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