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 #ifdef CONFIG_HIGHMEM 22 #include <asm/highmem.h> 23 #endif 24 25 /* 26 * Regarding 32-bit MIPS huge page support (and the tradeoff it entails): 27 * 28 * We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size, 29 * our 2-level table layout would normally have a PGD entry cover a contiguous 30 * 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t 31 * pointers, each pointing to a 4KB physical page). The problem is that 4MB, 32 * spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page 33 * support, not one of the standard supported sizes (1MB,4MB,16MB,...). 34 * To correct for this, when huge pages are enabled, we halve the number of 35 * pointers a PTE page holds, making its last half go to waste. Correspondingly, 36 * we double the number of PGD pages. Overall, page table memory overhead 37 * increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly. 38 * 39 * NOTE: We don't yet support huge pages if extended-addressing is enabled 40 * (i.e. EVA, XPA, 36-bit Alchemy/Netlogic). 41 */ 42 43 extern int temp_tlb_entry; 44 45 /* 46 * - add_temporary_entry() add a temporary TLB entry. We use TLB entries 47 * starting at the top and working down. This is for populating the 48 * TLB before trap_init() puts the TLB miss handler in place. It 49 * should be used only for entries matching the actual page tables, 50 * to prevent inconsistencies. 51 */ 52 extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1, 53 unsigned long entryhi, unsigned long pagemask); 54 55 /* 56 * Basically we have the same two-level (which is the logical three level 57 * Linux page table layout folded) page tables as the i386. Some day 58 * when we have proper page coloring support we can have a 1% quicker 59 * tlb refill handling mechanism, but for now it is a bit slower but 60 * works even with the cache aliasing problem the R4k and above have. 61 */ 62 63 /* PGDIR_SHIFT determines what a third-level page table entry can map */ 64 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT) 65 # define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2 - 1) 66 #else 67 # define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2) 68 #endif 69 70 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 71 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 72 73 /* 74 * Entries per page directory level: we use two-level, so 75 * we don't really have any PUD/PMD directory physically. 76 */ 77 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT) 78 # define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1) 79 #else 80 # define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2) 81 #endif 82 83 #define PGD_ORDER (__PGD_ORDER >= 0 ? __PGD_ORDER : 0) 84 #define PUD_ORDER aieeee_attempt_to_allocate_pud 85 #define PMD_ORDER aieeee_attempt_to_allocate_pmd 86 #define PTE_ORDER 0 87 88 #define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2) 89 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT) 90 # define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t) / 2) 91 #else 92 # define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) 93 #endif 94 95 #define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE) 96 97 #define VMALLOC_START MAP_BASE 98 99 #define PKMAP_END ((FIXADDR_START) & ~((LAST_PKMAP << PAGE_SHIFT)-1)) 100 #define PKMAP_BASE (PKMAP_END - PAGE_SIZE * LAST_PKMAP) 101 102 #ifdef CONFIG_HIGHMEM 103 # define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE) 104 #else 105 # define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE) 106 #endif 107 108 #ifdef CONFIG_PHYS_ADDR_T_64BIT 109 #define pte_ERROR(e) \ 110 printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e)) 111 #else 112 #define pte_ERROR(e) \ 113 printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e)) 114 #endif 115 #define pgd_ERROR(e) \ 116 printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) 117 118 extern void load_pgd(unsigned long pg_dir); 119 120 extern pte_t invalid_pte_table[PTRS_PER_PTE]; 121 122 /* 123 * Empty pgd/pmd entries point to the invalid_pte_table. 124 */ 125 static inline int pmd_none(pmd_t pmd) 126 { 127 return pmd_val(pmd) == (unsigned long) invalid_pte_table; 128 } 129 130 static inline int pmd_bad(pmd_t pmd) 131 { 132 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 133 /* pmd_huge(pmd) but inline */ 134 if (unlikely(pmd_val(pmd) & _PAGE_HUGE)) 135 return 0; 136 #endif 137 138 if (unlikely(pmd_val(pmd) & ~PAGE_MASK)) 139 return 1; 140 141 return 0; 142 } 143 144 static inline int pmd_present(pmd_t pmd) 145 { 146 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 147 } 148 149 static inline void pmd_clear(pmd_t *pmdp) 150 { 151 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 152 } 153 154 #if defined(CONFIG_XPA) 155 156 #define MAX_POSSIBLE_PHYSMEM_BITS 40 157 #define pte_pfn(x) (((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT)) 158 static inline pte_t 159 pfn_pte(unsigned long pfn, pgprot_t prot) 160 { 161 pte_t pte; 162 163 pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) | 164 (pgprot_val(prot) & ~_PFNX_MASK); 165 pte.pte_high = (pfn << _PFN_SHIFT) | 166 (pgprot_val(prot) & ~_PFN_MASK); 167 return pte; 168 } 169 170 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) 171 172 #define MAX_POSSIBLE_PHYSMEM_BITS 36 173 #define pte_pfn(x) ((unsigned long)((x).pte_high >> 6)) 174 175 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) 176 { 177 pte_t pte; 178 179 pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f); 180 pte.pte_low = pgprot_val(prot); 181 182 return pte; 183 } 184 185 #else 186 187 #define MAX_POSSIBLE_PHYSMEM_BITS 32 188 #ifdef CONFIG_CPU_VR41XX 189 #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) 190 #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) 191 #else 192 #define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT)) 193 #define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot)) 194 #define pfn_pmd(pfn, prot) __pmd(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot)) 195 #endif 196 #endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */ 197 198 #define pte_page(x) pfn_to_page(pte_pfn(x)) 199 200 #if defined(CONFIG_CPU_R3K_TLB) 201 202 /* Swap entries must have VALID bit cleared. */ 203 #define __swp_type(x) (((x).val >> 10) & 0x1f) 204 #define __swp_offset(x) ((x).val >> 15) 205 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 10) | ((offset) << 15) }) 206 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 207 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 208 209 #else 210 211 #if defined(CONFIG_XPA) 212 213 /* Swap entries must have VALID and GLOBAL bits cleared. */ 214 #define __swp_type(x) (((x).val >> 4) & 0x1f) 215 #define __swp_offset(x) ((x).val >> 9) 216 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 4) | ((offset) << 9) }) 217 #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high }) 218 #define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val }) 219 220 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) 221 222 /* Swap entries must have VALID and GLOBAL bits cleared. */ 223 #define __swp_type(x) (((x).val >> 2) & 0x1f) 224 #define __swp_offset(x) ((x).val >> 7) 225 #define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 2) | ((offset) << 7) }) 226 #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high }) 227 #define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val }) 228 229 #else 230 /* 231 * Constraints: 232 * _PAGE_PRESENT at bit 0 233 * _PAGE_MODIFIED at bit 4 234 * _PAGE_GLOBAL at bit 6 235 * _PAGE_VALID at bit 7 236 */ 237 #define __swp_type(x) (((x).val >> 8) & 0x1f) 238 #define __swp_offset(x) ((x).val >> 13) 239 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 8) | ((offset) << 13) }) 240 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 241 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 242 243 #endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */ 244 245 #endif /* defined(CONFIG_CPU_R3K_TLB) */ 246 247 #endif /* _ASM_PGTABLE_32_H */ 248