arch/powerpc/include/asm/nohash/pgtable.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_POWERPC_NOHASH_PGTABLE_H
   3 #define _ASM_POWERPC_NOHASH_PGTABLE_H
   4
   5 #if defined(CONFIG_PPC64)
   6 #include <asm/nohash/64/pgtable.h>
   7 #else
   8 #include <asm/nohash/32/pgtable.h>
   9 #endif
  10
  11 /* Permission masks used for kernel mappings */
  12 #define PAGE_KERNEL     __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
  13 #define PAGE_KERNEL_NC  __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)
  14 #define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
  15                                  _PAGE_NO_CACHE | _PAGE_GUARDED)
  16 #define PAGE_KERNEL_X   __pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
  17 #define PAGE_KERNEL_RO  __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
  18 #define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
  19
  20 /*
  21  * Protection used for kernel text. We want the debuggers to be able to
  22  * set breakpoints anywhere, so don't write protect the kernel text
  23  * on platforms where such control is possible.
  24  */
  25 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
  26         defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
  27 #define PAGE_KERNEL_TEXT        PAGE_KERNEL_X
  28 #else
  29 #define PAGE_KERNEL_TEXT        PAGE_KERNEL_ROX
  30 #endif
  31
  32 /* Make modules code happy. We don't set RO yet */
  33 #define PAGE_KERNEL_EXEC        PAGE_KERNEL_X
  34
  35 /* Advertise special mapping type for AGP */
  36 #define PAGE_AGP                (PAGE_KERNEL_NC)
  37 #define HAVE_PAGE_AGP
  38
  39 #ifndef __ASSEMBLY__
  40
  41 /* Generic accessors to PTE bits */
  42 #ifndef pte_write
  43 static inline int pte_write(pte_t pte)
  44 {
  45         return pte_val(pte) & _PAGE_RW;
  46 }
  47 #endif
  48 static inline int pte_read(pte_t pte)           { return 1; }
  49 static inline int pte_dirty(pte_t pte)          { return pte_val(pte) & _PAGE_DIRTY; }
  50 static inline int pte_special(pte_t pte)        { return pte_val(pte) & _PAGE_SPECIAL; }
  51 static inline int pte_none(pte_t pte)           { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
  52 static inline bool pte_hashpte(pte_t pte)       { return false; }
  53 static inline bool pte_ci(pte_t pte)            { return pte_val(pte) & _PAGE_NO_CACHE; }
  54 static inline bool pte_exec(pte_t pte)          { return pte_val(pte) & _PAGE_EXEC; }
  55
  56 #ifdef CONFIG_NUMA_BALANCING
  57 /*
  58  * These work without NUMA balancing but the kernel does not care. See the
  59  * comment in include/linux/pgtable.h . On powerpc, this will only
  60  * work for user pages and always return true for kernel pages.
  61  */
  62 static inline int pte_protnone(pte_t pte)
  63 {
  64         return pte_present(pte) && !pte_user(pte);
  65 }
  66
  67 static inline int pmd_protnone(pmd_t pmd)
  68 {
  69         return pte_protnone(pmd_pte(pmd));
  70 }
  71 #endif /* CONFIG_NUMA_BALANCING */
  72
  73 static inline int pte_present(pte_t pte)
  74 {
  75         return pte_val(pte) & _PAGE_PRESENT;
  76 }
  77
  78 static inline bool pte_hw_valid(pte_t pte)
  79 {
  80         return pte_val(pte) & _PAGE_PRESENT;
  81 }
  82
  83 /*
  84  * Don't just check for any non zero bits in __PAGE_USER, since for book3e
  85  * and PTE_64BIT, PAGE_KERNEL_X contains _PAGE_BAP_SR which is also in
  86  * _PAGE_USER.  Need to explicitly match _PAGE_BAP_UR bit in that case too.
  87  */
  88 #ifndef pte_user
  89 static inline bool pte_user(pte_t pte)
  90 {
  91         return (pte_val(pte) & _PAGE_USER) == _PAGE_USER;
  92 }
  93 #endif
  94
  95 /*
  96  * We only find page table entry in the last level
  97  * Hence no need for other accessors
  98  */
  99 #define pte_access_permitted pte_access_permitted
 100 static inline bool pte_access_permitted(pte_t pte, bool write)
 101 {
 102         /*
 103          * A read-only access is controlled by _PAGE_USER bit.
 104          * We have _PAGE_READ set for WRITE and EXECUTE
 105          */
 106         if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
 107                 return false;
 108
 109         if (write && !pte_write(pte))
 110                 return false;
 111
 112         return true;
 113 }
 114
 115 /* Conversion functions: convert a page and protection to a page entry,
 116  * and a page entry and page directory to the page they refer to.
 117  *
 118  * Even if PTEs can be unsigned long long, a PFN is always an unsigned
 119  * long for now.
 120  */
 121 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
 122         return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
 123                      pgprot_val(pgprot)); }
 124 static inline unsigned long pte_pfn(pte_t pte)  {
 125         return pte_val(pte) >> PTE_RPN_SHIFT; }
 126
 127 /* Generic modifiers for PTE bits */
 128 static inline pte_t pte_exprotect(pte_t pte)
 129 {
 130         return __pte(pte_val(pte) & ~_PAGE_EXEC);
 131 }
 132
 133 static inline pte_t pte_mkclean(pte_t pte)
 134 {
 135         return __pte(pte_val(pte) & ~_PAGE_DIRTY);
 136 }
 137
 138 static inline pte_t pte_mkold(pte_t pte)
 139 {
 140         return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
 141 }
 142
 143 static inline pte_t pte_mkspecial(pte_t pte)
 144 {
 145         return __pte(pte_val(pte) | _PAGE_SPECIAL);
 146 }
 147
 148 #ifndef pte_mkhuge
 149 static inline pte_t pte_mkhuge(pte_t pte)
 150 {
 151         return __pte(pte_val(pte));
 152 }
 153 #endif
 154
 155 #ifndef pte_mkprivileged
 156 static inline pte_t pte_mkprivileged(pte_t pte)
 157 {
 158         return __pte(pte_val(pte) & ~_PAGE_USER);
 159 }
 160 #endif
 161
 162 #ifndef pte_mkuser
 163 static inline pte_t pte_mkuser(pte_t pte)
 164 {
 165         return __pte(pte_val(pte) | _PAGE_USER);
 166 }
 167 #endif
 168
 169 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 170 {
 171         return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
 172 }
 173
 174 /* Insert a PTE, top-level function is out of line. It uses an inline
 175  * low level function in the respective pgtable-* files
 176  */
 177 extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 178                        pte_t pte);
 179
 180 /* This low level function performs the actual PTE insertion
 181  * Setting the PTE depends on the MMU type and other factors. It's
 182  * an horrible mess that I'm not going to try to clean up now but
 183  * I'm keeping it in one place rather than spread around
 184  */
 185 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 186                                 pte_t *ptep, pte_t pte, int percpu)
 187 {
 188         /* Second case is 32-bit with 64-bit PTE.  In this case, we
 189          * can just store as long as we do the two halves in the right order
 190          * with a barrier in between.
 191          * In the percpu case, we also fallback to the simple update
 192          */
 193         if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) {
 194                 __asm__ __volatile__("\
 195                         stw%X0 %2,%0\n\
 196                         mbar\n\
 197                         stw%X1 %L2,%1"
 198                 : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
 199                 : "r" (pte) : "memory");
 200                 return;
 201         }
 202         /* Anything else just stores the PTE normally. That covers all 64-bit
 203          * cases, and 32-bit non-hash with 32-bit PTEs.
 204          */
 205 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
 206         ptep->pte = ptep->pte1 = ptep->pte2 = ptep->pte3 = pte_val(pte);
 207 #else
 208         *ptep = pte;
 209 #endif
 210
 211         /*
 212          * With hardware tablewalk, a sync is needed to ensure that
 213          * subsequent accesses see the PTE we just wrote.  Unlike userspace
 214          * mappings, we can't tolerate spurious faults, so make sure
 215          * the new PTE will be seen the first time.
 216          */
 217         if (IS_ENABLED(CONFIG_PPC_BOOK3E_64) && is_kernel_addr(addr))
 218                 mb();
 219 }
 220
 221
 222 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 223 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
 224                                  pte_t *ptep, pte_t entry, int dirty);
 225
 226 /*
 227  * Macro to mark a page protection value as "uncacheable".
 228  */
 229
 230 #define _PAGE_CACHE_CTL (_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
 231                          _PAGE_WRITETHRU)
 232
 233 #define pgprot_noncached(prot)    (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
 234                                             _PAGE_NO_CACHE | _PAGE_GUARDED))
 235
 236 #define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
 237                                             _PAGE_NO_CACHE))
 238
 239 #define pgprot_cached(prot)       (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
 240                                             _PAGE_COHERENT))
 241
 242 #if _PAGE_WRITETHRU != 0
 243 #define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
 244                                             _PAGE_COHERENT | _PAGE_WRITETHRU))
 245 #else
 246 #define pgprot_cached_wthru(prot)       pgprot_noncached(prot)
 247 #endif
 248
 249 #define pgprot_cached_noncoherent(prot) \
 250                 (__pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL))
 251
 252 #define pgprot_writecombine pgprot_noncached_wc
 253
 254 struct file;
 255 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 256                                      unsigned long size, pgprot_t vma_prot);
 257 #define __HAVE_PHYS_MEM_ACCESS_PROT
 258
 259 #ifdef CONFIG_HUGETLB_PAGE
 260 static inline int hugepd_ok(hugepd_t hpd)
 261 {
 262 #ifdef CONFIG_PPC_8xx
 263         return ((hpd_val(hpd) & _PMD_PAGE_MASK) == _PMD_PAGE_8M);
 264 #else
 265         /* We clear the top bit to indicate hugepd */
 266         return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
 267 #endif
 268 }
 269
 270 static inline int pmd_huge(pmd_t pmd)
 271 {
 272         return 0;
 273 }
 274
 275 static inline int pud_huge(pud_t pud)
 276 {
 277         return 0;
 278 }
 279
 280 #define is_hugepd(hpd)          (hugepd_ok(hpd))
 281 #endif
 282
 283 /*
 284  * This gets called at the end of handling a page fault, when
 285  * the kernel has put a new PTE into the page table for the process.
 286  * We use it to ensure coherency between the i-cache and d-cache
 287  * for the page which has just been mapped in.
 288  */
 289 #if defined(CONFIG_PPC_FSL_BOOK3E) && defined(CONFIG_HUGETLB_PAGE)
 290 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
 291 #else
 292 static inline
 293 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) {}
 294 #endif
 295
 296 #endif /* __ASSEMBLY__ */
 297 #endif