patch-2.3.29 linux/include/asm-i386/pgalloc-3level.h

• Lines: 69
• Date: Sat Nov 20 10:09:05 1999
• Orig file: v2.3.28/linux/include/asm-i386/pgalloc-3level.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.28/linux/include/asm-i386/pgalloc-3level.h linux/include/asm-i386/pgalloc-3level.h
@@ -0,0 +1,68 @@
+#ifndef _I386_PGALLOC_3LEVEL_H
+#define _I386_PGALLOC_3LEVEL_H
+
+/*
+ * Intel Physical Address Extension (PAE) Mode - three-level page
+ * tables on PPro+ CPUs. Page-table allocation routines.
+ *
+ * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
+ */
+
+extern __inline__ pmd_t *get_pmd_slow(void)
+{
+	pmd_t *ret = (pmd_t *)__get_free_page(GFP_KERNEL);
+
+	if (ret)
+		memset(ret, 0, PAGE_SIZE);
+	return ret;
+}
+
+extern __inline__ pmd_t *get_pmd_fast(void)
+{
+	unsigned long *ret;
+
+	if ((ret = pmd_quicklist) != NULL) {
+		pmd_quicklist = (unsigned long *)(*ret);
+		ret[0] = 0;
+		pgtable_cache_size--;
+	} else
+		ret = (unsigned long *)get_pmd_slow();
+	return (pmd_t *)ret;
+}
+
+extern __inline__ void free_pmd_fast(pmd_t *pmd)
+{
+	*(unsigned long *)pmd = (unsigned long) pmd_quicklist;
+	pmd_quicklist = (unsigned long *) pmd;
+	pgtable_cache_size++;
+}
+
+extern __inline__ void free_pmd_slow(pmd_t *pmd)
+{
+	free_page((unsigned long)pmd);
+}
+
+extern inline pmd_t * pmd_alloc(pgd_t *pgd, unsigned long address)
+{
+	if (!pgd)
+		BUG();
+	address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
+	if (pgd_none(*pgd)) {
+		pmd_t *page = get_pmd_fast();
+
+		if (!page)
+			page = get_pmd_slow();
+		if (page) {
+			if (pgd_none(*pgd)) {
+				pgd_val(*pgd) = 1 + __pa(page);
+				__flush_tlb();
+				return page + address;
+			} else
+				free_pmd_fast(page);
+		} else
+			return NULL;
+	}
+	return (pmd_t *)pgd_page(*pgd) + address;
+}
+
+#endif /* _I386_PGALLOC_3LEVEL_H */