Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze
[linux-2.6] / arch / mips / mm / c-r3k.c
1 /*
2  * r2300.c: R2000 and R3000 specific mmu/cache code.
3  *
4  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
5  *
6  * with a lot of changes to make this thing work for R3000s
7  * Tx39XX R4k style caches added. HK
8  * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
9  * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
10  * Copyright (C) 2001, 2004, 2007  Maciej W. Rozycki
11  */
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/mm.h>
16
17 #include <asm/page.h>
18 #include <asm/pgtable.h>
19 #include <asm/mmu_context.h>
20 #include <asm/system.h>
21 #include <asm/isadep.h>
22 #include <asm/io.h>
23 #include <asm/bootinfo.h>
24 #include <asm/cpu.h>
25
26 static unsigned long icache_size, dcache_size;          /* Size in bytes */
27 static unsigned long icache_lsize, dcache_lsize;        /* Size in bytes */
28
29 unsigned long __cpuinit r3k_cache_size(unsigned long ca_flags)
30 {
31         unsigned long flags, status, dummy, size;
32         volatile unsigned long *p;
33
34         p = (volatile unsigned long *) KSEG0;
35
36         flags = read_c0_status();
37
38         /* isolate cache space */
39         write_c0_status((ca_flags|flags)&~ST0_IEC);
40
41         *p = 0xa5a55a5a;
42         dummy = *p;
43         status = read_c0_status();
44
45         if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
46                 size = 0;
47         } else {
48                 for (size = 128; size <= 0x40000; size <<= 1)
49                         *(p + size) = 0;
50                 *p = -1;
51                 for (size = 128;
52                      (size <= 0x40000) && (*(p + size) == 0);
53                      size <<= 1)
54                         ;
55                 if (size > 0x40000)
56                         size = 0;
57         }
58
59         write_c0_status(flags);
60
61         return size * sizeof(*p);
62 }
63
64 unsigned long __cpuinit r3k_cache_lsize(unsigned long ca_flags)
65 {
66         unsigned long flags, status, lsize, i;
67         volatile unsigned long *p;
68
69         p = (volatile unsigned long *) KSEG0;
70
71         flags = read_c0_status();
72
73         /* isolate cache space */
74         write_c0_status((ca_flags|flags)&~ST0_IEC);
75
76         for (i = 0; i < 128; i++)
77                 *(p + i) = 0;
78         *(volatile unsigned char *)p = 0;
79         for (lsize = 1; lsize < 128; lsize <<= 1) {
80                 *(p + lsize);
81                 status = read_c0_status();
82                 if (!(status & ST0_CM))
83                         break;
84         }
85         for (i = 0; i < 128; i += lsize)
86                 *(volatile unsigned char *)(p + i) = 0;
87
88         write_c0_status(flags);
89
90         return lsize * sizeof(*p);
91 }
92
93 static void __cpuinit r3k_probe_cache(void)
94 {
95         dcache_size = r3k_cache_size(ST0_ISC);
96         if (dcache_size)
97                 dcache_lsize = r3k_cache_lsize(ST0_ISC);
98
99         icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
100         if (icache_size)
101                 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
102 }
103
104 static void r3k_flush_icache_range(unsigned long start, unsigned long end)
105 {
106         unsigned long size, i, flags;
107         volatile unsigned char *p;
108
109         size = end - start;
110         if (size > icache_size || KSEGX(start) != KSEG0) {
111                 start = KSEG0;
112                 size = icache_size;
113         }
114         p = (char *)start;
115
116         flags = read_c0_status();
117
118         /* isolate cache space */
119         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
120
121         for (i = 0; i < size; i += 0x080) {
122                 asm(    "sb\t$0, 0x000(%0)\n\t"
123                         "sb\t$0, 0x004(%0)\n\t"
124                         "sb\t$0, 0x008(%0)\n\t"
125                         "sb\t$0, 0x00c(%0)\n\t"
126                         "sb\t$0, 0x010(%0)\n\t"
127                         "sb\t$0, 0x014(%0)\n\t"
128                         "sb\t$0, 0x018(%0)\n\t"
129                         "sb\t$0, 0x01c(%0)\n\t"
130                         "sb\t$0, 0x020(%0)\n\t"
131                         "sb\t$0, 0x024(%0)\n\t"
132                         "sb\t$0, 0x028(%0)\n\t"
133                         "sb\t$0, 0x02c(%0)\n\t"
134                         "sb\t$0, 0x030(%0)\n\t"
135                         "sb\t$0, 0x034(%0)\n\t"
136                         "sb\t$0, 0x038(%0)\n\t"
137                         "sb\t$0, 0x03c(%0)\n\t"
138                         "sb\t$0, 0x040(%0)\n\t"
139                         "sb\t$0, 0x044(%0)\n\t"
140                         "sb\t$0, 0x048(%0)\n\t"
141                         "sb\t$0, 0x04c(%0)\n\t"
142                         "sb\t$0, 0x050(%0)\n\t"
143                         "sb\t$0, 0x054(%0)\n\t"
144                         "sb\t$0, 0x058(%0)\n\t"
145                         "sb\t$0, 0x05c(%0)\n\t"
146                         "sb\t$0, 0x060(%0)\n\t"
147                         "sb\t$0, 0x064(%0)\n\t"
148                         "sb\t$0, 0x068(%0)\n\t"
149                         "sb\t$0, 0x06c(%0)\n\t"
150                         "sb\t$0, 0x070(%0)\n\t"
151                         "sb\t$0, 0x074(%0)\n\t"
152                         "sb\t$0, 0x078(%0)\n\t"
153                         "sb\t$0, 0x07c(%0)\n\t"
154                         : : "r" (p) );
155                 p += 0x080;
156         }
157
158         write_c0_status(flags);
159 }
160
161 static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
162 {
163         unsigned long size, i, flags;
164         volatile unsigned char *p;
165
166         size = end - start;
167         if (size > dcache_size || KSEGX(start) != KSEG0) {
168                 start = KSEG0;
169                 size = dcache_size;
170         }
171         p = (char *)start;
172
173         flags = read_c0_status();
174
175         /* isolate cache space */
176         write_c0_status((ST0_ISC|flags)&~ST0_IEC);
177
178         for (i = 0; i < size; i += 0x080) {
179                 asm(    "sb\t$0, 0x000(%0)\n\t"
180                         "sb\t$0, 0x004(%0)\n\t"
181                         "sb\t$0, 0x008(%0)\n\t"
182                         "sb\t$0, 0x00c(%0)\n\t"
183                         "sb\t$0, 0x010(%0)\n\t"
184                         "sb\t$0, 0x014(%0)\n\t"
185                         "sb\t$0, 0x018(%0)\n\t"
186                         "sb\t$0, 0x01c(%0)\n\t"
187                         "sb\t$0, 0x020(%0)\n\t"
188                         "sb\t$0, 0x024(%0)\n\t"
189                         "sb\t$0, 0x028(%0)\n\t"
190                         "sb\t$0, 0x02c(%0)\n\t"
191                         "sb\t$0, 0x030(%0)\n\t"
192                         "sb\t$0, 0x034(%0)\n\t"
193                         "sb\t$0, 0x038(%0)\n\t"
194                         "sb\t$0, 0x03c(%0)\n\t"
195                         "sb\t$0, 0x040(%0)\n\t"
196                         "sb\t$0, 0x044(%0)\n\t"
197                         "sb\t$0, 0x048(%0)\n\t"
198                         "sb\t$0, 0x04c(%0)\n\t"
199                         "sb\t$0, 0x050(%0)\n\t"
200                         "sb\t$0, 0x054(%0)\n\t"
201                         "sb\t$0, 0x058(%0)\n\t"
202                         "sb\t$0, 0x05c(%0)\n\t"
203                         "sb\t$0, 0x060(%0)\n\t"
204                         "sb\t$0, 0x064(%0)\n\t"
205                         "sb\t$0, 0x068(%0)\n\t"
206                         "sb\t$0, 0x06c(%0)\n\t"
207                         "sb\t$0, 0x070(%0)\n\t"
208                         "sb\t$0, 0x074(%0)\n\t"
209                         "sb\t$0, 0x078(%0)\n\t"
210                         "sb\t$0, 0x07c(%0)\n\t"
211                         : : "r" (p) );
212                 p += 0x080;
213         }
214
215         write_c0_status(flags);
216 }
217
218 static inline void r3k_flush_cache_all(void)
219 {
220 }
221
222 static inline void r3k___flush_cache_all(void)
223 {
224         r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
225         r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
226 }
227
228 static void r3k_flush_cache_mm(struct mm_struct *mm)
229 {
230 }
231
232 static void r3k_flush_cache_range(struct vm_area_struct *vma,
233                                   unsigned long start, unsigned long end)
234 {
235 }
236
237 static void r3k_flush_cache_page(struct vm_area_struct *vma,
238                                  unsigned long addr, unsigned long pfn)
239 {
240         unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
241         int exec = vma->vm_flags & VM_EXEC;
242         struct mm_struct *mm = vma->vm_mm;
243         pgd_t *pgdp;
244         pud_t *pudp;
245         pmd_t *pmdp;
246         pte_t *ptep;
247
248         pr_debug("cpage[%08lx,%08lx]\n",
249                  cpu_context(smp_processor_id(), mm), addr);
250
251         /* No ASID => no such page in the cache.  */
252         if (cpu_context(smp_processor_id(), mm) == 0)
253                 return;
254
255         pgdp = pgd_offset(mm, addr);
256         pudp = pud_offset(pgdp, addr);
257         pmdp = pmd_offset(pudp, addr);
258         ptep = pte_offset(pmdp, addr);
259
260         /* Invalid => no such page in the cache.  */
261         if (!(pte_val(*ptep) & _PAGE_PRESENT))
262                 return;
263
264         r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
265         if (exec)
266                 r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
267 }
268
269 static void local_r3k_flush_data_cache_page(void *addr)
270 {
271 }
272
273 static void r3k_flush_data_cache_page(unsigned long addr)
274 {
275 }
276
277 static void r3k_flush_cache_sigtramp(unsigned long addr)
278 {
279         unsigned long flags;
280
281         pr_debug("csigtramp[%08lx]\n", addr);
282
283         flags = read_c0_status();
284
285         write_c0_status(flags&~ST0_IEC);
286
287         /* Fill the TLB to avoid an exception with caches isolated. */
288         asm(    "lw\t$0, 0x000(%0)\n\t"
289                 "lw\t$0, 0x004(%0)\n\t"
290                 : : "r" (addr) );
291
292         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
293
294         asm(    "sb\t$0, 0x000(%0)\n\t"
295                 "sb\t$0, 0x004(%0)\n\t"
296                 : : "r" (addr) );
297
298         write_c0_status(flags);
299 }
300
301 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
302 {
303         /* Catch bad driver code */
304         BUG_ON(size == 0);
305
306         iob();
307         r3k_flush_dcache_range(start, start + size);
308 }
309
310 void __cpuinit r3k_cache_init(void)
311 {
312         extern void build_clear_page(void);
313         extern void build_copy_page(void);
314
315         r3k_probe_cache();
316
317         flush_cache_all = r3k_flush_cache_all;
318         __flush_cache_all = r3k___flush_cache_all;
319         flush_cache_mm = r3k_flush_cache_mm;
320         flush_cache_range = r3k_flush_cache_range;
321         flush_cache_page = r3k_flush_cache_page;
322         flush_icache_range = r3k_flush_icache_range;
323         local_flush_icache_range = r3k_flush_icache_range;
324
325         flush_cache_sigtramp = r3k_flush_cache_sigtramp;
326         local_flush_data_cache_page = local_r3k_flush_data_cache_page;
327         flush_data_cache_page = r3k_flush_data_cache_page;
328
329         _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
330         _dma_cache_wback = r3k_dma_cache_wback_inv;
331         _dma_cache_inv = r3k_dma_cache_wback_inv;
332
333         printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
334                 icache_size >> 10, icache_lsize);
335         printk("Primary data cache %ldkB, linesize %ld bytes.\n",
336                 dcache_size >> 10, dcache_lsize);
337
338         build_clear_page();
339         build_copy_page();
340 }