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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  */
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/cacheops.h>
19 #include <asm/page.h>
20 #include <asm/pgtable.h>
21 #include <asm/mmu_context.h>
22 #include <asm/isadep.h>
23 #include <asm/io.h>
24 #include <asm/bootinfo.h>
25 #include <asm/cpu.h>
26 
27 /* For R3000 cores with R4000 style caches */
28 static unsigned long icache_size, dcache_size;		/* Size in bytes */
29 
30 #include <asm/r4kcache.h>
31 
32 /* This sequence is required to ensure icache is disabled immediately */
33 #define TX39_STOP_STREAMING() \
34 __asm__ __volatile__( \
35 	".set	 push\n\t" \
36 	".set	 noreorder\n\t" \
37 	"b	 1f\n\t" \
38 	"nop\n\t" \
39 	"1:\n\t" \
40 	".set pop" \
41 	)
42 
43 /* TX39H-style cache flush routines. */
tx39h_flush_icache_all(void)44 static void tx39h_flush_icache_all(void)
45 {
46 	unsigned long flags, config;
47 
48 	/* disable icache (set ICE#) */
49 	local_irq_save(flags);
50 	config = read_c0_conf();
51 	write_c0_conf(config & ~TX39_CONF_ICE);
52 	TX39_STOP_STREAMING();
53 	blast_icache16();
54 	write_c0_conf(config);
55 	local_irq_restore(flags);
56 }
57 
tx39h_dma_cache_wback_inv(unsigned long addr,unsigned long size)58 static void tx39h_dma_cache_wback_inv(unsigned long addr, unsigned long size)
59 {
60 	/* Catch bad driver code */
61 	BUG_ON(size == 0);
62 
63 	iob();
64 	blast_inv_dcache_range(addr, addr + size);
65 }
66 
67 
68 /* TX39H2,TX39H3 */
tx39_blast_dcache_page(unsigned long addr)69 static inline void tx39_blast_dcache_page(unsigned long addr)
70 {
71 	if (current_cpu_type() != CPU_TX3912)
72 		blast_dcache16_page(addr);
73 }
74 
tx39_blast_dcache_page_indexed(unsigned long addr)75 static inline void tx39_blast_dcache_page_indexed(unsigned long addr)
76 {
77 	blast_dcache16_page_indexed(addr);
78 }
79 
tx39_blast_dcache(void)80 static inline void tx39_blast_dcache(void)
81 {
82 	blast_dcache16();
83 }
84 
tx39_blast_icache_page(unsigned long addr)85 static inline void tx39_blast_icache_page(unsigned long addr)
86 {
87 	unsigned long flags, config;
88 	/* disable icache (set ICE#) */
89 	local_irq_save(flags);
90 	config = read_c0_conf();
91 	write_c0_conf(config & ~TX39_CONF_ICE);
92 	TX39_STOP_STREAMING();
93 	blast_icache16_page(addr);
94 	write_c0_conf(config);
95 	local_irq_restore(flags);
96 }
97 
tx39_blast_icache_page_indexed(unsigned long addr)98 static inline void tx39_blast_icache_page_indexed(unsigned long addr)
99 {
100 	unsigned long flags, config;
101 	/* disable icache (set ICE#) */
102 	local_irq_save(flags);
103 	config = read_c0_conf();
104 	write_c0_conf(config & ~TX39_CONF_ICE);
105 	TX39_STOP_STREAMING();
106 	blast_icache16_page_indexed(addr);
107 	write_c0_conf(config);
108 	local_irq_restore(flags);
109 }
110 
tx39_blast_icache(void)111 static inline void tx39_blast_icache(void)
112 {
113 	unsigned long flags, config;
114 	/* disable icache (set ICE#) */
115 	local_irq_save(flags);
116 	config = read_c0_conf();
117 	write_c0_conf(config & ~TX39_CONF_ICE);
118 	TX39_STOP_STREAMING();
119 	blast_icache16();
120 	write_c0_conf(config);
121 	local_irq_restore(flags);
122 }
123 
tx39__flush_cache_vmap(void)124 static void tx39__flush_cache_vmap(void)
125 {
126 	tx39_blast_dcache();
127 }
128 
tx39__flush_cache_vunmap(void)129 static void tx39__flush_cache_vunmap(void)
130 {
131 	tx39_blast_dcache();
132 }
133 
tx39_flush_cache_all(void)134 static inline void tx39_flush_cache_all(void)
135 {
136 	if (!cpu_has_dc_aliases)
137 		return;
138 
139 	tx39_blast_dcache();
140 }
141 
tx39___flush_cache_all(void)142 static inline void tx39___flush_cache_all(void)
143 {
144 	tx39_blast_dcache();
145 	tx39_blast_icache();
146 }
147 
tx39_flush_cache_mm(struct mm_struct * mm)148 static void tx39_flush_cache_mm(struct mm_struct *mm)
149 {
150 	if (!cpu_has_dc_aliases)
151 		return;
152 
153 	if (cpu_context(smp_processor_id(), mm) != 0)
154 		tx39_blast_dcache();
155 }
156 
tx39_flush_cache_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)157 static void tx39_flush_cache_range(struct vm_area_struct *vma,
158 	unsigned long start, unsigned long end)
159 {
160 	if (!cpu_has_dc_aliases)
161 		return;
162 	if (!(cpu_context(smp_processor_id(), vma->vm_mm)))
163 		return;
164 
165 	tx39_blast_dcache();
166 }
167 
tx39_flush_cache_page(struct vm_area_struct * vma,unsigned long page,unsigned long pfn)168 static void tx39_flush_cache_page(struct vm_area_struct *vma, unsigned long page, unsigned long pfn)
169 {
170 	int exec = vma->vm_flags & VM_EXEC;
171 	struct mm_struct *mm = vma->vm_mm;
172 	pgd_t *pgdp;
173 	pud_t *pudp;
174 	pmd_t *pmdp;
175 	pte_t *ptep;
176 
177 	/*
178 	 * If ownes no valid ASID yet, cannot possibly have gotten
179 	 * this page into the cache.
180 	 */
181 	if (cpu_context(smp_processor_id(), mm) == 0)
182 		return;
183 
184 	page &= PAGE_MASK;
185 	pgdp = pgd_offset(mm, page);
186 	pudp = pud_offset(pgdp, page);
187 	pmdp = pmd_offset(pudp, page);
188 	ptep = pte_offset(pmdp, page);
189 
190 	/*
191 	 * If the page isn't marked valid, the page cannot possibly be
192 	 * in the cache.
193 	 */
194 	if (!(pte_val(*ptep) & _PAGE_PRESENT))
195 		return;
196 
197 	/*
198 	 * Doing flushes for another ASID than the current one is
199 	 * too difficult since stupid R4k caches do a TLB translation
200 	 * for every cache flush operation.  So we do indexed flushes
201 	 * in that case, which doesn't overly flush the cache too much.
202 	 */
203 	if ((mm == current->active_mm) && (pte_val(*ptep) & _PAGE_VALID)) {
204 		if (cpu_has_dc_aliases || exec)
205 			tx39_blast_dcache_page(page);
206 		if (exec)
207 			tx39_blast_icache_page(page);
208 
209 		return;
210 	}
211 
212 	/*
213 	 * Do indexed flush, too much work to get the (possible) TLB refills
214 	 * to work correctly.
215 	 */
216 	if (cpu_has_dc_aliases || exec)
217 		tx39_blast_dcache_page_indexed(page);
218 	if (exec)
219 		tx39_blast_icache_page_indexed(page);
220 }
221 
local_tx39_flush_data_cache_page(void * addr)222 static void local_tx39_flush_data_cache_page(void * addr)
223 {
224 	tx39_blast_dcache_page((unsigned long)addr);
225 }
226 
tx39_flush_data_cache_page(unsigned long addr)227 static void tx39_flush_data_cache_page(unsigned long addr)
228 {
229 	tx39_blast_dcache_page(addr);
230 }
231 
tx39_flush_icache_range(unsigned long start,unsigned long end)232 static void tx39_flush_icache_range(unsigned long start, unsigned long end)
233 {
234 	if (end - start > dcache_size)
235 		tx39_blast_dcache();
236 	else
237 		protected_blast_dcache_range(start, end);
238 
239 	if (end - start > icache_size)
240 		tx39_blast_icache();
241 	else {
242 		unsigned long flags, config;
243 		/* disable icache (set ICE#) */
244 		local_irq_save(flags);
245 		config = read_c0_conf();
246 		write_c0_conf(config & ~TX39_CONF_ICE);
247 		TX39_STOP_STREAMING();
248 		protected_blast_icache_range(start, end);
249 		write_c0_conf(config);
250 		local_irq_restore(flags);
251 	}
252 }
253 
tx39_flush_kernel_vmap_range(unsigned long vaddr,int size)254 static void tx39_flush_kernel_vmap_range(unsigned long vaddr, int size)
255 {
256 	BUG();
257 }
258 
tx39_dma_cache_wback_inv(unsigned long addr,unsigned long size)259 static void tx39_dma_cache_wback_inv(unsigned long addr, unsigned long size)
260 {
261 	unsigned long end;
262 
263 	if (((size | addr) & (PAGE_SIZE - 1)) == 0) {
264 		end = addr + size;
265 		do {
266 			tx39_blast_dcache_page(addr);
267 			addr += PAGE_SIZE;
268 		} while(addr != end);
269 	} else if (size > dcache_size) {
270 		tx39_blast_dcache();
271 	} else {
272 		blast_dcache_range(addr, addr + size);
273 	}
274 }
275 
tx39_dma_cache_inv(unsigned long addr,unsigned long size)276 static void tx39_dma_cache_inv(unsigned long addr, unsigned long size)
277 {
278 	unsigned long end;
279 
280 	if (((size | addr) & (PAGE_SIZE - 1)) == 0) {
281 		end = addr + size;
282 		do {
283 			tx39_blast_dcache_page(addr);
284 			addr += PAGE_SIZE;
285 		} while(addr != end);
286 	} else if (size > dcache_size) {
287 		tx39_blast_dcache();
288 	} else {
289 		blast_inv_dcache_range(addr, addr + size);
290 	}
291 }
292 
tx39_probe_cache(void)293 static __init void tx39_probe_cache(void)
294 {
295 	unsigned long config;
296 
297 	config = read_c0_conf();
298 
299 	icache_size = 1 << (10 + ((config & TX39_CONF_ICS_MASK) >>
300 				  TX39_CONF_ICS_SHIFT));
301 	dcache_size = 1 << (10 + ((config & TX39_CONF_DCS_MASK) >>
302 				  TX39_CONF_DCS_SHIFT));
303 
304 	current_cpu_data.icache.linesz = 16;
305 	switch (current_cpu_type()) {
306 	case CPU_TX3912:
307 		current_cpu_data.icache.ways = 1;
308 		current_cpu_data.dcache.ways = 1;
309 		current_cpu_data.dcache.linesz = 4;
310 		break;
311 
312 	case CPU_TX3927:
313 		current_cpu_data.icache.ways = 2;
314 		current_cpu_data.dcache.ways = 2;
315 		current_cpu_data.dcache.linesz = 16;
316 		break;
317 
318 	case CPU_TX3922:
319 	default:
320 		current_cpu_data.icache.ways = 1;
321 		current_cpu_data.dcache.ways = 1;
322 		current_cpu_data.dcache.linesz = 16;
323 		break;
324 	}
325 }
326 
tx39_cache_init(void)327 void tx39_cache_init(void)
328 {
329 	extern void build_clear_page(void);
330 	extern void build_copy_page(void);
331 	unsigned long config;
332 
333 	config = read_c0_conf();
334 	config &= ~TX39_CONF_WBON;
335 	write_c0_conf(config);
336 
337 	tx39_probe_cache();
338 
339 	switch (current_cpu_type()) {
340 	case CPU_TX3912:
341 		/* TX39/H core (writethru direct-map cache) */
342 		__flush_cache_vmap	= tx39__flush_cache_vmap;
343 		__flush_cache_vunmap	= tx39__flush_cache_vunmap;
344 		flush_cache_all = tx39h_flush_icache_all;
345 		__flush_cache_all	= tx39h_flush_icache_all;
346 		flush_cache_mm		= (void *) tx39h_flush_icache_all;
347 		flush_cache_range	= (void *) tx39h_flush_icache_all;
348 		flush_cache_page	= (void *) tx39h_flush_icache_all;
349 		flush_icache_range	= (void *) tx39h_flush_icache_all;
350 		local_flush_icache_range = (void *) tx39h_flush_icache_all;
351 
352 		local_flush_data_cache_page	= (void *) tx39h_flush_icache_all;
353 		flush_data_cache_page	= (void *) tx39h_flush_icache_all;
354 
355 		_dma_cache_wback_inv	= tx39h_dma_cache_wback_inv;
356 
357 		shm_align_mask		= PAGE_SIZE - 1;
358 
359 		break;
360 
361 	case CPU_TX3922:
362 	case CPU_TX3927:
363 	default:
364 		/* TX39/H2,H3 core (writeback 2way-set-associative cache) */
365 		/* board-dependent init code may set WBON */
366 
367 		__flush_cache_vmap	= tx39__flush_cache_vmap;
368 		__flush_cache_vunmap	= tx39__flush_cache_vunmap;
369 
370 		flush_cache_all = tx39_flush_cache_all;
371 		__flush_cache_all = tx39___flush_cache_all;
372 		flush_cache_mm = tx39_flush_cache_mm;
373 		flush_cache_range = tx39_flush_cache_range;
374 		flush_cache_page = tx39_flush_cache_page;
375 		flush_icache_range = tx39_flush_icache_range;
376 		local_flush_icache_range = tx39_flush_icache_range;
377 
378 		__flush_kernel_vmap_range = tx39_flush_kernel_vmap_range;
379 
380 		local_flush_data_cache_page = local_tx39_flush_data_cache_page;
381 		flush_data_cache_page = tx39_flush_data_cache_page;
382 
383 		_dma_cache_wback_inv = tx39_dma_cache_wback_inv;
384 		_dma_cache_wback = tx39_dma_cache_wback_inv;
385 		_dma_cache_inv = tx39_dma_cache_inv;
386 
387 		shm_align_mask = max_t(unsigned long,
388 				       (dcache_size / current_cpu_data.dcache.ways) - 1,
389 				       PAGE_SIZE - 1);
390 
391 		break;
392 	}
393 
394 	__flush_icache_user_range = flush_icache_range;
395 	__local_flush_icache_user_range = local_flush_icache_range;
396 
397 	current_cpu_data.icache.waysize = icache_size / current_cpu_data.icache.ways;
398 	current_cpu_data.dcache.waysize = dcache_size / current_cpu_data.dcache.ways;
399 
400 	current_cpu_data.icache.sets =
401 		current_cpu_data.icache.waysize / current_cpu_data.icache.linesz;
402 	current_cpu_data.dcache.sets =
403 		current_cpu_data.dcache.waysize / current_cpu_data.dcache.linesz;
404 
405 	if (current_cpu_data.dcache.waysize > PAGE_SIZE)
406 		current_cpu_data.dcache.flags |= MIPS_CACHE_ALIASES;
407 
408 	current_cpu_data.icache.waybit = 0;
409 	current_cpu_data.dcache.waybit = 0;
410 
411 	printk("Primary instruction cache %ldkB, linesize %d bytes\n",
412 		icache_size >> 10, current_cpu_data.icache.linesz);
413 	printk("Primary data cache %ldkB, linesize %d bytes\n",
414 		dcache_size >> 10, current_cpu_data.dcache.linesz);
415 
416 	build_clear_page();
417 	build_copy_page();
418 	tx39h_flush_icache_all();
419 }
420