1 files changed, 241 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h
new file mode 100644
index 000000000..b40a0e69f
--- /dev/null
+++ b/arch/mips/include/asm/pgtable-32.h
@@ -0,0 +1,241 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_PGTABLE_32_H
+#define _ASM_PGTABLE_32_H
+
+#include <asm/addrspace.h>
+#include <asm/page.h>
+
+#include <linux/linkage.h>
+#include <asm/cachectl.h>
+#include <asm/fixmap.h>
+
+#include <asm-generic/pgtable-nopmd.h>
+
+#ifdef CONFIG_HIGHMEM
+#include <asm/highmem.h>
+#endif
+
+/*
+ * Regarding 32-bit MIPS huge page support (and the tradeoff it entails):
+ *
+ *  We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size,
+ * our 2-level table layout would normally have a PGD entry cover a contiguous
+ * 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t
+ * pointers, each pointing to a 4KB physical page). The problem is that 4MB,
+ * spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page
+ * support, not one of the standard supported sizes (1MB,4MB,16MB,...).
+ *  To correct for this, when huge pages are enabled, we halve the number of
+ * pointers a PTE page holds, making its last half go to waste. Correspondingly,
+ * we double the number of PGD pages. Overall, page table memory overhead
+ * increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly.
+ *
+ * NOTE: We don't yet support huge pages if extended-addressing is enabled
+ *       (i.e. EVA, XPA, 36-bit Alchemy/Netlogic).
+ */
+
+extern int temp_tlb_entry;
+
+/*
+ * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
+ *	starting at the top and working down. This is for populating the
+ *	TLB before trap_init() puts the TLB miss handler in place. It
+ *	should be used only for entries matching the actual page tables,
+ *	to prevent inconsistencies.
+ */
+extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
+			       unsigned long entryhi, unsigned long pagemask);
+
+/*
+ * Basically we have the same two-level (which is the logical three level
+ * Linux page table layout folded) page tables as the i386.  Some day
+ * when we have proper page coloring support we can have a 1% quicker
+ * tlb refill handling mechanism, but for now it is a bit slower but
+ * works even with the cache aliasing problem the R4k and above have.
+ */
+
+/* PGDIR_SHIFT determines what a third-level page table entry can map */
+#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
+# define PGDIR_SHIFT	(2 * PAGE_SHIFT - PTE_T_LOG2 - 1)
+#else
+# define PGDIR_SHIFT	(2 * PAGE_SHIFT - PTE_T_LOG2)
+#endif
+
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+/*
+ * Entries per page directory level: we use two-level, so
+ * we don't really have any PUD/PMD directory physically.
+ */
+#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
+# define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1)
+#else
+# define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
+#endif
+
+#define PGD_TABLE_ORDER	(__PGD_TABLE_ORDER >= 0 ? __PGD_TABLE_ORDER : 0)
+#define PUD_TABLE_ORDER	aieeee_attempt_to_allocate_pud
+#define PMD_TABLE_ORDER	aieeee_attempt_to_allocate_pmd
+
+#define PTRS_PER_PGD	(USER_PTRS_PER_PGD * 2)
+#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
+# define PTRS_PER_PTE	(PAGE_SIZE / sizeof(pte_t) / 2)
+#else
+# define PTRS_PER_PTE	(PAGE_SIZE / sizeof(pte_t))
+#endif
+
+#define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)
+
+#define VMALLOC_START	  MAP_BASE
+
+#define PKMAP_END	((FIXADDR_START) & ~((LAST_PKMAP << PAGE_SHIFT)-1))
+#define PKMAP_BASE	(PKMAP_END - PAGE_SIZE * LAST_PKMAP)
+
+#ifdef CONFIG_HIGHMEM
+# define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
+#else
+# define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
+#endif
+
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
+#define pte_ERROR(e) \
+	printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
+#else
+#define pte_ERROR(e) \
+	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+#endif
+#define pgd_ERROR(e) \
+	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+extern void load_pgd(unsigned long pg_dir);
+
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
+
+/*
+ * Empty pgd/pmd entries point to the invalid_pte_table.
+ */
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
+}
+
+static inline int pmd_bad(pmd_t pmd)
+{
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
+	/* pmd_huge(pmd) but inline */
+	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
+		return 0;
+#endif
+
+	if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
+		return 1;
+
+	return 0;
+}
+
+static inline int pmd_present(pmd_t pmd)
+{
+	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
+}
+
+static inline void pmd_clear(pmd_t *pmdp)
+{
+	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
+}
+
+#if defined(CONFIG_XPA)
+
+#define MAX_POSSIBLE_PHYSMEM_BITS 40
+#define pte_pfn(x)		(((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
+static inline pte_t
+pfn_pte(unsigned long pfn, pgprot_t prot)
+{
+	pte_t pte;
+
+	pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) |
+				(pgprot_val(prot) & ~_PFNX_MASK);
+	pte.pte_high = (pfn << _PFN_SHIFT) |
+				(pgprot_val(prot) & ~_PFN_MASK);
+	return pte;
+}
+
+#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+
+#define MAX_POSSIBLE_PHYSMEM_BITS 36
+#define pte_pfn(x)		((unsigned long)((x).pte_high >> 6))
+
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
+{
+	pte_t pte;
+
+	pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f);
+	pte.pte_low = pgprot_val(prot);
+
+	return pte;
+}
+
+#else
+
+#define MAX_POSSIBLE_PHYSMEM_BITS 32
+#define pte_pfn(x)		((unsigned long)((x).pte >> _PFN_SHIFT))
+#define pfn_pte(pfn, prot)	__pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#define pfn_pmd(pfn, prot)	__pmd(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
+
+#define pte_page(x)		pfn_to_page(pte_pfn(x))
+
+#if defined(CONFIG_CPU_R3K_TLB)
+
+/* Swap entries must have VALID bit cleared. */
+#define __swp_type(x)			(((x).val >> 10) & 0x1f)
+#define __swp_offset(x)			((x).val >> 15)
+#define __swp_entry(type,offset)	((swp_entry_t) { ((type) << 10) | ((offset) << 15) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
+
+#else
+
+#if defined(CONFIG_XPA)
+
+/* Swap entries must have VALID and GLOBAL bits cleared. */
+#define __swp_type(x)			(((x).val >> 4) & 0x1f)
+#define __swp_offset(x)			 ((x).val >> 9)
+#define __swp_entry(type,offset)	((swp_entry_t)  { ((type) << 4) | ((offset) << 9) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_high })
+#define __swp_entry_to_pte(x)		((pte_t) { 0, (x).val })
+
+#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+
+/* Swap entries must have VALID and GLOBAL bits cleared. */
+#define __swp_type(x)			(((x).val >> 2) & 0x1f)
+#define __swp_offset(x)			 ((x).val >> 7)
+#define __swp_entry(type, offset)	((swp_entry_t)  { ((type) << 2) | ((offset) << 7) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_high })
+#define __swp_entry_to_pte(x)		((pte_t) { 0, (x).val })
+
+#else
+/*
+ * Constraints:
+ *      _PAGE_PRESENT at bit 0
+ *      _PAGE_MODIFIED at bit 4
+ *      _PAGE_GLOBAL at bit 6
+ *      _PAGE_VALID at bit 7
+ */
+#define __swp_type(x)			(((x).val >> 8) & 0x1f)
+#define __swp_offset(x)			 ((x).val >> 13)
+#define __swp_entry(type,offset)	((swp_entry_t)	{ ((type) << 8) | ((offset) << 13) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
+
+#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
+
+#endif /* defined(CONFIG_CPU_R3K_TLB) */
+
+#endif /* _ASM_PGTABLE_32_H */