Initial import

1 files changed, 174 insertions, 0 deletions

diff --git a/arch/mn10300/mm/pgtable.c b/arch/mn10300/mm/pgtable.c
new file mode 100644
index 000000000..e77a7c728
--- /dev/null
+++ b/arch/mn10300/mm/pgtable.c
@@ -0,0 +1,174 @@
+/* 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/gfp.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/quicklist.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+/*
+ * 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)
+	 */
+	local_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)
+		return NULL;
+	clear_highpage(pte);
+	if (!pgtable_page_ctor(pte)) {
+		__free_page(pte);
+		return NULL;
+	}
+	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.
+ * -- nyc
+ */
+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);
+}