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 #include <hv/hypervisor.h>
  20 #include <arch/chip.h>
  21
  22 /* PAGE_SHIFT and HPAGE_SHIFT determine the page sizes. */
  23 #define PAGE_SHIFT      HV_LOG2_PAGE_SIZE_SMALL
  24 #define HPAGE_SHIFT     HV_LOG2_PAGE_SIZE_LARGE
  25
  26 #define PAGE_SIZE       (_AC(1, UL) << PAGE_SHIFT)
  27 #define HPAGE_SIZE      (_AC(1, UL) << HPAGE_SHIFT)
  28
  29 #define PAGE_MASK       (~(PAGE_SIZE - 1))
  30 #define HPAGE_MASK      (~(HPAGE_SIZE - 1))
  31
  32 /*
  33  * If the Kconfig doesn't specify, set a maximum zone order that
  34  * is enough so that we can create huge pages from small pages given
  35  * the respective sizes of the two page types.  See <linux/mmzone.h>.
  36  */
  37 #ifndef CONFIG_FORCE_MAX_ZONEORDER
  38 #define CONFIG_FORCE_MAX_ZONEORDER (HPAGE_SHIFT - PAGE_SHIFT + 1)
  39 #endif
  40
  41 #ifndef __ASSEMBLY__
  42
  43 #include <linux/types.h>
  44 #include <linux/string.h>
  45
  46 struct page;
  47
  48 static inline void clear_page(void *page)
  49 {
  50         memset(page, 0, PAGE_SIZE);
  51 }
  52
  53 static inline void copy_page(void *to, void *from)
  54 {
  55         memcpy(to, from, PAGE_SIZE);
  56 }
  57
  58 static inline void clear_user_page(void *page, unsigned long vaddr,
  59                                 struct page *pg)
  60 {
  61         clear_page(page);
  62 }
  63
  64 static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
  65                                 struct page *topage)
  66 {
  67         copy_page(to, from);
  68 }
  69
  70 /*
  71  * Hypervisor page tables are made of the same basic structure.
  72  */
  73
  74 typedef HV_PTE pte_t;
  75 typedef HV_PTE pgd_t;
  76 typedef HV_PTE pgprot_t;
  77
  78 /*
  79  * User L2 page tables are managed as one L2 page table per page,
  80  * because we use the page allocator for them.  This keeps the allocation
  81  * simple and makes it potentially useful to implement HIGHPTE at some point.
  82  * However, it's also inefficient, since L2 page tables are much smaller
  83  * than pages (currently 2KB vs 64KB).  So we should revisit this.
  84  */
  85 typedef struct page *pgtable_t;
  86
  87 /* Must be a macro since it is used to create constants. */
  88 #define __pgprot(val) hv_pte(val)
  89
  90 /* Rarely-used initializers, typically with a "zero" value. */
  91 #define __pte(x) hv_pte(x)
  92 #define __pgd(x) hv_pte(x)
  93
  94 static inline u64 pgprot_val(pgprot_t pgprot)
  95 {
  96         return hv_pte_val(pgprot);
  97 }
  98
  99 static inline u64 pte_val(pte_t pte)
 100 {
 101         return hv_pte_val(pte);
 102 }
 103
 104 static inline u64 pgd_val(pgd_t pgd)
 105 {
 106         return hv_pte_val(pgd);
 107 }
 108
 109 #ifdef __tilegx__
 110
 111 typedef HV_PTE pmd_t;
 112
 113 #define __pmd(x) hv_pte(x)
 114
 115 static inline u64 pmd_val(pmd_t pmd)
 116 {
 117         return hv_pte_val(pmd);
 118 }
 119
 120 #endif
 121
 122 static inline __attribute_const__ int get_order(unsigned long size)
 123 {
 124         return BITS_PER_LONG - __builtin_clzl((size - 1) >> PAGE_SHIFT);
 125 }
 126
 127 #endif /* !__ASSEMBLY__ */
 128
 129 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
 130
 131 #define HUGE_MAX_HSTATE         2
 132
 133 #ifdef CONFIG_HUGETLB_PAGE
 134 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 135 #endif
 136
 137 /* Each memory controller has PAs distinct in their high bits. */
 138 #define NR_PA_HIGHBIT_SHIFT (CHIP_PA_WIDTH() - CHIP_LOG_NUM_MSHIMS())
 139 #define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
 140 #define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
 141 #define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
 142
 143 #ifdef __tilegx__
 144
 145 /*
 146  * We reserve the lower half of memory for user-space programs, and the
 147  * upper half for system code.  We re-map all of physical memory in the
 148  * upper half, which takes a quarter of our VA space.  Then we have
 149  * the vmalloc regions.  The supervisor code lives at 0xfffffff700000000,
 150  * with the hypervisor above that.
 151  *
 152  * Loadable kernel modules are placed immediately after the static
 153  * supervisor code, with each being allocated a 256MB region of
 154  * address space, so we don't have to worry about the range of "jal"
 155  * and other branch instructions.
 156  *
 157  * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
 158  * Similarly, for now we don't play any struct page mapping games.
 159  */
 160
 161 #if CHIP_PA_WIDTH() + 2 > CHIP_VA_WIDTH()
 162 # error Too much PA to map with the VA available!
 163 #endif
 164 #define HALF_VA_SPACE           (_AC(1, UL) << (CHIP_VA_WIDTH() - 1))
 165
 166 #define MEM_LOW_END             (HALF_VA_SPACE - 1)         /* low half */
 167 #define MEM_HIGH_START          (-HALF_VA_SPACE)            /* high half */
 168 #define PAGE_OFFSET             MEM_HIGH_START
 169 #define _VMALLOC_START          _AC(0xfffffff500000000, UL) /* 4 GB */
 170 #define HUGE_VMAP_BASE          _AC(0xfffffff600000000, UL) /* 4 GB */
 171 #define MEM_SV_START            _AC(0xfffffff700000000, UL) /* 256 MB */
 172 #define MEM_SV_INTRPT           MEM_SV_START
 173 #define MEM_MODULE_START        _AC(0xfffffff710000000, UL) /* 256 MB */
 174 #define MEM_MODULE_END          (MEM_MODULE_START + (256*1024*1024))
 175 #define MEM_HV_START            _AC(0xfffffff800000000, UL) /* 32 GB */
 176
 177 /* Highest DTLB address we will use */
 178 #define KERNEL_HIGH_VADDR       MEM_SV_START
 179
 180 /* Since we don't currently provide any fixmaps, we use an impossible VA. */
 181 #define FIXADDR_TOP             MEM_HV_START
 182
 183 #else /* !__tilegx__ */
 184
 185 /*
 186  * A PAGE_OFFSET of 0xC0000000 means that the kernel has
 187  * a virtual address space of one gigabyte, which limits the
 188  * amount of physical memory you can use to about 768MB.
 189  * If you want more physical memory than this then see the CONFIG_HIGHMEM
 190  * option in the kernel configuration.
 191  *
 192  * The top 16MB chunk in the table below is unavailable to Linux.  Since
 193  * the kernel interrupt vectors must live at ether 0xfe000000 or 0xfd000000
 194  * (depending on whether the kernel is at PL2 or Pl1), we map all of the
 195  * bottom of RAM at this address with a huge page table entry to minimize
 196  * its ITLB footprint (as well as at PAGE_OFFSET).  The last architected
 197  * requirement is that user interrupt vectors live at 0xfc000000, so we
 198  * make that range of memory available to user processes.  The remaining
 199  * regions are sized as shown; the first four addresses use the PL 1
 200  * values, and after that, we show "typical" values, since the actual
 201  * addresses depend on kernel #defines.
 202  *
 203  * MEM_HV_INTRPT                   0xfe000000
 204  * MEM_SV_INTRPT (kernel code)     0xfd000000
 205  * MEM_USER_INTRPT (user vector)   0xfc000000
 206  * FIX_KMAP_xxx                    0xf8000000 (via NR_CPUS * KM_TYPE_NR)
 207  * PKMAP_BASE                      0xf7000000 (via LAST_PKMAP)
 208  * HUGE_VMAP                       0xf3000000 (via CONFIG_NR_HUGE_VMAPS)
 209  * VMALLOC_START                   0xf0000000 (via __VMALLOC_RESERVE)
 210  * mapped LOWMEM                   0xc0000000
 211  */
 212
 213 #define MEM_USER_INTRPT         _AC(0xfc000000, UL)
 214 #if CONFIG_KERNEL_PL == 1
 215 #define MEM_SV_INTRPT           _AC(0xfd000000, UL)
 216 #define MEM_HV_INTRPT           _AC(0xfe000000, UL)
 217 #else
 218 #define MEM_GUEST_INTRPT        _AC(0xfd000000, UL)
 219 #define MEM_SV_INTRPT           _AC(0xfe000000, UL)
 220 #define MEM_HV_INTRPT           _AC(0xff000000, UL)
 221 #endif
 222
 223 #define INTRPT_SIZE             0x4000
 224
 225 /* Tolerate page size larger than the architecture interrupt region size. */
 226 #if PAGE_SIZE > INTRPT_SIZE
 227 #undef INTRPT_SIZE
 228 #define INTRPT_SIZE PAGE_SIZE
 229 #endif
 230
 231 #define KERNEL_HIGH_VADDR       MEM_USER_INTRPT
 232 #define FIXADDR_TOP             (KERNEL_HIGH_VADDR - PAGE_SIZE)
 233
 234 #define PAGE_OFFSET             _AC(CONFIG_PAGE_OFFSET, UL)
 235
 236 /* On 32-bit architectures we mix kernel modules in with other vmaps. */
 237 #define MEM_MODULE_START        VMALLOC_START
 238 #define MEM_MODULE_END          VMALLOC_END
 239
 240 #endif /* __tilegx__ */
 241
 242 #ifndef __ASSEMBLY__
 243
 244 #ifdef CONFIG_HIGHMEM
 245
 246 /* Map kernel virtual addresses to page frames, in HPAGE_SIZE chunks. */
 247 extern unsigned long pbase_map[];
 248 extern void *vbase_map[];
 249
 250 static inline unsigned long kaddr_to_pfn(const volatile void *_kaddr)
 251 {
 252         unsigned long kaddr = (unsigned long)_kaddr;
 253         return pbase_map[kaddr >> HPAGE_SHIFT] +
 254                 ((kaddr & (HPAGE_SIZE - 1)) >> PAGE_SHIFT);
 255 }
 256
 257 static inline void *pfn_to_kaddr(unsigned long pfn)
 258 {
 259         return vbase_map[__pfn_to_highbits(pfn)] + (pfn << PAGE_SHIFT);
 260 }
 261
 262 static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
 263 {
 264         unsigned long pfn = kaddr_to_pfn(kaddr);
 265         return ((phys_addr_t)pfn << PAGE_SHIFT) +
 266                 ((unsigned long)kaddr & (PAGE_SIZE-1));
 267 }
 268
 269 static inline void *phys_to_virt(phys_addr_t paddr)
 270 {
 271         return pfn_to_kaddr(paddr >> PAGE_SHIFT) + (paddr & (PAGE_SIZE-1));
 272 }
 273
 274 /* With HIGHMEM, we pack PAGE_OFFSET through high_memory with all valid VAs. */
 275 static inline int virt_addr_valid(const volatile void *kaddr)
 276 {
 277         extern void *high_memory;  /* copied from <linux/mm.h> */
 278         return ((unsigned long)kaddr >= PAGE_OFFSET && kaddr < high_memory);
 279 }
 280
 281 #else /* !CONFIG_HIGHMEM */
 282
 283 static inline unsigned long kaddr_to_pfn(const volatile void *kaddr)
 284 {
 285         return ((unsigned long)kaddr - PAGE_OFFSET) >> PAGE_SHIFT;
 286 }
 287
 288 static inline void *pfn_to_kaddr(unsigned long pfn)
 289 {
 290         return (void *)((pfn << PAGE_SHIFT) + PAGE_OFFSET);
 291 }
 292
 293 static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
 294 {
 295         return (phys_addr_t)((unsigned long)kaddr - PAGE_OFFSET);
 296 }
 297
 298 static inline void *phys_to_virt(phys_addr_t paddr)
 299 {
 300         return (void *)((unsigned long)paddr + PAGE_OFFSET);
 301 }
 302
 303 /* Check that the given address is within some mapped range of PAs. */
 304 #define virt_addr_valid(kaddr) pfn_valid(kaddr_to_pfn(kaddr))
 305
 306 #endif /* !CONFIG_HIGHMEM */
 307
 308 /* All callers are not consistent in how they call these functions. */
 309 #define __pa(kaddr) virt_to_phys((void *)(unsigned long)(kaddr))
 310 #define __va(paddr) phys_to_virt((phys_addr_t)(paddr))
 311
 312 extern int devmem_is_allowed(unsigned long pagenr);
 313
 314 #ifdef CONFIG_FLATMEM
 315 static inline int pfn_valid(unsigned long pfn)
 316 {
 317         return pfn < max_mapnr;
 318 }
 319 #endif
 320
 321 /* Provide as macros since these require some other headers included. */
 322 #define page_to_pa(page) ((phys_addr_t)(page_to_pfn(page)) << PAGE_SHIFT)
 323 #define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn((void *)(kaddr)))
 324 #define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
 325
 326 struct mm_struct;
 327 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 328
 329 #endif /* !__ASSEMBLY__ */
 330
 331 #define VM_DATA_DEFAULT_FLAGS \
 332         (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 333
 334 #include <asm-generic/memory_model.h>
 335
 336 #endif /* _ASM_TILE_PAGE_H */