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_folio(void * arg)110 static void sh4_flush_dcache_folio(void *arg)
111 {
112 struct folio *folio = arg;
113 #ifndef CONFIG_SMP
114 struct address_space *mapping = folio_flush_mapping(folio);
115
116 if (mapping && !mapping_mapped(mapping))
117 clear_bit(PG_dcache_clean, &folio->flags);
118 else
119 #endif
120 {
121 unsigned long pfn = folio_pfn(folio);
122 unsigned long addr = (unsigned long)folio_address(folio);
123 unsigned int i, nr = folio_nr_pages(folio);
124
125 for (i = 0; i < nr; i++) {
126 flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
127 (addr & shm_align_mask),
128 pfn * PAGE_SIZE);
129 addr += PAGE_SIZE;
130 pfn++;
131 }
132 }
133
134 wmb();
135 }
136
137 /* TODO: Selective icache invalidation through IC address array.. */
flush_icache_all(void)138 static void flush_icache_all(void)
139 {
140 unsigned long flags, ccr;
141
142 local_irq_save(flags);
143 jump_to_uncached();
144
145 /* Flush I-cache */
146 ccr = __raw_readl(SH_CCR);
147 ccr |= CCR_CACHE_ICI;
148 __raw_writel(ccr, SH_CCR);
149
150 /*
151 * back_to_cached() will take care of the barrier for us, don't add
152 * another one!
153 */
154
155 back_to_cached();
156 local_irq_restore(flags);
157 }
158
flush_dcache_all(void)159 static void flush_dcache_all(void)
160 {
161 unsigned long addr, end_addr, entry_offset;
162
163 end_addr = CACHE_OC_ADDRESS_ARRAY +
164 (current_cpu_data.dcache.sets <<
165 current_cpu_data.dcache.entry_shift) *
166 current_cpu_data.dcache.ways;
167
168 entry_offset = 1 << current_cpu_data.dcache.entry_shift;
169
170 for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) {
171 __raw_writel(0, addr); addr += entry_offset;
172 __raw_writel(0, addr); addr += entry_offset;
173 __raw_writel(0, addr); addr += entry_offset;
174 __raw_writel(0, addr); addr += entry_offset;
175 __raw_writel(0, addr); addr += entry_offset;
176 __raw_writel(0, addr); addr += entry_offset;
177 __raw_writel(0, addr); addr += entry_offset;
178 __raw_writel(0, addr); addr += entry_offset;
179 }
180 }
181
sh4_flush_cache_all(void * unused)182 static void sh4_flush_cache_all(void *unused)
183 {
184 flush_dcache_all();
185 flush_icache_all();
186 }
187
188 /*
189 * Note : (RPC) since the caches are physically tagged, the only point
190 * of flush_cache_mm for SH-4 is to get rid of aliases from the
191 * D-cache. The assumption elsewhere, e.g. flush_cache_range, is that
192 * lines can stay resident so long as the virtual address they were
193 * accessed with (hence cache set) is in accord with the physical
194 * address (i.e. tag). It's no different here.
195 *
196 * Caller takes mm->mmap_lock.
197 */
sh4_flush_cache_mm(void * arg)198 static void sh4_flush_cache_mm(void *arg)
199 {
200 struct mm_struct *mm = arg;
201
202 if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
203 return;
204
205 flush_dcache_all();
206 }
207
208 /*
209 * Write back and invalidate I/D-caches for the page.
210 *
211 * ADDR: Virtual Address (U0 address)
212 * PFN: Physical page number
213 */
sh4_flush_cache_page(void * args)214 static void sh4_flush_cache_page(void *args)
215 {
216 struct flusher_data *data = args;
217 struct vm_area_struct *vma;
218 struct page *page;
219 unsigned long address, pfn, phys;
220 int map_coherent = 0;
221 pmd_t *pmd;
222 pte_t *pte;
223 void *vaddr;
224
225 vma = data->vma;
226 address = data->addr1 & PAGE_MASK;
227 pfn = data->addr2;
228 phys = pfn << PAGE_SHIFT;
229 page = pfn_to_page(pfn);
230
231 if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
232 return;
233
234 pmd = pmd_off(vma->vm_mm, address);
235 pte = pte_offset_kernel(pmd, address);
236
237 /* If the page isn't present, there is nothing to do here. */
238 if (!(pte_val(*pte) & _PAGE_PRESENT))
239 return;
240
241 if ((vma->vm_mm == current->active_mm))
242 vaddr = NULL;
243 else {
244 /*
245 * Use kmap_coherent or kmap_atomic to do flushes for
246 * another ASID than the current one.
247 */
248 map_coherent = (current_cpu_data.dcache.n_aliases &&
249 test_bit(PG_dcache_clean, &page->flags) &&
250 page_mapcount(page));
251 if (map_coherent)
252 vaddr = kmap_coherent(page, address);
253 else
254 vaddr = kmap_atomic(page);
255
256 address = (unsigned long)vaddr;
257 }
258
259 flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
260 (address & shm_align_mask), phys);
261
262 if (vma->vm_flags & VM_EXEC)
263 flush_icache_all();
264
265 if (vaddr) {
266 if (map_coherent)
267 kunmap_coherent(vaddr);
268 else
269 kunmap_atomic(vaddr);
270 }
271 }
272
273 /*
274 * Write back and invalidate D-caches.
275 *
276 * START, END: Virtual Address (U0 address)
277 *
278 * NOTE: We need to flush the _physical_ page entry.
279 * Flushing the cache lines for U0 only isn't enough.
280 * We need to flush for P1 too, which may contain aliases.
281 */
sh4_flush_cache_range(void * args)282 static void sh4_flush_cache_range(void *args)
283 {
284 struct flusher_data *data = args;
285 struct vm_area_struct *vma;
286 unsigned long start, end;
287
288 vma = data->vma;
289 start = data->addr1;
290 end = data->addr2;
291
292 if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
293 return;
294
295 /*
296 * If cache is only 4k-per-way, there are never any 'aliases'. Since
297 * the cache is physically tagged, the data can just be left in there.
298 */
299 if (boot_cpu_data.dcache.n_aliases == 0)
300 return;
301
302 flush_dcache_all();
303
304 if (vma->vm_flags & VM_EXEC)
305 flush_icache_all();
306 }
307
308 /**
309 * __flush_cache_one
310 *
311 * @addr: address in memory mapped cache array
312 * @phys: P1 address to flush (has to match tags if addr has 'A' bit
313 * set i.e. associative write)
314 * @exec_offset: set to 0x20000000 if flush has to be executed from P2
315 * region else 0x0
316 *
317 * The offset into the cache array implied by 'addr' selects the
318 * 'colour' of the virtual address range that will be flushed. The
319 * operation (purge/write-back) is selected by the lower 2 bits of
320 * 'phys'.
321 */
__flush_cache_one(unsigned long addr,unsigned long phys,unsigned long exec_offset)322 static void __flush_cache_one(unsigned long addr, unsigned long phys,
323 unsigned long exec_offset)
324 {
325 int way_count;
326 unsigned long base_addr = addr;
327 struct cache_info *dcache;
328 unsigned long way_incr;
329 unsigned long a, ea, p;
330 unsigned long temp_pc;
331
332 dcache = &boot_cpu_data.dcache;
333 /* Write this way for better assembly. */
334 way_count = dcache->ways;
335 way_incr = dcache->way_incr;
336
337 /*
338 * Apply exec_offset (i.e. branch to P2 if required.).
339 *
340 * FIXME:
341 *
342 * If I write "=r" for the (temp_pc), it puts this in r6 hence
343 * trashing exec_offset before it's been added on - why? Hence
344 * "=&r" as a 'workaround'
345 */
346 asm volatile("mov.l 1f, %0\n\t"
347 "add %1, %0\n\t"
348 "jmp @%0\n\t"
349 "nop\n\t"
350 ".balign 4\n\t"
351 "1: .long 2f\n\t"
352 "2:\n" : "=&r" (temp_pc) : "r" (exec_offset));
353
354 /*
355 * We know there will be >=1 iteration, so write as do-while to avoid
356 * pointless nead-of-loop check for 0 iterations.
357 */
358 do {
359 ea = base_addr + PAGE_SIZE;
360 a = base_addr;
361 p = phys;
362
363 do {
364 *(volatile unsigned long *)a = p;
365 /*
366 * Next line: intentionally not p+32, saves an add, p
367 * will do since only the cache tag bits need to
368 * match.
369 */
370 *(volatile unsigned long *)(a+32) = p;
371 a += 64;
372 p += 64;
373 } while (a < ea);
374
375 base_addr += way_incr;
376 } while (--way_count != 0);
377 }
378
379 extern void __weak sh4__flush_region_init(void);
380
381 /*
382 * SH-4 has virtually indexed and physically tagged cache.
383 */
sh4_cache_init(void)384 void __init sh4_cache_init(void)
385 {
386 printk("PVR=%08x CVR=%08x PRR=%08x\n",
387 __raw_readl(CCN_PVR),
388 __raw_readl(CCN_CVR),
389 __raw_readl(CCN_PRR));
390
391 local_flush_icache_range = sh4_flush_icache_range;
392 local_flush_dcache_folio = sh4_flush_dcache_folio;
393 local_flush_cache_all = sh4_flush_cache_all;
394 local_flush_cache_mm = sh4_flush_cache_mm;
395 local_flush_cache_dup_mm = sh4_flush_cache_mm;
396 local_flush_cache_page = sh4_flush_cache_page;
397 local_flush_cache_range = sh4_flush_cache_range;
398
399 sh4__flush_region_init();
400 }
401
