xref: /openbmc/linux/arch/arm/include/asm/cacheflush.h (revision c4a05cf0)
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 
__flush_icache_all(void)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 
vivt_flush_cache_mm(struct mm_struct * mm)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
vivt_flush_cache_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)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 
vivt_flush_cache_pages(struct vm_area_struct * vma,unsigned long user_addr,unsigned long pfn,unsigned int nr)234 static inline void vivt_flush_cache_pages(struct vm_area_struct *vma,
235 		unsigned long user_addr, unsigned long pfn, unsigned int nr)
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 + nr * PAGE_SIZE,
242 				vma->vm_flags);
243 	}
244 }
245 
246 #ifndef CONFIG_CPU_CACHE_VIPT
247 #define flush_cache_mm(mm) \
248 		vivt_flush_cache_mm(mm)
249 #define flush_cache_range(vma,start,end) \
250 		vivt_flush_cache_range(vma,start,end)
251 #define flush_cache_pages(vma, addr, pfn, nr) \
252 		vivt_flush_cache_pages(vma, addr, pfn, nr)
253 #else
254 void flush_cache_mm(struct mm_struct *mm);
255 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
256 void flush_cache_pages(struct vm_area_struct *vma, unsigned long user_addr,
257 		unsigned long pfn, unsigned int nr);
258 #endif
259 
260 #define flush_cache_dup_mm(mm) flush_cache_mm(mm)
261 #define flush_cache_page(vma, addr, pfn) flush_cache_pages(vma, addr, pfn, 1)
262 
263 /*
264  * flush_icache_user_range is used when we want to ensure that the
265  * Harvard caches are synchronised for the user space address range.
266  * This is used for the ARM private sys_cacheflush system call.
267  */
268 #define flush_icache_user_range(s,e)	__cpuc_coherent_user_range(s,e)
269 
270 /*
271  * Perform necessary cache operations to ensure that data previously
272  * stored within this range of addresses can be executed by the CPU.
273  */
274 #define flush_icache_range(s,e)		__cpuc_coherent_kern_range(s,e)
275 
276 /*
277  * Perform necessary cache operations to ensure that the TLB will
278  * see data written in the specified area.
279  */
280 #define clean_dcache_area(start,size)	cpu_dcache_clean_area(start, size)
281 
282 /*
283  * flush_dcache_page is used when the kernel has written to the page
284  * cache page at virtual address page->virtual.
285  *
286  * If this page isn't mapped (ie, page_mapping == NULL), or it might
287  * have userspace mappings, then we _must_ always clean + invalidate
288  * the dcache entries associated with the kernel mapping.
289  *
290  * Otherwise we can defer the operation, and clean the cache when we are
291  * about to change to user space.  This is the same method as used on SPARC64.
292  * See update_mmu_cache for the user space part.
293  */
294 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
295 void flush_dcache_page(struct page *);
296 void flush_dcache_folio(struct folio *folio);
297 #define flush_dcache_folio flush_dcache_folio
298 
299 #define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
flush_kernel_vmap_range(void * addr,int size)300 static inline void flush_kernel_vmap_range(void *addr, int size)
301 {
302 	if ((cache_is_vivt() || cache_is_vipt_aliasing()))
303 	  __cpuc_flush_dcache_area(addr, (size_t)size);
304 }
invalidate_kernel_vmap_range(void * addr,int size)305 static inline void invalidate_kernel_vmap_range(void *addr, int size)
306 {
307 	if ((cache_is_vivt() || cache_is_vipt_aliasing()))
308 	  __cpuc_flush_dcache_area(addr, (size_t)size);
309 }
310 
311 #define ARCH_HAS_FLUSH_ANON_PAGE
flush_anon_page(struct vm_area_struct * vma,struct page * page,unsigned long vmaddr)312 static inline void flush_anon_page(struct vm_area_struct *vma,
313 			 struct page *page, unsigned long vmaddr)
314 {
315 	extern void __flush_anon_page(struct vm_area_struct *vma,
316 				struct page *, unsigned long);
317 	if (PageAnon(page))
318 		__flush_anon_page(vma, page, vmaddr);
319 }
320 
321 #define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)
322 #define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)
323 
324 /*
325  * flush_cache_vmap() is used when creating mappings (eg, via vmap,
326  * vmalloc, ioremap etc) in kernel space for pages.  On non-VIPT
327  * caches, since the direct-mappings of these pages may contain cached
328  * data, we need to do a full cache flush to ensure that writebacks
329  * don't corrupt data placed into these pages via the new mappings.
330  */
flush_cache_vmap(unsigned long start,unsigned long end)331 static inline void flush_cache_vmap(unsigned long start, unsigned long end)
332 {
333 	if (!cache_is_vipt_nonaliasing())
334 		flush_cache_all();
335 	else
336 		/*
337 		 * set_pte_at() called from vmap_pte_range() does not
338 		 * have a DSB after cleaning the cache line.
339 		 */
340 		dsb(ishst);
341 }
342 
343 #define flush_cache_vmap_early(start, end)	do { } while (0)
344 
flush_cache_vunmap(unsigned long start,unsigned long end)345 static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
346 {
347 	if (!cache_is_vipt_nonaliasing())
348 		flush_cache_all();
349 }
350 
351 /*
352  * Memory synchronization helpers for mixed cached vs non cached accesses.
353  *
354  * Some synchronization algorithms have to set states in memory with the
355  * cache enabled or disabled depending on the code path.  It is crucial
356  * to always ensure proper cache maintenance to update main memory right
357  * away in that case.
358  *
359  * Any cached write must be followed by a cache clean operation.
360  * Any cached read must be preceded by a cache invalidate operation.
361  * Yet, in the read case, a cache flush i.e. atomic clean+invalidate
362  * operation is needed to avoid discarding possible concurrent writes to the
363  * accessed memory.
364  *
365  * Also, in order to prevent a cached writer from interfering with an
366  * adjacent non-cached writer, each state variable must be located to
367  * a separate cache line.
368  */
369 
370 /*
371  * This needs to be >= the max cache writeback size of all
372  * supported platforms included in the current kernel configuration.
373  * This is used to align state variables to their own cache lines.
374  */
375 #define __CACHE_WRITEBACK_ORDER 6  /* guessed from existing platforms */
376 #define __CACHE_WRITEBACK_GRANULE (1 << __CACHE_WRITEBACK_ORDER)
377 
378 /*
379  * There is no __cpuc_clean_dcache_area but we use it anyway for
380  * code intent clarity, and alias it to __cpuc_flush_dcache_area.
381  */
382 #define __cpuc_clean_dcache_area __cpuc_flush_dcache_area
383 
384 /*
385  * Ensure preceding writes to *p by this CPU are visible to
386  * subsequent reads by other CPUs:
387  */
__sync_cache_range_w(volatile void * p,size_t size)388 static inline void __sync_cache_range_w(volatile void *p, size_t size)
389 {
390 	char *_p = (char *)p;
391 
392 	__cpuc_clean_dcache_area(_p, size);
393 	outer_clean_range(__pa(_p), __pa(_p + size));
394 }
395 
396 /*
397  * Ensure preceding writes to *p by other CPUs are visible to
398  * subsequent reads by this CPU.  We must be careful not to
399  * discard data simultaneously written by another CPU, hence the
400  * usage of flush rather than invalidate operations.
401  */
__sync_cache_range_r(volatile void * p,size_t size)402 static inline void __sync_cache_range_r(volatile void *p, size_t size)
403 {
404 	char *_p = (char *)p;
405 
406 #ifdef CONFIG_OUTER_CACHE
407 	if (outer_cache.flush_range) {
408 		/*
409 		 * Ensure dirty data migrated from other CPUs into our cache
410 		 * are cleaned out safely before the outer cache is cleaned:
411 		 */
412 		__cpuc_clean_dcache_area(_p, size);
413 
414 		/* Clean and invalidate stale data for *p from outer ... */
415 		outer_flush_range(__pa(_p), __pa(_p + size));
416 	}
417 #endif
418 
419 	/* ... and inner cache: */
420 	__cpuc_flush_dcache_area(_p, size);
421 }
422 
423 #define sync_cache_w(ptr) __sync_cache_range_w(ptr, sizeof *(ptr))
424 #define sync_cache_r(ptr) __sync_cache_range_r(ptr, sizeof *(ptr))
425 
426 /*
427  * Disabling cache access for one CPU in an ARMv7 SMP system is tricky.
428  * To do so we must:
429  *
430  * - Clear the SCTLR.C bit to prevent further cache allocations
431  * - Flush the desired level of cache
432  * - Clear the ACTLR "SMP" bit to disable local coherency
433  *
434  * ... and so without any intervening memory access in between those steps,
435  * not even to the stack.
436  *
437  * WARNING -- After this has been called:
438  *
439  * - No ldrex/strex (and similar) instructions must be used.
440  * - The CPU is obviously no longer coherent with the other CPUs.
441  * - This is unlikely to work as expected if Linux is running non-secure.
442  *
443  * Note:
444  *
445  * - This is known to apply to several ARMv7 processor implementations,
446  *   however some exceptions may exist.  Caveat emptor.
447  *
448  * - The clobber list is dictated by the call to v7_flush_dcache_*.
449  */
450 #define v7_exit_coherency_flush(level) \
451 	asm volatile( \
452 	".arch	armv7-a \n\t" \
453 	"mrc	p15, 0, r0, c1, c0, 0	@ get SCTLR \n\t" \
454 	"bic	r0, r0, #"__stringify(CR_C)" \n\t" \
455 	"mcr	p15, 0, r0, c1, c0, 0	@ set SCTLR \n\t" \
456 	"isb	\n\t" \
457 	"bl	v7_flush_dcache_"__stringify(level)" \n\t" \
458 	"mrc	p15, 0, r0, c1, c0, 1	@ get ACTLR \n\t" \
459 	"bic	r0, r0, #(1 << 6)	@ disable local coherency \n\t" \
460 	"mcr	p15, 0, r0, c1, c0, 1	@ set ACTLR \n\t" \
461 	"isb	\n\t" \
462 	"dsb" \
463 	: : : "r0","r1","r2","r3","r4","r5","r6", \
464 	      "r9","r10","ip","lr","memory" )
465 
466 void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
467 			     void *kaddr, unsigned long len);
468 
469 
470 #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
471 void check_cpu_icache_size(int cpuid);
472 #else
check_cpu_icache_size(int cpuid)473 static inline void check_cpu_icache_size(int cpuid) { }
474 #endif
475 
476 #endif
477