                * If there are no pages in this node, ignore it.
-                * Note that node 0 must always have some pages.
-                */
-               if (np->end == 0 || !node_online(node)) {
-                       if (node == 0)
-                               BUG();
-                       continue;
-               }
-
-               /*
-                * Initialise the bootmem allocator.
-                */
-               init_bootmem_node(NODE_DATA(node), map_pg, np->start, np->end);
-               free_bootmem_node_bank(node, mi);
-               map_pg += np->bootmap_pages;
-
-               /*
-                * If this is node 0, we need to reserve some areas ASAP -
-                * we may use bootmem on node 0 to setup the other nodes.
-                */
-               if (node == 0)
-                       reserve_node_zero(bootmap_pfn, bootmap_pages);
-       }
+#ifdef CONFIG_BLK_DEV_INITRD
+       pg_data_t *pgdat = NODE_DATA(node);
+       int res;
 
+       res = reserve_bootmem_node(pgdat, phys_initrd_start,
+                            phys_initrd_size, BOOTMEM_EXCLUSIVE);
 
-#ifdef CONFIG_BLK_DEV_INITRD
-       if (phys_initrd_size && initrd_node >= 0) {
-               reserve_bootmem_node(NODE_DATA(initrd_node), phys_initrd_start,
-                                    phys_initrd_size);
+       if (res == 0) {
                initrd_start = __phys_to_virt(phys_initrd_start);
                initrd_end = initrd_start + phys_initrd_size;
+       } else {
+               printk(KERN_ERR
+                       "INITRD: 0x%08lx+0x%08lx overlaps in-use "
+                       "memory region - disabling initrd\n",
+                       phys_initrd_start, phys_initrd_size);
        }
 #endif
-
-       BUG_ON(map_pg != bootmap_pfn + bootmap_pages);
 }
 
-/*
- * paging_init() sets up the page tables, initialises the zone memory
- * maps, and sets up the zero page, bad page and bad page tables.
- */
-void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
+static void __init bootmem_free_node(int node, struct meminfo *mi)
 {
-       void *zero_page;
-       int node;
+       unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
+       unsigned long start_pfn, end_pfn;
+       pg_data_t *pgdat = NODE_DATA(node);
+       int i;
 
-       bootmem_init(mi);
+       start_pfn = pgdat->bdata->node_min_pfn;
+       end_pfn = pgdat->bdata->node_low_pfn;
 
-       memcpy(&meminfo, mi, sizeof(meminfo));
+       /*
+        * initialise the zones within this node.
+        */
+       memset(zone_size, 0, sizeof(zone_size));
+       memset(zhole_size, 0, sizeof(zhole_size));
 
        /*
-        * allocate the zero page.  Note that we count on this going ok.
+        * The size of this node has already been determined.  If we need
+        * to do anything fancy with the allocation of this memory to the
+        * zones, now is the time to do it.
         */
-       zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
+       zone_size[0] = end_pfn - start_pfn;
 
        /*
-        * initialise the page tables.
+        * For each bank in this node, calculate the size of the holes.
+        *  holes = node_size - sum(bank_sizes_in_node)
         */
-       memtable_init(mi);
-       if (mdesc->map_io)
-               mdesc->map_io();
-       flush_tlb_all();
+       zhole_size[0] = zone_size[0];
+       for_each_nodebank(i, mi, node)
+               zhole_size[0] -= bank_pfn_size(&mi->bank[i]);
 
        /*
-        * initialise the zones within each node
+        * Adjust the sizes according to any special requirements for
+        * this machine type.
         */
-       for_each_online_node(node) {
-               unsigned long zone_size[MAX_NR_ZONES];
-               unsigned long zhole_size[MAX_NR_ZONES];
-               struct bootmem_data *bdata;
-               pg_data_t *pgdat;
-               int i;
+       arch_adjust_zones(node, zone_size, zhole_size);
 
-               /*
-                * Initialise the zone size information.
-                */
-               for (i = 0; i < MAX_NR_ZONES; i++) {
-                       zone_size[i]  = 0;
-                       zhole_size[i] = 0;
-               }
+       free_area_init_node(node, zone_size, start_pfn, zhole_size);
+}
+
+void __init bootmem_init(void)
+{
+       struct meminfo *mi = &meminfo;
+       unsigned long memend_pfn = 0;
+       int node, initrd_node;
 
-               pgdat = NODE_DATA(node);
-               bdata = pgdat->bdata;
+       /*
+        * Locate which node contains the ramdisk image, if any.
+        */
+       initrd_node = check_initrd(mi);
+
+       /*
+        * Run through each node initialising the bootmem allocator.
+        */
+       for_each_node(node) {
+               unsigned long end_pfn = bootmem_init_node(node, mi);
 
                /*
-                * The size of this node has already been determined.
-                * If we need to do anything fancy with the allocation
-                * of this memory to the zones, now is the time to do
-                * it.
+                * Reserve any special node zero regions.
                 */
-               zone_size[0] = bdata->node_low_pfn -
-                               (bdata->node_boot_start >> PAGE_SHIFT);
+               if (node == 0)
+                       reserve_node_zero(NODE_DATA(node));
 
                /*
-                * If this zone has zero size, skip it.
+                * If the initrd is in this node, reserve its memory.
                 */
-               if (!zone_size[0])
-                       continue;
+               if (node == initrd_node)
+                       bootmem_reserve_initrd(node);
 
                /*
-                * For each bank in this node, calculate the size of the
-                * holes.  holes = node_size - sum(bank_sizes_in_node)
+                * Remember the highest memory PFN.
                 */
-               zhole_size[0] = zone_size[0];
-               for (i = 0; i < mi->nr_banks; i++) {
-                       if (mi->bank[i].node != node)
-                               continue;
+               if (end_pfn > memend_pfn)
+                       memend_pfn = end_pfn;
+       }
 
-                       zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT;
-               }
+       /*
+        * sparse_init() needs the bootmem allocator up and running.
+        */
+       sparse_init();
 
-               /*
-                * Adjust the sizes according to any special
-                * requirements for this machine type.
-                */
-               arch_adjust_zones(node, zone_size, zhole_size);
+       /*
+        * Now free memory in each node - free_area_init_node needs
+        * the sparse mem_map arrays initialized by sparse_init()
+        * for memmap_init_zone(), otherwise all PFNs are invalid.
+        */
+       for_each_node(node)
+               bootmem_free_node(node, mi);
 
-               free_area_init_node(node, pgdat, zone_size,
-                               bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
-       }
+       high_memory = __va((memend_pfn << PAGE_SHIFT) - 1) + 1;
 
        /*
-        * finish off the bad pages once
-        * the mem_map is initialised
+        * This doesn't seem to be used by the Linux memory manager any
+        * more, but is used by ll_rw_block.  If we can get rid of it, we
+        * also get rid of some of the stuff above as well.
+        *
+        * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
+        * the system, not the maximum PFN.
         */
-       memzero(zero_page, PAGE_SIZE);
-       empty_zero_page = virt_to_page(zero_page);
-       flush_dcache_page(empty_zero_page);
+       max_pfn = max_low_pfn = memend_pfn - PHYS_PFN_OFFSET;
 }
 
-static inline void free_area(unsigned long addr, unsigned long end, char *s)
+static inline int free_area(unsigned long pfn, unsigned long end, char *s)
 {
-       unsigned int size = (end - addr) >> 10;
+       unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
 
-       for (; addr < end; addr += PAGE_SIZE) {
-               struct page *page = virt_to_page(addr);
+       for (; pfn < end; pfn++) {
+               struct page *page = pfn_to_page(pfn);
                ClearPageReserved(page);
-               set_page_count(page, 1);
-               free_page(addr);
-               totalram_pages++;
+               init_page_count(page);
+               __free_page(page);
+               pages++;
        }
 
        if (size && s)
                printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
+
+       return pages;
+}
+
+static inline void
+free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn)
+{
+       struct page *start_pg, *end_pg;
+       unsigned long pg, pgend;
+
+       /*
+        * Convert start_pfn/end_pfn to a struct page pointer.
+        */
+       start_pg = pfn_to_page(start_pfn);
+       end_pg = pfn_to_page(end_pfn);
+
+       /*
+        * Convert to physical addresses, and
+        * round start upwards and end downwards.
+        */
+       pg = PAGE_ALIGN(__pa(start_pg));
+       pgend = __pa(end_pg) & PAGE_MASK;
+
+       /*
+        * If there are free pages between these,
+        * free the section of the memmap array.
+        */
+       if (pg < pgend)
+               free_bootmem_node(NODE_DATA(node), pg, pgend - pg);
+}
+
+/*
+ * The mem_map array can get very big.  Free the unused area of the memory map.
+ */
+static void __init free_unused_memmap_node(int node, struct meminfo *mi)
+{
+       unsigned long bank_start, prev_bank_end = 0;
+       unsigned int i;
+
+       /*
+        * [FIXME] This relies on each bank being in address order.  This
+        * may not be the case, especially if the user has provided the
+        * information on the command line.
+        */
+       for_each_nodebank(i, mi, node) {
+               struct membank *bank = &mi->bank[i];
+
+               bank_start = bank_pfn_start(bank);
+               if (bank_start < prev_bank_end) {
+                       printk(KERN_ERR "MEM: unordered memory banks.  "
+                               "Not freeing memmap.\n");
+                       break;
+               }
+
+               /*
+                * If we had a previous bank, and there is a space
+                * between the current bank and the previous, free it.
+                */
+               if (prev_bank_end && prev_bank_end != bank_start)
+                       free_memmap(node, prev_bank_end, bank_start);
+
+               prev_bank_end = bank_pfn_end(bank);
+       }
 }
 
 /*
@@ -533,34 +482,40 @@ static inline void free_area(unsigned long addr, unsigned long end, char *s)
  */
 void __init mem_init(void)
 {
-       unsigned int codepages, datapages, initpages;
+       unsigned int codesize, datasize, initsize;
        int i, node;
 
-       codepages = &_etext - &_text;
-       datapages = &_end - &__data_start;
-       initpages = &__init_end - &__init_begin;
-
 #ifndef CONFIG_DISCONTIGMEM
-       max_mapnr   = virt_to_page(high_memory) - mem_map;
+       max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 #endif
 
-       /*
-        * We may have non-contiguous memory.
-        */
-       if (meminfo.nr_banks != 1)
-               create_memmap_holes(&meminfo);
-
        /* this will put all unused low memory onto the freelists */
        for_each_online_node(node) {
                pg_data_t *pgdat = NODE_DATA(node);
 
+               free_unused_memmap_node(node, &meminfo);
+
                if (pgdat->node_spanned_pages != 0)
                        totalram_pages += free_all_bootmem_node(pgdat);
        }
 
 #ifdef CONFIG_SA1111
        /* now that our DMA memory is actually so designated, we can free it */
-       free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL);
+       totalram_pages += free_area(PHYS_PFN_OFFSET,
+                                   __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
+#endif
+
+#ifdef CONFIG_HIGHMEM
+       /* set highmem page free */
+       for_each_online_node(node) {
+               for_each_nodebank (i, &meminfo, node) {
+                       unsigned long start = bank_pfn_start(&meminfo.bank[i]);
+                       unsigned long end = bank_pfn_end(&meminfo.bank[i]);
+                       if (start >= max_low_pfn + PHYS_PFN_OFFSET)
+                               totalhigh_pages += free_area(start, end, NULL);
+               }
+       }
+       totalram_pages += totalhigh_pages;
 #endif
 
        /*
@@ -568,18 +523,22 @@ void __init mem_init(void)
         * real number of pages we have in this system
         */
        printk(KERN_INFO "Memory:");
-
        num_physpages = 0;
        for (i = 0; i < meminfo.nr_banks; i++) {
-               num_physpages += meminfo.bank[i].size >> PAGE_SHIFT;
-               printk(" %ldMB", meminfo.bank[i].size >> 20);
+               num_physpages += bank_pfn_size(&meminfo.bank[i]);
+               printk(" %ldMB", bank_phys_size(&meminfo.bank[i]) >> 20);
        }
-
        printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
+
+       codesize = _etext - _text;
+       datasize = _end - _data;
+       initsize = __init_end - __init_begin;
+
        printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
-               "%dK data, %dK init)\n",
+               "%dK data, %dK init, %luK highmem)\n",
                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
-               codepages >> 10, datapages >> 10, initpages >> 10);
+               codesize >> 10, datasize >> 10, initsize >> 10,
+               (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 
        if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
                extern int sysctl_overcommit_memory;
@@ -594,11 +553,10 @@ void __init mem_init(void)
 
 void free_initmem(void)
 {
-       if (!machine_is_integrator() && !machine_is_cintegrator()) {
-               free_area((unsigned long)(&__init_begin),
-                         (unsigned long)(&__init_end),
-                         "init");
-       }
+       if (!machine_is_integrator() && !machine_is_cintegrator())
+               totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
+                                           __phys_to_pfn(__pa(__init_end)),
+                                           "init");
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -608,7 +566,9 @@ static int keep_initrd;
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
        if (!keep_initrd)
-               free_area(start, end, "initrd");
+               totalram_pages += free_area(__phys_to_pfn(__pa(start)),
+                                           __phys_to_pfn(__pa(end)),
+                                           "initrd");
 }
 
 static int __init keepinitrd_setup(char *__unused)