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/smp.h>
16 #include <linux/mm.h>
17
18 #include <asm/page.h>
19 #include <asm/pgtable.h>
20 #include <asm/mmu_context.h>
21 #include <asm/system.h>
22 #include <asm/isadep.h>
23 #include <asm/io.h>
24 #include <asm/bootinfo.h>
25 #include <asm/cpu.h>
26
27 static unsigned long icache_size, dcache_size; /* Size in bytes */
28 static unsigned long icache_lsize, dcache_lsize; /* Size in bytes */
29
r3k_cache_size(unsigned long ca_flags)30 unsigned long __cpuinit r3k_cache_size(unsigned long ca_flags)
31 {
32 unsigned long flags, status, dummy, size;
33 volatile unsigned long *p;
34
35 p = (volatile unsigned long *) KSEG0;
36
37 flags = read_c0_status();
38
39 /* isolate cache space */
40 write_c0_status((ca_flags|flags)&~ST0_IEC);
41
42 *p = 0xa5a55a5a;
43 dummy = *p;
44 status = read_c0_status();
45
46 if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
47 size = 0;
48 } else {
49 for (size = 128; size <= 0x40000; size <<= 1)
50 *(p + size) = 0;
51 *p = -1;
52 for (size = 128;
53 (size <= 0x40000) && (*(p + size) == 0);
54 size <<= 1)
55 ;
56 if (size > 0x40000)
57 size = 0;
58 }
59
60 write_c0_status(flags);
61
62 return size * sizeof(*p);
63 }
64
r3k_cache_lsize(unsigned long ca_flags)65 unsigned long __cpuinit r3k_cache_lsize(unsigned long ca_flags)
66 {
67 unsigned long flags, status, lsize, i;
68 volatile unsigned long *p;
69
70 p = (volatile unsigned long *) KSEG0;
71
72 flags = read_c0_status();
73
74 /* isolate cache space */
75 write_c0_status((ca_flags|flags)&~ST0_IEC);
76
77 for (i = 0; i < 128; i++)
78 *(p + i) = 0;
79 *(volatile unsigned char *)p = 0;
80 for (lsize = 1; lsize < 128; lsize <<= 1) {
81 *(p + lsize);
82 status = read_c0_status();
83 if (!(status & ST0_CM))
84 break;
85 }
86 for (i = 0; i < 128; i += lsize)
87 *(volatile unsigned char *)(p + i) = 0;
88
89 write_c0_status(flags);
90
91 return lsize * sizeof(*p);
92 }
93
r3k_probe_cache(void)94 static void __cpuinit r3k_probe_cache(void)
95 {
96 dcache_size = r3k_cache_size(ST0_ISC);
97 if (dcache_size)
98 dcache_lsize = r3k_cache_lsize(ST0_ISC);
99
100 icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
101 if (icache_size)
102 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
103 }
104
r3k_flush_icache_range(unsigned long start,unsigned long end)105 static void r3k_flush_icache_range(unsigned long start, unsigned long end)
106 {
107 unsigned long size, i, flags;
108 volatile unsigned char *p;
109
110 size = end - start;
111 if (size > icache_size || KSEGX(start) != KSEG0) {
112 start = KSEG0;
113 size = icache_size;
114 }
115 p = (char *)start;
116
117 flags = read_c0_status();
118
119 /* isolate cache space */
120 write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
121
122 for (i = 0; i < size; i += 0x080) {
123 asm( "sb\t$0, 0x000(%0)\n\t"
124 "sb\t$0, 0x004(%0)\n\t"
125 "sb\t$0, 0x008(%0)\n\t"
126 "sb\t$0, 0x00c(%0)\n\t"
127 "sb\t$0, 0x010(%0)\n\t"
128 "sb\t$0, 0x014(%0)\n\t"
129 "sb\t$0, 0x018(%0)\n\t"
130 "sb\t$0, 0x01c(%0)\n\t"
131 "sb\t$0, 0x020(%0)\n\t"
132 "sb\t$0, 0x024(%0)\n\t"
133 "sb\t$0, 0x028(%0)\n\t"
134 "sb\t$0, 0x02c(%0)\n\t"
135 "sb\t$0, 0x030(%0)\n\t"
136 "sb\t$0, 0x034(%0)\n\t"
137 "sb\t$0, 0x038(%0)\n\t"
138 "sb\t$0, 0x03c(%0)\n\t"
139 "sb\t$0, 0x040(%0)\n\t"
140 "sb\t$0, 0x044(%0)\n\t"
141 "sb\t$0, 0x048(%0)\n\t"
142 "sb\t$0, 0x04c(%0)\n\t"
143 "sb\t$0, 0x050(%0)\n\t"
144 "sb\t$0, 0x054(%0)\n\t"
145 "sb\t$0, 0x058(%0)\n\t"
146 "sb\t$0, 0x05c(%0)\n\t"
147 "sb\t$0, 0x060(%0)\n\t"
148 "sb\t$0, 0x064(%0)\n\t"
149 "sb\t$0, 0x068(%0)\n\t"
150 "sb\t$0, 0x06c(%0)\n\t"
151 "sb\t$0, 0x070(%0)\n\t"
152 "sb\t$0, 0x074(%0)\n\t"
153 "sb\t$0, 0x078(%0)\n\t"
154 "sb\t$0, 0x07c(%0)\n\t"
155 : : "r" (p) );
156 p += 0x080;
157 }
158
159 write_c0_status(flags);
160 }
161
r3k_flush_dcache_range(unsigned long start,unsigned long end)162 static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
163 {
164 unsigned long size, i, flags;
165 volatile unsigned char *p;
166
167 size = end - start;
168 if (size > dcache_size || KSEGX(start) != KSEG0) {
169 start = KSEG0;
170 size = dcache_size;
171 }
172 p = (char *)start;
173
174 flags = read_c0_status();
175
176 /* isolate cache space */
177 write_c0_status((ST0_ISC|flags)&~ST0_IEC);
178
179 for (i = 0; i < size; i += 0x080) {
180 asm( "sb\t$0, 0x000(%0)\n\t"
181 "sb\t$0, 0x004(%0)\n\t"
182 "sb\t$0, 0x008(%0)\n\t"
183 "sb\t$0, 0x00c(%0)\n\t"
184 "sb\t$0, 0x010(%0)\n\t"
185 "sb\t$0, 0x014(%0)\n\t"
186 "sb\t$0, 0x018(%0)\n\t"
187 "sb\t$0, 0x01c(%0)\n\t"
188 "sb\t$0, 0x020(%0)\n\t"
189 "sb\t$0, 0x024(%0)\n\t"
190 "sb\t$0, 0x028(%0)\n\t"
191 "sb\t$0, 0x02c(%0)\n\t"
192 "sb\t$0, 0x030(%0)\n\t"
193 "sb\t$0, 0x034(%0)\n\t"
194 "sb\t$0, 0x038(%0)\n\t"
195 "sb\t$0, 0x03c(%0)\n\t"
196 "sb\t$0, 0x040(%0)\n\t"
197 "sb\t$0, 0x044(%0)\n\t"
198 "sb\t$0, 0x048(%0)\n\t"
199 "sb\t$0, 0x04c(%0)\n\t"
200 "sb\t$0, 0x050(%0)\n\t"
201 "sb\t$0, 0x054(%0)\n\t"
202 "sb\t$0, 0x058(%0)\n\t"
203 "sb\t$0, 0x05c(%0)\n\t"
204 "sb\t$0, 0x060(%0)\n\t"
205 "sb\t$0, 0x064(%0)\n\t"
206 "sb\t$0, 0x068(%0)\n\t"
207 "sb\t$0, 0x06c(%0)\n\t"
208 "sb\t$0, 0x070(%0)\n\t"
209 "sb\t$0, 0x074(%0)\n\t"
210 "sb\t$0, 0x078(%0)\n\t"
211 "sb\t$0, 0x07c(%0)\n\t"
212 : : "r" (p) );
213 p += 0x080;
214 }
215
216 write_c0_status(flags);
217 }
218
r3k_flush_cache_all(void)219 static inline void r3k_flush_cache_all(void)
220 {
221 }
222
r3k___flush_cache_all(void)223 static inline void r3k___flush_cache_all(void)
224 {
225 r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
226 r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
227 }
228
r3k_flush_cache_mm(struct mm_struct * mm)229 static void r3k_flush_cache_mm(struct mm_struct *mm)
230 {
231 }
232
r3k_flush_cache_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)233 static void r3k_flush_cache_range(struct vm_area_struct *vma,
234 unsigned long start, unsigned long end)
235 {
236 }
237
r3k_flush_cache_page(struct vm_area_struct * vma,unsigned long addr,unsigned long pfn)238 static void r3k_flush_cache_page(struct vm_area_struct *vma,
239 unsigned long addr, unsigned long pfn)
240 {
241 unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
242 int exec = vma->vm_flags & VM_EXEC;
243 struct mm_struct *mm = vma->vm_mm;
244 pgd_t *pgdp;
245 pud_t *pudp;
246 pmd_t *pmdp;
247 pte_t *ptep;
248
249 pr_debug("cpage[%08lx,%08lx]\n",
250 cpu_context(smp_processor_id(), mm), addr);
251
252 /* No ASID => no such page in the cache. */
253 if (cpu_context(smp_processor_id(), mm) == 0)
254 return;
255
256 pgdp = pgd_offset(mm, addr);
257 pudp = pud_offset(pgdp, addr);
258 pmdp = pmd_offset(pudp, addr);
259 ptep = pte_offset(pmdp, addr);
260
261 /* Invalid => no such page in the cache. */
262 if (!(pte_val(*ptep) & _PAGE_PRESENT))
263 return;
264
265 r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
266 if (exec)
267 r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
268 }
269
local_r3k_flush_data_cache_page(void * addr)270 static void local_r3k_flush_data_cache_page(void *addr)
271 {
272 }
273
r3k_flush_data_cache_page(unsigned long addr)274 static void r3k_flush_data_cache_page(unsigned long addr)
275 {
276 }
277
r3k_flush_cache_sigtramp(unsigned long addr)278 static void r3k_flush_cache_sigtramp(unsigned long addr)
279 {
280 unsigned long flags;
281
282 pr_debug("csigtramp[%08lx]\n", addr);
283
284 flags = read_c0_status();
285
286 write_c0_status(flags&~ST0_IEC);
287
288 /* Fill the TLB to avoid an exception with caches isolated. */
289 asm( "lw\t$0, 0x000(%0)\n\t"
290 "lw\t$0, 0x004(%0)\n\t"
291 : : "r" (addr) );
292
293 write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
294
295 asm( "sb\t$0, 0x000(%0)\n\t"
296 "sb\t$0, 0x004(%0)\n\t"
297 : : "r" (addr) );
298
299 write_c0_status(flags);
300 }
301
r3k_dma_cache_wback_inv(unsigned long start,unsigned long size)302 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
303 {
304 /* Catch bad driver code */
305 BUG_ON(size == 0);
306
307 iob();
308 r3k_flush_dcache_range(start, start + size);
309 }
310
r3k_cache_init(void)311 void __cpuinit r3k_cache_init(void)
312 {
313 extern void build_clear_page(void);
314 extern void build_copy_page(void);
315
316 r3k_probe_cache();
317
318 flush_cache_all = r3k_flush_cache_all;
319 __flush_cache_all = r3k___flush_cache_all;
320 flush_cache_mm = r3k_flush_cache_mm;
321 flush_cache_range = r3k_flush_cache_range;
322 flush_cache_page = r3k_flush_cache_page;
323 flush_icache_range = r3k_flush_icache_range;
324 local_flush_icache_range = r3k_flush_icache_range;
325
326 flush_cache_sigtramp = r3k_flush_cache_sigtramp;
327 local_flush_data_cache_page = local_r3k_flush_data_cache_page;
328 flush_data_cache_page = r3k_flush_data_cache_page;
329
330 _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
331 _dma_cache_wback = r3k_dma_cache_wback_inv;
332 _dma_cache_inv = r3k_dma_cache_wback_inv;
333
334 printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
335 icache_size >> 10, icache_lsize);
336 printk("Primary data cache %ldkB, linesize %ld bytes.\n",
337 dcache_size >> 10, dcache_lsize);
338
339 build_clear_page();
340 build_copy_page();
341 }
342