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
r3k_cache_size(unsigned long ca_flags)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
r3k_cache_lsize(unsigned long ca_flags)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
r3k_probe_cache(void)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
r3k_flush_icache_range(unsigned long start,unsigned long end)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
r3k_flush_dcache_range(unsigned long start,unsigned long end)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
get_phys_page(unsigned long addr,struct mm_struct * mm)220 static inline unsigned long get_phys_page (unsigned long addr,
221 struct mm_struct *mm)
222 {
223 pgd_t *pgd;
224 pmd_t *pmd;
225 pte_t *pte;
226 unsigned long physpage;
227
228 pgd = pgd_offset(mm, addr);
229 pmd = pmd_offset(pgd, addr);
230 pte = pte_offset(pmd, addr);
231
232 if ((physpage = pte_val(*pte)) & _PAGE_VALID)
233 return KSEG0ADDR(physpage & PAGE_MASK);
234
235 return 0;
236 }
237
r3k_flush_cache_all(void)238 static inline void r3k_flush_cache_all(void)
239 {
240 }
241
r3k___flush_cache_all(void)242 static inline void r3k___flush_cache_all(void)
243 {
244 r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
245 r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
246 }
247
r3k_flush_cache_mm(struct mm_struct * mm)248 static void r3k_flush_cache_mm(struct mm_struct *mm)
249 {
250 }
251
r3k_flush_cache_range(struct mm_struct * mm,unsigned long start,unsigned long end)252 static void r3k_flush_cache_range(struct mm_struct *mm, unsigned long start,
253 unsigned long end)
254 {
255 }
256
r3k_flush_cache_page(struct vm_area_struct * vma,unsigned long page)257 static void r3k_flush_cache_page(struct vm_area_struct *vma,
258 unsigned long page)
259 {
260 }
261
r3k_flush_data_cache_page(unsigned long addr)262 static void r3k_flush_data_cache_page(unsigned long addr)
263 {
264 }
265
r3k_flush_icache_page(struct vm_area_struct * vma,struct page * page)266 static void r3k_flush_icache_page(struct vm_area_struct *vma, struct page *page)
267 {
268 struct mm_struct *mm = vma->vm_mm;
269 unsigned long physpage;
270
271 if (cpu_context(smp_processor_id(), mm) == 0)
272 return;
273
274 if (!(vma->vm_flags & VM_EXEC))
275 return;
276
277 #ifdef DEBUG_CACHE
278 printk("cpage[%d,%08lx]", cpu_context(smp_processor_id(), mm), page);
279 #endif
280
281 physpage = (unsigned long) page_address(page);
282 if (physpage)
283 r3k_flush_icache_range(physpage, physpage + PAGE_SIZE);
284 }
285
r3k_flush_cache_sigtramp(unsigned long addr)286 static void r3k_flush_cache_sigtramp(unsigned long addr)
287 {
288 unsigned long flags;
289
290 #ifdef DEBUG_CACHE
291 printk("csigtramp[%08lx]", addr);
292 #endif
293
294 flags = read_c0_status();
295
296 write_c0_status(flags&~ST0_IEC);
297
298 /* Fill the TLB to avoid an exception with caches isolated. */
299 asm ( "lw\t$0, 0x000(%0)\n\t"
300 "lw\t$0, 0x004(%0)\n\t"
301 : : "r" (addr) );
302
303 write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
304
305 asm ( "sb\t$0, 0x000(%0)\n\t"
306 "sb\t$0, 0x004(%0)\n\t"
307 : : "r" (addr) );
308
309 write_c0_status(flags);
310 }
311
r3k_dma_cache_wback_inv(unsigned long start,unsigned long size)312 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
313 {
314 /* Catch bad driver code */
315 BUG_ON(size == 0);
316
317 iob();
318 r3k_flush_dcache_range(start, start + size);
319 }
320
ld_mmu_r23000(void)321 void __init ld_mmu_r23000(void)
322 {
323 extern void build_clear_page(void);
324 extern void build_copy_page(void);
325
326 r3k_probe_cache();
327
328 _flush_cache_all = r3k_flush_cache_all;
329 ___flush_cache_all = r3k___flush_cache_all;
330 _flush_cache_mm = r3k_flush_cache_mm;
331 _flush_cache_range = r3k_flush_cache_range;
332 _flush_cache_page = r3k_flush_cache_page;
333 _flush_icache_page = r3k_flush_icache_page;
334 _flush_icache_range = r3k_flush_icache_range;
335
336 _flush_cache_sigtramp = r3k_flush_cache_sigtramp;
337 _flush_data_cache_page = r3k_flush_data_cache_page;
338
339 _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
340 _dma_cache_wback = r3k_dma_cache_wback_inv;
341 _dma_cache_inv = r3k_dma_cache_wback_inv;
342
343 printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
344 icache_size >> 10, icache_lsize);
345 printk("Primary data cache %ldkB, linesize %ld bytes.\n",
346 dcache_size >> 10, dcache_lsize);
347
348 build_clear_page();
349 build_copy_page();
350 }
351