root/arch/arm64/include/asm/memory.h

INCLUDED FROM

DEFINITIONS

1. kaslr_offset
2. __tag_set
3. virt_to_phys
4. phys_to_virt

   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/compiler.h>
  14 #include <linux/const.h>
  15 #include <linux/sizes.h>
  16 #include <linux/types.h>
  17 #include <asm/bug.h>
  18 #include <asm/page-def.h>
  19 
  20 /*
  21  * Size of the PCI I/O space. This must remain a power of two so that
  22  * IO_SPACE_LIMIT acts as a mask for the low bits of I/O addresses.
  23  */
  24 #define PCI_IO_SIZE             SZ_16M
  25 
  26 /*
  27  * VMEMMAP_SIZE - allows the whole linear region to be covered by
  28  *                a struct page array
  29  *
  30  * If we are configured with a 52-bit kernel VA then our VMEMMAP_SIZE
  31  * needs to cover the memory region from the beginning of the 52-bit
  32  * PAGE_OFFSET all the way to PAGE_END for 48-bit. This allows us to
  33  * keep a constant PAGE_OFFSET and "fallback" to using the higher end
  34  * of the VMEMMAP where 52-bit support is not available in hardware.
  35  */
  36 #define VMEMMAP_SIZE ((_PAGE_END(VA_BITS_MIN) - PAGE_OFFSET) \
  37                         >> (PAGE_SHIFT - STRUCT_PAGE_MAX_SHIFT))
  38 
  39 /*
  40  * PAGE_OFFSET - the virtual address of the start of the linear map, at the
  41  *               start of the TTBR1 address space.
  42  * PAGE_END - the end of the linear map, where all other kernel mappings begin.
  43  * KIMAGE_VADDR - the virtual address of the start of the kernel image.
  44  * VA_BITS - the maximum number of bits for virtual addresses.
  45  */
  46 #define VA_BITS                 (CONFIG_ARM64_VA_BITS)
  47 #define _PAGE_OFFSET(va)        (-(UL(1) << (va)))
  48 #define PAGE_OFFSET             (_PAGE_OFFSET(VA_BITS))
  49 #define KIMAGE_VADDR            (MODULES_END)
  50 #define BPF_JIT_REGION_START    (KASAN_SHADOW_END)
  51 #define BPF_JIT_REGION_SIZE     (SZ_128M)
  52 #define BPF_JIT_REGION_END      (BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE)
  53 #define MODULES_END             (MODULES_VADDR + MODULES_VSIZE)
  54 #define MODULES_VADDR           (BPF_JIT_REGION_END)
  55 #define MODULES_VSIZE           (SZ_128M)
  56 #define VMEMMAP_START           (-VMEMMAP_SIZE - SZ_2M)
  57 #define PCI_IO_END              (VMEMMAP_START - SZ_2M)
  58 #define PCI_IO_START            (PCI_IO_END - PCI_IO_SIZE)
  59 #define FIXADDR_TOP             (PCI_IO_START - SZ_2M)
  60 
  61 #if VA_BITS > 48
  62 #define VA_BITS_MIN             (48)
  63 #else
  64 #define VA_BITS_MIN             (VA_BITS)
  65 #endif
  66 
  67 #define _PAGE_END(va)           (-(UL(1) << ((va) - 1)))
  68 
  69 #define KERNEL_START            _text
  70 #define KERNEL_END              _end
  71 
  72 #ifdef CONFIG_ARM64_VA_BITS_52
  73 #define MAX_USER_VA_BITS        52
  74 #else
  75 #define MAX_USER_VA_BITS        VA_BITS
  76 #endif
  77 
  78 /*
  79  * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual
  80  * address space for the shadow region respectively. They can bloat the stack
  81  * significantly, so double the (minimum) stack size when they are in use.
  82  */
  83 #ifdef CONFIG_KASAN
  84 #define KASAN_SHADOW_OFFSET     _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
  85 #define KASAN_SHADOW_END        ((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) \
  86                                         + KASAN_SHADOW_OFFSET)
  87 #define KASAN_THREAD_SHIFT      1
  88 #else
  89 #define KASAN_THREAD_SHIFT      0
  90 #define KASAN_SHADOW_END        (_PAGE_END(VA_BITS_MIN))
  91 #endif /* CONFIG_KASAN */
  92 
  93 #define MIN_THREAD_SHIFT        (14 + KASAN_THREAD_SHIFT)
  94 
  95 /*
  96  * VMAP'd stacks are allocated at page granularity, so we must ensure that such
  97  * stacks are a multiple of page size.
  98  */
  99 #if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
 100 #define THREAD_SHIFT            PAGE_SHIFT
 101 #else
 102 #define THREAD_SHIFT            MIN_THREAD_SHIFT
 103 #endif
 104 
 105 #if THREAD_SHIFT >= PAGE_SHIFT
 106 #define THREAD_SIZE_ORDER       (THREAD_SHIFT - PAGE_SHIFT)
 107 #endif
 108 
 109 #define THREAD_SIZE             (UL(1) << THREAD_SHIFT)
 110 
 111 /*
 112  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
 113  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
 114  * assembly.
 115  */
 116 #ifdef CONFIG_VMAP_STACK
 117 #define THREAD_ALIGN            (2 * THREAD_SIZE)
 118 #else
 119 #define THREAD_ALIGN            THREAD_SIZE
 120 #endif
 121 
 122 #define IRQ_STACK_SIZE          THREAD_SIZE
 123 
 124 #define OVERFLOW_STACK_SIZE     SZ_4K
 125 
 126 /*
 127  * Alignment of kernel segments (e.g. .text, .data).
 128  */
 129 #if defined(CONFIG_DEBUG_ALIGN_RODATA)
 130 /*
 131  *  4 KB granule:   1 level 2 entry
 132  * 16 KB granule: 128 level 3 entries, with contiguous bit
 133  * 64 KB granule:  32 level 3 entries, with contiguous bit
 134  */
 135 #define SEGMENT_ALIGN           SZ_2M
 136 #else
 137 /*
 138  *  4 KB granule:  16 level 3 entries, with contiguous bit
 139  * 16 KB granule:   4 level 3 entries, without contiguous bit
 140  * 64 KB granule:   1 level 3 entry
 141  */
 142 #define SEGMENT_ALIGN           SZ_64K
 143 #endif
 144 
 145 /*
 146  * Memory types available.
 147  */
 148 #define MT_DEVICE_nGnRnE        0
 149 #define MT_DEVICE_nGnRE         1
 150 #define MT_DEVICE_GRE           2
 151 #define MT_NORMAL_NC            3
 152 #define MT_NORMAL               4
 153 #define MT_NORMAL_WT            5
 154 
 155 /*
 156  * Memory types for Stage-2 translation
 157  */
 158 #define MT_S2_NORMAL            0xf
 159 #define MT_S2_DEVICE_nGnRE      0x1
 160 
 161 /*
 162  * Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
 163  * Stage-2 enforces Normal-WB and Device-nGnRE
 164  */
 165 #define MT_S2_FWB_NORMAL        6
 166 #define MT_S2_FWB_DEVICE_nGnRE  1
 167 
 168 #ifdef CONFIG_ARM64_4K_PAGES
 169 #define IOREMAP_MAX_ORDER       (PUD_SHIFT)
 170 #else
 171 #define IOREMAP_MAX_ORDER       (PMD_SHIFT)
 172 #endif
 173 
 174 #ifndef __ASSEMBLY__
 175 extern u64                      vabits_actual;
 176 #define PAGE_END                (_PAGE_END(vabits_actual))
 177 
 178 #include <linux/bitops.h>
 179 #include <linux/mmdebug.h>
 180 
 181 extern s64                      physvirt_offset;
 182 extern 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 (minus TEXT_OFFSET) */
 187 extern u64                      kimage_vaddr;
 188 
 189 /* the offset between the kernel virtual and physical mappings */
 190 extern u64                      kimage_voffset;
 191 
 192 static 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 #ifdef CONFIG_KASAN_SW_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 */
 236 
 237 static 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 /*
 244  * Physical vs virtual RAM address space conversion.  These are
 245  * private definitions which should NOT be used outside memory.h
 246  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
 247  */
 248 
 249 
 250 /*
 251  * The linear kernel range starts at the bottom of the virtual address
 252  * space. Testing the top bit for the start of the region is a
 253  * sufficient check and avoids having to worry about the tag.
 254  */
 255 #define __is_lm_address(addr)   (!(((u64)addr) & BIT(vabits_actual - 1)))
 256 
 257 #define __lm_to_phys(addr)      (((addr) + physvirt_offset))
 258 #define __kimg_to_phys(addr)    ((addr) - kimage_voffset)
 259 
 260 #define __virt_to_phys_nodebug(x) ({                                    \
 261         phys_addr_t __x = (phys_addr_t)(__tag_reset(x));                \
 262         __is_lm_address(__x) ? __lm_to_phys(__x) : __kimg_to_phys(__x); \
 263 })
 264 
 265 #define __pa_symbol_nodebug(x)  __kimg_to_phys((phys_addr_t)(x))
 266 
 267 #ifdef CONFIG_DEBUG_VIRTUAL
 268 extern phys_addr_t __virt_to_phys(unsigned long x);
 269 extern phys_addr_t __phys_addr_symbol(unsigned long x);
 270 #else
 271 #define __virt_to_phys(x)       __virt_to_phys_nodebug(x)
 272 #define __phys_addr_symbol(x)   __pa_symbol_nodebug(x)
 273 #endif /* CONFIG_DEBUG_VIRTUAL */
 274 
 275 #define __phys_to_virt(x)       ((unsigned long)((x) - physvirt_offset))
 276 #define __phys_to_kimg(x)       ((unsigned long)((x) + kimage_voffset))
 277 
 278 /*
 279  * Convert a page to/from a physical address
 280  */
 281 #define page_to_phys(page)      (__pfn_to_phys(page_to_pfn(page)))
 282 #define phys_to_page(phys)      (pfn_to_page(__phys_to_pfn(phys)))
 283 
 284 /*
 285  * Note: Drivers should NOT use these.  They are the wrong
 286  * translation for translating DMA addresses.  Use the driver
 287  * DMA support - see dma-mapping.h.
 288  */
 289 #define virt_to_phys virt_to_phys
 290 static inline phys_addr_t virt_to_phys(const volatile void *x)
 291 {
 292         return __virt_to_phys((unsigned long)(x));
 293 }
 294 
 295 #define phys_to_virt phys_to_virt
 296 static inline void *phys_to_virt(phys_addr_t x)
 297 {
 298         return (void *)(__phys_to_virt(x));
 299 }
 300 
 301 /*
 302  * Drivers should NOT use these either.
 303  */
 304 #define __pa(x)                 __virt_to_phys((unsigned long)(x))
 305 #define __pa_symbol(x)          __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
 306 #define __pa_nodebug(x)         __virt_to_phys_nodebug((unsigned long)(x))
 307 #define __va(x)                 ((void *)__phys_to_virt((phys_addr_t)(x)))
 308 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 309 #define virt_to_pfn(x)          __phys_to_pfn(__virt_to_phys((unsigned long)(x)))
 310 #define sym_to_pfn(x)           __phys_to_pfn(__pa_symbol(x))
 311 
 312 /*
 313  *  virt_to_page(x)     convert a _valid_ virtual address to struct page *
 314  *  virt_addr_valid(x)  indicates whether a virtual address is valid
 315  */
 316 #define ARCH_PFN_OFFSET         ((unsigned long)PHYS_PFN_OFFSET)
 317 
 318 #if !defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_DEBUG_VIRTUAL)
 319 #define virt_to_page(x)         pfn_to_page(virt_to_pfn(x))
 320 #else
 321 #define page_to_virt(x) ({                                              \
 322         __typeof__(x) __page = x;                                       \
 323         u64 __idx = ((u64)__page - VMEMMAP_START) / sizeof(struct page);\
 324         u64 __addr = PAGE_OFFSET + (__idx * PAGE_SIZE);                 \
 325         (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
 326 })
 327 
 328 #define virt_to_page(x) ({                                              \
 329         u64 __idx = (__tag_reset((u64)x) - PAGE_OFFSET) / PAGE_SIZE;    \
 330         u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));     \
 331         (struct page *)__addr;                                          \
 332 })
 333 #endif /* !CONFIG_SPARSEMEM_VMEMMAP || CONFIG_DEBUG_VIRTUAL */
 334 
 335 #define virt_addr_valid(addr)   ({                                      \
 336         __typeof__(addr) __addr = addr;                                 \
 337         __is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr));      \
 338 })
 339 
 340 #endif /* !ASSEMBLY */
 341 
 342 /*
 343  * Given that the GIC architecture permits ITS implementations that can only be
 344  * configured with a LPI table address once, GICv3 systems with many CPUs may
 345  * end up reserving a lot of different regions after a kexec for their LPI
 346  * tables (one per CPU), as we are forced to reuse the same memory after kexec
 347  * (and thus reserve it persistently with EFI beforehand)
 348  */
 349 #if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
 350 # define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
 351 #endif
 352 
 353 #include <asm-generic/memory_model.h>
 354 
 355 #endif /* __ASM_MEMORY_H */