1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * r2300.c: R2000 and R3000 specific mmu/cache code.
4 *
5 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
6 *
7 * with a lot of changes to make this thing work for R3000s
8 * Tx39XX R4k style caches added. HK
9 * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
10 * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
11 * Copyright (C) 2001, 2004, 2007 Maciej W. Rozycki
12 */
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/mmu_context.h>
20 #include <asm/isadep.h>
21 #include <asm/io.h>
22 #include <asm/bootinfo.h>
23 #include <asm/cpu.h>
24
25 static unsigned long icache_size, dcache_size; /* Size in bytes */
26 static unsigned long icache_lsize, dcache_lsize; /* Size in bytes */
27
28 unsigned long r3k_cache_size(unsigned long ca_flags)
29 {
30 unsigned long flags, status, dummy, size;
31 volatile unsigned long *p;
32
33 p = (volatile unsigned long *) KSEG0;
34
35 flags = read_c0_status();
36
37 /* isolate cache space */
38 write_c0_status((ca_flags|flags)&~ST0_IEC);
39
40 *p = 0xa5a55a5a;
41 dummy = *p;
42 status = read_c0_status();
43
44 if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
45 size = 0;
46 } else {
47 for (size = 128; size <= 0x40000; size <<= 1)
48 *(p + size) = 0;
49 *p = -1;
50 for (size = 128;
51 (size <= 0x40000) && (*(p + size) == 0);
52 size <<= 1)
53 ;
54 if (size > 0x40000)
55 size = 0;
56 }
57
58 write_c0_status(flags);
59
60 return size * sizeof(*p);
61 }
62
63 unsigned long r3k_cache_lsize(unsigned long ca_flags)
64 {
65 unsigned long flags, status, lsize, i;
66 volatile unsigned long *p;
67
68 p = (volatile unsigned long *) KSEG0;
69
70 flags = read_c0_status();
71
72 /* isolate cache space */
73 write_c0_status((ca_flags|flags)&~ST0_IEC);
74
75 for (i = 0; i < 128; i++)
76 *(p + i) = 0;
77 *(volatile unsigned char *)p = 0;
78 for (lsize = 1; lsize < 128; lsize <<= 1) {
79 *(p + lsize);
80 status = read_c0_status();
81 if (!(status & ST0_CM))
82 break;
83 }
84 for (i = 0; i < 128; i += lsize)
85 *(volatile unsigned char *)(p + i) = 0;
86
87 write_c0_status(flags);
88
89 return lsize * sizeof(*p);
90 }
91
92 static void r3k_probe_cache(void)
93 {
94 dcache_size = r3k_cache_size(ST0_ISC);
95 if (dcache_size)
96 dcache_lsize = r3k_cache_lsize(ST0_ISC);
97
98 icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
99 if (icache_size)
100 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
101 }
102
103 static void r3k_flush_icache_range(unsigned long start, unsigned long end)
104 {
105 unsigned long size, i, flags;
106 volatile unsigned char *p;
107
108 size = end - start;
109 if (size > icache_size || KSEGX(start) != KSEG0) {
110 start = KSEG0;
111 size = icache_size;
112 }
113 p = (char *)start;
114
115 flags = read_c0_status();
116
117 /* isolate cache space */
118 write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
119
120 for (i = 0; i < size; i += 0x080) {
121 asm( "sb\t$0, 0x000(%0)\n\t"
122 "sb\t$0, 0x004(%0)\n\t"
123 "sb\t$0, 0x008(%0)\n\t"
124 "sb\t$0, 0x00c(%0)\n\t"
125 "sb\t$0, 0x010(%0)\n\t"
126 "sb\t$0, 0x014(%0)\n\t"
127 "sb\t$0, 0x018(%0)\n\t"
128 "sb\t$0, 0x01c(%0)\n\t"
129 "sb\t$0, 0x020(%0)\n\t"
130 "sb\t$0, 0x024(%0)\n\t"
131 "sb\t$0, 0x028(%0)\n\t"
132 "sb\t$0, 0x02c(%0)\n\t"
133 "sb\t$0, 0x030(%0)\n\t"
134 "sb\t$0, 0x034(%0)\n\t"
135 "sb\t$0, 0x038(%0)\n\t"
136 "sb\t$0, 0x03c(%0)\n\t"
137 "sb\t$0, 0x040(%0)\n\t"
138 "sb\t$0, 0x044(%0)\n\t"
139 "sb\t$0, 0x048(%0)\n\t"
140 "sb\t$0, 0x04c(%0)\n\t"
141 "sb\t$0, 0x050(%0)\n\t"
142 "sb\t$0, 0x054(%0)\n\t"
143 "sb\t$0, 0x058(%0)\n\t"
144 "sb\t$0, 0x05c(%0)\n\t"
145 "sb\t$0, 0x060(%0)\n\t"
146 "sb\t$0, 0x064(%0)\n\t"
147 "sb\t$0, 0x068(%0)\n\t"
148 "sb\t$0, 0x06c(%0)\n\t"
149 "sb\t$0, 0x070(%0)\n\t"
150 "sb\t$0, 0x074(%0)\n\t"
151 "sb\t$0, 0x078(%0)\n\t"
152 "sb\t$0, 0x07c(%0)\n\t"
153 : : "r" (p) );
154 p += 0x080;
155 }
156
157 write_c0_status(flags);
158 }
159
160 static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
161 {
162 unsigned long size, i, flags;
163 volatile unsigned char *p;
164
165 size = end - start;
166 if (size > dcache_size || KSEGX(start) != KSEG0) {
167 start = KSEG0;
168 size = dcache_size;
169 }
170 p = (char *)start;
171
172 flags = read_c0_status();
173
174 /* isolate cache space */
175 write_c0_status((ST0_ISC|flags)&~ST0_IEC);
176
177 for (i = 0; i < size; i += 0x080) {
178 asm( "sb\t$0, 0x000(%0)\n\t"
179 "sb\t$0, 0x004(%0)\n\t"
180 "sb\t$0, 0x008(%0)\n\t"
181 "sb\t$0, 0x00c(%0)\n\t"
182 "sb\t$0, 0x010(%0)\n\t"
183 "sb\t$0, 0x014(%0)\n\t"
184 "sb\t$0, 0x018(%0)\n\t"
185 "sb\t$0, 0x01c(%0)\n\t"
186 "sb\t$0, 0x020(%0)\n\t"
187 "sb\t$0, 0x024(%0)\n\t"
188 "sb\t$0, 0x028(%0)\n\t"
189 "sb\t$0, 0x02c(%0)\n\t"
190 "sb\t$0, 0x030(%0)\n\t"
191 "sb\t$0, 0x034(%0)\n\t"
192 "sb\t$0, 0x038(%0)\n\t"
193 "sb\t$0, 0x03c(%0)\n\t"
194 "sb\t$0, 0x040(%0)\n\t"
195 "sb\t$0, 0x044(%0)\n\t"
196 "sb\t$0, 0x048(%0)\n\t"
197 "sb\t$0, 0x04c(%0)\n\t"
198 "sb\t$0, 0x050(%0)\n\t"
199 "sb\t$0, 0x054(%0)\n\t"
200 "sb\t$0, 0x058(%0)\n\t"
201 "sb\t$0, 0x05c(%0)\n\t"
202 "sb\t$0, 0x060(%0)\n\t"
203 "sb\t$0, 0x064(%0)\n\t"
204 "sb\t$0, 0x068(%0)\n\t"
205 "sb\t$0, 0x06c(%0)\n\t"
206 "sb\t$0, 0x070(%0)\n\t"
207 "sb\t$0, 0x074(%0)\n\t"
208 "sb\t$0, 0x078(%0)\n\t"
209 "sb\t$0, 0x07c(%0)\n\t"
210 : : "r" (p) );
211 p += 0x080;
212 }
213
214 write_c0_status(flags);
215 }
216
217 static inline void r3k_flush_cache_all(void)
218 {
219 }
220
221 static inline void r3k___flush_cache_all(void)
222 {
223 r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
224 r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
225 }
226
227 static void r3k_flush_cache_mm(struct mm_struct *mm)
228 {
229 }
230
231 static void r3k_flush_cache_range(struct vm_area_struct *vma,
232 unsigned long start, unsigned long end)
233 {
234 }
235
236 static void r3k_flush_cache_page(struct vm_area_struct *vma,
237 unsigned long addr, unsigned long pfn)
238 {
239 unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
240 int exec = vma->vm_flags & VM_EXEC;
241 struct mm_struct *mm = vma->vm_mm;
242 pmd_t *pmdp;
243 pte_t *ptep;
244
245 pr_debug("cpage[%08llx,%08lx]\n",
246 cpu_context(smp_processor_id(), mm), addr);
247
248 /* No ASID => no such page in the cache. */
249 if (cpu_context(smp_processor_id(), mm) == 0)
250 return;
251
252 pmdp = pmd_off(mm, addr);
253 ptep = pte_offset_kernel(pmdp, addr);
254
255 /* Invalid => no such page in the cache. */
256 if (!(pte_val(*ptep) & _PAGE_PRESENT))
257 return;
258
259 r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
260 if (exec)
261 r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
262 }
263
264 static void r3k_flush_data_cache_page(unsigned long addr)
265 {
266 }
267
268 static void r3k_flush_kernel_vmap_range(unsigned long vaddr, int size)
269 {
270 BUG();
271 }
272
273 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
274 {
275 /* Catch bad driver code */
276 BUG_ON(size == 0);
277
278 iob();
279 r3k_flush_dcache_range(start, start + size);
280 }
281
282 void r3k_cache_init(void)
283 {
284 extern void build_clear_page(void);
285 extern void build_copy_page(void);
286
287 r3k_probe_cache();
288
289 flush_cache_all = r3k_flush_cache_all;
290 __flush_cache_all = r3k___flush_cache_all;
291 flush_cache_mm = r3k_flush_cache_mm;
292 flush_cache_range = r3k_flush_cache_range;
293 flush_cache_page = r3k_flush_cache_page;
294 flush_icache_range = r3k_flush_icache_range;
295 local_flush_icache_range = r3k_flush_icache_range;
296 __flush_icache_user_range = r3k_flush_icache_range;
297 __local_flush_icache_user_range = r3k_flush_icache_range;
298
299 __flush_kernel_vmap_range = r3k_flush_kernel_vmap_range;
300
301 flush_data_cache_page = r3k_flush_data_cache_page;
302
303 _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
304 _dma_cache_wback = r3k_dma_cache_wback_inv;
305 _dma_cache_inv = r3k_dma_cache_wback_inv;
306
307 pr_info("Primary instruction cache %ldkB, linesize %ld bytes.\n",
308 icache_size >> 10, icache_lsize);
309 pr_info("Primary data cache %ldkB, linesize %ld bytes.\n",
310 dcache_size >> 10, dcache_lsize);
311
312 build_clear_page();
313 build_copy_page();
314 }
315
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