1 files changed, 197 insertions, 0 deletions

diff --git a/arch/mn10300/mm/pgtable.c b/arch/mn10300/mm/pgtable.c
new file mode 100644
index 000000000000..a477038752ba
--- /dev/null
+++ b/arch/mn10300/mm/pgtable.c
@@ -0,0 +1,197 @@
+/* MN10300 Page table management
+ *
+ * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Modified by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#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 <linux/quicklist.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+void show_mem(void)
+{
+        unsigned long i;
+        int free = 0, total = 0, reserved = 0, shared = 0;
+
+        int cached = 0;
+        printk(KERN_INFO "Mem-info:\n");
+        show_free_areas();
+        i = max_mapnr;
+        while (i-- > 0) {
+                total++;
+                if (PageReserved(mem_map + i))
+                        reserved++;
+                else if (PageSwapCache(mem_map + i))
+                        cached++;
+                else if (!page_count(mem_map + i))
+                        free++;
+                else
+                        shared += page_count(mem_map + i) - 1;
+        }
+        printk(KERN_INFO "%d pages of RAM\n", total);
+        printk(KERN_INFO "%d free pages\n", free);
+        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);
+}
+
+/*
+ * 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_ERR "set_pmd_pfn: vaddr misaligned\n");
+                return; /* BUG(); */
+        }
+        if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */
+                printk(KERN_ERR "set_pmd_pfn: pfn misaligned\n");
+                return; /* BUG(); */
+        }
+        pgd = swapper_pg_dir + pgd_index(vaddr);
+        if (pgd_none(*pgd)) {
+                printk(KERN_ERR "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);
+}
+
+pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+{
+        pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
+        if (pte)
+                clear_page(pte);
+        return pte;
+}
+
+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, 0);
+#else
+        pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+#endif
+        if (pte)
+                clear_highpage(pte);
+        return pte;
+}
+
+/*
+ * 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.
+ * If the locking proves to be non-performant, a ticketing scheme with
+ * checks at dup_mmap(), exec(), and other mmlist addition points
+ * could be used. 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)
+                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);
+}
+
+void pgd_ctor(void *pgd)
+{
+        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)
+{
+        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)
+{
+        return quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+        quicklist_free(0, pgd_dtor, pgd);
+}
+
+void __init pgtable_cache_init(void)
+{
+}
+
+void check_pgt_cache(void)
+{
+        quicklist_trim(0, pgd_dtor, 25, 16);
+}