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_16KB)
  24 #define PAGE_SHIFT      14
  25 #define CTX_PAGE_FLAG   HV_CTX_PG_SM_16K
  26 #elif defined(CONFIG_PAGE_SIZE_64KB)
  27 #define PAGE_SHIFT      16
  28 #define CTX_PAGE_FLAG   HV_CTX_PG_SM_64K
  29 #else
  30 #define PAGE_SHIFT      HV_LOG2_DEFAULT_PAGE_SIZE_SMALL
  31 #define CTX_PAGE_FLAG   0
  32 #endif
  33 #define HPAGE_SHIFT     HV_LOG2_DEFAULT_PAGE_SIZE_LARGE
  34
  35 #define PAGE_SIZE       (_AC(1, UL) << PAGE_SHIFT)
  36 #define HPAGE_SIZE      (_AC(1, UL) << HPAGE_SHIFT)
  37
  38 #define PAGE_MASK       (~(PAGE_SIZE - 1))
  39 #define HPAGE_MASK      (~(HPAGE_SIZE - 1))
  40
  41 /*
  42  * If the Kconfig doesn't specify, set a maximum zone order that
  43  * is enough so that we can create huge pages from small pages given
  44  * the respective sizes of the two page types.  See <linux/mmzone.h>.
  45  */
  46 #ifndef CONFIG_FORCE_MAX_ZONEORDER
  47 #define CONFIG_FORCE_MAX_ZONEORDER (HPAGE_SHIFT - PAGE_SHIFT + 1)
  48 #endif
  49
  50 #ifndef __ASSEMBLY__
  51
  52 #include <linux/types.h>
  53 #include <linux/string.h>
  54
  55 struct page;
  56
  57 static inline void clear_page(void *page)
  58 {
  59         memset(page, 0, PAGE_SIZE);
  60 }
  61
  62 static inline void copy_page(void *to, void *from)
  63 {
  64         memcpy(to, from, PAGE_SIZE);
  65 }
  66
  67 static inline void clear_user_page(void *page, unsigned long vaddr,
  68                                 struct page *pg)
  69 {
  70         clear_page(page);
  71 }
  72
  73 static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
  74                                 struct page *topage)
  75 {
  76         copy_page(to, from);
  77 }
  78
  79 /*
  80  * Hypervisor page tables are made of the same basic structure.
  81  */
  82
  83 typedef HV_PTE pte_t;
  84 typedef HV_PTE pgd_t;
  85 typedef HV_PTE pgprot_t;
  86
  87 /*
  88  * User L2 page tables are managed as one L2 page table per page,
  89  * because we use the page allocator for them.  This keeps the allocation
  90  * simple, but it's also inefficient, since L2 page tables are much smaller
  91  * than pages (currently 2KB vs 64KB).  So we should revisit this.
  92  */
  93 typedef struct page *pgtable_t;
  94
  95 /* Must be a macro since it is used to create constants. */
  96 #define __pgprot(val) hv_pte(val)
  97
  98 /* Rarely-used initializers, typically with a "zero" value. */
  99 #define __pte(x) hv_pte(x)
 100 #define __pgd(x) hv_pte(x)
 101
 102 static inline u64 pgprot_val(pgprot_t pgprot)
 103 {
 104         return hv_pte_val(pgprot);
 105 }
 106
 107 static inline u64 pte_val(pte_t pte)
 108 {
 109         return hv_pte_val(pte);
 110 }
 111
 112 static inline u64 pgd_val(pgd_t pgd)
 113 {
 114         return hv_pte_val(pgd);
 115 }
 116
 117 #ifdef __tilegx__
 118
 119 typedef HV_PTE pmd_t;
 120
 121 #define __pmd(x) hv_pte(x)
 122
 123 static inline u64 pmd_val(pmd_t pmd)
 124 {
 125         return hv_pte_val(pmd);
 126 }
 127
 128 #endif
 129
 130 static inline __attribute_const__ int get_order(unsigned long size)
 131 {
 132         return BITS_PER_LONG - __builtin_clzl((size - 1) >> PAGE_SHIFT);
 133 }
 134
 135 #endif /* !__ASSEMBLY__ */
 136
 137 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
 138
 139 #define HUGE_MAX_HSTATE         6
 140
 141 #ifdef CONFIG_HUGETLB_PAGE
 142 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 143 #endif
 144
 145 /* Allow overriding how much VA or PA the kernel will use. */
 146 #define MAX_PA_WIDTH CHIP_PA_WIDTH()
 147 #define MAX_VA_WIDTH CHIP_VA_WIDTH()
 148
 149 /* Each memory controller has PAs distinct in their high bits. */
 150 #define NR_PA_HIGHBIT_SHIFT (MAX_PA_WIDTH - CHIP_LOG_NUM_MSHIMS())
 151 #define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
 152 #define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
 153 #define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
 154
 155 #ifdef __tilegx__
 156
 157 /*
 158  * We reserve the lower half of memory for user-space programs, and the
 159  * upper half for system code.  We re-map all of physical memory in the
 160  * upper half, which takes a quarter of our VA space.  Then we have
 161  * the vmalloc regions.  The supervisor code lives at the highest address,
 162  * with the hypervisor above that.
 163  *
 164  * Loadable kernel modules are placed immediately after the static
 165  * supervisor code, with each being allocated a 256MB region of
 166  * address space, so we don't have to worry about the range of "jal"
 167  * and other branch instructions.
 168  *
 169  * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
 170  * Similarly, for now we don't play any struct page mapping games.
 171  */
 172
 173 #if MAX_PA_WIDTH + 2 > MAX_VA_WIDTH
 174 # error Too much PA to map with the VA available!
 175 #endif
 176
 177 #define PAGE_OFFSET             (-(_AC(1, UL) << (MAX_VA_WIDTH - 1)))
 178 #define KERNEL_HIGH_VADDR       _AC(0xfffffff800000000, UL)  /* high 32GB */
 179 #define FIXADDR_BASE            (KERNEL_HIGH_VADDR - 0x300000000) /* 4 GB */
 180 #define FIXADDR_TOP             (KERNEL_HIGH_VADDR - 0x200000000) /* 4 GB */
 181 #define _VMALLOC_START          FIXADDR_TOP
 182 #define MEM_SV_START            (KERNEL_HIGH_VADDR - 0x100000000) /* 256 MB */
 183 #define MEM_MODULE_START        (MEM_SV_START + (256*1024*1024)) /* 256 MB */
 184 #define MEM_MODULE_END          (MEM_MODULE_START + (256*1024*1024))
 185
 186 #else /* !__tilegx__ */
 187
 188 /*
 189  * A PAGE_OFFSET of 0xC0000000 means that the kernel has
 190  * a virtual address space of one gigabyte, which limits the
 191  * amount of physical memory you can use to about 768MB.
 192  * If you want more physical memory than this then see the CONFIG_HIGHMEM
 193  * option in the kernel configuration.
 194  *
 195  * The top 16MB chunk in the table below is unavailable to Linux.  Since
 196  * the kernel interrupt vectors must live at ether 0xfe000000 or 0xfd000000
 197  * (depending on whether the kernel is at PL2 or Pl1), we map all of the
 198  * bottom of RAM at this address with a huge page table entry to minimize
 199  * its ITLB footprint (as well as at PAGE_OFFSET).  The last architected
 200  * requirement is that user interrupt vectors live at 0xfc000000, so we
 201  * make that range of memory available to user processes.  The remaining
 202  * regions are sized as shown; the first four addresses use the PL 1
 203  * values, and after that, we show "typical" values, since the actual
 204  * addresses depend on kernel #defines.
 205  *
 206  * MEM_HV_START                    0xfe000000
 207  * MEM_SV_START  (kernel code)     0xfd000000
 208  * MEM_USER_INTRPT (user vector)   0xfc000000
 209  * FIX_KMAP_xxx                    0xfa000000 (via NR_CPUS * KM_TYPE_NR)
 210  * PKMAP_BASE                      0xf9000000 (via LAST_PKMAP)
 211  * VMALLOC_START                   0xf7000000 (via VMALLOC_RESERVE)
 212  * mapped LOWMEM                   0xc0000000
 213  */
 214
 215 #define MEM_USER_INTRPT         _AC(0xfc000000, UL)
 216 #define MEM_SV_START            _AC(0xfd000000, UL)
 217 #define MEM_HV_START            _AC(0xfe000000, UL)
 218
 219 #define INTRPT_SIZE             0x4000
 220
 221 /* Tolerate page size larger than the architecture interrupt region size. */
 222 #if PAGE_SIZE > INTRPT_SIZE
 223 #undef INTRPT_SIZE
 224 #define INTRPT_SIZE PAGE_SIZE
 225 #endif
 226
 227 #define KERNEL_HIGH_VADDR       MEM_USER_INTRPT
 228 #define FIXADDR_TOP             (KERNEL_HIGH_VADDR - PAGE_SIZE)
 229
 230 #define PAGE_OFFSET             _AC(CONFIG_PAGE_OFFSET, UL)
 231
 232 /* On 32-bit architectures we mix kernel modules in with other vmaps. */
 233 #define MEM_MODULE_START        VMALLOC_START
 234 #define MEM_MODULE_END          VMALLOC_END
 235
 236 #endif /* __tilegx__ */
 237
 238 #if !defined(__ASSEMBLY__) && !defined(VDSO_BUILD)
 239
 240 #ifdef CONFIG_HIGHMEM
 241
 242 /* Map kernel virtual addresses to page frames, in HPAGE_SIZE chunks. */
 243 extern unsigned long pbase_map[];
 244 extern void *vbase_map[];
 245
 246 static inline unsigned long kaddr_to_pfn(const volatile void *_kaddr)
 247 {
 248         unsigned long kaddr = (unsigned long)_kaddr;
 249         return pbase_map[kaddr >> HPAGE_SHIFT] +
 250                 ((kaddr & (HPAGE_SIZE - 1)) >> PAGE_SHIFT);
 251 }
 252
 253 static inline void *pfn_to_kaddr(unsigned long pfn)
 254 {
 255         return vbase_map[__pfn_to_highbits(pfn)] + (pfn << PAGE_SHIFT);
 256 }
 257
 258 static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
 259 {
 260         unsigned long pfn = kaddr_to_pfn(kaddr);
 261         return ((phys_addr_t)pfn << PAGE_SHIFT) +
 262                 ((unsigned long)kaddr & (PAGE_SIZE-1));
 263 }
 264
 265 static inline void *phys_to_virt(phys_addr_t paddr)
 266 {
 267         return pfn_to_kaddr(paddr >> PAGE_SHIFT) + (paddr & (PAGE_SIZE-1));
 268 }
 269
 270 /* With HIGHMEM, we pack PAGE_OFFSET through high_memory with all valid VAs. */
 271 static inline int virt_addr_valid(const volatile void *kaddr)
 272 {
 273         extern void *high_memory;  /* copied from <linux/mm.h> */
 274         return ((unsigned long)kaddr >= PAGE_OFFSET && kaddr < high_memory);
 275 }
 276
 277 #else /* !CONFIG_HIGHMEM */
 278
 279 static inline unsigned long kaddr_to_pfn(const volatile void *kaddr)
 280 {
 281         return ((unsigned long)kaddr - PAGE_OFFSET) >> PAGE_SHIFT;
 282 }
 283
 284 static inline void *pfn_to_kaddr(unsigned long pfn)
 285 {
 286         return (void *)((pfn << PAGE_SHIFT) + PAGE_OFFSET);
 287 }
 288
 289 static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
 290 {
 291         return (phys_addr_t)((unsigned long)kaddr - PAGE_OFFSET);
 292 }
 293
 294 static inline void *phys_to_virt(phys_addr_t paddr)
 295 {
 296         return (void *)((unsigned long)paddr + PAGE_OFFSET);
 297 }
 298
 299 /* Check that the given address is within some mapped range of PAs. */
 300 #define virt_addr_valid(kaddr) pfn_valid(kaddr_to_pfn(kaddr))
 301
 302 #endif /* !CONFIG_HIGHMEM */
 303
 304 /* All callers are not consistent in how they call these functions. */
 305 #define __pa(kaddr) virt_to_phys((void *)(unsigned long)(kaddr))
 306 #define __va(paddr) phys_to_virt((phys_addr_t)(paddr))
 307
 308 extern int devmem_is_allowed(unsigned long pagenr);
 309
 310 #ifdef CONFIG_FLATMEM
 311 static inline int pfn_valid(unsigned long pfn)
 312 {
 313         return pfn < max_mapnr;
 314 }
 315 #endif
 316
 317 /* Provide as macros since these require some other headers included. */
 318 #define page_to_pa(page) ((phys_addr_t)(page_to_pfn(page)) << PAGE_SHIFT)
 319 #define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn((void *)(kaddr)))
 320 #define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
 321
 322 struct mm_struct;
 323 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 324 extern pte_t *virt_to_kpte(unsigned long kaddr);
 325
 326 #endif /* !__ASSEMBLY__ */
 327
 328 #define VM_DATA_DEFAULT_FLAGS \
 329         (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 330
 331 #include <asm-generic/memory_model.h>
 332
 333 #endif /* _ASM_TILE_PAGE_H */