arch/arm64/include/asm/memory.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Based on arch/arm/include/asm/memory.h
   4  *
   5  * Copyright (C) 2000-2002 Russell King
   6  * Copyright (C) 2012 ARM Ltd.
   7  *
   8  * Note: this file should not be included by non-asm/.h files
   9  */
  10 #ifndef __ASM_MEMORY_H
  11 #define __ASM_MEMORY_H
  12
  13 #include <linux/const.h>
  14 #include <linux/sizes.h>
  15 #include <asm/page-def.h>
  16
  17 /*
  18  * Size of the PCI I/O space. This must remain a power of two so that
  19  * IO_SPACE_LIMIT acts as a mask for the low bits of I/O addresses.
  20  */
  21 #define PCI_IO_SIZE             SZ_16M
  22
  23 /*
  24  * VMEMMAP_SIZE - allows the whole linear region to be covered by
  25  *                a struct page array
  26  *
  27  * If we are configured with a 52-bit kernel VA then our VMEMMAP_SIZE
  28  * needs to cover the memory region from the beginning of the 52-bit
  29  * PAGE_OFFSET all the way to PAGE_END for 48-bit. This allows us to
  30  * keep a constant PAGE_OFFSET and "fallback" to using the higher end
  31  * of the VMEMMAP where 52-bit support is not available in hardware.
  32  */
  33 #define VMEMMAP_RANGE   (_PAGE_END(VA_BITS_MIN) - PAGE_OFFSET)
  34 #define VMEMMAP_SIZE    ((VMEMMAP_RANGE >> PAGE_SHIFT) * sizeof(struct page))
  35
  36 /*
  37  * PAGE_OFFSET - the virtual address of the start of the linear map, at the
  38  *               start of the TTBR1 address space.
  39  * PAGE_END - the end of the linear map, where all other kernel mappings begin.
  40  * KIMAGE_VADDR - the virtual address of the start of the kernel image.
  41  * VA_BITS - the maximum number of bits for virtual addresses.
  42  */
  43 #define VA_BITS                 (CONFIG_ARM64_VA_BITS)
  44 #define _PAGE_OFFSET(va)        (-(UL(1) << (va)))
  45 #define PAGE_OFFSET             (_PAGE_OFFSET(VA_BITS))
  46 #define KIMAGE_VADDR            (MODULES_END)
  47 #define MODULES_END             (MODULES_VADDR + MODULES_VSIZE)
  48 #define MODULES_VADDR           (_PAGE_END(VA_BITS_MIN))
  49 #define MODULES_VSIZE           (SZ_2G)
  50 #define VMEMMAP_START           (VMEMMAP_END - VMEMMAP_SIZE)
  51 #define VMEMMAP_END             (-UL(SZ_1G))
  52 #define PCI_IO_START            (VMEMMAP_END + SZ_8M)
  53 #define PCI_IO_END              (PCI_IO_START + PCI_IO_SIZE)
  54 #define FIXADDR_TOP             (-UL(SZ_8M))
  55
  56 #if VA_BITS > 48
  57 #ifdef CONFIG_ARM64_16K_PAGES
  58 #define VA_BITS_MIN             (47)
  59 #else
  60 #define VA_BITS_MIN             (48)
  61 #endif
  62 #else
  63 #define VA_BITS_MIN             (VA_BITS)
  64 #endif
  65
  66 #define _PAGE_END(va)           (-(UL(1) << ((va) - 1)))
  67
  68 #define KERNEL_START            _text
  69 #define KERNEL_END              _end
  70
  71 /*
  72  * Generic and Software Tag-Based KASAN modes require 1/8th and 1/16th of the
  73  * kernel virtual address space for storing the shadow memory respectively.
  74  *
  75  * The mapping between a virtual memory address and its corresponding shadow
  76  * memory address is defined based on the formula:
  77  *
  78  *     shadow_addr = (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
  79  *
  80  * where KASAN_SHADOW_SCALE_SHIFT is the order of the number of bits that map
  81  * to a single shadow byte and KASAN_SHADOW_OFFSET is a constant that offsets
  82  * the mapping. Note that KASAN_SHADOW_OFFSET does not point to the start of
  83  * the shadow memory region.
  84  *
  85  * Based on this mapping, we define two constants:
  86  *
  87  *     KASAN_SHADOW_START: the start of the shadow memory region;
  88  *     KASAN_SHADOW_END: the end of the shadow memory region.
  89  *
  90  * KASAN_SHADOW_END is defined first as the shadow address that corresponds to
  91  * the upper bound of possible virtual kernel memory addresses UL(1) << 64
  92  * according to the mapping formula.
  93  *
  94  * KASAN_SHADOW_START is defined second based on KASAN_SHADOW_END. The shadow
  95  * memory start must map to the lowest possible kernel virtual memory address
  96  * and thus it depends on the actual bitness of the address space.
  97  *
  98  * As KASAN inserts redzones between stack variables, this increases the stack
  99  * memory usage significantly. Thus, we double the (minimum) stack size.
 100  */
 101 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 102 #define KASAN_SHADOW_OFFSET     _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
 103 #define KASAN_SHADOW_END        ((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) + KASAN_SHADOW_OFFSET)
 104 #define _KASAN_SHADOW_START(va) (KASAN_SHADOW_END - (UL(1) << ((va) - KASAN_SHADOW_SCALE_SHIFT)))
 105 #define KASAN_SHADOW_START      _KASAN_SHADOW_START(vabits_actual)
 106 #define PAGE_END                KASAN_SHADOW_START
 107 #define KASAN_THREAD_SHIFT      1
 108 #else
 109 #define KASAN_THREAD_SHIFT      0
 110 #define PAGE_END                (_PAGE_END(VA_BITS_MIN))
 111 #endif /* CONFIG_KASAN */
 112
 113 #define MIN_THREAD_SHIFT        (14 + KASAN_THREAD_SHIFT)
 114
 115 /*
 116  * VMAP'd stacks are allocated at page granularity, so we must ensure that such
 117  * stacks are a multiple of page size.
 118  */
 119 #if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
 120 #define THREAD_SHIFT            PAGE_SHIFT
 121 #else
 122 #define THREAD_SHIFT            MIN_THREAD_SHIFT
 123 #endif
 124
 125 #if THREAD_SHIFT >= PAGE_SHIFT
 126 #define THREAD_SIZE_ORDER       (THREAD_SHIFT - PAGE_SHIFT)
 127 #endif
 128
 129 #define THREAD_SIZE             (UL(1) << THREAD_SHIFT)
 130
 131 /*
 132  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
 133  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
 134  * assembly.
 135  */
 136 #ifdef CONFIG_VMAP_STACK
 137 #define THREAD_ALIGN            (2 * THREAD_SIZE)
 138 #else
 139 #define THREAD_ALIGN            THREAD_SIZE
 140 #endif
 141
 142 #define IRQ_STACK_SIZE          THREAD_SIZE
 143
 144 #define OVERFLOW_STACK_SIZE     SZ_4K
 145
 146 /*
 147  * With the minimum frame size of [x29, x30], exactly half the combined
 148  * sizes of the hyp and overflow stacks is the maximum size needed to
 149  * save the unwinded stacktrace; plus an additional entry to delimit the
 150  * end.
 151  */
 152 #define NVHE_STACKTRACE_SIZE    ((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long))
 153
 154 /*
 155  * Alignment of kernel segments (e.g. .text, .data).
 156  *
 157  *  4 KB granule:  16 level 3 entries, with contiguous bit
 158  * 16 KB granule:   4 level 3 entries, without contiguous bit
 159  * 64 KB granule:   1 level 3 entry
 160  */
 161 #define SEGMENT_ALIGN           SZ_64K
 162
 163 /*
 164  * Memory types available.
 165  *
 166  * IMPORTANT: MT_NORMAL must be index 0 since vm_get_page_prot() may 'or' in
 167  *            the MT_NORMAL_TAGGED memory type for PROT_MTE mappings. Note
 168  *            that protection_map[] only contains MT_NORMAL attributes.
 169  */
 170 #define MT_NORMAL               0
 171 #define MT_NORMAL_TAGGED        1
 172 #define MT_NORMAL_NC            2
 173 #define MT_DEVICE_nGnRnE        3
 174 #define MT_DEVICE_nGnRE         4
 175
 176 /*
 177  * Memory types for Stage-2 translation
 178  */
 179 #define MT_S2_NORMAL            0xf
 180 #define MT_S2_NORMAL_NC         0x5
 181 #define MT_S2_DEVICE_nGnRE      0x1
 182
 183 /*
 184  * Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
 185  * Stage-2 enforces Normal-WB and Device-nGnRE
 186  */
 187 #define MT_S2_FWB_NORMAL        6
 188 #define MT_S2_FWB_NORMAL_NC     5
 189 #define MT_S2_FWB_DEVICE_nGnRE  1
 190
 191 #ifdef CONFIG_ARM64_4K_PAGES
 192 #define IOREMAP_MAX_ORDER       (PUD_SHIFT)
 193 #else
 194 #define IOREMAP_MAX_ORDER       (PMD_SHIFT)
 195 #endif
 196
 197 /*
 198  *  Open-coded (swapper_pg_dir - reserved_pg_dir) as this cannot be calculated
 199  *  until link time.
 200  */
 201 #define RESERVED_SWAPPER_OFFSET (PAGE_SIZE)
 202
 203 /*
 204  *  Open-coded (swapper_pg_dir - tramp_pg_dir) as this cannot be calculated
 205  *  until link time.
 206  */
 207 #define TRAMP_SWAPPER_OFFSET    (2 * PAGE_SIZE)
 208
 209 #ifndef __ASSEMBLY__
 210
 211 #include <linux/bitops.h>
 212 #include <linux/compiler.h>
 213 #include <linux/mmdebug.h>
 214 #include <linux/types.h>
 215 #include <asm/boot.h>
 216 #include <asm/bug.h>
 217 #include <asm/sections.h>
 218 #include <asm/sysreg.h>
 219
 220 static inline u64 __pure read_tcr(void)
 221 {
 222         u64  tcr;
 223
 224         // read_sysreg() uses asm volatile, so avoid it here
 225         asm("mrs %0, tcr_el1" : "=r"(tcr));
 226         return tcr;
 227 }
 228
 229 #if VA_BITS > 48
 230 // For reasons of #include hell, we can't use TCR_T1SZ_OFFSET/TCR_T1SZ_MASK here
 231 #define vabits_actual           (64 - ((read_tcr() >> 16) & 63))
 232 #else
 233 #define vabits_actual           ((u64)VA_BITS)
 234 #endif
 235
 236 extern s64                      memstart_addr;
 237 /* PHYS_OFFSET - the physical address of the start of memory. */
 238 #define PHYS_OFFSET             ({ VM_BUG_ON(memstart_addr & 1); memstart_addr; })
 239
 240 /* the offset between the kernel virtual and physical mappings */
 241 extern u64                      kimage_voffset;
 242
 243 static inline unsigned long kaslr_offset(void)
 244 {
 245         return (u64)&_text - KIMAGE_VADDR;
 246 }
 247
 248 #ifdef CONFIG_RANDOMIZE_BASE
 249 void kaslr_init(void);
 250 static inline bool kaslr_enabled(void)
 251 {
 252         extern bool __kaslr_is_enabled;
 253         return __kaslr_is_enabled;
 254 }
 255 #else
 256 static inline void kaslr_init(void) { }
 257 static inline bool kaslr_enabled(void) { return false; }
 258 #endif
 259
 260 /*
 261  * Allow all memory at the discovery stage. We will clip it later.
 262  */
 263 #define MIN_MEMBLOCK_ADDR       0
 264 #define MAX_MEMBLOCK_ADDR       U64_MAX
 265
 266 /*
 267  * PFNs are used to describe any physical page; this means
 268  * PFN 0 == physical address 0.
 269  *
 270  * This is the PFN of the first RAM page in the kernel
 271  * direct-mapped view.  We assume this is the first page
 272  * of RAM in the mem_map as well.
 273  */
 274 #define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
 275
 276 /*
 277  * When dealing with data aborts, watchpoints, or instruction traps we may end
 278  * up with a tagged userland pointer. Clear the tag to get a sane pointer to
 279  * pass on to access_ok(), for instance.
 280  */
 281 #define __untagged_addr(addr)   \
 282         ((__force __typeof__(addr))sign_extend64((__force u64)(addr), 55))
 283
 284 #define untagged_addr(addr)     ({                                      \
 285         u64 __addr = (__force u64)(addr);                                       \
 286         __addr &= __untagged_addr(__addr);                              \
 287         (__force __typeof__(addr))__addr;                               \
 288 })
 289
 290 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
 291 #define __tag_shifted(tag)      ((u64)(tag) << 56)
 292 #define __tag_reset(addr)       __untagged_addr(addr)
 293 #define __tag_get(addr)         (__u8)((u64)(addr) >> 56)
 294 #else
 295 #define __tag_shifted(tag)      0UL
 296 #define __tag_reset(addr)       (addr)
 297 #define __tag_get(addr)         0
 298 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
 299
 300 static inline const void *__tag_set(const void *addr, u8 tag)
 301 {
 302         u64 __addr = (u64)addr & ~__tag_shifted(0xff);
 303         return (const void *)(__addr | __tag_shifted(tag));
 304 }
 305
 306 #ifdef CONFIG_KASAN_HW_TAGS
 307 #define arch_enable_tag_checks_sync()           mte_enable_kernel_sync()
 308 #define arch_enable_tag_checks_async()          mte_enable_kernel_async()
 309 #define arch_enable_tag_checks_asymm()          mte_enable_kernel_asymm()
 310 #define arch_suppress_tag_checks_start()        mte_enable_tco()
 311 #define arch_suppress_tag_checks_stop()         mte_disable_tco()
 312 #define arch_force_async_tag_fault()            mte_check_tfsr_exit()
 313 #define arch_get_random_tag()                   mte_get_random_tag()
 314 #define arch_get_mem_tag(addr)                  mte_get_mem_tag(addr)
 315 #define arch_set_mem_tag_range(addr, size, tag, init)   \
 316                         mte_set_mem_tag_range((addr), (size), (tag), (init))
 317 #endif /* CONFIG_KASAN_HW_TAGS */
 318
 319 /*
 320  * Physical vs virtual RAM address space conversion.  These are
 321  * private definitions which should NOT be used outside memory.h
 322  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
 323  */
 324
 325
 326 /*
 327  * Check whether an arbitrary address is within the linear map, which
 328  * lives in the [PAGE_OFFSET, PAGE_END) interval at the bottom of the
 329  * kernel's TTBR1 address range.
 330  */
 331 #define __is_lm_address(addr)   (((u64)(addr) - PAGE_OFFSET) < (PAGE_END - PAGE_OFFSET))
 332
 333 #define __lm_to_phys(addr)      (((addr) - PAGE_OFFSET) + PHYS_OFFSET)
 334 #define __kimg_to_phys(addr)    ((addr) - kimage_voffset)
 335
 336 #define __virt_to_phys_nodebug(x) ({                                    \
 337         phys_addr_t __x = (phys_addr_t)(__tag_reset(x));                \
 338         __is_lm_address(__x) ? __lm_to_phys(__x) : __kimg_to_phys(__x); \
 339 })
 340
 341 #define __pa_symbol_nodebug(x)  __kimg_to_phys((phys_addr_t)(x))
 342
 343 #ifdef CONFIG_DEBUG_VIRTUAL
 344 extern phys_addr_t __virt_to_phys(unsigned long x);
 345 extern phys_addr_t __phys_addr_symbol(unsigned long x);
 346 #else
 347 #define __virt_to_phys(x)       __virt_to_phys_nodebug(x)
 348 #define __phys_addr_symbol(x)   __pa_symbol_nodebug(x)
 349 #endif /* CONFIG_DEBUG_VIRTUAL */
 350
 351 #define __phys_to_virt(x)       ((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
 352 #define __phys_to_kimg(x)       ((unsigned long)((x) + kimage_voffset))
 353
 354 /*
 355  * Convert a page to/from a physical address
 356  */
 357 #define page_to_phys(page)      (__pfn_to_phys(page_to_pfn(page)))
 358 #define phys_to_page(phys)      (pfn_to_page(__phys_to_pfn(phys)))
 359
 360 /*
 361  * Note: Drivers should NOT use these.  They are the wrong
 362  * translation for translating DMA addresses.  Use the driver
 363  * DMA support - see dma-mapping.h.
 364  */
 365 #define virt_to_phys virt_to_phys
 366 static inline phys_addr_t virt_to_phys(const volatile void *x)
 367 {
 368         return __virt_to_phys((unsigned long)(x));
 369 }
 370
 371 #define phys_to_virt phys_to_virt
 372 static inline void *phys_to_virt(phys_addr_t x)
 373 {
 374         return (void *)(__phys_to_virt(x));
 375 }
 376
 377 /* Needed already here for resolving __phys_to_pfn() in virt_to_pfn() */
 378 #include <asm-generic/memory_model.h>
 379
 380 static inline unsigned long virt_to_pfn(const void *kaddr)
 381 {
 382         return __phys_to_pfn(virt_to_phys(kaddr));
 383 }
 384
 385 /*
 386  * Drivers should NOT use these either.
 387  */
 388 #define __pa(x)                 __virt_to_phys((unsigned long)(x))
 389 #define __pa_symbol(x)          __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
 390 #define __pa_nodebug(x)         __virt_to_phys_nodebug((unsigned long)(x))
 391 #define __va(x)                 ((void *)__phys_to_virt((phys_addr_t)(x)))
 392 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 393 #define sym_to_pfn(x)           __phys_to_pfn(__pa_symbol(x))
 394
 395 /*
 396  *  virt_to_page(x)     convert a _valid_ virtual address to struct page *
 397  *  virt_addr_valid(x)  indicates whether a virtual address is valid
 398  */
 399 #define ARCH_PFN_OFFSET         ((unsigned long)PHYS_PFN_OFFSET)
 400
 401 #if defined(CONFIG_DEBUG_VIRTUAL)
 402 #define page_to_virt(x) ({                                              \
 403         __typeof__(x) __page = x;                                       \
 404         void *__addr = __va(page_to_phys(__page));                      \
 405         (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
 406 })
 407 #define virt_to_page(x)         pfn_to_page(virt_to_pfn(x))
 408 #else
 409 #define page_to_virt(x) ({                                              \
 410         __typeof__(x) __page = x;                                       \
 411         u64 __idx = ((u64)__page - VMEMMAP_START) / sizeof(struct page);\
 412         u64 __addr = PAGE_OFFSET + (__idx * PAGE_SIZE);                 \
 413         (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
 414 })
 415
 416 #define virt_to_page(x) ({                                              \
 417         u64 __idx = (__tag_reset((u64)x) - PAGE_OFFSET) / PAGE_SIZE;    \
 418         u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));     \
 419         (struct page *)__addr;                                          \
 420 })
 421 #endif /* CONFIG_DEBUG_VIRTUAL */
 422
 423 #define virt_addr_valid(addr)   ({                                      \
 424         __typeof__(addr) __addr = __tag_reset(addr);                    \
 425         __is_lm_address(__addr) && pfn_is_map_memory(virt_to_pfn(__addr));      \
 426 })
 427
 428 void dump_mem_limit(void);
 429 #endif /* !ASSEMBLY */
 430
 431 /*
 432  * Given that the GIC architecture permits ITS implementations that can only be
 433  * configured with a LPI table address once, GICv3 systems with many CPUs may
 434  * end up reserving a lot of different regions after a kexec for their LPI
 435  * tables (one per CPU), as we are forced to reuse the same memory after kexec
 436  * (and thus reserve it persistently with EFI beforehand)
 437  */
 438 #if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
 439 # define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
 440 #endif
 441
 442 /*
 443  * memory regions which marked with flag MEMBLOCK_NOMAP(for example, the memory
 444  * of the EFI_UNUSABLE_MEMORY type) may divide a continuous memory block into
 445  * multiple parts. As a result, the number of memory regions is large.
 446  */
 447 #ifdef CONFIG_EFI
 448 #define INIT_MEMBLOCK_MEMORY_REGIONS    (INIT_MEMBLOCK_REGIONS * 8)
 449 #endif
 450
 451
 452 #endif /* __ASM_MEMORY_H */