1 /*
2 * arch/sh/mm/cache-sh4.c
3 *
4 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka
5 * Copyright (C) 2001 - 2009 Paul Mundt
6 * Copyright (C) 2003 Richard Curnow
7 * Copyright (c) 2007 STMicroelectronics (R&D) Ltd.
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13 #include <linux/init.h>
14 #include <linux/mm.h>
15 #include <linux/io.h>
16 #include <linux/mutex.h>
17 #include <linux/fs.h>
18 #include <linux/highmem.h>
19 #include <linux/pagemap.h>
20 #include <asm/mmu_context.h>
21 #include <asm/cache_insns.h>
22 #include <asm/cacheflush.h>
23
24 /*
25 * The maximum number of pages we support up to when doing ranged dcache
26 * flushing. Anything exceeding this will simply flush the dcache in its
27 * entirety.
28 */
29 #define MAX_ICACHE_PAGES 32
30
31 static void __flush_cache_one(unsigned long addr, unsigned long phys,
32 unsigned long exec_offset);
33
34 /*
35 * Write back the range of D-cache, and purge the I-cache.
36 *
37 * Called from kernel/module.c:sys_init_module and routine for a.out format,
38 * signal handler code and kprobes code
39 */
sh4_flush_icache_range(void * args)40 static void sh4_flush_icache_range(void *args)
41 {
42 struct flusher_data *data = args;
43 unsigned long start, end;
44 unsigned long flags, v;
45 int i;
46
47 start = data->addr1;
48 end = data->addr2;
49
50 /* If there are too many pages then just blow away the caches */
51 if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
52 local_flush_cache_all(NULL);
53 return;
54 }
55
56 /*
57 * Selectively flush d-cache then invalidate the i-cache.
58 * This is inefficient, so only use this for small ranges.
59 */
60 start &= ~(L1_CACHE_BYTES-1);
61 end += L1_CACHE_BYTES-1;
62 end &= ~(L1_CACHE_BYTES-1);
63
64 local_irq_save(flags);
65 jump_to_uncached();
66
67 for (v = start; v < end; v += L1_CACHE_BYTES) {
68 unsigned long icacheaddr;
69 int j, n;
70
71 __ocbwb(v);
72
73 icacheaddr = CACHE_IC_ADDRESS_ARRAY | (v &
74 cpu_data->icache.entry_mask);
75
76 /* Clear i-cache line valid-bit */
77 n = boot_cpu_data.icache.n_aliases;
78 for (i = 0; i < cpu_data->icache.ways; i++) {
79 for (j = 0; j < n; j++)
80 __raw_writel(0, icacheaddr + (j * PAGE_SIZE));
81 icacheaddr += cpu_data->icache.way_incr;
82 }
83 }
84
85 back_to_cached();
86 local_irq_restore(flags);
87 }
88
flush_cache_one(unsigned long start,unsigned long phys)89 static inline void flush_cache_one(unsigned long start, unsigned long phys)
90 {
91 unsigned long flags, exec_offset = 0;
92
93 /*
94 * All types of SH-4 require PC to be uncached to operate on the I-cache.
95 * Some types of SH-4 require PC to be uncached to operate on the D-cache.
96 */
97 if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) ||
98 (start < CACHE_OC_ADDRESS_ARRAY))
99 exec_offset = cached_to_uncached;
100
101 local_irq_save(flags);
102 __flush_cache_one(start, phys, exec_offset);
103 local_irq_restore(flags);
104 }
105
106 /*
107 * Write back & invalidate the D-cache of the page.
108 * (To avoid "alias" issues)
109 */
sh4_flush_dcache_page(void * arg)110 static void sh4_flush_dcache_page(void *arg)
111 {
112 struct page *page = arg;
113 unsigned long addr = (unsigned long)page_address(page);
114 #ifndef CONFIG_SMP
115 struct address_space *mapping = page_mapping_file(page);
116
117 if (mapping && !mapping_mapped(mapping))
118 clear_bit(PG_dcache_clean, &page->flags);
119 else
120 #endif
121 flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
122 (addr & shm_align_mask), page_to_phys(page));
123
124 wmb();
125 }
126
127 /* TODO: Selective icache invalidation through IC address array.. */
flush_icache_all(void)128 static void flush_icache_all(void)
129 {
130 unsigned long flags, ccr;
131
132 local_irq_save(flags);
133 jump_to_uncached();
134
135 /* Flush I-cache */
136 ccr = __raw_readl(SH_CCR);
137 ccr |= CCR_CACHE_ICI;
138 __raw_writel(ccr, SH_CCR);
139
140 /*
141 * back_to_cached() will take care of the barrier for us, don't add
142 * another one!
143 */
144
145 back_to_cached();
146 local_irq_restore(flags);
147 }
148
flush_dcache_all(void)149 static void flush_dcache_all(void)
150 {
151 unsigned long addr, end_addr, entry_offset;
152
153 end_addr = CACHE_OC_ADDRESS_ARRAY +
154 (current_cpu_data.dcache.sets <<
155 current_cpu_data.dcache.entry_shift) *
156 current_cpu_data.dcache.ways;
157
158 entry_offset = 1 << current_cpu_data.dcache.entry_shift;
159
160 for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) {
161 __raw_writel(0, addr); addr += entry_offset;
162 __raw_writel(0, addr); addr += entry_offset;
163 __raw_writel(0, addr); addr += entry_offset;
164 __raw_writel(0, addr); addr += entry_offset;
165 __raw_writel(0, addr); addr += entry_offset;
166 __raw_writel(0, addr); addr += entry_offset;
167 __raw_writel(0, addr); addr += entry_offset;
168 __raw_writel(0, addr); addr += entry_offset;
169 }
170 }
171
sh4_flush_cache_all(void * unused)172 static void sh4_flush_cache_all(void *unused)
173 {
174 flush_dcache_all();
175 flush_icache_all();
176 }
177
178 /*
179 * Note : (RPC) since the caches are physically tagged, the only point
180 * of flush_cache_mm for SH-4 is to get rid of aliases from the
181 * D-cache. The assumption elsewhere, e.g. flush_cache_range, is that
182 * lines can stay resident so long as the virtual address they were
183 * accessed with (hence cache set) is in accord with the physical
184 * address (i.e. tag). It's no different here.
185 *
186 * Caller takes mm->mmap_lock.
187 */
sh4_flush_cache_mm(void * arg)188 static void sh4_flush_cache_mm(void *arg)
189 {
190 struct mm_struct *mm = arg;
191
192 if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
193 return;
194
195 flush_dcache_all();
196 }
197
198 /*
199 * Write back and invalidate I/D-caches for the page.
200 *
201 * ADDR: Virtual Address (U0 address)
202 * PFN: Physical page number
203 */
sh4_flush_cache_page(void * args)204 static void sh4_flush_cache_page(void *args)
205 {
206 struct flusher_data *data = args;
207 struct vm_area_struct *vma;
208 struct page *page;
209 unsigned long address, pfn, phys;
210 int map_coherent = 0;
211 pmd_t *pmd;
212 pte_t *pte;
213 void *vaddr;
214
215 vma = data->vma;
216 address = data->addr1 & PAGE_MASK;
217 pfn = data->addr2;
218 phys = pfn << PAGE_SHIFT;
219 page = pfn_to_page(pfn);
220
221 if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
222 return;
223
224 pmd = pmd_off(vma->vm_mm, address);
225 pte = pte_offset_kernel(pmd, address);
226
227 /* If the page isn't present, there is nothing to do here. */
228 if (!(pte_val(*pte) & _PAGE_PRESENT))
229 return;
230
231 if ((vma->vm_mm == current->active_mm))
232 vaddr = NULL;
233 else {
234 /*
235 * Use kmap_coherent or kmap_atomic to do flushes for
236 * another ASID than the current one.
237 */
238 map_coherent = (current_cpu_data.dcache.n_aliases &&
239 test_bit(PG_dcache_clean, &page->flags) &&
240 page_mapcount(page));
241 if (map_coherent)
242 vaddr = kmap_coherent(page, address);
243 else
244 vaddr = kmap_atomic(page);
245
246 address = (unsigned long)vaddr;
247 }
248
249 flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
250 (address & shm_align_mask), phys);
251
252 if (vma->vm_flags & VM_EXEC)
253 flush_icache_all();
254
255 if (vaddr) {
256 if (map_coherent)
257 kunmap_coherent(vaddr);
258 else
259 kunmap_atomic(vaddr);
260 }
261 }
262
263 /*
264 * Write back and invalidate D-caches.
265 *
266 * START, END: Virtual Address (U0 address)
267 *
268 * NOTE: We need to flush the _physical_ page entry.
269 * Flushing the cache lines for U0 only isn't enough.
270 * We need to flush for P1 too, which may contain aliases.
271 */
sh4_flush_cache_range(void * args)272 static void sh4_flush_cache_range(void *args)
273 {
274 struct flusher_data *data = args;
275 struct vm_area_struct *vma;
276 unsigned long start, end;
277
278 vma = data->vma;
279 start = data->addr1;
280 end = data->addr2;
281
282 if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
283 return;
284
285 /*
286 * If cache is only 4k-per-way, there are never any 'aliases'. Since
287 * the cache is physically tagged, the data can just be left in there.
288 */
289 if (boot_cpu_data.dcache.n_aliases == 0)
290 return;
291
292 flush_dcache_all();
293
294 if (vma->vm_flags & VM_EXEC)
295 flush_icache_all();
296 }
297
298 /**
299 * __flush_cache_one
300 *
301 * @addr: address in memory mapped cache array
302 * @phys: P1 address to flush (has to match tags if addr has 'A' bit
303 * set i.e. associative write)
304 * @exec_offset: set to 0x20000000 if flush has to be executed from P2
305 * region else 0x0
306 *
307 * The offset into the cache array implied by 'addr' selects the
308 * 'colour' of the virtual address range that will be flushed. The
309 * operation (purge/write-back) is selected by the lower 2 bits of
310 * 'phys'.
311 */
__flush_cache_one(unsigned long addr,unsigned long phys,unsigned long exec_offset)312 static void __flush_cache_one(unsigned long addr, unsigned long phys,
313 unsigned long exec_offset)
314 {
315 int way_count;
316 unsigned long base_addr = addr;
317 struct cache_info *dcache;
318 unsigned long way_incr;
319 unsigned long a, ea, p;
320 unsigned long temp_pc;
321
322 dcache = &boot_cpu_data.dcache;
323 /* Write this way for better assembly. */
324 way_count = dcache->ways;
325 way_incr = dcache->way_incr;
326
327 /*
328 * Apply exec_offset (i.e. branch to P2 if required.).
329 *
330 * FIXME:
331 *
332 * If I write "=r" for the (temp_pc), it puts this in r6 hence
333 * trashing exec_offset before it's been added on - why? Hence
334 * "=&r" as a 'workaround'
335 */
336 asm volatile("mov.l 1f, %0\n\t"
337 "add %1, %0\n\t"
338 "jmp @%0\n\t"
339 "nop\n\t"
340 ".balign 4\n\t"
341 "1: .long 2f\n\t"
342 "2:\n" : "=&r" (temp_pc) : "r" (exec_offset));
343
344 /*
345 * We know there will be >=1 iteration, so write as do-while to avoid
346 * pointless nead-of-loop check for 0 iterations.
347 */
348 do {
349 ea = base_addr + PAGE_SIZE;
350 a = base_addr;
351 p = phys;
352
353 do {
354 *(volatile unsigned long *)a = p;
355 /*
356 * Next line: intentionally not p+32, saves an add, p
357 * will do since only the cache tag bits need to
358 * match.
359 */
360 *(volatile unsigned long *)(a+32) = p;
361 a += 64;
362 p += 64;
363 } while (a < ea);
364
365 base_addr += way_incr;
366 } while (--way_count != 0);
367 }
368
369 extern void __weak sh4__flush_region_init(void);
370
371 /*
372 * SH-4 has virtually indexed and physically tagged cache.
373 */
sh4_cache_init(void)374 void __init sh4_cache_init(void)
375 {
376 printk("PVR=%08x CVR=%08x PRR=%08x\n",
377 __raw_readl(CCN_PVR),
378 __raw_readl(CCN_CVR),
379 __raw_readl(CCN_PRR));
380
381 local_flush_icache_range = sh4_flush_icache_range;
382 local_flush_dcache_page = sh4_flush_dcache_page;
383 local_flush_cache_all = sh4_flush_cache_all;
384 local_flush_cache_mm = sh4_flush_cache_mm;
385 local_flush_cache_dup_mm = sh4_flush_cache_mm;
386 local_flush_cache_page = sh4_flush_cache_page;
387 local_flush_cache_range = sh4_flush_cache_range;
388
389 sh4__flush_region_init();
390 }
391