Merge branch 'master' of git://oak/home/sfr/kernels/iseries/work
[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  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 #undef DEBUG_CACHE
30
31 unsigned long __init r3k_cache_size(unsigned long ca_flags)
32 {
33         unsigned long flags, status, dummy, size;
34         volatile unsigned long *p;
35
36         p = (volatile unsigned long *) KSEG0;
37
38         flags = read_c0_status();
39
40         /* isolate cache space */
41         write_c0_status((ca_flags|flags)&~ST0_IEC);
42
43         *p = 0xa5a55a5a;
44         dummy = *p;
45         status = read_c0_status();
46
47         if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
48                 size = 0;
49         } else {
50                 for (size = 128; size <= 0x40000; size <<= 1)
51                         *(p + size) = 0;
52                 *p = -1;
53                 for (size = 128;
54                      (size <= 0x40000) && (*(p + size) == 0);
55                      size <<= 1)
56                         ;
57                 if (size > 0x40000)
58                         size = 0;
59         }
60
61         write_c0_status(flags);
62
63         return size * sizeof(*p);
64 }
65
66 unsigned long __init r3k_cache_lsize(unsigned long ca_flags)
67 {
68         unsigned long flags, status, lsize, i;
69         volatile unsigned long *p;
70
71         p = (volatile unsigned long *) KSEG0;
72
73         flags = read_c0_status();
74
75         /* isolate cache space */
76         write_c0_status((ca_flags|flags)&~ST0_IEC);
77
78         for (i = 0; i < 128; i++)
79                 *(p + i) = 0;
80         *(volatile unsigned char *)p = 0;
81         for (lsize = 1; lsize < 128; lsize <<= 1) {
82                 *(p + lsize);
83                 status = read_c0_status();
84                 if (!(status & ST0_CM))
85                         break;
86         }
87         for (i = 0; i < 128; i += lsize)
88                 *(volatile unsigned char *)(p + i) = 0;
89
90         write_c0_status(flags);
91
92         return lsize * sizeof(*p);
93 }
94
95 static void __init r3k_probe_cache(void)
96 {
97         dcache_size = r3k_cache_size(ST0_ISC);
98         if (dcache_size)
99                 dcache_lsize = r3k_cache_lsize(ST0_ISC);
100
101         icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
102         if (icache_size)
103                 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
104 }
105
106 static void r3k_flush_icache_range(unsigned long start, unsigned long end)
107 {
108         unsigned long size, i, flags;
109         volatile unsigned char *p;
110
111         size = end - start;
112         if (size > icache_size || KSEGX(start) != KSEG0) {
113                 start = KSEG0;
114                 size = icache_size;
115         }
116         p = (char *)start;
117
118         flags = read_c0_status();
119
120         /* isolate cache space */
121         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
122
123         for (i = 0; i < size; i += 0x080) {
124                 asm (   "sb\t$0, 0x000(%0)\n\t"
125                         "sb\t$0, 0x004(%0)\n\t"
126                         "sb\t$0, 0x008(%0)\n\t"
127                         "sb\t$0, 0x00c(%0)\n\t"
128                         "sb\t$0, 0x010(%0)\n\t"
129                         "sb\t$0, 0x014(%0)\n\t"
130                         "sb\t$0, 0x018(%0)\n\t"
131                         "sb\t$0, 0x01c(%0)\n\t"
132                         "sb\t$0, 0x020(%0)\n\t"
133                         "sb\t$0, 0x024(%0)\n\t"
134                         "sb\t$0, 0x028(%0)\n\t"
135                         "sb\t$0, 0x02c(%0)\n\t"
136                         "sb\t$0, 0x030(%0)\n\t"
137                         "sb\t$0, 0x034(%0)\n\t"
138                         "sb\t$0, 0x038(%0)\n\t"
139                         "sb\t$0, 0x03c(%0)\n\t"
140                         "sb\t$0, 0x040(%0)\n\t"
141                         "sb\t$0, 0x044(%0)\n\t"
142                         "sb\t$0, 0x048(%0)\n\t"
143                         "sb\t$0, 0x04c(%0)\n\t"
144                         "sb\t$0, 0x050(%0)\n\t"
145                         "sb\t$0, 0x054(%0)\n\t"
146                         "sb\t$0, 0x058(%0)\n\t"
147                         "sb\t$0, 0x05c(%0)\n\t"
148                         "sb\t$0, 0x060(%0)\n\t"
149                         "sb\t$0, 0x064(%0)\n\t"
150                         "sb\t$0, 0x068(%0)\n\t"
151                         "sb\t$0, 0x06c(%0)\n\t"
152                         "sb\t$0, 0x070(%0)\n\t"
153                         "sb\t$0, 0x074(%0)\n\t"
154                         "sb\t$0, 0x078(%0)\n\t"
155                         "sb\t$0, 0x07c(%0)\n\t"
156                         : : "r" (p) );
157                 p += 0x080;
158         }
159
160         write_c0_status(flags);
161 }
162
163 static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
164 {
165         unsigned long size, i, flags;
166         volatile unsigned char *p;
167
168         size = end - start;
169         if (size > dcache_size || KSEGX(start) != KSEG0) {
170                 start = KSEG0;
171                 size = dcache_size;
172         }
173         p = (char *)start;
174
175         flags = read_c0_status();
176
177         /* isolate cache space */
178         write_c0_status((ST0_ISC|flags)&~ST0_IEC);
179
180         for (i = 0; i < size; i += 0x080) {
181                 asm (   "sb\t$0, 0x000(%0)\n\t"
182                         "sb\t$0, 0x004(%0)\n\t"
183                         "sb\t$0, 0x008(%0)\n\t"
184                         "sb\t$0, 0x00c(%0)\n\t"
185                         "sb\t$0, 0x010(%0)\n\t"
186                         "sb\t$0, 0x014(%0)\n\t"
187                         "sb\t$0, 0x018(%0)\n\t"
188                         "sb\t$0, 0x01c(%0)\n\t"
189                         "sb\t$0, 0x020(%0)\n\t"
190                         "sb\t$0, 0x024(%0)\n\t"
191                         "sb\t$0, 0x028(%0)\n\t"
192                         "sb\t$0, 0x02c(%0)\n\t"
193                         "sb\t$0, 0x030(%0)\n\t"
194                         "sb\t$0, 0x034(%0)\n\t"
195                         "sb\t$0, 0x038(%0)\n\t"
196                         "sb\t$0, 0x03c(%0)\n\t"
197                         "sb\t$0, 0x040(%0)\n\t"
198                         "sb\t$0, 0x044(%0)\n\t"
199                         "sb\t$0, 0x048(%0)\n\t"
200                         "sb\t$0, 0x04c(%0)\n\t"
201                         "sb\t$0, 0x050(%0)\n\t"
202                         "sb\t$0, 0x054(%0)\n\t"
203                         "sb\t$0, 0x058(%0)\n\t"
204                         "sb\t$0, 0x05c(%0)\n\t"
205                         "sb\t$0, 0x060(%0)\n\t"
206                         "sb\t$0, 0x064(%0)\n\t"
207                         "sb\t$0, 0x068(%0)\n\t"
208                         "sb\t$0, 0x06c(%0)\n\t"
209                         "sb\t$0, 0x070(%0)\n\t"
210                         "sb\t$0, 0x074(%0)\n\t"
211                         "sb\t$0, 0x078(%0)\n\t"
212                         "sb\t$0, 0x07c(%0)\n\t"
213                         : : "r" (p) );
214                 p += 0x080;
215         }
216
217         write_c0_status(flags);
218 }
219
220 static inline unsigned long get_phys_page (unsigned long addr,
221                                            struct mm_struct *mm)
222 {
223         pgd_t *pgd;
224         pud_t *pud;
225         pmd_t *pmd;
226         pte_t *pte;
227         unsigned long physpage;
228
229         pgd = pgd_offset(mm, addr);
230         pud = pud_offset(pgd, addr);
231         pmd = pmd_offset(pud, addr);
232         pte = pte_offset(pmd, addr);
233
234         if ((physpage = pte_val(*pte)) & _PAGE_VALID)
235                 return KSEG0ADDR(physpage & PAGE_MASK);
236
237         return 0;
238 }
239
240 static inline void r3k_flush_cache_all(void)
241 {
242 }
243
244 static inline void r3k___flush_cache_all(void)
245 {
246         r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
247         r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
248 }
249
250 static void r3k_flush_cache_mm(struct mm_struct *mm)
251 {
252 }
253
254 static void r3k_flush_cache_range(struct vm_area_struct *vma,
255         unsigned long start, unsigned long end)
256 {
257 }
258
259 static void r3k_flush_cache_page(struct vm_area_struct *vma, unsigned long page, unsigned long pfn)
260 {
261 }
262
263 static void local_r3k_flush_data_cache_page(unsigned long addr)
264 {
265 }
266
267 static void r3k_flush_data_cache_page(unsigned long addr)
268 {
269 }
270
271 static void r3k_flush_cache_sigtramp(unsigned long addr)
272 {
273         unsigned long flags;
274
275 #ifdef DEBUG_CACHE
276         printk("csigtramp[%08lx]", addr);
277 #endif
278
279         flags = read_c0_status();
280
281         write_c0_status(flags&~ST0_IEC);
282
283         /* Fill the TLB to avoid an exception with caches isolated. */
284         asm (   "lw\t$0, 0x000(%0)\n\t"
285                 "lw\t$0, 0x004(%0)\n\t"
286                 : : "r" (addr) );
287
288         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
289
290         asm (   "sb\t$0, 0x000(%0)\n\t"
291                 "sb\t$0, 0x004(%0)\n\t"
292                 : : "r" (addr) );
293
294         write_c0_status(flags);
295 }
296
297 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
298 {
299         /* Catch bad driver code */
300         BUG_ON(size == 0);
301
302         iob();
303         r3k_flush_dcache_range(start, start + size);
304 }
305
306 void __init r3k_cache_init(void)
307 {
308         extern void build_clear_page(void);
309         extern void build_copy_page(void);
310
311         r3k_probe_cache();
312
313         flush_cache_all = r3k_flush_cache_all;
314         __flush_cache_all = r3k___flush_cache_all;
315         flush_cache_mm = r3k_flush_cache_mm;
316         flush_cache_range = r3k_flush_cache_range;
317         flush_cache_page = r3k_flush_cache_page;
318         flush_icache_range = r3k_flush_icache_range;
319
320         flush_cache_sigtramp = r3k_flush_cache_sigtramp;
321         local_flush_data_cache_page = local_r3k_flush_data_cache_page;
322         flush_data_cache_page = r3k_flush_data_cache_page;
323
324         _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
325         _dma_cache_wback = r3k_dma_cache_wback_inv;
326         _dma_cache_inv = r3k_dma_cache_wback_inv;
327
328         printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
329                 icache_size >> 10, icache_lsize);
330         printk("Primary data cache %ldkB, linesize %ld bytes.\n",
331                 dcache_size >> 10, dcache_lsize);
332
333         build_clear_page();
334         build_copy_page();
335 }