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 #if defined(CONFIG_PAGE_SIZE_4KB)  /* tilepro only */
  24 #define PAGE_SHIFT      12
  25 #define CTX_PAGE_FLAG   HV_CTX_PG_SM_4K
  26 #elif defined(CONFIG_PAGE_SIZE_16KB)
  27 #define PAGE_SHIFT      14
  28 #define CTX_PAGE_FLAG   HV_CTX_PG_SM_16K
  29 #elif defined(CONFIG_PAGE_SIZE_64KB)
  30 #define PAGE_SHIFT      16
  31 #define CTX_PAGE_FLAG   HV_CTX_PG_SM_64K
  32 #else
  33 #error Page size not specified in Kconfig
  34 #endif
  35 #define HPAGE_SHIFT     HV_LOG2_DEFAULT_PAGE_SIZE_LARGE
  36
  37 #define PAGE_SIZE       (_AC(1, UL) << PAGE_SHIFT)
  38 #define HPAGE_SIZE      (_AC(1, UL) << HPAGE_SHIFT)
  39
  40 #define PAGE_MASK       (~(PAGE_SIZE - 1))
  41 #define HPAGE_MASK      (~(HPAGE_SIZE - 1))
  42
  43 /*
  44  * If the Kconfig doesn't specify, set a maximum zone order that
  45  * is enough so that we can create huge pages from small pages given
  46  * the respective sizes of the two page types.  See <linux/mmzone.h>.
  47  */
  48 #ifndef CONFIG_FORCE_MAX_ZONEORDER
  49 #define CONFIG_FORCE_MAX_ZONEORDER (HPAGE_SHIFT - PAGE_SHIFT + 1)
  50 #endif
  51
  52 #ifndef __ASSEMBLY__
  53
  54 #include <linux/types.h>
  55 #include <linux/string.h>
  56
  57 struct page;
  58
  59 static inline void clear_page(void *page)
  60 {
  61         memset(page, 0, PAGE_SIZE);
  62 }
  63
  64 static inline void copy_page(void *to, void *from)
  65 {
  66         memcpy(to, from, PAGE_SIZE);
  67 }
  68
  69 static inline void clear_user_page(void *page, unsigned long vaddr,
  70                                 struct page *pg)
  71 {
  72         clear_page(page);
  73 }
  74
  75 static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
  76                                 struct page *topage)
  77 {
  78         copy_page(to, from);
  79 }
  80
  81 /*
  82  * Hypervisor page tables are made of the same basic structure.
  83  */
  84
  85 typedef HV_PTE pte_t;
  86 typedef HV_PTE pgd_t;
  87 typedef HV_PTE pgprot_t;
  88
  89 /*
  90  * User L2 page tables are managed as one L2 page table per page,
  91  * because we use the page allocator for them.  This keeps the allocation
  92  * simple, but it's also inefficient, since L2 page tables are much smaller
  93  * than pages (currently 2KB vs 64KB).  So we should revisit this.
  94  */
  95 typedef struct page *pgtable_t;
  96
  97 /* Must be a macro since it is used to create constants. */
  98 #define __pgprot(val) hv_pte(val)
  99
 100 /* Rarely-used initializers, typically with a "zero" value. */
 101 #define __pte(x) hv_pte(x)
 102 #define __pgd(x) hv_pte(x)
 103
 104 static inline u64 pgprot_val(pgprot_t pgprot)
 105 {
 106         return hv_pte_val(pgprot);
 107 }
 108
 109 static inline u64 pte_val(pte_t pte)
 110 {
 111         return hv_pte_val(pte);
 112 }
 113
 114 static inline u64 pgd_val(pgd_t pgd)
 115 {
 116         return hv_pte_val(pgd);
 117 }
 118
 119 #ifdef __tilegx__
 120
 121 typedef HV_PTE pmd_t;
 122
 123 #define __pmd(x) hv_pte(x)
 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         6
 142
 143 #ifdef CONFIG_HUGETLB_PAGE
 144 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 145 #endif
 146
 147 /* Allow overriding how much VA or PA the kernel will use. */
 148 #define MAX_PA_WIDTH CHIP_PA_WIDTH()
 149 #define MAX_VA_WIDTH CHIP_VA_WIDTH()
 150
 151 /* Each memory controller has PAs distinct in their high bits. */
 152 #define NR_PA_HIGHBIT_SHIFT (MAX_PA_WIDTH - CHIP_LOG_NUM_MSHIMS())
 153 #define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
 154 #define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
 155 #define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
 156
 157 #ifdef __tilegx__
 158
 159 /*
 160  * We reserve the lower half of memory for user-space programs, and the
 161  * upper half for system code.  We re-map all of physical memory in the
 162  * upper half, which takes a quarter of our VA space.  Then we have
 163  * the vmalloc regions.  The supervisor code lives at the highest address,
 164  * with the hypervisor above that.
 165  *
 166  * Loadable kernel modules are placed immediately after the static
 167  * supervisor code, with each being allocated a 256MB region of
 168  * address space, so we don't have to worry about the range of "jal"
 169  * and other branch instructions.
 170  *
 171  * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
 172  * Similarly, for now we don't play any struct page mapping games.
 173  */
 174
 175 #if MAX_PA_WIDTH + 2 > MAX_VA_WIDTH
 176 # error Too much PA to map with the VA available!
 177 #endif
 178
 179 #define PAGE_OFFSET             (-(_AC(1, UL) << (MAX_VA_WIDTH - 1)))
 180 #define KERNEL_HIGH_VADDR       _AC(0xfffffff800000000, UL)  /* high 32GB */
 181 #define FIXADDR_BASE            (KERNEL_HIGH_VADDR - 0x300000000) /* 4 GB */
 182 #define FIXADDR_TOP             (KERNEL_HIGH_VADDR - 0x200000000) /* 4 GB */
 183 #define _VMALLOC_START          FIXADDR_TOP
 184 #define MEM_SV_START            (KERNEL_HIGH_VADDR - 0x100000000) /* 256 MB */
 185 #define MEM_MODULE_START        (MEM_SV_START + (256*1024*1024)) /* 256 MB */
 186 #define MEM_MODULE_END          (MEM_MODULE_START + (256*1024*1024))
 187
 188 #else /* !__tilegx__ */
 189
 190 /*
 191  * A PAGE_OFFSET of 0xC0000000 means that the kernel has
 192  * a virtual address space of one gigabyte, which limits the
 193  * amount of physical memory you can use to about 768MB.
 194  * If you want more physical memory than this then see the CONFIG_HIGHMEM
 195  * option in the kernel configuration.
 196  *
 197  * The top 16MB chunk in the table below is unavailable to Linux.  Since
 198  * the kernel interrupt vectors must live at ether 0xfe000000 or 0xfd000000
 199  * (depending on whether the kernel is at PL2 or Pl1), we map all of the
 200  * bottom of RAM at this address with a huge page table entry to minimize
 201  * its ITLB footprint (as well as at PAGE_OFFSET).  The last architected
 202  * requirement is that user interrupt vectors live at 0xfc000000, so we
 203  * make that range of memory available to user processes.  The remaining
 204  * regions are sized as shown; the first four addresses use the PL 1
 205  * values, and after that, we show "typical" values, since the actual
 206  * addresses depend on kernel #defines.
 207  *
 208  * MEM_HV_START                    0xfe000000
 209  * MEM_SV_START  (kernel code)     0xfd000000
 210  * MEM_USER_INTRPT (user vector)   0xfc000000
 211  * FIX_KMAP_xxx                    0xfa000000 (via NR_CPUS * KM_TYPE_NR)
 212  * PKMAP_BASE                      0xf9000000 (via LAST_PKMAP)
 213  * VMALLOC_START                   0xf7000000 (via VMALLOC_RESERVE)
 214  * mapped LOWMEM                   0xc0000000
 215  */
 216
 217 #define MEM_USER_INTRPT         _AC(0xfc000000, UL)
 218 #define MEM_SV_START            _AC(0xfd000000, UL)
 219 #define MEM_HV_START            _AC(0xfe000000, UL)
 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 #if !defined(__ASSEMBLY__) && !defined(VDSO_BUILD)
 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((void *)(kaddr)))
 322 #define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
 323
 324 /*
 325  * The kernel text is mapped at MEM_SV_START as read-only.  To allow
 326  * modifying kernel text, it is also mapped at PAGE_OFFSET as read-write.
 327  * This macro converts a kernel address to its writable kernel text mapping,
 328  * which is used to modify the text code on a running kernel by kgdb,
 329  * ftrace, kprobe, jump label, etc.
 330  */
 331 #define ktext_writable_addr(kaddr) \
 332         ((unsigned long)(kaddr) - MEM_SV_START + PAGE_OFFSET)
 333
 334 struct mm_struct;
 335 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 336 extern pte_t *virt_to_kpte(unsigned long kaddr);
 337
 338 #endif /* !__ASSEMBLY__ */
 339
 340 #define VM_DATA_DEFAULT_FLAGS \
 341         (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 342
 343 #include <asm-generic/memory_model.h>
 344
 345 #endif /* _ASM_TILE_PAGE_H */