root/arch/arm/include/asm/cacheflush.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. __flush_icache_all
  2. vivt_flush_cache_mm
  3. vivt_flush_cache_range
  4. vivt_flush_cache_page
  5. flush_kernel_vmap_range
  6. invalidate_kernel_vmap_range
  7. flush_anon_page
  8. flush_cache_vmap
  9. flush_cache_vunmap
  10. __sync_cache_range_w
  11. __sync_cache_range_r
  12. check_cpu_icache_size

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *  arch/arm/include/asm/cacheflush.h
   4  *
   5  *  Copyright (C) 1999-2002 Russell King
   6  */
   7 #ifndef _ASMARM_CACHEFLUSH_H
   8 #define _ASMARM_CACHEFLUSH_H
   9 
  10 #include <linux/mm.h>
  11 
  12 #include <asm/glue-cache.h>
  13 #include <asm/shmparam.h>
  14 #include <asm/cachetype.h>
  15 #include <asm/outercache.h>
  16 
  17 #define CACHE_COLOUR(vaddr)     ((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)
  18 
  19 /*
  20  * This flag is used to indicate that the page pointed to by a pte is clean
  21  * and does not require cleaning before returning it to the user.
  22  */
  23 #define PG_dcache_clean PG_arch_1
  24 
  25 /*
  26  *      MM Cache Management
  27  *      ===================
  28  *
  29  *      The arch/arm/mm/cache-*.S and arch/arm/mm/proc-*.S files
  30  *      implement these methods.
  31  *
  32  *      Start addresses are inclusive and end addresses are exclusive;
  33  *      start addresses should be rounded down, end addresses up.
  34  *
  35  *      See Documentation/core-api/cachetlb.rst for more information.
  36  *      Please note that the implementation of these, and the required
  37  *      effects are cache-type (VIVT/VIPT/PIPT) specific.
  38  *
  39  *      flush_icache_all()
  40  *
  41  *              Unconditionally clean and invalidate the entire icache.
  42  *              Currently only needed for cache-v6.S and cache-v7.S, see
  43  *              __flush_icache_all for the generic implementation.
  44  *
  45  *      flush_kern_all()
  46  *
  47  *              Unconditionally clean and invalidate the entire cache.
  48  *
  49  *     flush_kern_louis()
  50  *
  51  *             Flush data cache levels up to the level of unification
  52  *             inner shareable and invalidate the I-cache.
  53  *             Only needed from v7 onwards, falls back to flush_cache_all()
  54  *             for all other processor versions.
  55  *
  56  *      flush_user_all()
  57  *
  58  *              Clean and invalidate all user space cache entries
  59  *              before a change of page tables.
  60  *
  61  *      flush_user_range(start, end, flags)
  62  *
  63  *              Clean and invalidate a range of cache entries in the
  64  *              specified address space before a change of page tables.
  65  *              - start - user start address (inclusive, page aligned)
  66  *              - end   - user end address   (exclusive, page aligned)
  67  *              - flags - vma->vm_flags field
  68  *
  69  *      coherent_kern_range(start, end)
  70  *
  71  *              Ensure coherency between the Icache and the Dcache in the
  72  *              region described by start, end.  If you have non-snooping
  73  *              Harvard caches, you need to implement this function.
  74  *              - start  - virtual start address
  75  *              - end    - virtual end address
  76  *
  77  *      coherent_user_range(start, end)
  78  *
  79  *              Ensure coherency between the Icache and the Dcache in the
  80  *              region described by start, end.  If you have non-snooping
  81  *              Harvard caches, you need to implement this function.
  82  *              - start  - virtual start address
  83  *              - end    - virtual end address
  84  *
  85  *      flush_kern_dcache_area(kaddr, size)
  86  *
  87  *              Ensure that the data held in page is written back.
  88  *              - kaddr  - page address
  89  *              - size   - region size
  90  *
  91  *      DMA Cache Coherency
  92  *      ===================
  93  *
  94  *      dma_flush_range(start, end)
  95  *
  96  *              Clean and invalidate the specified virtual address range.
  97  *              - start  - virtual start address
  98  *              - end    - virtual end address
  99  */
 100 
 101 struct cpu_cache_fns {
 102         void (*flush_icache_all)(void);
 103         void (*flush_kern_all)(void);
 104         void (*flush_kern_louis)(void);
 105         void (*flush_user_all)(void);
 106         void (*flush_user_range)(unsigned long, unsigned long, unsigned int);
 107 
 108         void (*coherent_kern_range)(unsigned long, unsigned long);
 109         int  (*coherent_user_range)(unsigned long, unsigned long);
 110         void (*flush_kern_dcache_area)(void *, size_t);
 111 
 112         void (*dma_map_area)(const void *, size_t, int);
 113         void (*dma_unmap_area)(const void *, size_t, int);
 114 
 115         void (*dma_flush_range)(const void *, const void *);
 116 } __no_randomize_layout;
 117 
 118 /*
 119  * Select the calling method
 120  */
 121 #ifdef MULTI_CACHE
 122 
 123 extern struct cpu_cache_fns cpu_cache;
 124 
 125 #define __cpuc_flush_icache_all         cpu_cache.flush_icache_all
 126 #define __cpuc_flush_kern_all           cpu_cache.flush_kern_all
 127 #define __cpuc_flush_kern_louis         cpu_cache.flush_kern_louis
 128 #define __cpuc_flush_user_all           cpu_cache.flush_user_all
 129 #define __cpuc_flush_user_range         cpu_cache.flush_user_range
 130 #define __cpuc_coherent_kern_range      cpu_cache.coherent_kern_range
 131 #define __cpuc_coherent_user_range      cpu_cache.coherent_user_range
 132 #define __cpuc_flush_dcache_area        cpu_cache.flush_kern_dcache_area
 133 
 134 /*
 135  * These are private to the dma-mapping API.  Do not use directly.
 136  * Their sole purpose is to ensure that data held in the cache
 137  * is visible to DMA, or data written by DMA to system memory is
 138  * visible to the CPU.
 139  */
 140 #define dmac_flush_range                cpu_cache.dma_flush_range
 141 
 142 #else
 143 
 144 extern void __cpuc_flush_icache_all(void);
 145 extern void __cpuc_flush_kern_all(void);
 146 extern void __cpuc_flush_kern_louis(void);
 147 extern void __cpuc_flush_user_all(void);
 148 extern void __cpuc_flush_user_range(unsigned long, unsigned long, unsigned int);
 149 extern void __cpuc_coherent_kern_range(unsigned long, unsigned long);
 150 extern int  __cpuc_coherent_user_range(unsigned long, unsigned long);
 151 extern void __cpuc_flush_dcache_area(void *, size_t);
 152 
 153 /*
 154  * These are private to the dma-mapping API.  Do not use directly.
 155  * Their sole purpose is to ensure that data held in the cache
 156  * is visible to DMA, or data written by DMA to system memory is
 157  * visible to the CPU.
 158  */
 159 extern void dmac_flush_range(const void *, const void *);
 160 
 161 #endif
 162 
 163 /*
 164  * Copy user data from/to a page which is mapped into a different
 165  * processes address space.  Really, we want to allow our "user
 166  * space" model to handle this.
 167  */
 168 extern void copy_to_user_page(struct vm_area_struct *, struct page *,
 169         unsigned long, void *, const void *, unsigned long);
 170 #define copy_from_user_page(vma, page, vaddr, dst, src, len) \
 171         do {                                                    \
 172                 memcpy(dst, src, len);                          \
 173         } while (0)
 174 
 175 /*
 176  * Convert calls to our calling convention.
 177  */
 178 
 179 /* Invalidate I-cache */
 180 #define __flush_icache_all_generic()                                    \
 181         asm("mcr        p15, 0, %0, c7, c5, 0"                          \
 182             : : "r" (0));
 183 
 184 /* Invalidate I-cache inner shareable */
 185 #define __flush_icache_all_v7_smp()                                     \
 186         asm("mcr        p15, 0, %0, c7, c1, 0"                          \
 187             : : "r" (0));
 188 
 189 /*
 190  * Optimized __flush_icache_all for the common cases. Note that UP ARMv7
 191  * will fall through to use __flush_icache_all_generic.
 192  */
 193 #if (defined(CONFIG_CPU_V7) && \
 194      (defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K))) || \
 195         defined(CONFIG_SMP_ON_UP)
 196 #define __flush_icache_preferred        __cpuc_flush_icache_all
 197 #elif __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
 198 #define __flush_icache_preferred        __flush_icache_all_v7_smp
 199 #elif __LINUX_ARM_ARCH__ == 6 && defined(CONFIG_ARM_ERRATA_411920)
 200 #define __flush_icache_preferred        __cpuc_flush_icache_all
 201 #else
 202 #define __flush_icache_preferred        __flush_icache_all_generic
 203 #endif
 204 
 205 static inline void __flush_icache_all(void)
 206 {
 207         __flush_icache_preferred();
 208         dsb(ishst);
 209 }
 210 
 211 /*
 212  * Flush caches up to Level of Unification Inner Shareable
 213  */
 214 #define flush_cache_louis()             __cpuc_flush_kern_louis()
 215 
 216 #define flush_cache_all()               __cpuc_flush_kern_all()
 217 
 218 static inline void vivt_flush_cache_mm(struct mm_struct *mm)
 219 {
 220         if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm)))
 221                 __cpuc_flush_user_all();
 222 }
 223 
 224 static inline void
 225 vivt_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 226 {
 227         struct mm_struct *mm = vma->vm_mm;
 228 
 229         if (!mm || cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm)))
 230                 __cpuc_flush_user_range(start & PAGE_MASK, PAGE_ALIGN(end),
 231                                         vma->vm_flags);
 232 }
 233 
 234 static inline void
 235 vivt_flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
 236 {
 237         struct mm_struct *mm = vma->vm_mm;
 238 
 239         if (!mm || cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) {
 240                 unsigned long addr = user_addr & PAGE_MASK;
 241                 __cpuc_flush_user_range(addr, addr + PAGE_SIZE, vma->vm_flags);
 242         }
 243 }
 244 
 245 #ifndef CONFIG_CPU_CACHE_VIPT
 246 #define flush_cache_mm(mm) \
 247                 vivt_flush_cache_mm(mm)
 248 #define flush_cache_range(vma,start,end) \
 249                 vivt_flush_cache_range(vma,start,end)
 250 #define flush_cache_page(vma,addr,pfn) \
 251                 vivt_flush_cache_page(vma,addr,pfn)
 252 #else
 253 extern void flush_cache_mm(struct mm_struct *mm);
 254 extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
 255 extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn);
 256 #endif
 257 
 258 #define flush_cache_dup_mm(mm) flush_cache_mm(mm)
 259 
 260 /*
 261  * flush_cache_user_range is used when we want to ensure that the
 262  * Harvard caches are synchronised for the user space address range.
 263  * This is used for the ARM private sys_cacheflush system call.
 264  */
 265 #define flush_cache_user_range(s,e)     __cpuc_coherent_user_range(s,e)
 266 
 267 /*
 268  * Perform necessary cache operations to ensure that data previously
 269  * stored within this range of addresses can be executed by the CPU.
 270  */
 271 #define flush_icache_range(s,e)         __cpuc_coherent_kern_range(s,e)
 272 
 273 /*
 274  * Perform necessary cache operations to ensure that the TLB will
 275  * see data written in the specified area.
 276  */
 277 #define clean_dcache_area(start,size)   cpu_dcache_clean_area(start, size)
 278 
 279 /*
 280  * flush_dcache_page is used when the kernel has written to the page
 281  * cache page at virtual address page->virtual.
 282  *
 283  * If this page isn't mapped (ie, page_mapping == NULL), or it might
 284  * have userspace mappings, then we _must_ always clean + invalidate
 285  * the dcache entries associated with the kernel mapping.
 286  *
 287  * Otherwise we can defer the operation, and clean the cache when we are
 288  * about to change to user space.  This is the same method as used on SPARC64.
 289  * See update_mmu_cache for the user space part.
 290  */
 291 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 292 extern void flush_dcache_page(struct page *);
 293 
 294 static inline void flush_kernel_vmap_range(void *addr, int size)
 295 {
 296         if ((cache_is_vivt() || cache_is_vipt_aliasing()))
 297           __cpuc_flush_dcache_area(addr, (size_t)size);
 298 }
 299 static inline void invalidate_kernel_vmap_range(void *addr, int size)
 300 {
 301         if ((cache_is_vivt() || cache_is_vipt_aliasing()))
 302           __cpuc_flush_dcache_area(addr, (size_t)size);
 303 }
 304 
 305 #define ARCH_HAS_FLUSH_ANON_PAGE
 306 static inline void flush_anon_page(struct vm_area_struct *vma,
 307                          struct page *page, unsigned long vmaddr)
 308 {
 309         extern void __flush_anon_page(struct vm_area_struct *vma,
 310                                 struct page *, unsigned long);
 311         if (PageAnon(page))
 312                 __flush_anon_page(vma, page, vmaddr);
 313 }
 314 
 315 #define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
 316 extern void flush_kernel_dcache_page(struct page *);
 317 
 318 #define flush_dcache_mmap_lock(mapping)         xa_lock_irq(&mapping->i_pages)
 319 #define flush_dcache_mmap_unlock(mapping)       xa_unlock_irq(&mapping->i_pages)
 320 
 321 #define flush_icache_user_range(vma,page,addr,len) \
 322         flush_dcache_page(page)
 323 
 324 /*
 325  * We don't appear to need to do anything here.  In fact, if we did, we'd
 326  * duplicate cache flushing elsewhere performed by flush_dcache_page().
 327  */
 328 #define flush_icache_page(vma,page)     do { } while (0)
 329 
 330 /*
 331  * flush_cache_vmap() is used when creating mappings (eg, via vmap,
 332  * vmalloc, ioremap etc) in kernel space for pages.  On non-VIPT
 333  * caches, since the direct-mappings of these pages may contain cached
 334  * data, we need to do a full cache flush to ensure that writebacks
 335  * don't corrupt data placed into these pages via the new mappings.
 336  */
 337 static inline void flush_cache_vmap(unsigned long start, unsigned long end)
 338 {
 339         if (!cache_is_vipt_nonaliasing())
 340                 flush_cache_all();
 341         else
 342                 /*
 343                  * set_pte_at() called from vmap_pte_range() does not
 344                  * have a DSB after cleaning the cache line.
 345                  */
 346                 dsb(ishst);
 347 }
 348 
 349 static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
 350 {
 351         if (!cache_is_vipt_nonaliasing())
 352                 flush_cache_all();
 353 }
 354 
 355 /*
 356  * Memory synchronization helpers for mixed cached vs non cached accesses.
 357  *
 358  * Some synchronization algorithms have to set states in memory with the
 359  * cache enabled or disabled depending on the code path.  It is crucial
 360  * to always ensure proper cache maintenance to update main memory right
 361  * away in that case.
 362  *
 363  * Any cached write must be followed by a cache clean operation.
 364  * Any cached read must be preceded by a cache invalidate operation.
 365  * Yet, in the read case, a cache flush i.e. atomic clean+invalidate
 366  * operation is needed to avoid discarding possible concurrent writes to the
 367  * accessed memory.
 368  *
 369  * Also, in order to prevent a cached writer from interfering with an
 370  * adjacent non-cached writer, each state variable must be located to
 371  * a separate cache line.
 372  */
 373 
 374 /*
 375  * This needs to be >= the max cache writeback size of all
 376  * supported platforms included in the current kernel configuration.
 377  * This is used to align state variables to their own cache lines.
 378  */
 379 #define __CACHE_WRITEBACK_ORDER 6  /* guessed from existing platforms */
 380 #define __CACHE_WRITEBACK_GRANULE (1 << __CACHE_WRITEBACK_ORDER)
 381 
 382 /*
 383  * There is no __cpuc_clean_dcache_area but we use it anyway for
 384  * code intent clarity, and alias it to __cpuc_flush_dcache_area.
 385  */
 386 #define __cpuc_clean_dcache_area __cpuc_flush_dcache_area
 387 
 388 /*
 389  * Ensure preceding writes to *p by this CPU are visible to
 390  * subsequent reads by other CPUs:
 391  */
 392 static inline void __sync_cache_range_w(volatile void *p, size_t size)
 393 {
 394         char *_p = (char *)p;
 395 
 396         __cpuc_clean_dcache_area(_p, size);
 397         outer_clean_range(__pa(_p), __pa(_p + size));
 398 }
 399 
 400 /*
 401  * Ensure preceding writes to *p by other CPUs are visible to
 402  * subsequent reads by this CPU.  We must be careful not to
 403  * discard data simultaneously written by another CPU, hence the
 404  * usage of flush rather than invalidate operations.
 405  */
 406 static inline void __sync_cache_range_r(volatile void *p, size_t size)
 407 {
 408         char *_p = (char *)p;
 409 
 410 #ifdef CONFIG_OUTER_CACHE
 411         if (outer_cache.flush_range) {
 412                 /*
 413                  * Ensure dirty data migrated from other CPUs into our cache
 414                  * are cleaned out safely before the outer cache is cleaned:
 415                  */
 416                 __cpuc_clean_dcache_area(_p, size);
 417 
 418                 /* Clean and invalidate stale data for *p from outer ... */
 419                 outer_flush_range(__pa(_p), __pa(_p + size));
 420         }
 421 #endif
 422 
 423         /* ... and inner cache: */
 424         __cpuc_flush_dcache_area(_p, size);
 425 }
 426 
 427 #define sync_cache_w(ptr) __sync_cache_range_w(ptr, sizeof *(ptr))
 428 #define sync_cache_r(ptr) __sync_cache_range_r(ptr, sizeof *(ptr))
 429 
 430 /*
 431  * Disabling cache access for one CPU in an ARMv7 SMP system is tricky.
 432  * To do so we must:
 433  *
 434  * - Clear the SCTLR.C bit to prevent further cache allocations
 435  * - Flush the desired level of cache
 436  * - Clear the ACTLR "SMP" bit to disable local coherency
 437  *
 438  * ... and so without any intervening memory access in between those steps,
 439  * not even to the stack.
 440  *
 441  * WARNING -- After this has been called:
 442  *
 443  * - No ldrex/strex (and similar) instructions must be used.
 444  * - The CPU is obviously no longer coherent with the other CPUs.
 445  * - This is unlikely to work as expected if Linux is running non-secure.
 446  *
 447  * Note:
 448  *
 449  * - This is known to apply to several ARMv7 processor implementations,
 450  *   however some exceptions may exist.  Caveat emptor.
 451  *
 452  * - The clobber list is dictated by the call to v7_flush_dcache_*.
 453  *   fp is preserved to the stack explicitly prior disabling the cache
 454  *   since adding it to the clobber list is incompatible with having
 455  *   CONFIG_FRAME_POINTER=y.  ip is saved as well if ever r12-clobbering
 456  *   trampoline are inserted by the linker and to keep sp 64-bit aligned.
 457  */
 458 #define v7_exit_coherency_flush(level) \
 459         asm volatile( \
 460         ".arch  armv7-a \n\t" \
 461         "stmfd  sp!, {fp, ip} \n\t" \
 462         "mrc    p15, 0, r0, c1, c0, 0   @ get SCTLR \n\t" \
 463         "bic    r0, r0, #"__stringify(CR_C)" \n\t" \
 464         "mcr    p15, 0, r0, c1, c0, 0   @ set SCTLR \n\t" \
 465         "isb    \n\t" \
 466         "bl     v7_flush_dcache_"__stringify(level)" \n\t" \
 467         "mrc    p15, 0, r0, c1, c0, 1   @ get ACTLR \n\t" \
 468         "bic    r0, r0, #(1 << 6)       @ disable local coherency \n\t" \
 469         "mcr    p15, 0, r0, c1, c0, 1   @ set ACTLR \n\t" \
 470         "isb    \n\t" \
 471         "dsb    \n\t" \
 472         "ldmfd  sp!, {fp, ip}" \
 473         : : : "r0","r1","r2","r3","r4","r5","r6","r7", \
 474               "r9","r10","lr","memory" )
 475 
 476 void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
 477                              void *kaddr, unsigned long len);
 478 
 479 
 480 #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
 481 void check_cpu_icache_size(int cpuid);
 482 #else
 483 static inline void check_cpu_icache_size(int cpuid) { }
 484 #endif
 485 
 486 #endif

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