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