[safe/jmp/linux-2.6] / arch / powerpc / mm / mem.c

/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/suspend.h>
#include <linux/lmb.h>

#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/sections.h>
#include <asm/vdso.h>

#include "mmu_decl.h"

#ifndef CPU_FTR_COHERENT_ICACHE
#define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
#define CPU_FTR_NOEXECUTE       0
#endif

int init_bootmem_done;
int mem_init_done;
unsigned long memory_limit;

int page_is_ram(unsigned long pfn)
{
        unsigned long paddr = (pfn << PAGE_SHIFT);

#ifndef CONFIG_PPC64    /* XXX for now */
        return paddr < __pa(high_memory);
#else
        int i;
        for (i=0; i < lmb.memory.cnt; i++) {
                unsigned long base;

                base = lmb.memory.region[i].base;

                if ((paddr >= base) &&
                        (paddr < (base + lmb.memory.region[i].size))) {
                        return 1;
                }
        }

        return 0;
#endif
}

pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
                              unsigned long size, pgprot_t vma_prot)
{
        if (ppc_md.phys_mem_access_prot)
                return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

        if (!page_is_ram(pfn))
                vma_prot = __pgprot(pgprot_val(vma_prot)
                                    | _PAGE_GUARDED | _PAGE_NO_CACHE);
        return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);

#ifdef CONFIG_MEMORY_HOTPLUG

void online_page(struct page *page)
{
        ClearPageReserved(page);
        init_page_count(page);
        __free_page(page);
        totalram_pages++;
        num_physpages++;
}

#ifdef CONFIG_NUMA
int memory_add_physaddr_to_nid(u64 start)
{
        return hot_add_scn_to_nid(start);
}
#endif

int arch_add_memory(int nid, u64 start, u64 size)
{
        struct pglist_data *pgdata;
        struct zone *zone;
        unsigned long start_pfn = start >> PAGE_SHIFT;
        unsigned long nr_pages = size >> PAGE_SHIFT;

        pgdata = NODE_DATA(nid);

        start = (unsigned long)__va(start);
        create_section_mapping(start, start + size);

        /* this should work for most non-highmem platforms */
        zone = pgdata->node_zones;

        return __add_pages(zone, start_pfn, nr_pages);
}

#ifdef CONFIG_MEMORY_HOTREMOVE
int remove_memory(u64 start, u64 size)
{
        unsigned long start_pfn, end_pfn;
        int ret;

        start_pfn = start >> PAGE_SHIFT;
        end_pfn = start_pfn + (size >> PAGE_SHIFT);
        ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
        if (ret)
                goto out;
        /* Arch-specific calls go here - next patch */
out:
        return ret;
}
#endif /* CONFIG_MEMORY_HOTREMOVE */

/*
 * walk_memory_resource() needs to make sure there is no holes in a given
 * memory range. On PPC64, since this range comes from /sysfs, the range
 * is guaranteed to be valid, non-overlapping and can not contain any
 * holes. By the time we get here (memory add or remove), /proc/device-tree
 * is updated and correct. Only reason we need to check against device-tree
 * would be if we allow user-land to specify a memory range through a
 * system call/ioctl etc. instead of doing offline/online through /sysfs.
 */
int
walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
                        int (*func)(unsigned long, unsigned long, void *))
{
        return  (*func)(start_pfn, nr_pages, arg);
}

#endif /* CONFIG_MEMORY_HOTPLUG */

void show_mem(void)
{
        unsigned long total = 0, reserved = 0;
        unsigned long shared = 0, cached = 0;
        unsigned long highmem = 0;
        struct page *page;
        pg_data_t *pgdat;
        unsigned long i;

        printk("Mem-info:\n");
        show_free_areas();
        printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
        for_each_online_pgdat(pgdat) {
                unsigned long flags;
                pgdat_resize_lock(pgdat, &flags);
                for (i = 0; i < pgdat->node_spanned_pages; i++) {
                        if (!pfn_valid(pgdat->node_start_pfn + i))
                                continue;
                        page = pgdat_page_nr(pgdat, i);
                        total++;
                        if (PageHighMem(page))
                                highmem++;
                        if (PageReserved(page))
                                reserved++;
                        else if (PageSwapCache(page))
                                cached++;
                        else if (page_count(page))
                                shared += page_count(page) - 1;
                }
                pgdat_resize_unlock(pgdat, &flags);
        }
        printk("%ld pages of RAM\n", total);
#ifdef CONFIG_HIGHMEM
        printk("%ld pages of HIGHMEM\n", highmem);
#endif
        printk("%ld reserved pages\n", reserved);
        printk("%ld pages shared\n", shared);
        printk("%ld pages swap cached\n", cached);
}

/*
 * Initialize the bootmem system and give it all the memory we
 * have available.  If we are using highmem, we only put the
 * lowmem into the bootmem system.
 */
#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init do_init_bootmem(void)
{
        unsigned long i;
        unsigned long start, bootmap_pages;
        unsigned long total_pages;
        int boot_mapsize;

        max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
        total_pages = total_lowmem >> PAGE_SHIFT;
#endif

        /*
         * Find an area to use for the bootmem bitmap.  Calculate the size of
         * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
         * Add 1 additional page in case the address isn't page-aligned.
         */
        bootmap_pages = bootmem_bootmap_pages(total_pages);

        start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);

        boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);

        /* Add active regions with valid PFNs */
        for (i = 0; i < lmb.memory.cnt; i++) {
                unsigned long start_pfn, end_pfn;
                start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
                end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
                add_active_range(0, start_pfn, end_pfn);
        }

        /* Add all physical memory to the bootmem map, mark each area
         * present.
         */
#ifdef CONFIG_HIGHMEM
        free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);

        /* reserve the sections we're already using */
        for (i = 0; i < lmb.reserved.cnt; i++) {
                unsigned long addr = lmb.reserved.region[i].base +
                                     lmb_size_bytes(&lmb.reserved, i) - 1;
                if (addr < total_lowmem)
                        reserve_bootmem(lmb.reserved.region[i].base,
                                        lmb_size_bytes(&lmb.reserved, i),
                                        BOOTMEM_DEFAULT);
                else if (lmb.reserved.region[i].base < total_lowmem) {
                        unsigned long adjusted_size = total_lowmem -
                                      lmb.reserved.region[i].base;
                        reserve_bootmem(lmb.reserved.region[i].base,
                                        adjusted_size, BOOTMEM_DEFAULT);
                }
        }
#else
        free_bootmem_with_active_regions(0, max_pfn);

        /* reserve the sections we're already using */
        for (i = 0; i < lmb.reserved.cnt; i++)
                reserve_bootmem(lmb.reserved.region[i].base,
                                lmb_size_bytes(&lmb.reserved, i),
                                BOOTMEM_DEFAULT);

#endif
        /* XXX need to clip this if using highmem? */
        sparse_memory_present_with_active_regions(0);

        init_bootmem_done = 1;
}

/* mark pages that don't exist as nosave */
static int __init mark_nonram_nosave(void)
{
        unsigned long lmb_next_region_start_pfn,
                      lmb_region_max_pfn;
        int i;

        for (i = 0; i < lmb.memory.cnt - 1; i++) {
                lmb_region_max_pfn =
                        (lmb.memory.region[i].base >> PAGE_SHIFT) +
                        (lmb.memory.region[i].size >> PAGE_SHIFT);
                lmb_next_region_start_pfn =
                        lmb.memory.region[i+1].base >> PAGE_SHIFT;

                if (lmb_region_max_pfn < lmb_next_region_start_pfn)
                        register_nosave_region(lmb_region_max_pfn,
                                               lmb_next_region_start_pfn);
        }

        return 0;
}

/*
 * paging_init() sets up the page tables - in fact we've already done this.
 */
void __init paging_init(void)
{
        unsigned long total_ram = lmb_phys_mem_size();
        unsigned long top_of_ram = lmb_end_of_DRAM();
        unsigned long max_zone_pfns[MAX_NR_ZONES];

#ifdef CONFIG_HIGHMEM
        map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
        pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
                        (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
        map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
        kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
                        (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
                         KMAP_FIX_BEGIN);
        kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */

        printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
               top_of_ram, total_ram);
        printk(KERN_DEBUG "Memory hole size: %ldMB\n",
               (top_of_ram - total_ram) >> 20);
        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
#ifdef CONFIG_HIGHMEM
        max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
        max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
#else
        max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
#endif
        free_area_init_nodes(max_zone_pfns);

        mark_nonram_nosave();
}
#endif /* ! CONFIG_NEED_MULTIPLE_NODES */

void __init mem_init(void)
{
#ifdef CONFIG_NEED_MULTIPLE_NODES
        int nid;
#endif
        pg_data_t *pgdat;
        unsigned long i;
        struct page *page;
        unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;

        num_physpages = lmb.memory.size >> PAGE_SHIFT;
        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

#ifdef CONFIG_NEED_MULTIPLE_NODES
        for_each_online_node(nid) {
                if (NODE_DATA(nid)->node_spanned_pages != 0) {
                        printk("freeing bootmem node %d\n", nid);
                        totalram_pages +=
                                free_all_bootmem_node(NODE_DATA(nid));
                }
        }
#else
        max_mapnr = max_pfn;
        totalram_pages += free_all_bootmem();
#endif
        for_each_online_pgdat(pgdat) {
                for (i = 0; i < pgdat->node_spanned_pages; i++) {
                        if (!pfn_valid(pgdat->node_start_pfn + i))
                                continue;
                        page = pgdat_page_nr(pgdat, i);
                        if (PageReserved(page))
                                reservedpages++;
                }
        }

        codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
        datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
        initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
        bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;

#ifdef CONFIG_HIGHMEM
        {
                unsigned long pfn, highmem_mapnr;

                highmem_mapnr = total_lowmem >> PAGE_SHIFT;
                for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
                        struct page *page = pfn_to_page(pfn);
                        if (lmb_is_reserved(pfn << PAGE_SHIFT))
                                continue;
                        ClearPageReserved(page);
                        init_page_count(page);
                        __free_page(page);
                        totalhigh_pages++;
                        reservedpages--;
                }
                totalram_pages += totalhigh_pages;
                printk(KERN_DEBUG "High memory: %luk\n",
                       totalhigh_pages << (PAGE_SHIFT-10));
        }
#endif /* CONFIG_HIGHMEM */

        printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
               "%luk reserved, %luk data, %luk bss, %luk init)\n",
                (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
                num_physpages << (PAGE_SHIFT-10),
                codesize >> 10,
                reservedpages << (PAGE_SHIFT-10),
                datasize >> 10,
                bsssize >> 10,
                initsize >> 10);

        mem_init_done = 1;
}

/*
 * This is called when a page has been modified by the kernel.
 * It just marks the page as not i-cache clean.  We do the i-cache
 * flush later when the page is given to a user process, if necessary.
 */
void flush_dcache_page(struct page *page)
{
        if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
                return;
        /* avoid an atomic op if possible */
        if (test_bit(PG_arch_1, &page->flags))
                clear_bit(PG_arch_1, &page->flags);
}
EXPORT_SYMBOL(flush_dcache_page);

void flush_dcache_icache_page(struct page *page)
{
#ifdef CONFIG_BOOKE
        void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
        __flush_dcache_icache(start);
        kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
#elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
        /* On 8xx there is no need to kmap since highmem is not supported */
        __flush_dcache_icache(page_address(page)); 
#else
        __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
#endif

}
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
        clear_page(page);

        /*
         * We shouldnt have to do this, but some versions of glibc
         * require it (ld.so assumes zero filled pages are icache clean)
         * - Anton
         */
        flush_dcache_page(pg);
}
EXPORT_SYMBOL(clear_user_page);

void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
                    struct page *pg)
{
        copy_page(vto, vfrom);

        /*
         * We should be able to use the following optimisation, however
         * there are two problems.
         * Firstly a bug in some versions of binutils meant PLT sections
         * were not marked executable.
         * Secondly the first word in the GOT section is blrl, used
         * to establish the GOT address. Until recently the GOT was
         * not marked executable.
         * - Anton
         */
#if 0
        if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
                return;
#endif

        flush_dcache_page(pg);
}

void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
                             unsigned long addr, int len)
{
        unsigned long maddr;

        maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
        flush_icache_range(maddr, maddr + len);
        kunmap(page);
}
EXPORT_SYMBOL(flush_icache_user_range);

/*
 * This is called at the end of handling a user page fault, when the
 * fault has been handled by updating a PTE in the linux page tables.
 * We use it to preload an HPTE into the hash table corresponding to
 * the updated linux PTE.
 * 
 * This must always be called with the pte lock held.
 */
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
                      pte_t pte)
{
#ifdef CONFIG_PPC_STD_MMU
        unsigned long access = 0, trap;
#endif
        unsigned long pfn = pte_pfn(pte);

        /* handle i-cache coherency */
        if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
            !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
            pfn_valid(pfn)) {
                struct page *page = pfn_to_page(pfn);
#ifdef CONFIG_8xx
                /* On 8xx, cache control instructions (particularly
                 * "dcbst" from flush_dcache_icache) fault as write
                 * operation if there is an unpopulated TLB entry
                 * for the address in question. To workaround that,
                 * we invalidate the TLB here, thus avoiding dcbst
                 * misbehaviour.
                 */
                _tlbie(address, 0 /* 8xx doesn't care about PID */);
#endif
                /* The _PAGE_USER test should really be _PAGE_EXEC, but
                 * older glibc versions execute some code from no-exec
                 * pages, which for now we are supporting.  If exec-only
                 * pages are ever implemented, this will have to change.
                 */
                if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER)
                    && !test_bit(PG_arch_1, &page->flags)) {
                        if (vma->vm_mm == current->active_mm) {
                                __flush_dcache_icache((void *) address);
                        } else
                                flush_dcache_icache_page(page);
                        set_bit(PG_arch_1, &page->flags);
                }
        }

#ifdef CONFIG_PPC_STD_MMU
        /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
        if (!pte_young(pte) || address >= TASK_SIZE)
                return;

        /* We try to figure out if we are coming from an instruction
         * access fault and pass that down to __hash_page so we avoid
         * double-faulting on execution of fresh text. We have to test
         * for regs NULL since init will get here first thing at boot
         *
         * We also avoid filling the hash if not coming from a fault
         */
        if (current->thread.regs == NULL)
                return;
        trap = TRAP(current->thread.regs);
        if (trap == 0x400)
                access |= _PAGE_EXEC;
        else if (trap != 0x300)
                return;
        hash_preload(vma->vm_mm, address, access, trap);
#endif /* CONFIG_PPC_STD_MMU */
}