linux/arch/arm64/include/asm/memory.h
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   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_SHIFT   (PAGE_SHIFT - STRUCT_PAGE_MAX_SHIFT)
  34#define VMEMMAP_SIZE    ((_PAGE_END(VA_BITS_MIN) - PAGE_OFFSET) >> VMEMMAP_SHIFT)
  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 BPF_JIT_REGION_START    (_PAGE_END(VA_BITS_MIN))
  48#define BPF_JIT_REGION_SIZE     (SZ_128M)
  49#define BPF_JIT_REGION_END      (BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE)
  50#define MODULES_END             (MODULES_VADDR + MODULES_VSIZE)
  51#define MODULES_VADDR           (BPF_JIT_REGION_END)
  52#define MODULES_VSIZE           (SZ_128M)
  53#define VMEMMAP_START           (-(UL(1) << (VA_BITS - VMEMMAP_SHIFT)))
  54#define VMEMMAP_END             (VMEMMAP_START + VMEMMAP_SIZE)
  55#define PCI_IO_END              (VMEMMAP_START - SZ_8M)
  56#define PCI_IO_START            (PCI_IO_END - PCI_IO_SIZE)
  57#define FIXADDR_TOP             (VMEMMAP_START - SZ_32M)
  58
  59#if VA_BITS > 48
  60#define VA_BITS_MIN             (48)
  61#else
  62#define VA_BITS_MIN             (VA_BITS)
  63#endif
  64
  65#define _PAGE_END(va)           (-(UL(1) << ((va) - 1)))
  66
  67#define KERNEL_START            _text
  68#define KERNEL_END              _end
  69
  70/*
  71 * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual
  72 * address space for the shadow region respectively. They can bloat the stack
  73 * significantly, so double the (minimum) stack size when they are in use.
  74 */
  75#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
  76#define KASAN_SHADOW_OFFSET     _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
  77#define KASAN_SHADOW_END        ((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) \
  78                                        + KASAN_SHADOW_OFFSET)
  79#define PAGE_END                (KASAN_SHADOW_END - (1UL << (vabits_actual - KASAN_SHADOW_SCALE_SHIFT)))
  80#define KASAN_THREAD_SHIFT      1
  81#else
  82#define KASAN_THREAD_SHIFT      0
  83#define PAGE_END                (_PAGE_END(VA_BITS_MIN))
  84#endif /* CONFIG_KASAN */
  85
  86#define MIN_THREAD_SHIFT        (14 + KASAN_THREAD_SHIFT)
  87
  88/*
  89 * VMAP'd stacks are allocated at page granularity, so we must ensure that such
  90 * stacks are a multiple of page size.
  91 */
  92#if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
  93#define THREAD_SHIFT            PAGE_SHIFT
  94#else
  95#define THREAD_SHIFT            MIN_THREAD_SHIFT
  96#endif
  97
  98#if THREAD_SHIFT >= PAGE_SHIFT
  99#define THREAD_SIZE_ORDER       (THREAD_SHIFT - PAGE_SHIFT)
 100#endif
 101
 102#define THREAD_SIZE             (UL(1) << THREAD_SHIFT)
 103
 104/*
 105 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
 106 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
 107 * assembly.
 108 */
 109#ifdef CONFIG_VMAP_STACK
 110#define THREAD_ALIGN            (2 * THREAD_SIZE)
 111#else
 112#define THREAD_ALIGN            THREAD_SIZE
 113#endif
 114
 115#define IRQ_STACK_SIZE          THREAD_SIZE
 116
 117#define OVERFLOW_STACK_SIZE     SZ_4K
 118
 119/*
 120 * Alignment of kernel segments (e.g. .text, .data).
 121 *
 122 *  4 KB granule:  16 level 3 entries, with contiguous bit
 123 * 16 KB granule:   4 level 3 entries, without contiguous bit
 124 * 64 KB granule:   1 level 3 entry
 125 */
 126#define SEGMENT_ALIGN           SZ_64K
 127
 128/*
 129 * Memory types available.
 130 *
 131 * IMPORTANT: MT_NORMAL must be index 0 since vm_get_page_prot() may 'or' in
 132 *            the MT_NORMAL_TAGGED memory type for PROT_MTE mappings. Note
 133 *            that protection_map[] only contains MT_NORMAL attributes.
 134 */
 135#define MT_NORMAL               0
 136#define MT_NORMAL_TAGGED        1
 137#define MT_NORMAL_NC            2
 138#define MT_DEVICE_nGnRnE        3
 139#define MT_DEVICE_nGnRE         4
 140
 141/*
 142 * Memory types for Stage-2 translation
 143 */
 144#define MT_S2_NORMAL            0xf
 145#define MT_S2_DEVICE_nGnRE      0x1
 146
 147/*
 148 * Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
 149 * Stage-2 enforces Normal-WB and Device-nGnRE
 150 */
 151#define MT_S2_FWB_NORMAL        6
 152#define MT_S2_FWB_DEVICE_nGnRE  1
 153
 154#ifdef CONFIG_ARM64_4K_PAGES
 155#define IOREMAP_MAX_ORDER       (PUD_SHIFT)
 156#else
 157#define IOREMAP_MAX_ORDER       (PMD_SHIFT)
 158#endif
 159
 160/*
 161 *  Open-coded (swapper_pg_dir - reserved_pg_dir) as this cannot be calculated
 162 *  until link time.
 163 */
 164#define RESERVED_SWAPPER_OFFSET (PAGE_SIZE)
 165
 166/*
 167 *  Open-coded (swapper_pg_dir - tramp_pg_dir) as this cannot be calculated
 168 *  until link time.
 169 */
 170#define TRAMP_SWAPPER_OFFSET    (2 * PAGE_SIZE)
 171
 172#ifndef __ASSEMBLY__
 173
 174#include <linux/bitops.h>
 175#include <linux/compiler.h>
 176#include <linux/mmdebug.h>
 177#include <linux/types.h>
 178#include <asm/bug.h>
 179
 180extern u64                      vabits_actual;
 181
 182extern s64                      memstart_addr;
 183/* PHYS_OFFSET - the physical address of the start of memory. */
 184#define PHYS_OFFSET             ({ VM_BUG_ON(memstart_addr & 1); memstart_addr; })
 185
 186/* the virtual base of the kernel image */
 187extern u64                      kimage_vaddr;
 188
 189/* the offset between the kernel virtual and physical mappings */
 190extern u64                      kimage_voffset;
 191
 192static inline unsigned long kaslr_offset(void)
 193{
 194        return kimage_vaddr - KIMAGE_VADDR;
 195}
 196
 197/*
 198 * Allow all memory at the discovery stage. We will clip it later.
 199 */
 200#define MIN_MEMBLOCK_ADDR       0
 201#define MAX_MEMBLOCK_ADDR       U64_MAX
 202
 203/*
 204 * PFNs are used to describe any physical page; this means
 205 * PFN 0 == physical address 0.
 206 *
 207 * This is the PFN of the first RAM page in the kernel
 208 * direct-mapped view.  We assume this is the first page
 209 * of RAM in the mem_map as well.
 210 */
 211#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
 212
 213/*
 214 * When dealing with data aborts, watchpoints, or instruction traps we may end
 215 * up with a tagged userland pointer. Clear the tag to get a sane pointer to
 216 * pass on to access_ok(), for instance.
 217 */
 218#define __untagged_addr(addr)   \
 219        ((__force __typeof__(addr))sign_extend64((__force u64)(addr), 55))
 220
 221#define untagged_addr(addr)     ({                                      \
 222        u64 __addr = (__force u64)(addr);                                       \
 223        __addr &= __untagged_addr(__addr);                              \
 224        (__force __typeof__(addr))__addr;                               \
 225})
 226
 227#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
 228#define __tag_shifted(tag)      ((u64)(tag) << 56)
 229#define __tag_reset(addr)       __untagged_addr(addr)
 230#define __tag_get(addr)         (__u8)((u64)(addr) >> 56)
 231#else
 232#define __tag_shifted(tag)      0UL
 233#define __tag_reset(addr)       (addr)
 234#define __tag_get(addr)         0
 235#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
 236
 237static inline const void *__tag_set(const void *addr, u8 tag)
 238{
 239        u64 __addr = (u64)addr & ~__tag_shifted(0xff);
 240        return (const void *)(__addr | __tag_shifted(tag));
 241}
 242
 243#ifdef CONFIG_KASAN_HW_TAGS
 244#define arch_enable_tagging_sync()              mte_enable_kernel_sync()
 245#define arch_enable_tagging_async()             mte_enable_kernel_async()
 246#define arch_set_tagging_report_once(state)     mte_set_report_once(state)
 247#define arch_force_async_tag_fault()            mte_check_tfsr_exit()
 248#define arch_init_tags(max_tag)                 mte_init_tags(max_tag)
 249#define arch_get_random_tag()                   mte_get_random_tag()
 250#define arch_get_mem_tag(addr)                  mte_get_mem_tag(addr)
 251#define arch_set_mem_tag_range(addr, size, tag, init)   \
 252                        mte_set_mem_tag_range((addr), (size), (tag), (init))
 253#endif /* CONFIG_KASAN_HW_TAGS */
 254
 255/*
 256 * Physical vs virtual RAM address space conversion.  These are
 257 * private definitions which should NOT be used outside memory.h
 258 * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
 259 */
 260
 261
 262/*
 263 * Check whether an arbitrary address is within the linear map, which
 264 * lives in the [PAGE_OFFSET, PAGE_END) interval at the bottom of the
 265 * kernel's TTBR1 address range.
 266 */
 267#define __is_lm_address(addr)   (((u64)(addr) - PAGE_OFFSET) < (PAGE_END - PAGE_OFFSET))
 268
 269#define __lm_to_phys(addr)      (((addr) - PAGE_OFFSET) + PHYS_OFFSET)
 270#define __kimg_to_phys(addr)    ((addr) - kimage_voffset)
 271
 272#define __virt_to_phys_nodebug(x) ({                                    \
 273        phys_addr_t __x = (phys_addr_t)(__tag_reset(x));                \
 274        __is_lm_address(__x) ? __lm_to_phys(__x) : __kimg_to_phys(__x); \
 275})
 276
 277#define __pa_symbol_nodebug(x)  __kimg_to_phys((phys_addr_t)(x))
 278
 279#ifdef CONFIG_DEBUG_VIRTUAL
 280extern phys_addr_t __virt_to_phys(unsigned long x);
 281extern phys_addr_t __phys_addr_symbol(unsigned long x);
 282#else
 283#define __virt_to_phys(x)       __virt_to_phys_nodebug(x)
 284#define __phys_addr_symbol(x)   __pa_symbol_nodebug(x)
 285#endif /* CONFIG_DEBUG_VIRTUAL */
 286
 287#define __phys_to_virt(x)       ((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
 288#define __phys_to_kimg(x)       ((unsigned long)((x) + kimage_voffset))
 289
 290/*
 291 * Convert a page to/from a physical address
 292 */
 293#define page_to_phys(page)      (__pfn_to_phys(page_to_pfn(page)))
 294#define phys_to_page(phys)      (pfn_to_page(__phys_to_pfn(phys)))
 295
 296/*
 297 * Note: Drivers should NOT use these.  They are the wrong
 298 * translation for translating DMA addresses.  Use the driver
 299 * DMA support - see dma-mapping.h.
 300 */
 301#define virt_to_phys virt_to_phys
 302static inline phys_addr_t virt_to_phys(const volatile void *x)
 303{
 304        return __virt_to_phys((unsigned long)(x));
 305}
 306
 307#define phys_to_virt phys_to_virt
 308static inline void *phys_to_virt(phys_addr_t x)
 309{
 310        return (void *)(__phys_to_virt(x));
 311}
 312
 313/*
 314 * Drivers should NOT use these either.
 315 */
 316#define __pa(x)                 __virt_to_phys((unsigned long)(x))
 317#define __pa_symbol(x)          __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
 318#define __pa_nodebug(x)         __virt_to_phys_nodebug((unsigned long)(x))
 319#define __va(x)                 ((void *)__phys_to_virt((phys_addr_t)(x)))
 320#define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 321#define virt_to_pfn(x)          __phys_to_pfn(__virt_to_phys((unsigned long)(x)))
 322#define sym_to_pfn(x)           __phys_to_pfn(__pa_symbol(x))
 323
 324/*
 325 *  virt_to_page(x)     convert a _valid_ virtual address to struct page *
 326 *  virt_addr_valid(x)  indicates whether a virtual address is valid
 327 */
 328#define ARCH_PFN_OFFSET         ((unsigned long)PHYS_PFN_OFFSET)
 329
 330#if defined(CONFIG_DEBUG_VIRTUAL)
 331#define page_to_virt(x) ({                                              \
 332        __typeof__(x) __page = x;                                       \
 333        void *__addr = __va(page_to_phys(__page));                      \
 334        (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
 335})
 336#define virt_to_page(x)         pfn_to_page(virt_to_pfn(x))
 337#else
 338#define page_to_virt(x) ({                                              \
 339        __typeof__(x) __page = x;                                       \
 340        u64 __idx = ((u64)__page - VMEMMAP_START) / sizeof(struct page);\
 341        u64 __addr = PAGE_OFFSET + (__idx * PAGE_SIZE);                 \
 342        (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
 343})
 344
 345#define virt_to_page(x) ({                                              \
 346        u64 __idx = (__tag_reset((u64)x) - PAGE_OFFSET) / PAGE_SIZE;    \
 347        u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));     \
 348        (struct page *)__addr;                                          \
 349})
 350#endif /* CONFIG_DEBUG_VIRTUAL */
 351
 352#define virt_addr_valid(addr)   ({                                      \
 353        __typeof__(addr) __addr = __tag_reset(addr);                    \
 354        __is_lm_address(__addr) && pfn_is_map_memory(virt_to_pfn(__addr));      \
 355})
 356
 357void dump_mem_limit(void);
 358#endif /* !ASSEMBLY */
 359
 360/*
 361 * Given that the GIC architecture permits ITS implementations that can only be
 362 * configured with a LPI table address once, GICv3 systems with many CPUs may
 363 * end up reserving a lot of different regions after a kexec for their LPI
 364 * tables (one per CPU), as we are forced to reuse the same memory after kexec
 365 * (and thus reserve it persistently with EFI beforehand)
 366 */
 367#if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
 368# define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
 369#endif
 370
 371#include <asm-generic/memory_model.h>
 372
 373#endif /* __ASM_MEMORY_H */
 374