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authorRalf Baechle <ralf@linux-mips.org>2000-01-27 01:05:20 +0000
committerRalf Baechle <ralf@linux-mips.org>2000-01-27 01:05:20 +0000
commit546db14ee74118296f425f3b91634fb767d67290 (patch)
tree22b613a3da8d4bf663eec5e155af01b87fdf9094 /include/asm-i386/pgtable-3level.h
parent1e25e41c4f5474e14452094492dbc169b800e4c8 (diff)
Merge with Linux 2.3.23. The new bootmem stuff has broken various
platforms. At this time I've only verified that IP22 support compiles and IP27 actually works.
Diffstat (limited to 'include/asm-i386/pgtable-3level.h')
-rw-r--r--include/asm-i386/pgtable-3level.h131
1 files changed, 131 insertions, 0 deletions
diff --git a/include/asm-i386/pgtable-3level.h b/include/asm-i386/pgtable-3level.h
new file mode 100644
index 000000000..99d718115
--- /dev/null
+++ b/include/asm-i386/pgtable-3level.h
@@ -0,0 +1,131 @@
+#ifndef _I386_PGTABLE_3LEVEL_H
+#define _I386_PGTABLE_3LEVEL_H
+
+/*
+ * Intel Physical Address Extension (PAE) Mode - three-level page
+ * tables on PPro+ CPUs.
+ *
+ * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
+ */
+
+/*
+ * PGDIR_SHIFT determines what a top-level page table entry can map
+ */
+#define PGDIR_SHIFT 30
+#define PTRS_PER_PGD 4
+
+/*
+ * PMD_SHIFT determines the size of the area a middle-level
+ * page table can map
+ */
+#define PMD_SHIFT 21
+#define PTRS_PER_PMD 512
+
+/*
+ * entries per page directory level
+ */
+#define PTRS_PER_PTE 512
+
+#define pte_ERROR(e) \
+ printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
+#define pmd_ERROR(e) \
+ printk("%s:%d: bad pmd %016Lx.\n", __FILE__, __LINE__, pmd_val(e))
+#define pgd_ERROR(e) \
+ printk("%s:%d: bad pgd %016Lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+/*
+ * Subtle, in PAE mode we cannot have zeroes in the top level
+ * page directory, the CPU enforces this.
+ */
+#define pgd_none(x) (pgd_val(x) == 1ULL)
+extern inline int pgd_bad(pgd_t pgd) { return 0; }
+extern inline int pgd_present(pgd_t pgd) { return !pgd_none(pgd); }
+/*
+ * Pentium-II errata A13: in PAE mode we explicitly have to flush
+ * the TLB via cr3 if the top-level pgd is changed... This was one tough
+ * thing to find out - guess i should first read all the documentation
+ * next time around ;)
+ */
+extern inline void __pgd_clear (pgd_t * pgd)
+{
+ pgd_val(*pgd) = 1; // no zero allowed!
+}
+
+extern inline void pgd_clear (pgd_t * pgd)
+{
+ __pgd_clear(pgd);
+ __flush_tlb();
+}
+
+#define pgd_page(pgd) \
+((unsigned long) __va(pgd_val(pgd) & PAGE_MASK))
+
+/* Find an entry in the second-level page table.. */
+#define pmd_offset(dir, address) ((pmd_t *) pgd_page(*(dir)) + \
+ __pmd_offset(address))
+
+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;
+}
+
+/*
+ * Subtle. offset can overflow 32 bits and that's a feature - we can do
+ * up to 16 TB swap on PAE. (Not that anyone should need that much
+ * swapspace, but who knows?)
+ */
+#define SWP_ENTRY(type,offset) __pte((((type) << 1) | ((offset) << 8ULL)))
+
+#endif /* _I386_PGTABLE_3LEVEL_H */