Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  linux/arch/i386/mm/pgtable.c

 */

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/mm.h>

#include <linux/nmi.h>

#include <linux/swap.h>

#include <linux/smp.h>

#include <linux/highmem.h>

#include <linux/slab.h>

#include <linux/pagemap.h>

#include <linux/spinlock.h>

#include <linux/module.h>

#include <linux/quicklist.h>

#include <asm/system.h>

#include <asm/pgtable.h>

#include <asm/pgalloc.h>

#include <asm/fixmap.h>

#include <asm/e820.h>

#include <asm/tlb.h>

#include <asm/tlbflush.h>

void show_mem(void)

{

        int total = 0, reserved = 0;

        int shared = 0, cached = 0;

        int highmem = 0;

        struct page *page;

        pg_data_t *pgdat;

        unsigned long i;

        unsigned long flags;

        printk(KERN_INFO "Mem-info:\n");

        show_free_areas();

        printk(KERN_INFO "Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));

        for_each_online_pgdat(pgdat) {

                pgdat_resize_lock(pgdat, &flags);

                for (i = 0; i < pgdat->node_spanned_pages; ++i) {

                        if (unlikely(i % MAX_ORDER_NR_PAGES == 0))

                                touch_nmi_watchdog();

                        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(KERN_INFO "%d pages of RAM\n", total);

        printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);

        printk(KERN_INFO "%d reserved pages\n", reserved);

        printk(KERN_INFO "%d pages shared\n", shared);

        printk(KERN_INFO "%d pages swap cached\n", cached);

        printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));

        printk(KERN_INFO "%lu pages writeback\n",

                                        global_page_state(NR_WRITEBACK));

        printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));

        printk(KERN_INFO "%lu pages slab\n",

                global_page_state(NR_SLAB_RECLAIMABLE) +

                global_page_state(NR_SLAB_UNRECLAIMABLE));

        printk(KERN_INFO "%lu pages pagetables\n",

                                        global_page_state(NR_PAGETABLE));

}

/*

 * Associate a virtual page frame with a given physical page frame

 * and protection flags for that frame.

 */

static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)

{

        pgd_t *pgd;

        pud_t *pud;

        pmd_t *pmd;

        pte_t *pte;

        pgd = swapper_pg_dir + pgd_index(vaddr);

        if (pgd_none(*pgd)) {

                BUG();

                return;

        }

        pud = pud_offset(pgd, vaddr);

        if (pud_none(*pud)) {

                BUG();

                return;

        }

        pmd = pmd_offset(pud, vaddr);

        if (pmd_none(*pmd)) {

                BUG();

                return;

        }

        pte = pte_offset_kernel(pmd, vaddr);

        if (pgprot_val(flags))

                set_pte_present(&init_mm, vaddr, pte, pfn_pte(pfn, flags));

        else

                pte_clear(&init_mm, vaddr, pte);

        /*

         * It's enough to flush this one mapping.

         * (PGE mappings get flushed as well)

         */

        __flush_tlb_one(vaddr);

}

/*

 * Associate a large virtual page frame with a given physical page frame

 * and protection flags for that frame. pfn is for the base of the page,

 * vaddr is what the page gets mapped to - both must be properly aligned.

 * The pmd must already be instantiated. Assumes PAE mode.

 */

void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)

{

        pgd_t *pgd;

        pud_t *pud;

        pmd_t *pmd;

        if (vaddr & (PMD_SIZE-1)) {             /* vaddr is misaligned */

                printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");

                return; /* BUG(); */

        }

        if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */

                printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");

                return; /* BUG(); */

        }

        pgd = swapper_pg_dir + pgd_index(vaddr);

        if (pgd_none(*pgd)) {

                printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");

                return; /* BUG(); */

        }

        pud = pud_offset(pgd, vaddr);

        pmd = pmd_offset(pud, vaddr);

        set_pmd(pmd, pfn_pmd(pfn, flags));

        /*

         * It's enough to flush this one mapping.

         * (PGE mappings get flushed as well)

         */

        __flush_tlb_one(vaddr);

}

static int fixmaps;

unsigned long __FIXADDR_TOP = 0xfffff000;

EXPORT_SYMBOL(__FIXADDR_TOP);

void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)

{

        unsigned long address = __fix_to_virt(idx);

        if (idx >= __end_of_fixed_addresses) {

                BUG();

                return;

        }

        set_pte_pfn(address, phys >> PAGE_SHIFT, flags);

        fixmaps++;

}

/**

 * reserve_top_address - reserves a hole in the top of kernel address space

 * @reserve - size of hole to reserve

 *

 * Can be used to relocate the fixmap area and poke a hole in the top

 * of kernel address space to make room for a hypervisor.

 */

void reserve_top_address(unsigned long reserve)

{

        BUG_ON(fixmaps > 0);

        printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",

               (int)-reserve);

        __FIXADDR_TOP = -reserve - PAGE_SIZE;

        __VMALLOC_RESERVE += reserve;

}

pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)

{

        return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);

}

struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)

{

        struct page *pte;

#ifdef CONFIG_HIGHPTE

        pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);

#else

        pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);

#endif

        return pte;

}

void pmd_ctor(struct kmem_cache *cache, void *pmd)

{

        memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));

}

/*

 * List of all pgd's needed for non-PAE so it can invalidate entries

 * in both cached and uncached pgd's; not needed for PAE since the

 * kernel pmd is shared. If PAE were not to share the pmd a similar

 * tactic would be needed. This is essentially codepath-based locking

 * against pageattr.c; it is the unique case in which a valid change

 * of kernel pagetables can't be lazily synchronized by vmalloc faults.

 * vmalloc faults work because attached pagetables are never freed.

 * -- wli

 */

DEFINE_SPINLOCK(pgd_lock);

struct page *pgd_list;

static inline void pgd_list_add(pgd_t *pgd)

{

        struct page *page = virt_to_page(pgd);

        page->index = (unsigned long)pgd_list;

        if (pgd_list)

                set_page_private(pgd_list, (unsigned long)&page->index);

        pgd_list = page;

        set_page_private(page, (unsigned long)&pgd_list);

}

static inline void pgd_list_del(pgd_t *pgd)

{

        struct page *next, **pprev, *page = virt_to_page(pgd);

        next = (struct page *)page->index;

        pprev = (struct page **)page_private(page);

        *pprev = next;

        if (next)

                set_page_private(next, (unsigned long)pprev);

}

#if (PTRS_PER_PMD == 1)

/* Non-PAE pgd constructor */

static void pgd_ctor(void *pgd)

{

        unsigned long flags;

        /* !PAE, no pagetable sharing */

        memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));

        spin_lock_irqsave(&pgd_lock, flags);

        /* must happen under lock */

        clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,

                        swapper_pg_dir + USER_PTRS_PER_PGD,

                        KERNEL_PGD_PTRS);

        paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,

                                __pa(swapper_pg_dir) >> PAGE_SHIFT,

                                USER_PTRS_PER_PGD,

                                KERNEL_PGD_PTRS);

        pgd_list_add(pgd);

        spin_unlock_irqrestore(&pgd_lock, flags);

}

#else  /* PTRS_PER_PMD > 1 */

/* PAE pgd constructor */

static void pgd_ctor(void *pgd)

{

        /* PAE, kernel PMD may be shared */

        if (SHARED_KERNEL_PMD) {

                clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,

                                swapper_pg_dir + USER_PTRS_PER_PGD,

                                KERNEL_PGD_PTRS);

        } else {

                unsigned long flags;

                memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));

                spin_lock_irqsave(&pgd_lock, flags);

                pgd_list_add(pgd);

                spin_unlock_irqrestore(&pgd_lock, flags);

        }

}

#endif  /* PTRS_PER_PMD */

static void pgd_dtor(void *pgd)

{

        unsigned long flags; /* can be called from interrupt context */

        if (SHARED_KERNEL_PMD)

                return;

        paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);

        spin_lock_irqsave(&pgd_lock, flags);

        pgd_list_del(pgd);

        spin_unlock_irqrestore(&pgd_lock, flags);

}

#define UNSHARED_PTRS_PER_PGD                           \

        (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)

/* If we allocate a pmd for part of the kernel address space, then

   make sure its initialized with the appropriate kernel mappings.

   Otherwise use a cached zeroed pmd.  */

static pmd_t *pmd_cache_alloc(int idx)

{

        pmd_t *pmd;

        if (idx >= USER_PTRS_PER_PGD) {

                pmd = (pmd_t *)__get_free_page(GFP_KERNEL);

                if (pmd)

                        memcpy(pmd,

                               (void *)pgd_page_vaddr(swapper_pg_dir[idx]),

                               sizeof(pmd_t) * PTRS_PER_PMD);

        } else

                pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);

        return pmd;

}

static void pmd_cache_free(pmd_t *pmd, int idx)

{

        if (idx >= USER_PTRS_PER_PGD)

                free_page((unsigned long)pmd);

        else

                kmem_cache_free(pmd_cache, pmd);

}

pgd_t *pgd_alloc(struct mm_struct *mm)

{

        int i;

        pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);

        if (PTRS_PER_PMD == 1 || !pgd)

                return pgd;

        for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {

                pmd_t *pmd = pmd_cache_alloc(i);

                if (!pmd)

                        goto out_oom;

                paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);

                set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));

        }

        return pgd;

out_oom:

        for (i--; i >= 0; i--) {

                pgd_t pgdent = pgd[i];

                void* pmd = (void *)__va(pgd_val(pgdent)-1);

                paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);

                pmd_cache_free(pmd, i);

        }

        quicklist_free(0, pgd_dtor, pgd);

        return NULL;

}

void pgd_free(pgd_t *pgd)

{

        int i;

        /* in the PAE case user pgd entries are overwritten before usage */

        if (PTRS_PER_PMD > 1)

                for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {

                        pgd_t pgdent = pgd[i];

                        void* pmd = (void *)__va(pgd_val(pgdent)-1);

                        paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);

                        pmd_cache_free(pmd, i);

                }

        /* in the non-PAE case, free_pgtables() clears user pgd entries */

        quicklist_free(0, pgd_dtor, pgd);

}

void check_pgt_cache(void)

{

        quicklist_trim(0, pgd_dtor, 25, 16);

}