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      1 /*
      2  * This file is subject to the terms and conditions of the GNU General Public
      3  * License.  See the file "COPYING" in the main directory of this archive
      4  * for more details.
      5  *
      6  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
      7  * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
      8  */
      9 #ifndef _ASM_PGTABLE_32_H
     10 #define _ASM_PGTABLE_32_H
     11 
     12 #include <asm/addrspace.h>
     13 #include <asm/page.h>
     14 
     15 #include <linux/linkage.h>
     16 #include <asm/cachectl.h>
     17 #include <asm/fixmap.h>
     18 
     19 #include <asm-generic/pgtable-nopmd.h>
     20 
     21 /*
     22  * Basically we have the same two-level (which is the logical three level
     23  * Linux page table layout folded) page tables as the i386.  Some day
     24  * when we have proper page coloring support we can have a 1% quicker
     25  * tlb refill handling mechanism, but for now it is a bit slower but
     26  * works even with the cache aliasing problem the R4k and above have.
     27  */
     28 
     29 /* PGDIR_SHIFT determines what a third-level page table entry can map */
     30 #define PGDIR_SHIFT	(2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
     31 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
     32 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
     33 
     34 /*
     35  * Entries per page directory level: we use two-level, so
     36  * we don't really have any PUD/PMD directory physically.
     37  */
     38 #define __PGD_ORDER	(32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
     39 #define PGD_ORDER	(__PGD_ORDER >= 0 ? __PGD_ORDER : 0)
     40 #define PUD_ORDER	aieeee_attempt_to_allocate_pud
     41 #define PMD_ORDER	1
     42 #define PTE_ORDER	0
     43 
     44 #define PTRS_PER_PGD	(USER_PTRS_PER_PGD * 2)
     45 #define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
     46 
     47 #define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)
     48 #define FIRST_USER_ADDRESS	0
     49 
     50 #define VMALLOC_START     MAP_BASE
     51 
     52 #define PKMAP_BASE		(0xfe000000UL)
     53 
     54 #ifdef CONFIG_HIGHMEM
     55 # define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
     56 #else
     57 # define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
     58 #endif
     59 
     60 #ifdef CONFIG_64BIT_PHYS_ADDR
     61 #define pte_ERROR(e) \
     62 	printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
     63 #else
     64 #define pte_ERROR(e) \
     65 	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
     66 #endif
     67 #define pgd_ERROR(e) \
     68 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
     69 
     70 extern void load_pgd(unsigned long pg_dir);
     71 
     72 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
     73 
     74 /*
     75  * Empty pgd/pmd entries point to the invalid_pte_table.
     76  */
     77 static inline int pmd_none(pmd_t pmd)
     78 {
     79 	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
     80 }
     81 
     82 #define pmd_bad(pmd)		(pmd_val(pmd) & ~PAGE_MASK)
     83 
     84 static inline int pmd_present(pmd_t pmd)
     85 {
     86 	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
     87 }
     88 
     89 static inline void pmd_clear(pmd_t *pmdp)
     90 {
     91 	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
     92 }
     93 
     94 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
     95 #define pte_page(x)		pfn_to_page(pte_pfn(x))
     96 #define pte_pfn(x)		((unsigned long)((x).pte_high >> 6))
     97 static inline pte_t
     98 pfn_pte(unsigned long pfn, pgprot_t prot)
     99 {
    100 	pte_t pte;
    101 	pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f);
    102 	pte.pte_low = pgprot_val(prot);
    103 	return pte;
    104 }
    105 
    106 #else
    107 
    108 #define pte_page(x)		pfn_to_page(pte_pfn(x))
    109 
    110 #ifdef CONFIG_CPU_VR41XX
    111 #define pte_pfn(x)		((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
    112 #define pfn_pte(pfn, prot)	__pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
    113 #else
    114 #define pte_pfn(x)		((unsigned long)((x).pte >> _PFN_SHIFT))
    115 #define pfn_pte(pfn, prot)	__pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
    116 #endif
    117 #endif /* defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32) */
    118 
    119 #define __pgd_offset(address)	pgd_index(address)
    120 #define __pud_offset(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
    121 #define __pmd_offset(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
    122 
    123 /* to find an entry in a kernel page-table-directory */
    124 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
    125 
    126 #define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
    127 
    128 /* to find an entry in a page-table-directory */
    129 #define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
    130 
    131 /* Find an entry in the third-level page table.. */
    132 #define __pte_offset(address)						\
    133 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
    134 #define pte_offset(dir, address)					\
    135 	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
    136 #define pte_offset_kernel(dir, address)					\
    137 	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
    138 
    139 #define pte_offset_map(dir, address)                                    \
    140 	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
    141 #define pte_unmap(pte) ((void)(pte))
    142 
    143 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
    144 
    145 /* Swap entries must have VALID bit cleared. */
    146 #define __swp_type(x)		(((x).val >> 10) & 0x1f)
    147 #define __swp_offset(x)		((x).val >> 15)
    148 #define __swp_entry(type,offset)	\
    149 	((swp_entry_t) { ((type) << 10) | ((offset) << 15) })
    150 
    151 /*
    152  * Bits 0, 4, 8, and 9 are taken, split up 28 bits of offset into this range:
    153  */
    154 #define PTE_FILE_MAX_BITS	28
    155 
    156 #define pte_to_pgoff(_pte)	((((_pte).pte >> 1 ) & 0x07) | \
    157 				 (((_pte).pte >> 2 ) & 0x38) | \
    158 				 (((_pte).pte >> 10) <<  6 ))
    159 
    160 #define pgoff_to_pte(off)	((pte_t) { (((off) & 0x07) << 1 ) | \
    161 					   (((off) & 0x38) << 2 ) | \
    162 					   (((off) >>  6 ) << 10) | \
    163 					   _PAGE_FILE })
    164 
    165 #else
    166 
    167 /* Swap entries must have VALID and GLOBAL bits cleared. */
    168 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
    169 #define __swp_type(x)		(((x).val >> 2) & 0x1f)
    170 #define __swp_offset(x) 	 ((x).val >> 7)
    171 #define __swp_entry(type,offset)	\
    172 		((swp_entry_t)  { ((type) << 2) | ((offset) << 7) })
    173 #else
    174 #define __swp_type(x)		(((x).val >> 8) & 0x1f)
    175 #define __swp_offset(x) 	 ((x).val >> 13)
    176 #define __swp_entry(type,offset)	\
    177 		((swp_entry_t)  { ((type) << 8) | ((offset) << 13) })
    178 #endif /* defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32) */
    179 
    180 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
    181 /*
    182  * Bits 0 and 1 of pte_high are taken, use the rest for the page offset...
    183  */
    184 #define PTE_FILE_MAX_BITS	30
    185 
    186 #define pte_to_pgoff(_pte)	((_pte).pte_high >> 2)
    187 #define pgoff_to_pte(off) 	((pte_t) { _PAGE_FILE, (off) << 2 })
    188 
    189 #else
    190 /*
    191  * Bits 0, 4, 6, and 7 are taken, split up 28 bits of offset into this range:
    192  */
    193 #define PTE_FILE_MAX_BITS	28
    194 
    195 #define pte_to_pgoff(_pte)	((((_pte).pte >> 1) & 0x7) | \
    196 				 (((_pte).pte >> 2) & 0x8) | \
    197 				 (((_pte).pte >> 8) <<  4))
    198 
    199 #define pgoff_to_pte(off)	((pte_t) { (((off) & 0x7) << 1) | \
    200 					   (((off) & 0x8) << 2) | \
    201 					   (((off) >>  4) << 8) | \
    202 					   _PAGE_FILE })
    203 #endif
    204 
    205 #endif
    206 
    207 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
    208 #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
    209 #define __swp_entry_to_pte(x)	((pte_t) { 0, (x).val })
    210 #else
    211 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
    212 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
    213 #endif
    214 
    215 #endif /* _ASM_PGTABLE_32_H */
    216