release/src-rt-6.x.4708/linux/linux-2.6.36/arch/tile/include/asm/page.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_PAGE_H
  16 #define _ASM_TILE_PAGE_H
  17
  18 #include <linux/const.h>
  19
  20 /* PAGE_SHIFT and HPAGE_SHIFT determine the page sizes. */
  21 #define PAGE_SHIFT      16
  22 #define HPAGE_SHIFT     24
  23
  24 #define PAGE_SIZE       (_AC(1, UL) << PAGE_SHIFT)
  25 #define HPAGE_SIZE      (_AC(1, UL) << HPAGE_SHIFT)
  26
  27 #define PAGE_MASK       (~(PAGE_SIZE - 1))
  28 #define HPAGE_MASK      (~(HPAGE_SIZE - 1))
  29
  30 #ifdef __KERNEL__
  31
  32 #include <hv/hypervisor.h>
  33 #include <arch/chip.h>
  34
  35 /*
  36  * The {,H}PAGE_SHIFT values must match the HV_LOG2_PAGE_SIZE_xxx
  37  * definitions in <hv/hypervisor.h>.  We validate this at build time
  38  * here, and again at runtime during early boot.  We provide a
  39  * separate definition since userspace doesn't have <hv/hypervisor.h>.
  40  *
  41  * Be careful to distinguish PAGE_SHIFT from HV_PTE_INDEX_PFN, since
  42  * they are the same on i386 but not TILE.
  43  */
  44 #if HV_LOG2_PAGE_SIZE_SMALL != PAGE_SHIFT
  45 # error Small page size mismatch in Linux
  46 #endif
  47 #if HV_LOG2_PAGE_SIZE_LARGE != HPAGE_SHIFT
  48 # error Huge page size mismatch in Linux
  49 #endif
  50
  51 #ifndef __ASSEMBLY__
  52
  53 #include <linux/types.h>
  54 #include <linux/string.h>
  55
  56 struct page;
  57
  58 static inline void clear_page(void *page)
  59 {
  60         memset(page, 0, PAGE_SIZE);
  61 }
  62
  63 static inline void copy_page(void *to, void *from)
  64 {
  65         memcpy(to, from, PAGE_SIZE);
  66 }
  67
  68 static inline void clear_user_page(void *page, unsigned long vaddr,
  69                                 struct page *pg)
  70 {
  71         clear_page(page);
  72 }
  73
  74 static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
  75                                 struct page *topage)
  76 {
  77         copy_page(to, from);
  78 }
  79
  80 /*
  81  * Hypervisor page tables are made of the same basic structure.
  82  */
  83
  84 typedef __u64 pteval_t;
  85 typedef __u64 pmdval_t;
  86 typedef __u64 pudval_t;
  87 typedef __u64 pgdval_t;
  88 typedef __u64 pgprotval_t;
  89
  90 typedef HV_PTE pte_t;
  91 typedef HV_PTE pgd_t;
  92 typedef HV_PTE pgprot_t;
  93
  94 /*
  95  * User L2 page tables are managed as one L2 page table per page,
  96  * because we use the page allocator for them.  This keeps the allocation
  97  * simple and makes it potentially useful to implement HIGHPTE at some point.
  98  * However, it's also inefficient, since L2 page tables are much smaller
  99  * than pages (currently 2KB vs 64KB).  So we should revisit this.
 100  */
 101 typedef struct page *pgtable_t;
 102
 103 /* Must be a macro since it is used to create constants. */
 104 #define __pgprot(val) hv_pte(val)
 105
 106 static inline u64 pgprot_val(pgprot_t pgprot)
 107 {
 108         return hv_pte_val(pgprot);
 109 }
 110
 111 static inline u64 pte_val(pte_t pte)
 112 {
 113         return hv_pte_val(pte);
 114 }
 115
 116 static inline u64 pgd_val(pgd_t pgd)
 117 {
 118         return hv_pte_val(pgd);
 119 }
 120
 121 #ifdef __tilegx__
 122
 123 typedef HV_PTE pmd_t;
 124
 125 static inline u64 pmd_val(pmd_t pmd)
 126 {
 127         return hv_pte_val(pmd);
 128 }
 129
 130 #endif
 131
 132 static inline __attribute_const__ int get_order(unsigned long size)
 133 {
 134         return BITS_PER_LONG - __builtin_clzl((size - 1) >> PAGE_SHIFT);
 135 }
 136
 137 #endif /* !__ASSEMBLY__ */
 138
 139 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
 140
 141 #define HUGE_MAX_HSTATE         2
 142
 143 #ifdef CONFIG_HUGETLB_PAGE
 144 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 145 #endif
 146
 147 /* Each memory controller has PAs distinct in their high bits. */
 148 #define NR_PA_HIGHBIT_SHIFT (CHIP_PA_WIDTH() - CHIP_LOG_NUM_MSHIMS())
 149 #define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
 150 #define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
 151 #define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
 152
 153 #ifdef __tilegx__
 154
 155 /*
 156  * We reserve the lower half of memory for user-space programs, and the
 157  * upper half for system code.  We re-map all of physical memory in the
 158  * upper half, which takes a quarter of our VA space.  Then we have
 159  * the vmalloc regions.  The supervisor code lives at 0xfffffff700000000,
 160  * with the hypervisor above that.
 161  *
 162  * Loadable kernel modules are placed immediately after the static
 163  * supervisor code, with each being allocated a 256MB region of
 164  * address space, so we don't have to worry about the range of "jal"
 165  * and other branch instructions.
 166  *
 167  * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
 168  * Similarly, for now we don't play any struct page mapping games.
 169  */
 170
 171 #if CHIP_PA_WIDTH() + 2 > CHIP_VA_WIDTH()
 172 # error Too much PA to map with the VA available!
 173 #endif
 174 #define HALF_VA_SPACE           (_AC(1, UL) << (CHIP_VA_WIDTH() - 1))
 175
 176 #define MEM_LOW_END             (HALF_VA_SPACE - 1)         /* low half */
 177 #define MEM_HIGH_START          (-HALF_VA_SPACE)            /* high half */
 178 #define PAGE_OFFSET             MEM_HIGH_START
 179 #define _VMALLOC_START          _AC(0xfffffff500000000, UL) /* 4 GB */
 180 #define HUGE_VMAP_BASE          _AC(0xfffffff600000000, UL) /* 4 GB */
 181 #define MEM_SV_START            _AC(0xfffffff700000000, UL) /* 256 MB */
 182 #define MEM_SV_INTRPT           MEM_SV_START
 183 #define MEM_MODULE_START        _AC(0xfffffff710000000, UL) /* 256 MB */
 184 #define MEM_MODULE_END          (MEM_MODULE_START + (256*1024*1024))
 185 #define MEM_HV_START            _AC(0xfffffff800000000, UL) /* 32 GB */
 186
 187 /* Highest DTLB address we will use */
 188 #define KERNEL_HIGH_VADDR       MEM_SV_START
 189
 190 /* Since we don't currently provide any fixmaps, we use an impossible VA. */
 191 #define FIXADDR_TOP             MEM_HV_START
 192
 193 #else /* !__tilegx__ */
 194
 195 /*
 196  * A PAGE_OFFSET of 0xC0000000 means that the kernel has
 197  * a virtual address space of one gigabyte, which limits the
 198  * amount of physical memory you can use to about 768MB.
 199  * If you want more physical memory than this then see the CONFIG_HIGHMEM
 200  * option in the kernel configuration.
 201  *
 202  * The top two 16MB chunks in the table below (VIRT and HV) are
 203  * unavailable to Linux.  Since the kernel interrupt vectors must live
 204  * at 0xfd000000, we map all of the bottom of RAM at this address with
 205  * a huge page table entry to minimize its ITLB footprint (as well as
 206  * at PAGE_OFFSET).  The last architected requirement is that user
 207  * interrupt vectors live at 0xfc000000, so we make that range of
 208  * memory available to user processes.  The remaining regions are sized
 209  * as shown; after the first four addresses, we show "typical" values,
 210  * since the actual addresses depend on kernel #defines.
 211  *
 212  * MEM_VIRT_INTRPT                 0xff000000
 213  * MEM_HV_INTRPT                   0xfe000000
 214  * MEM_SV_INTRPT (kernel code)     0xfd000000
 215  * MEM_USER_INTRPT (user vector)   0xfc000000
 216  * FIX_KMAP_xxx                    0xf8000000 (via NR_CPUS * KM_TYPE_NR)
 217  * PKMAP_BASE                      0xf7000000 (via LAST_PKMAP)
 218  * HUGE_VMAP                       0xf3000000 (via CONFIG_NR_HUGE_VMAPS)
 219  * VMALLOC_START                   0xf0000000 (via __VMALLOC_RESERVE)
 220  * mapped LOWMEM                   0xc0000000
 221  */
 222
 223 #define MEM_USER_INTRPT         _AC(0xfc000000, UL)
 224 #define MEM_SV_INTRPT           _AC(0xfd000000, UL)
 225 #define MEM_HV_INTRPT           _AC(0xfe000000, UL)
 226 #define MEM_VIRT_INTRPT         _AC(0xff000000, UL)
 227
 228 #define INTRPT_SIZE             0x4000
 229
 230 /* Tolerate page size larger than the architecture interrupt region size. */
 231 #if PAGE_SIZE > INTRPT_SIZE
 232 #undef INTRPT_SIZE
 233 #define INTRPT_SIZE PAGE_SIZE
 234 #endif
 235
 236 #define KERNEL_HIGH_VADDR       MEM_USER_INTRPT
 237 #define FIXADDR_TOP             (KERNEL_HIGH_VADDR - PAGE_SIZE)
 238
 239 #define PAGE_OFFSET             _AC(CONFIG_PAGE_OFFSET, UL)
 240
 241 /* On 32-bit architectures we mix kernel modules in with other vmaps. */
 242 #define MEM_MODULE_START        VMALLOC_START
 243 #define MEM_MODULE_END          VMALLOC_END
 244
 245 #endif /* __tilegx__ */
 246
 247 #ifndef __ASSEMBLY__
 248
 249 #ifdef CONFIG_HIGHMEM
 250
 251 /* Map kernel virtual addresses to page frames, in HPAGE_SIZE chunks. */
 252 extern unsigned long pbase_map[];
 253 extern void *vbase_map[];
 254
 255 static inline unsigned long kaddr_to_pfn(const volatile void *_kaddr)
 256 {
 257         unsigned long kaddr = (unsigned long)_kaddr;
 258         return pbase_map[kaddr >> HPAGE_SHIFT] +
 259                 ((kaddr & (HPAGE_SIZE - 1)) >> PAGE_SHIFT);
 260 }
 261
 262 static inline void *pfn_to_kaddr(unsigned long pfn)
 263 {
 264         return vbase_map[__pfn_to_highbits(pfn)] + (pfn << PAGE_SHIFT);
 265 }
 266
 267 static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
 268 {
 269         unsigned long pfn = kaddr_to_pfn(kaddr);
 270         return ((phys_addr_t)pfn << PAGE_SHIFT) +
 271                 ((unsigned long)kaddr & (PAGE_SIZE-1));
 272 }
 273
 274 static inline void *phys_to_virt(phys_addr_t paddr)
 275 {
 276         return pfn_to_kaddr(paddr >> PAGE_SHIFT) + (paddr & (PAGE_SIZE-1));
 277 }
 278
 279 /* With HIGHMEM, we pack PAGE_OFFSET through high_memory with all valid VAs. */
 280 static inline int virt_addr_valid(const volatile void *kaddr)
 281 {
 282         extern void *high_memory;  /* copied from <linux/mm.h> */
 283         return ((unsigned long)kaddr >= PAGE_OFFSET && kaddr < high_memory);
 284 }
 285
 286 #else /* !CONFIG_HIGHMEM */
 287
 288 static inline unsigned long kaddr_to_pfn(const volatile void *kaddr)
 289 {
 290         return ((unsigned long)kaddr - PAGE_OFFSET) >> PAGE_SHIFT;
 291 }
 292
 293 static inline void *pfn_to_kaddr(unsigned long pfn)
 294 {
 295         return (void *)((pfn << PAGE_SHIFT) + PAGE_OFFSET);
 296 }
 297
 298 static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
 299 {
 300         return (phys_addr_t)((unsigned long)kaddr - PAGE_OFFSET);
 301 }
 302
 303 static inline void *phys_to_virt(phys_addr_t paddr)
 304 {
 305         return (void *)((unsigned long)paddr + PAGE_OFFSET);
 306 }
 307
 308 /* Check that the given address is within some mapped range of PAs. */
 309 #define virt_addr_valid(kaddr) pfn_valid(kaddr_to_pfn(kaddr))
 310
 311 #endif /* !CONFIG_HIGHMEM */
 312
 313 /* All callers are not consistent in how they call these functions. */
 314 #define __pa(kaddr) virt_to_phys((void *)(unsigned long)(kaddr))
 315 #define __va(paddr) phys_to_virt((phys_addr_t)(paddr))
 316
 317 extern int devmem_is_allowed(unsigned long pagenr);
 318
 319 #ifdef CONFIG_FLATMEM
 320 static inline int pfn_valid(unsigned long pfn)
 321 {
 322         return pfn < max_mapnr;
 323 }
 324 #endif
 325
 326 /* Provide as macros since these require some other headers included. */
 327 #define page_to_pa(page) ((phys_addr_t)(page_to_pfn(page)) << PAGE_SHIFT)
 328 #define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn(kaddr))
 329 #define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
 330
 331 struct mm_struct;
 332 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 333
 334 #endif /* !__ASSEMBLY__ */
 335
 336 #define VM_DATA_DEFAULT_FLAGS \
 337         (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 338
 339 #include <asm-generic/memory_model.h>
 340
 341 #endif /* __KERNEL__ */
 342
 343 #endif /* _ASM_TILE_PAGE_H */