Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 760 insertions, 0 deletions

diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c
new file mode 100644
index 000000000000..f5a87db8b498
--- /dev/null
+++ b/arch/arm/mm/mm-armv.c
@@ -0,0 +1,760 @@
+/*
+ *  linux/arch/arm/mm/mm-armv.c
+ *
+ *  Copyright (C) 1998-2002 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.
+ *
+ *  Page table sludge for ARM v3 and v4 processor architectures.
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/nodemask.h>
+
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/io.h>
+#include <asm/setup.h>
+#include <asm/tlbflush.h>
+
+#include <asm/mach/map.h>
+
+#define CPOLICY_UNCACHED        0
+#define CPOLICY_BUFFERED        1
+#define CPOLICY_WRITETHROUGH    2
+#define CPOLICY_WRITEBACK       3
+#define CPOLICY_WRITEALLOC      4
+
+static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
+static unsigned int ecc_mask __initdata = 0;
+pgprot_t pgprot_kernel;
+
+EXPORT_SYMBOL(pgprot_kernel);
+
+struct cachepolicy {
+        const char      policy[16];
+        unsigned int    cr_mask;
+        unsigned int    pmd;
+        unsigned int    pte;
+};
+
+static struct cachepolicy cache_policies[] __initdata = {
+        {
+                .policy         = "uncached",
+                .cr_mask        = CR_W|CR_C,
+                .pmd            = PMD_SECT_UNCACHED,
+                .pte            = 0,
+        }, {
+                .policy         = "buffered",
+                .cr_mask        = CR_C,
+                .pmd            = PMD_SECT_BUFFERED,
+                .pte            = PTE_BUFFERABLE,
+        }, {
+                .policy         = "writethrough",
+                .cr_mask        = 0,
+                .pmd            = PMD_SECT_WT,
+                .pte            = PTE_CACHEABLE,
+        }, {
+                .policy         = "writeback",
+                .cr_mask        = 0,
+                .pmd            = PMD_SECT_WB,
+                .pte            = PTE_BUFFERABLE|PTE_CACHEABLE,
+        }, {
+                .policy         = "writealloc",
+                .cr_mask        = 0,
+                .pmd            = PMD_SECT_WBWA,
+                .pte            = PTE_BUFFERABLE|PTE_CACHEABLE,
+        }
+};
+
+/*
+ * These are useful for identifing cache coherency
+ * problems by allowing the cache or the cache and
+ * writebuffer to be turned off.  (Note: the write
+ * buffer should not be on and the cache off).
+ */
+static void __init early_cachepolicy(char **p)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
+                int len = strlen(cache_policies[i].policy);
+
+                if (memcmp(*p, cache_policies[i].policy, len) == 0) {
+                        cachepolicy = i;
+                        cr_alignment &= ~cache_policies[i].cr_mask;
+                        cr_no_alignment &= ~cache_policies[i].cr_mask;
+                        *p += len;
+                        break;
+                }
+        }
+        if (i == ARRAY_SIZE(cache_policies))
+                printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n");
+        flush_cache_all();
+        set_cr(cr_alignment);
+}
+
+static void __init early_nocache(char **__unused)
+{
+        char *p = "buffered";
+        printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p);
+        early_cachepolicy(&p);
+}
+
+static void __init early_nowrite(char **__unused)
+{
+        char *p = "uncached";
+        printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p);
+        early_cachepolicy(&p);
+}
+
+static void __init early_ecc(char **p)
+{
+        if (memcmp(*p, "on", 2) == 0) {
+                ecc_mask = PMD_PROTECTION;
+                *p += 2;
+        } else if (memcmp(*p, "off", 3) == 0) {
+                ecc_mask = 0;
+                *p += 3;
+        }
+}
+
+__early_param("nocache", early_nocache);
+__early_param("nowb", early_nowrite);
+__early_param("cachepolicy=", early_cachepolicy);
+__early_param("ecc=", early_ecc);
+
+static int __init noalign_setup(char *__unused)
+{
+        cr_alignment &= ~CR_A;
+        cr_no_alignment &= ~CR_A;
+        set_cr(cr_alignment);
+        return 1;
+}
+
+__setup("noalign", noalign_setup);
+
+#define FIRST_KERNEL_PGD_NR     (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD)
+
+/*
+ * need to get a 16k page for level 1
+ */
+pgd_t *get_pgd_slow(struct mm_struct *mm)
+{
+        pgd_t *new_pgd, *init_pgd;
+        pmd_t *new_pmd, *init_pmd;
+        pte_t *new_pte, *init_pte;
+
+        new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
+        if (!new_pgd)
+                goto no_pgd;
+
+        memzero(new_pgd, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
+
+        init_pgd = pgd_offset_k(0);
+
+        if (!vectors_high()) {
+                /*
+                 * This lock is here just to satisfy pmd_alloc and pte_lock
+                 */
+                spin_lock(&mm->page_table_lock);
+
+                /*
+                 * On ARM, first page must always be allocated since it
+                 * contains the machine vectors.
+                 */
+                new_pmd = pmd_alloc(mm, new_pgd, 0);
+                if (!new_pmd)
+                        goto no_pmd;
+
+                new_pte = pte_alloc_map(mm, new_pmd, 0);
+                if (!new_pte)
+                        goto no_pte;
+
+                init_pmd = pmd_offset(init_pgd, 0);
+                init_pte = pte_offset_map_nested(init_pmd, 0);
+                set_pte(new_pte, *init_pte);
+                pte_unmap_nested(init_pte);
+                pte_unmap(new_pte);
+
+                spin_unlock(&mm->page_table_lock);
+        }
+
+        /*
+         * Copy over the kernel and IO PGD entries
+         */
+        memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
+                       (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
+
+        clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
+
+        return new_pgd;
+
+no_pte:
+        spin_unlock(&mm->page_table_lock);
+        pmd_free(new_pmd);
+        free_pages((unsigned long)new_pgd, 2);
+        return NULL;
+
+no_pmd:
+        spin_unlock(&mm->page_table_lock);
+        free_pages((unsigned long)new_pgd, 2);
+        return NULL;
+
+no_pgd:
+        return NULL;
+}
+
+void free_pgd_slow(pgd_t *pgd)
+{
+        pmd_t *pmd;
+        struct page *pte;
+
+        if (!pgd)
+                return;
+
+        /* pgd is always present and good */
+        pmd = (pmd_t *)pgd;
+        if (pmd_none(*pmd))
+                goto free;
+        if (pmd_bad(*pmd)) {
+                pmd_ERROR(*pmd);
+                pmd_clear(pmd);
+                goto free;
+        }
+
+        pte = pmd_page(*pmd);
+        pmd_clear(pmd);
+        dec_page_state(nr_page_table_pages);
+        pte_free(pte);
+        pmd_free(pmd);
+free:
+        free_pages((unsigned long) pgd, 2);
+}
+
+/*
+ * Create a SECTION PGD between VIRT and PHYS in domain
+ * DOMAIN with protection PROT.  This operates on half-
+ * pgdir entry increments.
+ */
+static inline void
+alloc_init_section(unsigned long virt, unsigned long phys, int prot)
+{
+        pmd_t *pmdp;
+
+        pmdp = pmd_offset(pgd_offset_k(virt), virt);
+        if (virt & (1 << 20))
+                pmdp++;
+
+        *pmdp = __pmd(phys | prot);
+        flush_pmd_entry(pmdp);
+}
+
+/*
+ * Create a SUPER SECTION PGD between VIRT and PHYS with protection PROT
+ */
+static inline void
+alloc_init_supersection(unsigned long virt, unsigned long phys, int prot)
+{
+        int i;
+
+        for (i = 0; i < 16; i += 1) {
+                alloc_init_section(virt, phys & SUPERSECTION_MASK,
+                                   prot | PMD_SECT_SUPER);
+
+                virt += (PGDIR_SIZE / 2);
+                phys += (PGDIR_SIZE / 2);
+        }
+}
+
+/*
+ * Add a PAGE mapping between VIRT and PHYS in domain
+ * DOMAIN with protection PROT.  Note that due to the
+ * way we map the PTEs, we must allocate two PTE_SIZE'd
+ * blocks - one for the Linux pte table, and one for
+ * the hardware pte table.
+ */
+static inline void
+alloc_init_page(unsigned long virt, unsigned long phys, unsigned int prot_l1, pgprot_t prot)
+{
+        pmd_t *pmdp;
+        pte_t *ptep;
+
+        pmdp = pmd_offset(pgd_offset_k(virt), virt);
+
+        if (pmd_none(*pmdp)) {
+                unsigned long pmdval;
+                ptep = alloc_bootmem_low_pages(2 * PTRS_PER_PTE *
+                                               sizeof(pte_t));
+
+                pmdval = __pa(ptep) | prot_l1;
+                pmdp[0] = __pmd(pmdval);
+                pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
+                flush_pmd_entry(pmdp);
+        }
+        ptep = pte_offset_kernel(pmdp, virt);
+
+        set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
+}
+
+/*
+ * Clear any PGD mapping.  On a two-level page table system,
+ * the clearance is done by the middle-level functions (pmd)
+ * rather than the top-level (pgd) functions.
+ */
+static inline void clear_mapping(unsigned long virt)
+{
+        pmd_clear(pmd_offset(pgd_offset_k(virt), virt));
+}
+
+struct mem_types {
+        unsigned int    prot_pte;
+        unsigned int    prot_l1;
+        unsigned int    prot_sect;
+        unsigned int    domain;
+};
+
+static struct mem_types mem_types[] __initdata = {
+        [MT_DEVICE] = {
+                .prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+                                L_PTE_WRITE,
+                .prot_l1   = PMD_TYPE_TABLE,
+                .prot_sect = PMD_TYPE_SECT | PMD_SECT_UNCACHED |
+                                PMD_SECT_AP_WRITE,
+                .domain    = DOMAIN_IO,
+        },
+        [MT_CACHECLEAN] = {
+                .prot_sect = PMD_TYPE_SECT,
+                .domain    = DOMAIN_KERNEL,
+        },
+        [MT_MINICLEAN] = {
+                .prot_sect = PMD_TYPE_SECT | PMD_SECT_MINICACHE,
+                .domain    = DOMAIN_KERNEL,
+        },
+        [MT_LOW_VECTORS] = {
+                .prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+                                L_PTE_EXEC,
+                .prot_l1   = PMD_TYPE_TABLE,
+                .domain    = DOMAIN_USER,
+        },
+        [MT_HIGH_VECTORS] = {
+                .prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+                                L_PTE_USER | L_PTE_EXEC,
+                .prot_l1   = PMD_TYPE_TABLE,
+                .domain    = DOMAIN_USER,
+        },
+        [MT_MEMORY] = {
+                .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
+                .domain    = DOMAIN_KERNEL,
+        },
+        [MT_ROM] = {
+                .prot_sect = PMD_TYPE_SECT,
+                .domain    = DOMAIN_KERNEL,
+        },
+        [MT_IXP2000_DEVICE] = { /* IXP2400 requires XCB=101 for on-chip I/O */
+                .prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+                                L_PTE_WRITE,
+                .prot_l1   = PMD_TYPE_TABLE,
+                .prot_sect = PMD_TYPE_SECT | PMD_SECT_UNCACHED |
+                                PMD_SECT_AP_WRITE | PMD_SECT_BUFFERABLE |
+                                PMD_SECT_TEX(1),
+                .domain    = DOMAIN_IO,
+        }
+};
+
+/*
+ * Adjust the PMD section entries according to the CPU in use.
+ */
+static void __init build_mem_type_table(void)
+{
+        struct cachepolicy *cp;
+        unsigned int cr = get_cr();
+        int cpu_arch = cpu_architecture();
+        int i;
+
+#if defined(CONFIG_CPU_DCACHE_DISABLE)
+        if (cachepolicy > CPOLICY_BUFFERED)
+                cachepolicy = CPOLICY_BUFFERED;
+#elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
+        if (cachepolicy > CPOLICY_WRITETHROUGH)
+                cachepolicy = CPOLICY_WRITETHROUGH;
+#endif
+        if (cpu_arch < CPU_ARCH_ARMv5) {
+                if (cachepolicy >= CPOLICY_WRITEALLOC)
+                        cachepolicy = CPOLICY_WRITEBACK;
+                ecc_mask = 0;
+        }
+
+        if (cpu_arch <= CPU_ARCH_ARMv5) {
+                for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
+                        if (mem_types[i].prot_l1)
+                                mem_types[i].prot_l1 |= PMD_BIT4;
+                        if (mem_types[i].prot_sect)
+                                mem_types[i].prot_sect |= PMD_BIT4;
+                }
+        }
+
+        /*
+         * ARMv6 and above have extended page tables.
+         */
+        if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
+                /*
+                 * bit 4 becomes XN which we must clear for the
+                 * kernel memory mapping.
+                 */
+                mem_types[MT_MEMORY].prot_sect &= ~PMD_BIT4;
+                mem_types[MT_ROM].prot_sect &= ~PMD_BIT4;
+                /*
+                 * Mark cache clean areas read only from SVC mode
+                 * and no access from userspace.
+                 */
+                mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
+                mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
+        }
+
+        cp = &cache_policies[cachepolicy];
+
+        if (cpu_arch >= CPU_ARCH_ARMv5) {
+                mem_types[MT_LOW_VECTORS].prot_pte |= cp->pte & PTE_CACHEABLE;
+                mem_types[MT_HIGH_VECTORS].prot_pte |= cp->pte & PTE_CACHEABLE;
+        } else {
+                mem_types[MT_LOW_VECTORS].prot_pte |= cp->pte;
+                mem_types[MT_HIGH_VECTORS].prot_pte |= cp->pte;
+                mem_types[MT_MINICLEAN].prot_sect &= ~PMD_SECT_TEX(1);
+        }
+
+        mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
+        mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
+        mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
+        mem_types[MT_ROM].prot_sect |= cp->pmd;
+
+        for (i = 0; i < 16; i++) {
+                unsigned long v = pgprot_val(protection_map[i]);
+                v &= (~(PTE_BUFFERABLE|PTE_CACHEABLE)) | cp->pte;
+                protection_map[i] = __pgprot(v);
+        }
+
+        pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
+                                 L_PTE_DIRTY | L_PTE_WRITE |
+                                 L_PTE_EXEC | cp->pte);
+
+        switch (cp->pmd) {
+        case PMD_SECT_WT:
+                mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
+                break;
+        case PMD_SECT_WB:
+        case PMD_SECT_WBWA:
+                mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
+                break;
+        }
+        printk("Memory policy: ECC %sabled, Data cache %s\n",
+                ecc_mask ? "en" : "dis", cp->policy);
+}
+
+#define vectors_base()  (vectors_high() ? 0xffff0000 : 0)
+
+/*
+ * Create the page directory entries and any necessary
+ * page tables for the mapping specified by `md'.  We
+ * are able to cope here with varying sizes and address
+ * offsets, and we take full advantage of sections and
+ * supersections.
+ */
+static void __init create_mapping(struct map_desc *md)
+{
+        unsigned long virt, length;
+        int prot_sect, prot_l1, domain;
+        pgprot_t prot_pte;
+        long off;
+
+        if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
+                printk(KERN_WARNING "BUG: not creating mapping for "
+                       "0x%08lx at 0x%08lx in user region\n",
+                       md->physical, md->virtual);
+                return;
+        }
+
+        if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
+            md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
+                printk(KERN_WARNING "BUG: mapping for 0x%08lx at 0x%08lx "
+                       "overlaps vmalloc space\n",
+                       md->physical, md->virtual);
+        }
+
+        domain    = mem_types[md->type].domain;
+        prot_pte  = __pgprot(mem_types[md->type].prot_pte);
+        prot_l1   = mem_types[md->type].prot_l1 | PMD_DOMAIN(domain);
+        prot_sect = mem_types[md->type].prot_sect | PMD_DOMAIN(domain);
+
+        virt   = md->virtual;
+        off    = md->physical - virt;
+        length = md->length;
+
+        if (mem_types[md->type].prot_l1 == 0 &&
+            (virt & 0xfffff || (virt + off) & 0xfffff || (virt + length) & 0xfffff)) {
+                printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not "
+                       "be mapped using pages, ignoring.\n",
+                       md->physical, md->virtual);
+                return;
+        }
+
+        while ((virt & 0xfffff || (virt + off) & 0xfffff) && length >= PAGE_SIZE) {
+                alloc_init_page(virt, virt + off, prot_l1, prot_pte);
+
+                virt   += PAGE_SIZE;
+                length -= PAGE_SIZE;
+        }
+
+        /* N.B. ARMv6 supersections are only defined to work with domain 0.
+         *      Since domain assignments can in fact be arbitrary, the
+         *      'domain == 0' check below is required to insure that ARMv6
+         *      supersections are only allocated for domain 0 regardless
+         *      of the actual domain assignments in use.
+         */
+        if (cpu_architecture() >= CPU_ARCH_ARMv6 && domain == 0) {
+                /* Align to supersection boundary */
+                while ((virt & ~SUPERSECTION_MASK || (virt + off) &
+                        ~SUPERSECTION_MASK) && length >= (PGDIR_SIZE / 2)) {
+                        alloc_init_section(virt, virt + off, prot_sect);
+
+                        virt   += (PGDIR_SIZE / 2);
+                        length -= (PGDIR_SIZE / 2);
+                }
+
+                while (length >= SUPERSECTION_SIZE) {
+                        alloc_init_supersection(virt, virt + off, prot_sect);
+
+                        virt   += SUPERSECTION_SIZE;
+                        length -= SUPERSECTION_SIZE;
+                }
+        }
+
+        /*
+         * A section mapping covers half a "pgdir" entry.
+         */
+        while (length >= (PGDIR_SIZE / 2)) {
+                alloc_init_section(virt, virt + off, prot_sect);
+
+                virt   += (PGDIR_SIZE / 2);
+                length -= (PGDIR_SIZE / 2);
+        }
+
+        while (length >= PAGE_SIZE) {
+                alloc_init_page(virt, virt + off, prot_l1, prot_pte);
+
+                virt   += PAGE_SIZE;
+                length -= PAGE_SIZE;
+        }
+}
+
+/*
+ * In order to soft-boot, we need to insert a 1:1 mapping in place of
+ * the user-mode pages.  This will then ensure that we have predictable
+ * results when turning the mmu off
+ */
+void setup_mm_for_reboot(char mode)
+{
+        unsigned long pmdval;
+        pgd_t *pgd;
+        pmd_t *pmd;
+        int i;
+        int cpu_arch = cpu_architecture();
+
+        if (current->mm && current->mm->pgd)
+                pgd = current->mm->pgd;
+        else
+                pgd = init_mm.pgd;
+
+        for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++) {
+                pmdval = (i << PGDIR_SHIFT) |
+                         PMD_SECT_AP_WRITE | PMD_SECT_AP_READ |
+                         PMD_TYPE_SECT;
+                if (cpu_arch <= CPU_ARCH_ARMv5)
+                        pmdval |= PMD_BIT4;
+                pmd = pmd_offset(pgd + i, i << PGDIR_SHIFT);
+                pmd[0] = __pmd(pmdval);
+                pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1)));
+                flush_pmd_entry(pmd);
+        }
+}
+
+extern void _stext, _etext;
+
+/*
+ * Setup initial mappings.  We use the page we allocated for zero page to hold
+ * the mappings, which will get overwritten by the vectors in traps_init().
+ * The mappings must be in virtual address order.
+ */
+void __init memtable_init(struct meminfo *mi)
+{
+        struct map_desc *init_maps, *p, *q;
+        unsigned long address = 0;
+        int i;
+
+        build_mem_type_table();
+
+        init_maps = p = alloc_bootmem_low_pages(PAGE_SIZE);
+
+#ifdef CONFIG_XIP_KERNEL
+        p->physical   = CONFIG_XIP_PHYS_ADDR & PMD_MASK;
+        p->virtual    = (unsigned long)&_stext & PMD_MASK;
+        p->length     = ((unsigned long)&_etext - p->virtual + ~PMD_MASK) & PMD_MASK;
+        p->type       = MT_ROM;
+        p ++;
+#endif
+
+        for (i = 0; i < mi->nr_banks; i++) {
+                if (mi->bank[i].size == 0)
+                        continue;
+
+                p->physical   = mi->bank[i].start;
+                p->virtual    = __phys_to_virt(p->physical);
+                p->length     = mi->bank[i].size;
+                p->type       = MT_MEMORY;
+                p ++;
+        }
+
+#ifdef FLUSH_BASE
+        p->physical   = FLUSH_BASE_PHYS;
+        p->virtual    = FLUSH_BASE;
+        p->length     = PGDIR_SIZE;
+        p->type       = MT_CACHECLEAN;
+        p ++;
+#endif
+
+#ifdef FLUSH_BASE_MINICACHE
+        p->physical   = FLUSH_BASE_PHYS + PGDIR_SIZE;
+        p->virtual    = FLUSH_BASE_MINICACHE;
+        p->length     = PGDIR_SIZE;
+        p->type       = MT_MINICLEAN;
+        p ++;
+#endif
+
+        /*
+         * Go through the initial mappings, but clear out any
+         * pgdir entries that are not in the description.
+         */
+        q = init_maps;
+        do {
+                if (address < q->virtual || q == p) {
+                        clear_mapping(address);
+                        address += PGDIR_SIZE;
+                } else {
+                        create_mapping(q);
+
+                        address = q->virtual + q->length;
+                        address = (address + PGDIR_SIZE - 1) & PGDIR_MASK;
+
+                        q ++;
+                }
+        } while (address != 0);
+
+        /*
+         * Create a mapping for the machine vectors at the high-vectors
+         * location (0xffff0000).  If we aren't using high-vectors, also
+         * create a mapping at the low-vectors virtual address.
+         */
+        init_maps->physical   = virt_to_phys(init_maps);
+        init_maps->virtual    = 0xffff0000;
+        init_maps->length     = PAGE_SIZE;
+        init_maps->type       = MT_HIGH_VECTORS;
+        create_mapping(init_maps);
+
+        if (!vectors_high()) {
+                init_maps->virtual = 0;
+                init_maps->type = MT_LOW_VECTORS;
+                create_mapping(init_maps);
+        }
+
+        flush_cache_all();
+        flush_tlb_all();
+}
+
+/*
+ * Create the architecture specific mappings
+ */
+void __init iotable_init(struct map_desc *io_desc, int nr)
+{
+        int i;
+
+        for (i = 0; i < nr; i++)
+                create_mapping(io_desc + i);
+}
+
+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);
+}
+
+static inline void 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 (i = 0; i < mi->nr_banks; i++) {
+                if (mi->bank[i].size == 0 || mi->bank[i].node != node)
+                        continue;
+
+                bank_start = mi->bank[i].start >> PAGE_SHIFT;
+                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 = PAGE_ALIGN(mi->bank[i].start +
+                                           mi->bank[i].size) >> PAGE_SHIFT;
+        }
+}
+
+/*
+ * The mem_map array can get very big.  Free
+ * the unused area of the memory map.
+ */
+void __init create_memmap_holes(struct meminfo *mi)
+{
+        int node;
+
+        for_each_online_node(node)
+                free_unused_memmap_node(node, mi);
+}