This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / frv / mm / pgalloc.c

diff --git a/arch/frv/mm/pgalloc.c b/arch/frv/mm/pgalloc.c
new file mode 100644 (file)
index 0000000..4eaec0f
--- /dev/null
+++ b/arch/frv/mm/pgalloc.c
@@ -0,0 +1,159 @@
+/* pgalloc.c: page directory & page table allocation
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written 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 License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((aligned(PAGE_SIZE)));
+kmem_cache_t *pgd_cache;
+
+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 *page;
+
+#ifdef CONFIG_HIGHPTE
+       page = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT, 0);
+#else
+       page = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
+#endif
+       if (page)
+               clear_highpage(page);
+       flush_dcache_page(page);
+       return page;
+}
+
+void __set_pmd(pmd_t *pmdptr, unsigned long pmd)
+{
+       unsigned long *__ste_p = pmdptr->ste;
+       int loop;
+
+       if (!pmd) {
+               memset(__ste_p, 0, PME_SIZE);
+       }
+       else {
+               BUG_ON(pmd & (0x3f00 | xAMPRx_SS | 0xe));
+
+               for (loop = PME_SIZE; loop > 0; loop -= 4) {
+                       *__ste_p++ = pmd;
+                       pmd += __frv_PT_SIZE;
+               }
+       }
+
+       frv_dcache_writeback((unsigned long) pmdptr, (unsigned long) (pmdptr + 1));
+}
+
+/*
+ * 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)
+               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_PGDS_IN_LAST_PML4,
+              swapper_pg_dir + USER_PGDS_IN_LAST_PML4,
+              (PTRS_PER_PGD - USER_PGDS_IN_LAST_PML4) * sizeof(pgd_t));
+
+       if (PTRS_PER_PMD > 1)
+               return;
+
+       pgd_list_add(pgd);
+       spin_unlock_irqrestore(&pgd_lock, flags);
+       memset(pgd, 0, USER_PGDS_IN_LAST_PML4 * 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)
+{
+       pgd_t *pgd;
+
+       pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
+       if (!pgd)
+               return pgd;
+
+       return pgd;
+}
+
+void pgd_free(pgd_t *pgd)
+{
+       /* in the non-PAE case, clear_page_tables() clears user pgd entries */
+       kmem_cache_free(pgd_cache, pgd);
+}
+
+void __init pgtable_cache_init(void)
+{
+       pgd_cache = kmem_cache_create("pgd",
+                                     PTRS_PER_PGD * sizeof(pgd_t),
+                                     PTRS_PER_PGD * sizeof(pgd_t),
+                                     0,
+                                     pgd_ctor,
+                                     pgd_dtor);
+       if (!pgd_cache)
+               panic("pgtable_cache_init(): Cannot create pgd cache");
+}