1 files changed, 260 insertions, 0 deletions

diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
new file mode 100644
index 00000000000..0742d54f8bb
--- /dev/null
+++ b/arch/i386/mm/pgtable.c
@@ -0,0 +1,260 @@
+/*
+ *  linux/arch/i386/mm/pgtable.c
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.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 <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;
+
+        printk("Mem-info:\n");
+        show_free_areas();
+        printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
+        for_each_pgdat(pgdat) {
+                for (i = 0; i < pgdat->node_spanned_pages; ++i) {
+                        page = pgdat->node_mem_map + 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;
+                }
+        }
+        printk("%d pages of RAM\n", total);
+        printk("%d pages of HIGHMEM\n",highmem);
+        printk("%d reserved pages\n",reserved);
+        printk("%d pages shared\n",shared);
+        printk("%d pages swap cached\n",cached);
+}
+
+/*
+ * 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);
+        /* <pfn,flags> stored as-is, to permit clearing entries */
+        set_pte(pte, pfn_pte(pfn, flags));
+
+        /*
+         * 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 ("set_pmd_pfn: vaddr misaligned\n");
+                return; /* BUG(); */
+        }
+        if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */
+                printk ("set_pmd_pfn: pfn misaligned\n");
+                return; /* BUG(); */
+        }
+        pgd = swapper_pg_dir + pgd_index(vaddr);
+        if (pgd_none(*pgd)) {
+                printk ("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);
+}
+
+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);
+}
+
+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(void *pmd, kmem_cache_t *cache, unsigned long flags)
+{
+        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.
+ * The locking scheme was chosen on the basis of manfred's
+ * recommendations and having no core impact whatsoever.
+ * -- 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)
+                pgd_list->private = (unsigned long)&page->index;
+        pgd_list = page;
+        page->private = (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;
+        *pprev = next;
+        if (next)
+                next->private = (unsigned long)pprev;
+}
+
+void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
+{
+        unsigned long flags;
+
+        if (PTRS_PER_PMD == 1)
+                spin_lock_irqsave(&pgd_lock, flags);
+
+        memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
+                        swapper_pg_dir + USER_PTRS_PER_PGD,
+                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+
+        if (PTRS_PER_PMD > 1)
+                return;
+
+        pgd_list_add(pgd);
+        spin_unlock_irqrestore(&pgd_lock, flags);
+        memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+}
+
+/* never called when PTRS_PER_PMD > 1 */
+void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
+{
+        unsigned long flags; /* can be called from interrupt context */
+
+        spin_lock_irqsave(&pgd_lock, flags);
+        pgd_list_del(pgd);
+        spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+        int i;
+        pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
+
+        if (PTRS_PER_PMD == 1 || !pgd)
+                return pgd;
+
+        for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
+                pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+                if (!pmd)
+                        goto out_oom;
+                set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
+        }
+        return pgd;
+
+out_oom:
+        for (i--; i >= 0; i--)
+                kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
+        kmem_cache_free(pgd_cache, 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 < USER_PTRS_PER_PGD; ++i)
+                        kmem_cache_free(pmd_cache, (void *)__va(pgd_val(pgd[i])-1));
+        /* in the non-PAE case, clear_page_range() clears user pgd entries */
+        kmem_cache_free(pgd_cache, pgd);
+}