[PATCH] revised Memory Add Fixes for ppc64

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / 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
 *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
 *  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/config.h>
#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 <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/prom.h>
#include <asm/lmb.h>
#include <asm/sections.h>
#ifdef CONFIG_PPC64
#include <asm/vdso.h>
#endif

#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;

extern void hash_preload(struct mm_struct *mm, unsigned long ea,
                         unsigned long access, unsigned long trap);

/*
 * This is called by /dev/mem to know if a given address has to
 * be mapped non-cacheable or not
 */
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
}
EXPORT_SYMBOL(page_is_ram);

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);
        free_cold_page(page);
        totalram_pages++;
        num_physpages++;
}

/*
 * This works only for the non-NUMA case.  Later, we'll need a lookup
 * to convert from real physical addresses to nid, that doesn't use
 * pfn_to_nid().
 */
int __devinit add_memory(u64 start, u64 size)
{
        struct pglist_data *pgdata = NODE_DATA(0);
        struct zone *zone;
        unsigned long start_pfn = start >> PAGE_SHIFT;
        unsigned long nr_pages = size >> PAGE_SHIFT;

        start += KERNELBASE;
        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);

        return 0;
}

/*
 * First pass at this code will check to determine if the remove
 * request is within the RMO.  Do not allow removal within the RMO.
 */
int __devinit remove_memory(u64 start, u64 size)
{
        struct zone *zone;
        unsigned long start_pfn, end_pfn, nr_pages;

        start_pfn = start >> PAGE_SHIFT;
        nr_pages = size >> PAGE_SHIFT;
        end_pfn = start_pfn + nr_pages;

        printk("%s(): Attempting to remove memoy in range "
                        "%lx to %lx\n", __func__, start, start+size);
        /*
         * check for range within RMO
         */
        zone = page_zone(pfn_to_page(start_pfn));

        printk("%s(): memory will be removed from "
                        "the %s zone\n", __func__, zone->name);

        /*
         * not handling removing memory ranges that
         * overlap multiple zones yet
         */
        if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
                goto overlap;

        /* make sure it is NOT in RMO */
        if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
                printk("%s(): range to be removed must NOT be in RMO!\n",
                        __func__);
                goto in_rmo;
        }

        return __remove_pages(zone, start_pfn, nr_pages);

overlap:
        printk("%s(): memory range to be removed overlaps "
                "multiple zones!!!\n", __func__);
in_rmo:
        return -1;
}
#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_pgdat(pgdat) {
                unsigned long flags;
                pgdat_resize_lock(pgdat, &flags);
                for (i = 0; i < pgdat->node_spanned_pages; i++) {
                        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);
        BUG_ON(!start);

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

        /* Add all physical memory to the bootmem map, mark each area
         * present.
         */
        for (i = 0; i < lmb.memory.cnt; i++) {
                unsigned long base = lmb.memory.region[i].base;
                unsigned long size = lmb_size_bytes(&lmb.memory, i);
#ifdef CONFIG_HIGHMEM
                if (base >= total_lowmem)
                        continue;
                if (base + size > total_lowmem)
                        size = total_lowmem - base;
#endif
                free_bootmem(base, size);
        }

        /* 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));

        /* XXX need to clip this if using highmem? */
        for (i = 0; i < lmb.memory.cnt; i++)
                memory_present(0, lmb_start_pfn(&lmb.memory, i),
                               lmb_end_pfn(&lmb.memory, i));
        init_bootmem_done = 1;
}

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

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

        printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
               top_of_ram, total_ram);
        printk(KERN_INFO "Memory hole size: %ldMB\n",
               (top_of_ram - total_ram) >> 20);
        /*
         * All pages are DMA-able so we put them all in the DMA zone.
         */
        memset(zones_size, 0, sizeof(zones_size));
        memset(zholes_size, 0, sizeof(zholes_size));

        zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
        zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;

#ifdef CONFIG_HIGHMEM
        zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
        zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
        zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
#else
        zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
        zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */

        free_area_init_node(0, NODE_DATA(0), zones_size,
                            __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
}
#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 = max_pfn;        /* RAM is assumed contiguous */
        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 %x\n", nid);
                        totalram_pages +=
                                free_all_bootmem_node(NODE_DATA(nid));
                }
        }
#else
        max_mapnr = num_physpages;
        totalram_pages += free_all_bootmem();
#endif
        for_each_pgdat(pgdat) {
                for (i = 0; i < pgdat->node_spanned_pages; i++) {
                        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);

                        ClearPageReserved(page);
                        set_page_count(page, 1);
                        __free_page(page);
                        totalhigh_pages++;
                }
                totalram_pages += totalhigh_pages;
                printk(KERN_INFO "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;

#ifdef CONFIG_PPC64
        /* Initialize the vDSO */
        vdso_init();
#endif
}

/*
 * 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);

        if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
                return;
        /*
         * We shouldnt have to do this, but some versions of glibc
         * require it (ld.so assumes zero filled pages are icache clean)
         * - Anton
         */

        /* avoid an atomic op if possible */
        if (test_bit(PG_arch_1, &pg->flags))
                clear_bit(PG_arch_1, &pg->flags);
}
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

        if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
                return;

        /* avoid an atomic op if possible */
        if (test_bit(PG_arch_1, &pg->flags))
                clear_bit(PG_arch_1, &pg->flags);
}

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 mm->page_table_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);
                if (!PageReserved(page)
                    && !test_bit(PG_arch_1, &page->flags)) {
                        if (vma->vm_mm == current->active_mm) {
#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);
#endif
                                __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 */
}