arch/powerpc/include/asm/page.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 #ifndef _ASM_POWERPC_PAGE_H
   3 #define _ASM_POWERPC_PAGE_H
   4
   5 /*
   6  * Copyright (C) 2001,2005 IBM Corporation.
   7  */
   8
   9 #ifndef __ASSEMBLY__
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/bug.h>
  13 #else
  14 #include <asm/types.h>
  15 #endif
  16 #include <asm/asm-const.h>
  17
  18 /*
  19  * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
  20  * on PPC44x and 4K/16K on 8xx). For PPC64 we support either 4K or 64K software
  21  * page size. When using 64K pages however, whether we are really supporting
  22  * 64K pages in HW or not is irrelevant to those definitions.
  23  */
  24 #include <vdso/page.h>
  25
  26 #ifndef __ASSEMBLY__
  27 #ifndef CONFIG_HUGETLB_PAGE
  28 #define HPAGE_SHIFT PAGE_SHIFT
  29 #elif defined(CONFIG_PPC_BOOK3S_64)
  30 extern unsigned int hpage_shift;
  31 #define HPAGE_SHIFT hpage_shift
  32 #elif defined(CONFIG_PPC_8xx)
  33 #define HPAGE_SHIFT             19      /* 512k pages */
  34 #elif defined(CONFIG_PPC_E500)
  35 #define HPAGE_SHIFT             22      /* 4M pages */
  36 #endif
  37 #define HPAGE_SIZE              ((1UL) << HPAGE_SHIFT)
  38 #define HPAGE_MASK              (~(HPAGE_SIZE - 1))
  39 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
  40 #define HUGE_MAX_HSTATE         (MMU_PAGE_COUNT-1)
  41 #endif
  42
  43 /*
  44  * KERNELBASE is the virtual address of the start of the kernel, it's often
  45  * the same as PAGE_OFFSET, but _might not be_.
  46  *
  47  * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
  48  *
  49  * PAGE_OFFSET is the virtual address of the start of lowmem.
  50  *
  51  * PHYSICAL_START is the physical address of the start of the kernel.
  52  *
  53  * MEMORY_START is the physical address of the start of lowmem.
  54  *
  55  * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
  56  * ppc32 and based on how they are set we determine MEMORY_START.
  57  *
  58  * For the linear mapping the following equation should be true:
  59  * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
  60  *
  61  * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
  62  *
  63  * There are two ways to determine a physical address from a virtual one:
  64  * va = pa + PAGE_OFFSET - MEMORY_START
  65  * va = pa + KERNELBASE - PHYSICAL_START
  66  *
  67  * If you want to know something's offset from the start of the kernel you
  68  * should subtract KERNELBASE.
  69  *
  70  * If you want to test if something's a kernel address, use is_kernel_addr().
  71  */
  72
  73 #define KERNELBASE      ASM_CONST(CONFIG_KERNEL_START)
  74 #define PAGE_OFFSET     ASM_CONST(CONFIG_PAGE_OFFSET)
  75 #define LOAD_OFFSET     ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
  76
  77 #if defined(CONFIG_NONSTATIC_KERNEL)
  78 #ifndef __ASSEMBLY__
  79
  80 extern phys_addr_t memstart_addr;
  81 extern phys_addr_t kernstart_addr;
  82
  83 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32)
  84 extern long long virt_phys_offset;
  85 #endif
  86
  87 #endif /* __ASSEMBLY__ */
  88 #define PHYSICAL_START  kernstart_addr
  89
  90 #else   /* !CONFIG_NONSTATIC_KERNEL */
  91 #define PHYSICAL_START  ASM_CONST(CONFIG_PHYSICAL_START)
  92 #endif
  93
  94 /* See Description below for VIRT_PHYS_OFFSET */
  95 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
  96 #ifdef CONFIG_RELOCATABLE
  97 #define VIRT_PHYS_OFFSET virt_phys_offset
  98 #else
  99 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
 100 #endif
 101 #endif
 102
 103 #ifdef CONFIG_PPC64
 104 #define MEMORY_START    0UL
 105 #elif defined(CONFIG_NONSTATIC_KERNEL)
 106 #define MEMORY_START    memstart_addr
 107 #else
 108 #define MEMORY_START    (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
 109 #endif
 110
 111 #ifdef CONFIG_FLATMEM
 112 #define ARCH_PFN_OFFSET         ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
 113 #endif
 114
 115 /*
 116  * On Book-E parts we need __va to parse the device tree and we can't
 117  * determine MEMORY_START until then.  However we can determine PHYSICAL_START
 118  * from information at hand (program counter, TLB lookup).
 119  *
 120  * On BookE with RELOCATABLE && PPC32
 121  *
 122  *   With RELOCATABLE && PPC32,  we support loading the kernel at any physical
 123  *   address without any restriction on the page alignment.
 124  *
 125  *   We find the runtime address of _stext and relocate ourselves based on
 126  *   the following calculation:
 127  *
 128  *        virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
 129  *                              MODULO(_stext.run,256M)
 130  *   and create the following mapping:
 131  *
 132  *        ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
 133  *
 134  *   When we process relocations, we cannot depend on the
 135  *   existing equation for the __va()/__pa() translations:
 136  *
 137  *         __va(x) = (x)  - PHYSICAL_START + KERNELBASE
 138  *
 139  *   Where:
 140  *       PHYSICAL_START = kernstart_addr = Physical address of _stext
 141  *       KERNELBASE = Compiled virtual address of _stext.
 142  *
 143  *   This formula holds true iff, kernel load address is TLB page aligned.
 144  *
 145  *   In our case, we need to also account for the shift in the kernel Virtual
 146  *   address.
 147  *
 148  *   E.g.,
 149  *
 150  *   Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
 151  *   In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
 152  *
 153  *   Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
 154  *                 = 0xbc100000 , which is wrong.
 155  *
 156  *   Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
 157  *              according to our mapping.
 158  *
 159  *   Hence we use the following formula to get the translations right:
 160  *
 161  *        __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
 162  *
 163  *        Where :
 164  *              PHYSICAL_START = dynamic load address.(kernstart_addr variable)
 165  *              Effective KERNELBASE = virtual_base =
 166  *                                   = ALIGN_DOWN(KERNELBASE,256M) +
 167  *                                              MODULO(PHYSICAL_START,256M)
 168  *
 169  *      To make the cost of __va() / __pa() more light weight, we introduce
 170  *      a new variable virt_phys_offset, which will hold :
 171  *
 172  *      virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
 173  *                       = ALIGN_DOWN(KERNELBASE,256M) -
 174  *                              ALIGN_DOWN(PHYSICALSTART,256M)
 175  *
 176  *      Hence :
 177  *
 178  *      __va(x) = x - PHYSICAL_START + Effective KERNELBASE
 179  *              = x + virt_phys_offset
 180  *
 181  *              and
 182  *      __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
 183  *              = x - virt_phys_offset
 184  *
 185  * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
 186  * the other definitions for __va & __pa.
 187  */
 188 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
 189 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
 190 #define __pa(x) ((phys_addr_t)(unsigned long)(x) - VIRT_PHYS_OFFSET)
 191 #else
 192 #ifdef CONFIG_PPC64
 193
 194 #define VIRTUAL_WARN_ON(x)      WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x))
 195
 196 /*
 197  * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
 198  * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
 199  * This also results in better code generation.
 200  */
 201 #define __va(x)                                                         \
 202 ({                                                                      \
 203         VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET);             \
 204         (void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET);        \
 205 })
 206
 207 #define __pa(x)                                                         \
 208 ({                                                                      \
 209         VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET);              \
 210         (unsigned long)(x) & 0x0fffffffffffffffUL;                      \
 211 })
 212
 213 #else /* 32-bit, non book E */
 214 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
 215 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
 216 #endif
 217 #endif
 218
 219 #ifndef __ASSEMBLY__
 220 static inline unsigned long virt_to_pfn(const void *kaddr)
 221 {
 222         return __pa(kaddr) >> PAGE_SHIFT;
 223 }
 224
 225 static inline const void *pfn_to_kaddr(unsigned long pfn)
 226 {
 227         return __va(pfn << PAGE_SHIFT);
 228 }
 229 #endif
 230
 231 #define virt_to_page(kaddr)     pfn_to_page(virt_to_pfn(kaddr))
 232 #define virt_addr_valid(vaddr)  ({                                      \
 233         unsigned long _addr = (unsigned long)vaddr;                     \
 234         _addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory &&   \
 235         pfn_valid(virt_to_pfn((void *)_addr));                          \
 236 })
 237
 238 /*
 239  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
 240  * and needs to be executable.  This means the whole heap ends
 241  * up being executable.
 242  */
 243 #define VM_DATA_DEFAULT_FLAGS32 VM_DATA_FLAGS_TSK_EXEC
 244 #define VM_DATA_DEFAULT_FLAGS64 VM_DATA_FLAGS_NON_EXEC
 245
 246 #ifdef __powerpc64__
 247 #include <asm/page_64.h>
 248 #else
 249 #include <asm/page_32.h>
 250 #endif
 251
 252 /*
 253  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
 254  * "kernelness", use is_kernel_addr() - it should do what you want.
 255  */
 256 #ifdef CONFIG_PPC_BOOK3E_64
 257 #define is_kernel_addr(x)       ((x) >= 0x8000000000000000ul)
 258 #elif defined(CONFIG_PPC_BOOK3S_64)
 259 #define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 260 #else
 261 #define is_kernel_addr(x)       ((x) >= TASK_SIZE)
 262 #endif
 263
 264 #ifndef __ASSEMBLY__
 265
 266 #ifdef CONFIG_PPC_BOOK3S_64
 267 #include <asm/pgtable-be-types.h>
 268 #else
 269 #include <asm/pgtable-types.h>
 270 #endif
 271
 272 struct page;
 273 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 274 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 275                 struct page *p);
 276 extern int devmem_is_allowed(unsigned long pfn);
 277
 278 #ifdef CONFIG_PPC_SMLPAR
 279 void arch_free_page(struct page *page, int order);
 280 #define HAVE_ARCH_FREE_PAGE
 281 #endif
 282
 283 struct vm_area_struct;
 284
 285 extern unsigned long kernstart_virt_addr;
 286
 287 static inline unsigned long kaslr_offset(void)
 288 {
 289         return kernstart_virt_addr - KERNELBASE;
 290 }
 291
 292 #include <asm-generic/memory_model.h>
 293 #endif /* __ASSEMBLY__ */
 294
 295 #endif /* _ASM_POWERPC_PAGE_H */