xref: /linux/arch/arc/mm/cache.c (revision c06983f853bc58eafe05f75dfd7e8bdafba3cd8c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ARC Cache Management
4  *
5  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
6  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
7  */
8 
9 #include <linux/module.h>
10 #include <linux/mm.h>
11 #include <linux/sched.h>
12 #include <linux/cache.h>
13 #include <linux/mmu_context.h>
14 #include <linux/syscalls.h>
15 #include <linux/uaccess.h>
16 #include <linux/pagemap.h>
17 #include <asm/cacheflush.h>
18 #include <asm/cachectl.h>
19 #include <asm/setup.h>
20 
21 #ifdef CONFIG_ISA_ARCV2
22 #define USE_RGN_FLSH	1
23 #endif
24 
25 static int l2_line_sz;
26 static int ioc_exists;
27 int slc_enable = 1, ioc_enable = 1;
28 unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */
29 unsigned long perip_end = 0xFFFFFFFF; /* legacy value */
30 
31 static struct cpuinfo_arc_cache {
32 	unsigned int sz_k, line_len, colors;
33 } ic_info, dc_info, slc_info;
34 
35 void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr,
36 			       unsigned long sz, const int op, const int full_page);
37 
38 void (*__dma_cache_wback_inv)(phys_addr_t start, unsigned long sz);
39 void (*__dma_cache_inv)(phys_addr_t start, unsigned long sz);
40 void (*__dma_cache_wback)(phys_addr_t start, unsigned long sz);
41 
42 static int read_decode_cache_bcr_arcv2(int c, char *buf, int len)
43 {
44 	struct cpuinfo_arc_cache *p_slc = &slc_info;
45 	struct bcr_identity ident;
46 	struct bcr_generic sbcr;
47 	struct bcr_clust_cfg cbcr;
48 	struct bcr_volatile vol;
49 	int n = 0;
50 
51 	READ_BCR(ARC_REG_SLC_BCR, sbcr);
52 	if (sbcr.ver) {
53 		struct bcr_slc_cfg  slc_cfg;
54 		READ_BCR(ARC_REG_SLC_CFG, slc_cfg);
55 		p_slc->sz_k = 128 << slc_cfg.sz;
56 		l2_line_sz = p_slc->line_len = (slc_cfg.lsz == 0) ? 128 : 64;
57 		n += scnprintf(buf + n, len - n,
58 			       "SLC\t\t: %uK, %uB Line%s\n",
59 			       p_slc->sz_k, p_slc->line_len, IS_USED_RUN(slc_enable));
60 	}
61 
62 	READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
63 	if (cbcr.c) {
64 		ioc_exists = 1;
65 
66 		/*
67 		 * As for today we don't support both IOC and ZONE_HIGHMEM enabled
68 		 * simultaneously. This happens because as of today IOC aperture covers
69 		 * only ZONE_NORMAL (low mem) and any dma transactions outside this
70 		 * region won't be HW coherent.
71 		 * If we want to use both IOC and ZONE_HIGHMEM we can use
72 		 * bounce_buffer to handle dma transactions to HIGHMEM.
73 		 * Also it is possible to modify dma_direct cache ops or increase IOC
74 		 * aperture size if we are planning to use HIGHMEM without PAE.
75 		 */
76 		if (IS_ENABLED(CONFIG_HIGHMEM) || is_pae40_enabled())
77 			ioc_enable = 0;
78 	} else {
79 		ioc_enable = 0;
80 	}
81 
82 	READ_BCR(AUX_IDENTITY, ident);
83 
84 	/* HS 2.0 didn't have AUX_VOL */
85 	if (ident.family > 0x51) {
86 		READ_BCR(AUX_VOL, vol);
87 		perip_base = vol.start << 28;
88 		/* HS 3.0 has limit and strict-ordering fields */
89 		if (ident.family > 0x52)
90 			perip_end = (vol.limit << 28) - 1;
91 	}
92 
93 	n += scnprintf(buf + n, len - n, "Peripherals\t: %#lx%s%s\n",
94 		       perip_base,
95 		       IS_AVAIL3(ioc_exists, ioc_enable, ", IO-Coherency (per-device) "));
96 
97 	return n;
98 }
99 
100 int arc_cache_mumbojumbo(int c, char *buf, int len)
101 {
102 	struct cpuinfo_arc_cache *p_ic = &ic_info, *p_dc = &dc_info;
103 	struct bcr_cache ibcr, dbcr;
104 	int vipt, assoc;
105 	int n = 0;
106 
107 	READ_BCR(ARC_REG_IC_BCR, ibcr);
108 	if (!ibcr.ver)
109 		goto dc_chk;
110 
111 	if (is_isa_arcompact() && (ibcr.ver <= 3)) {
112 		BUG_ON(ibcr.config != 3);
113 		assoc = 2;		/* Fixed to 2w set assoc */
114 	} else if (is_isa_arcv2() && (ibcr.ver >= 4)) {
115 		assoc = 1 << ibcr.config;	/* 1,2,4,8 */
116 	}
117 
118 	p_ic->line_len = 8 << ibcr.line_len;
119 	p_ic->sz_k = 1 << (ibcr.sz - 1);
120 	p_ic->colors = p_ic->sz_k/assoc/TO_KB(PAGE_SIZE);
121 
122 	n += scnprintf(buf + n, len - n,
123 			"I-Cache\t\t: %uK, %dway/set, %uB Line, VIPT%s%s\n",
124 			p_ic->sz_k, assoc, p_ic->line_len,
125 			p_ic->colors > 1 ? " aliasing" : "",
126 			IS_USED_CFG(CONFIG_ARC_HAS_ICACHE));
127 
128 dc_chk:
129 	READ_BCR(ARC_REG_DC_BCR, dbcr);
130 	if (!dbcr.ver)
131 		goto slc_chk;
132 
133 	if (is_isa_arcompact() && (dbcr.ver <= 3)) {
134 		BUG_ON(dbcr.config != 2);
135 		vipt = 1;
136 		assoc = 4;		/* Fixed to 4w set assoc */
137 		p_dc->colors = p_dc->sz_k/assoc/TO_KB(PAGE_SIZE);
138 	} else if (is_isa_arcv2() && (dbcr.ver >= 4)) {
139 		vipt = 0;
140 		assoc = 1 << dbcr.config;	/* 1,2,4,8 */
141 		p_dc->colors = 1;		/* PIPT so can't VIPT alias */
142 	}
143 
144 	p_dc->line_len = 16 << dbcr.line_len;
145 	p_dc->sz_k = 1 << (dbcr.sz - 1);
146 
147 	n += scnprintf(buf + n, len - n,
148 			"D-Cache\t\t: %uK, %dway/set, %uB Line, %s%s\n",
149 			p_dc->sz_k, assoc, p_dc->line_len,
150 			vipt ? "VIPT" : "PIPT",
151 			IS_USED_CFG(CONFIG_ARC_HAS_DCACHE));
152 
153 slc_chk:
154 	if (is_isa_arcv2())
155 		n += read_decode_cache_bcr_arcv2(c, buf + n, len - n);
156 
157 	return n;
158 }
159 
160 /*
161  * Line Operation on {I,D}-Cache
162  */
163 
164 #define OP_INV		0x1
165 #define OP_FLUSH	0x2
166 #define OP_FLUSH_N_INV	0x3
167 #define OP_INV_IC	0x4
168 
169 /*
170  * Cache Flush programming model
171  *
172  * ARC700 MMUv3 I$ and D$ are both VIPT and can potentially alias.
173  * Programming model requires both paddr and vaddr irrespecive of aliasing
174  * considerations:
175  *  - vaddr in {I,D}C_IV?L
176  *  - paddr in {I,D}C_PTAG
177  *
178  * In HS38x (MMUv4), D$ is PIPT, I$ is VIPT and can still alias.
179  * Programming model is different for aliasing vs. non-aliasing I$
180  *  - D$ / Non-aliasing I$: only paddr in {I,D}C_IV?L
181  *  - Aliasing I$: same as ARC700 above (so MMUv3 routine used for MMUv4 I$)
182  *
183  *  - If PAE40 is enabled, independent of aliasing considerations, the higher
184  *    bits needs to be written into PTAG_HI
185  */
186 
187 static inline
188 void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
189 			  unsigned long sz, const int op, const int full_page)
190 {
191 	unsigned int aux_cmd, aux_tag;
192 	int num_lines;
193 
194 	if (op == OP_INV_IC) {
195 		aux_cmd = ARC_REG_IC_IVIL;
196 		aux_tag = ARC_REG_IC_PTAG;
197 	} else {
198 		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
199 		aux_tag = ARC_REG_DC_PTAG;
200 	}
201 
202 	/* Ensure we properly floor/ceil the non-line aligned/sized requests
203 	 * and have @paddr - aligned to cache line and integral @num_lines.
204 	 * This however can be avoided for page sized since:
205 	 *  -@paddr will be cache-line aligned already (being page aligned)
206 	 *  -@sz will be integral multiple of line size (being page sized).
207 	 */
208 	if (!full_page) {
209 		sz += paddr & ~CACHE_LINE_MASK;
210 		paddr &= CACHE_LINE_MASK;
211 		vaddr &= CACHE_LINE_MASK;
212 	}
213 	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
214 
215 	/*
216 	 * MMUv3, cache ops require paddr in PTAG reg
217 	 * if V-P const for loop, PTAG can be written once outside loop
218 	 */
219 	if (full_page)
220 		write_aux_reg(aux_tag, paddr);
221 
222 	/*
223 	 * This is technically for MMU v4, using the MMU v3 programming model
224 	 * Special work for HS38 aliasing I-cache configuration with PAE40
225 	 *   - upper 8 bits of paddr need to be written into PTAG_HI
226 	 *   - (and needs to be written before the lower 32 bits)
227 	 * Note that PTAG_HI is hoisted outside the line loop
228 	 */
229 	if (is_pae40_enabled() && op == OP_INV_IC)
230 		write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
231 
232 	while (num_lines-- > 0) {
233 		if (!full_page) {
234 			write_aux_reg(aux_tag, paddr);
235 			paddr += L1_CACHE_BYTES;
236 		}
237 
238 		write_aux_reg(aux_cmd, vaddr);
239 		vaddr += L1_CACHE_BYTES;
240 	}
241 }
242 
243 #ifndef USE_RGN_FLSH
244 
245 /*
246  */
247 static inline
248 void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
249 			  unsigned long sz, const int op, const int full_page)
250 {
251 	unsigned int aux_cmd;
252 	int num_lines;
253 
254 	if (op == OP_INV_IC) {
255 		aux_cmd = ARC_REG_IC_IVIL;
256 	} else {
257 		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
258 		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
259 	}
260 
261 	/* Ensure we properly floor/ceil the non-line aligned/sized requests
262 	 * and have @paddr - aligned to cache line and integral @num_lines.
263 	 * This however can be avoided for page sized since:
264 	 *  -@paddr will be cache-line aligned already (being page aligned)
265 	 *  -@sz will be integral multiple of line size (being page sized).
266 	 */
267 	if (!full_page) {
268 		sz += paddr & ~CACHE_LINE_MASK;
269 		paddr &= CACHE_LINE_MASK;
270 	}
271 
272 	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
273 
274 	/*
275 	 * For HS38 PAE40 configuration
276 	 *   - upper 8 bits of paddr need to be written into PTAG_HI
277 	 *   - (and needs to be written before the lower 32 bits)
278 	 */
279 	if (is_pae40_enabled()) {
280 		if (op == OP_INV_IC)
281 			/*
282 			 * Non aliasing I-cache in HS38,
283 			 * aliasing I-cache handled in __cache_line_loop_v3()
284 			 */
285 			write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
286 		else
287 			write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
288 	}
289 
290 	while (num_lines-- > 0) {
291 		write_aux_reg(aux_cmd, paddr);
292 		paddr += L1_CACHE_BYTES;
293 	}
294 }
295 
296 #else
297 
298 /*
299  * optimized flush operation which takes a region as opposed to iterating per line
300  */
301 static inline
302 void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
303 			  unsigned long sz, const int op, const int full_page)
304 {
305 	unsigned int s, e;
306 
307 	/* Only for Non aliasing I-cache in HS38 */
308 	if (op == OP_INV_IC) {
309 		s = ARC_REG_IC_IVIR;
310 		e = ARC_REG_IC_ENDR;
311 	} else {
312 		s = ARC_REG_DC_STARTR;
313 		e = ARC_REG_DC_ENDR;
314 	}
315 
316 	if (!full_page) {
317 		/* for any leading gap between @paddr and start of cache line */
318 		sz += paddr & ~CACHE_LINE_MASK;
319 		paddr &= CACHE_LINE_MASK;
320 
321 		/*
322 		 *  account for any trailing gap to end of cache line
323 		 *  this is equivalent to DIV_ROUND_UP() in line ops above
324 		 */
325 		sz += L1_CACHE_BYTES - 1;
326 	}
327 
328 	if (is_pae40_enabled()) {
329 		/* TBD: check if crossing 4TB boundary */
330 		if (op == OP_INV_IC)
331 			write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
332 		else
333 			write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
334 	}
335 
336 	/* ENDR needs to be set ahead of START */
337 	write_aux_reg(e, paddr + sz);	/* ENDR is exclusive */
338 	write_aux_reg(s, paddr);
339 
340 	/* caller waits on DC_CTRL.FS */
341 }
342 
343 #endif
344 
345 #ifdef CONFIG_ARC_MMU_V3
346 #define __cache_line_loop	__cache_line_loop_v3
347 #else
348 #define __cache_line_loop	__cache_line_loop_v4
349 #endif
350 
351 #ifdef CONFIG_ARC_HAS_DCACHE
352 
353 /***************************************************************
354  * Machine specific helpers for Entire D-Cache or Per Line ops
355  */
356 
357 #ifndef USE_RGN_FLSH
358 /*
359  * this version avoids extra read/write of DC_CTRL for flush or invalid ops
360  * in the non region flush regime (such as for ARCompact)
361  */
362 static inline void __before_dc_op(const int op)
363 {
364 	if (op == OP_FLUSH_N_INV) {
365 		/* Dcache provides 2 cmd: FLUSH or INV
366 		 * INV in turn has sub-modes: DISCARD or FLUSH-BEFORE
367 		 * flush-n-inv is achieved by INV cmd but with IM=1
368 		 * So toggle INV sub-mode depending on op request and default
369 		 */
370 		const unsigned int ctl = ARC_REG_DC_CTRL;
371 		write_aux_reg(ctl, read_aux_reg(ctl) | DC_CTRL_INV_MODE_FLUSH);
372 	}
373 }
374 
375 #else
376 
377 static inline void __before_dc_op(const int op)
378 {
379 	const unsigned int ctl = ARC_REG_DC_CTRL;
380 	unsigned int val = read_aux_reg(ctl);
381 
382 	if (op == OP_FLUSH_N_INV) {
383 		val |= DC_CTRL_INV_MODE_FLUSH;
384 	}
385 
386 	if (op != OP_INV_IC) {
387 		/*
388 		 * Flush / Invalidate is provided by DC_CTRL.RNG_OP 0 or 1
389 		 * combined Flush-n-invalidate uses DC_CTRL.IM = 1 set above
390 		 */
391 		val &= ~DC_CTRL_RGN_OP_MSK;
392 		if (op & OP_INV)
393 			val |= DC_CTRL_RGN_OP_INV;
394 	}
395 	write_aux_reg(ctl, val);
396 }
397 
398 #endif
399 
400 
401 static inline void __after_dc_op(const int op)
402 {
403 	if (op & OP_FLUSH) {
404 		const unsigned int ctl = ARC_REG_DC_CTRL;
405 		unsigned int reg;
406 
407 		/* flush / flush-n-inv both wait */
408 		while ((reg = read_aux_reg(ctl)) & DC_CTRL_FLUSH_STATUS)
409 			;
410 
411 		/* Switch back to default Invalidate mode */
412 		if (op == OP_FLUSH_N_INV)
413 			write_aux_reg(ctl, reg & ~DC_CTRL_INV_MODE_FLUSH);
414 	}
415 }
416 
417 /*
418  * Operation on Entire D-Cache
419  * @op = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
420  * Note that constant propagation ensures all the checks are gone
421  * in generated code
422  */
423 static inline void __dc_entire_op(const int op)
424 {
425 	int aux;
426 
427 	__before_dc_op(op);
428 
429 	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
430 		aux = ARC_REG_DC_IVDC;
431 	else
432 		aux = ARC_REG_DC_FLSH;
433 
434 	write_aux_reg(aux, 0x1);
435 
436 	__after_dc_op(op);
437 }
438 
439 static inline void __dc_disable(void)
440 {
441 	const int r = ARC_REG_DC_CTRL;
442 
443 	__dc_entire_op(OP_FLUSH_N_INV);
444 	write_aux_reg(r, read_aux_reg(r) | DC_CTRL_DIS);
445 }
446 
447 static void __dc_enable(void)
448 {
449 	const int r = ARC_REG_DC_CTRL;
450 
451 	write_aux_reg(r, read_aux_reg(r) & ~DC_CTRL_DIS);
452 }
453 
454 /* For kernel mappings cache operation: index is same as paddr */
455 #define __dc_line_op_k(p, sz, op)	__dc_line_op(p, p, sz, op)
456 
457 /*
458  * D-Cache Line ops: Per Line INV (discard or wback+discard) or FLUSH (wback)
459  */
460 static inline void __dc_line_op(phys_addr_t paddr, unsigned long vaddr,
461 				unsigned long sz, const int op)
462 {
463 	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
464 	unsigned long flags;
465 
466 	local_irq_save(flags);
467 
468 	__before_dc_op(op);
469 
470 	__cache_line_loop(paddr, vaddr, sz, op, full_page);
471 
472 	__after_dc_op(op);
473 
474 	local_irq_restore(flags);
475 }
476 
477 #else
478 
479 #define __dc_entire_op(op)
480 #define __dc_disable()
481 #define __dc_enable()
482 #define __dc_line_op(paddr, vaddr, sz, op)
483 #define __dc_line_op_k(paddr, sz, op)
484 
485 #endif /* CONFIG_ARC_HAS_DCACHE */
486 
487 #ifdef CONFIG_ARC_HAS_ICACHE
488 
489 static inline void __ic_entire_inv(void)
490 {
491 	write_aux_reg(ARC_REG_IC_IVIC, 1);
492 	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
493 }
494 
495 static inline void
496 __ic_line_inv_vaddr_local(phys_addr_t paddr, unsigned long vaddr,
497 			  unsigned long sz)
498 {
499 	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
500 	unsigned long flags;
501 
502 	local_irq_save(flags);
503 	(*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC, full_page);
504 	local_irq_restore(flags);
505 }
506 
507 #ifndef CONFIG_SMP
508 
509 #define __ic_line_inv_vaddr(p, v, s)	__ic_line_inv_vaddr_local(p, v, s)
510 
511 #else
512 
513 struct ic_inv_args {
514 	phys_addr_t paddr, vaddr;
515 	int sz;
516 };
517 
518 static void __ic_line_inv_vaddr_helper(void *info)
519 {
520         struct ic_inv_args *ic_inv = info;
521 
522         __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
523 }
524 
525 static void __ic_line_inv_vaddr(phys_addr_t paddr, unsigned long vaddr,
526 				unsigned long sz)
527 {
528 	struct ic_inv_args ic_inv = {
529 		.paddr = paddr,
530 		.vaddr = vaddr,
531 		.sz    = sz
532 	};
533 
534 	on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
535 }
536 
537 #endif	/* CONFIG_SMP */
538 
539 #else	/* !CONFIG_ARC_HAS_ICACHE */
540 
541 #define __ic_entire_inv()
542 #define __ic_line_inv_vaddr(pstart, vstart, sz)
543 
544 #endif /* CONFIG_ARC_HAS_ICACHE */
545 
546 static noinline void slc_op_rgn(phys_addr_t paddr, unsigned long sz, const int op)
547 {
548 #ifdef CONFIG_ISA_ARCV2
549 	/*
550 	 * SLC is shared between all cores and concurrent aux operations from
551 	 * multiple cores need to be serialized using a spinlock
552 	 * A concurrent operation can be silently ignored and/or the old/new
553 	 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
554 	 * below)
555 	 */
556 	static DEFINE_SPINLOCK(lock);
557 	unsigned long flags;
558 	unsigned int ctrl;
559 	phys_addr_t end;
560 
561 	spin_lock_irqsave(&lock, flags);
562 
563 	/*
564 	 * The Region Flush operation is specified by CTRL.RGN_OP[11..9]
565 	 *  - b'000 (default) is Flush,
566 	 *  - b'001 is Invalidate if CTRL.IM == 0
567 	 *  - b'001 is Flush-n-Invalidate if CTRL.IM == 1
568 	 */
569 	ctrl = read_aux_reg(ARC_REG_SLC_CTRL);
570 
571 	/* Don't rely on default value of IM bit */
572 	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
573 		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
574 	else
575 		ctrl |= SLC_CTRL_IM;
576 
577 	if (op & OP_INV)
578 		ctrl |= SLC_CTRL_RGN_OP_INV;	/* Inv or flush-n-inv */
579 	else
580 		ctrl &= ~SLC_CTRL_RGN_OP_INV;
581 
582 	write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
583 
584 	/*
585 	 * Lower bits are ignored, no need to clip
586 	 * END needs to be setup before START (latter triggers the operation)
587 	 * END can't be same as START, so add (l2_line_sz - 1) to sz
588 	 */
589 	end = paddr + sz + l2_line_sz - 1;
590 	if (is_pae40_enabled())
591 		write_aux_reg(ARC_REG_SLC_RGN_END1, upper_32_bits(end));
592 
593 	write_aux_reg(ARC_REG_SLC_RGN_END, lower_32_bits(end));
594 
595 	if (is_pae40_enabled())
596 		write_aux_reg(ARC_REG_SLC_RGN_START1, upper_32_bits(paddr));
597 
598 	write_aux_reg(ARC_REG_SLC_RGN_START, lower_32_bits(paddr));
599 
600 	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
601 	read_aux_reg(ARC_REG_SLC_CTRL);
602 
603 	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
604 
605 	spin_unlock_irqrestore(&lock, flags);
606 #endif
607 }
608 
609 static __maybe_unused noinline void slc_op_line(phys_addr_t paddr, unsigned long sz, const int op)
610 {
611 #ifdef CONFIG_ISA_ARCV2
612 	/*
613 	 * SLC is shared between all cores and concurrent aux operations from
614 	 * multiple cores need to be serialized using a spinlock
615 	 * A concurrent operation can be silently ignored and/or the old/new
616 	 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
617 	 * below)
618 	 */
619 	static DEFINE_SPINLOCK(lock);
620 
621 	const unsigned long SLC_LINE_MASK = ~(l2_line_sz - 1);
622 	unsigned int ctrl, cmd;
623 	unsigned long flags;
624 	int num_lines;
625 
626 	spin_lock_irqsave(&lock, flags);
627 
628 	ctrl = read_aux_reg(ARC_REG_SLC_CTRL);
629 
630 	/* Don't rely on default value of IM bit */
631 	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
632 		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
633 	else
634 		ctrl |= SLC_CTRL_IM;
635 
636 	write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
637 
638 	cmd = op & OP_INV ? ARC_AUX_SLC_IVDL : ARC_AUX_SLC_FLDL;
639 
640 	sz += paddr & ~SLC_LINE_MASK;
641 	paddr &= SLC_LINE_MASK;
642 
643 	num_lines = DIV_ROUND_UP(sz, l2_line_sz);
644 
645 	while (num_lines-- > 0) {
646 		write_aux_reg(cmd, paddr);
647 		paddr += l2_line_sz;
648 	}
649 
650 	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
651 	read_aux_reg(ARC_REG_SLC_CTRL);
652 
653 	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
654 
655 	spin_unlock_irqrestore(&lock, flags);
656 #endif
657 }
658 
659 #define slc_op(paddr, sz, op)	slc_op_rgn(paddr, sz, op)
660 
661 noinline static void slc_entire_op(const int op)
662 {
663 	unsigned int ctrl, r = ARC_REG_SLC_CTRL;
664 
665 	ctrl = read_aux_reg(r);
666 
667 	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
668 		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
669 	else
670 		ctrl |= SLC_CTRL_IM;
671 
672 	write_aux_reg(r, ctrl);
673 
674 	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
675 		write_aux_reg(ARC_REG_SLC_INVALIDATE, 0x1);
676 	else
677 		write_aux_reg(ARC_REG_SLC_FLUSH, 0x1);
678 
679 	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
680 	read_aux_reg(r);
681 
682 	/* Important to wait for flush to complete */
683 	while (read_aux_reg(r) & SLC_CTRL_BUSY);
684 }
685 
686 static inline void arc_slc_disable(void)
687 {
688 	const int r = ARC_REG_SLC_CTRL;
689 
690 	slc_entire_op(OP_FLUSH_N_INV);
691 	write_aux_reg(r, read_aux_reg(r) | SLC_CTRL_DIS);
692 }
693 
694 static inline void arc_slc_enable(void)
695 {
696 	const int r = ARC_REG_SLC_CTRL;
697 
698 	write_aux_reg(r, read_aux_reg(r) & ~SLC_CTRL_DIS);
699 }
700 
701 /***********************************************************
702  * Exported APIs
703  */
704 
705 void flush_dcache_folio(struct folio *folio)
706 {
707 	clear_bit(PG_dc_clean, &folio->flags);
708 	return;
709 }
710 EXPORT_SYMBOL(flush_dcache_folio);
711 
712 void flush_dcache_page(struct page *page)
713 {
714 	return flush_dcache_folio(page_folio(page));
715 }
716 EXPORT_SYMBOL(flush_dcache_page);
717 
718 /*
719  * DMA ops for systems with L1 cache only
720  * Make memory coherent with L1 cache by flushing/invalidating L1 lines
721  */
722 static void __dma_cache_wback_inv_l1(phys_addr_t start, unsigned long sz)
723 {
724 	__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
725 }
726 
727 static void __dma_cache_inv_l1(phys_addr_t start, unsigned long sz)
728 {
729 	__dc_line_op_k(start, sz, OP_INV);
730 }
731 
732 static void __dma_cache_wback_l1(phys_addr_t start, unsigned long sz)
733 {
734 	__dc_line_op_k(start, sz, OP_FLUSH);
735 }
736 
737 /*
738  * DMA ops for systems with both L1 and L2 caches, but without IOC
739  * Both L1 and L2 lines need to be explicitly flushed/invalidated
740  */
741 static void __dma_cache_wback_inv_slc(phys_addr_t start, unsigned long sz)
742 {
743 	__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
744 	slc_op(start, sz, OP_FLUSH_N_INV);
745 }
746 
747 static void __dma_cache_inv_slc(phys_addr_t start, unsigned long sz)
748 {
749 	__dc_line_op_k(start, sz, OP_INV);
750 	slc_op(start, sz, OP_INV);
751 }
752 
753 static void __dma_cache_wback_slc(phys_addr_t start, unsigned long sz)
754 {
755 	__dc_line_op_k(start, sz, OP_FLUSH);
756 	slc_op(start, sz, OP_FLUSH);
757 }
758 
759 /*
760  * Exported DMA API
761  */
762 void dma_cache_wback_inv(phys_addr_t start, unsigned long sz)
763 {
764 	__dma_cache_wback_inv(start, sz);
765 }
766 EXPORT_SYMBOL(dma_cache_wback_inv);
767 
768 void dma_cache_inv(phys_addr_t start, unsigned long sz)
769 {
770 	__dma_cache_inv(start, sz);
771 }
772 EXPORT_SYMBOL(dma_cache_inv);
773 
774 void dma_cache_wback(phys_addr_t start, unsigned long sz)
775 {
776 	__dma_cache_wback(start, sz);
777 }
778 EXPORT_SYMBOL(dma_cache_wback);
779 
780 /*
781  * This is API for making I/D Caches consistent when modifying
782  * kernel code (loadable modules, kprobes, kgdb...)
783  * This is called on insmod, with kernel virtual address for CODE of
784  * the module. ARC cache maintenance ops require PHY address thus we
785  * need to convert vmalloc addr to PHY addr
786  */
787 void flush_icache_range(unsigned long kstart, unsigned long kend)
788 {
789 	unsigned int tot_sz;
790 
791 	WARN(kstart < TASK_SIZE, "%s() can't handle user vaddr", __func__);
792 
793 	/* Shortcut for bigger flush ranges.
794 	 * Here we don't care if this was kernel virtual or phy addr
795 	 */
796 	tot_sz = kend - kstart;
797 	if (tot_sz > PAGE_SIZE) {
798 		flush_cache_all();
799 		return;
800 	}
801 
802 	/* Case: Kernel Phy addr (0x8000_0000 onwards) */
803 	if (likely(kstart > PAGE_OFFSET)) {
804 		/*
805 		 * The 2nd arg despite being paddr will be used to index icache
806 		 * This is OK since no alternate virtual mappings will exist
807 		 * given the callers for this case: kprobe/kgdb in built-in
808 		 * kernel code only.
809 		 */
810 		__sync_icache_dcache(kstart, kstart, kend - kstart);
811 		return;
812 	}
813 
814 	/*
815 	 * Case: Kernel Vaddr (0x7000_0000 to 0x7fff_ffff)
816 	 * (1) ARC Cache Maintenance ops only take Phy addr, hence special
817 	 *     handling of kernel vaddr.
818 	 *
819 	 * (2) Despite @tot_sz being < PAGE_SIZE (bigger cases handled already),
820 	 *     it still needs to handle  a 2 page scenario, where the range
821 	 *     straddles across 2 virtual pages and hence need for loop
822 	 */
823 	while (tot_sz > 0) {
824 		unsigned int off, sz;
825 		unsigned long phy, pfn;
826 
827 		off = kstart % PAGE_SIZE;
828 		pfn = vmalloc_to_pfn((void *)kstart);
829 		phy = (pfn << PAGE_SHIFT) + off;
830 		sz = min_t(unsigned int, tot_sz, PAGE_SIZE - off);
831 		__sync_icache_dcache(phy, kstart, sz);
832 		kstart += sz;
833 		tot_sz -= sz;
834 	}
835 }
836 EXPORT_SYMBOL(flush_icache_range);
837 
838 /*
839  * General purpose helper to make I and D cache lines consistent.
840  * @paddr is phy addr of region
841  * @vaddr is typically user vaddr (breakpoint) or kernel vaddr (vmalloc)
842  *    However in one instance, when called by kprobe (for a breakpt in
843  *    builtin kernel code) @vaddr will be paddr only, meaning CDU operation will
844  *    use a paddr to index the cache (despite VIPT). This is fine since a
845  *    builtin kernel page will not have any virtual mappings.
846  *    kprobe on loadable module will be kernel vaddr.
847  */
848 void __sync_icache_dcache(phys_addr_t paddr, unsigned long vaddr, int len)
849 {
850 	__dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
851 	__ic_line_inv_vaddr(paddr, vaddr, len);
852 }
853 
854 /* wrapper to compile time eliminate alignment checks in flush loop */
855 void __inv_icache_pages(phys_addr_t paddr, unsigned long vaddr, unsigned nr)
856 {
857 	__ic_line_inv_vaddr(paddr, vaddr, nr * PAGE_SIZE);
858 }
859 
860 /*
861  * wrapper to clearout kernel or userspace mappings of a page
862  * For kernel mappings @vaddr == @paddr
863  */
864 void __flush_dcache_pages(phys_addr_t paddr, unsigned long vaddr, unsigned nr)
865 {
866 	__dc_line_op(paddr, vaddr & PAGE_MASK, nr * PAGE_SIZE, OP_FLUSH_N_INV);
867 }
868 
869 noinline void flush_cache_all(void)
870 {
871 	unsigned long flags;
872 
873 	local_irq_save(flags);
874 
875 	__ic_entire_inv();
876 	__dc_entire_op(OP_FLUSH_N_INV);
877 
878 	local_irq_restore(flags);
879 
880 }
881 
882 void copy_user_highpage(struct page *to, struct page *from,
883 	unsigned long u_vaddr, struct vm_area_struct *vma)
884 {
885 	struct folio *src = page_folio(from);
886 	struct folio *dst = page_folio(to);
887 	void *kfrom = kmap_atomic(from);
888 	void *kto = kmap_atomic(to);
889 
890 	copy_page(kto, kfrom);
891 
892 	clear_bit(PG_dc_clean, &dst->flags);
893 	clear_bit(PG_dc_clean, &src->flags);
894 
895 	kunmap_atomic(kto);
896 	kunmap_atomic(kfrom);
897 }
898 
899 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
900 {
901 	struct folio *folio = page_folio(page);
902 	clear_page(to);
903 	clear_bit(PG_dc_clean, &folio->flags);
904 }
905 EXPORT_SYMBOL(clear_user_page);
906 
907 /**********************************************************************
908  * Explicit Cache flush request from user space via syscall
909  * Needed for JITs which generate code on the fly
910  */
911 SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags)
912 {
913 	/* TBD: optimize this */
914 	flush_cache_all();
915 	return 0;
916 }
917 
918 /*
919  * IO-Coherency (IOC) setup rules:
920  *
921  * 1. Needs to be at system level, so only once by Master core
922  *    Non-Masters need not be accessing caches at that time
923  *    - They are either HALT_ON_RESET and kick started much later or
924  *    - if run on reset, need to ensure that arc_platform_smp_wait_to_boot()
925  *      doesn't perturb caches or coherency unit
926  *
927  * 2. caches (L1 and SLC) need to be purged (flush+inv) before setting up IOC,
928  *    otherwise any straggler data might behave strangely post IOC enabling
929  *
930  * 3. All Caches need to be disabled when setting up IOC to elide any in-flight
931  *    Coherency transactions
932  */
933 static noinline void __init arc_ioc_setup(void)
934 {
935 	unsigned int ioc_base, mem_sz;
936 
937 	/*
938 	 * If IOC was already enabled (due to bootloader) it technically needs to
939 	 * be reconfigured with aperture base,size corresponding to Linux memory map
940 	 * which will certainly be different than uboot's. But disabling and
941 	 * reenabling IOC when DMA might be potentially active is tricky business.
942 	 * To avoid random memory issues later, just panic here and ask user to
943 	 * upgrade bootloader to one which doesn't enable IOC
944 	 */
945 	if (read_aux_reg(ARC_REG_IO_COH_ENABLE) & ARC_IO_COH_ENABLE_BIT)
946 		panic("IOC already enabled, please upgrade bootloader!\n");
947 
948 	if (!ioc_enable)
949 		return;
950 
951 	/* Flush + invalidate + disable L1 dcache */
952 	__dc_disable();
953 
954 	/* Flush + invalidate SLC */
955 	if (read_aux_reg(ARC_REG_SLC_BCR))
956 		slc_entire_op(OP_FLUSH_N_INV);
957 
958 	/*
959 	 * currently IOC Aperture covers entire DDR
960 	 * TBD: fix for PGU + 1GB of low mem
961 	 * TBD: fix for PAE
962 	 */
963 	mem_sz = arc_get_mem_sz();
964 
965 	if (!is_power_of_2(mem_sz) || mem_sz < 4096)
966 		panic("IOC Aperture size must be power of 2 larger than 4KB");
967 
968 	/*
969 	 * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
970 	 * so setting 0x11 implies 512MB, 0x12 implies 1GB...
971 	 */
972 	write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2);
973 
974 	/* for now assume kernel base is start of IOC aperture */
975 	ioc_base = CONFIG_LINUX_RAM_BASE;
976 
977 	if (ioc_base % mem_sz != 0)
978 		panic("IOC Aperture start must be aligned to the size of the aperture");
979 
980 	write_aux_reg(ARC_REG_IO_COH_AP0_BASE, ioc_base >> 12);
981 	write_aux_reg(ARC_REG_IO_COH_PARTIAL, ARC_IO_COH_PARTIAL_BIT);
982 	write_aux_reg(ARC_REG_IO_COH_ENABLE, ARC_IO_COH_ENABLE_BIT);
983 
984 	/* Re-enable L1 dcache */
985 	__dc_enable();
986 }
987 
988 /*
989  * Cache related boot time checks/setups only needed on master CPU:
990  *  - Geometry checks (kernel build and hardware agree: e.g. L1_CACHE_BYTES)
991  *    Assume SMP only, so all cores will have same cache config. A check on
992  *    one core suffices for all
993  *  - IOC setup / dma callbacks only need to be done once
994  */
995 static noinline void __init arc_cache_init_master(void)
996 {
997 	if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
998 		struct cpuinfo_arc_cache *ic = &ic_info;
999 
1000 		if (!ic->line_len)
1001 			panic("cache support enabled but non-existent cache\n");
1002 
1003 		if (ic->line_len != L1_CACHE_BYTES)
1004 			panic("ICache line [%d] != kernel Config [%d]",
1005 			      ic->line_len, L1_CACHE_BYTES);
1006 
1007 		/*
1008 		 * In MMU v4 (HS38x) the aliasing icache config uses IVIL/PTAG
1009 		 * pair to provide vaddr/paddr respectively, just as in MMU v3
1010 		 */
1011 		if (is_isa_arcv2() && ic->colors > 1)
1012 			_cache_line_loop_ic_fn = __cache_line_loop_v3;
1013 		else
1014 			_cache_line_loop_ic_fn = __cache_line_loop;
1015 	}
1016 
1017 	if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
1018 		struct cpuinfo_arc_cache *dc = &dc_info;
1019 
1020 		if (!dc->line_len)
1021 			panic("cache support enabled but non-existent cache\n");
1022 
1023 		if (dc->line_len != L1_CACHE_BYTES)
1024 			panic("DCache line [%d] != kernel Config [%d]",
1025 			      dc->line_len, L1_CACHE_BYTES);
1026 
1027 		/* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */
1028 		if (is_isa_arcompact() && dc->colors > 1) {
1029 			panic("Aliasing VIPT cache not supported\n");
1030 		}
1031 	}
1032 
1033 	/*
1034 	 * Check that SMP_CACHE_BYTES (and hence ARCH_DMA_MINALIGN) is larger
1035 	 * or equal to any cache line length.
1036 	 */
1037 	BUILD_BUG_ON_MSG(L1_CACHE_BYTES > SMP_CACHE_BYTES,
1038 			 "SMP_CACHE_BYTES must be >= any cache line length");
1039 	if (is_isa_arcv2() && (l2_line_sz > SMP_CACHE_BYTES))
1040 		panic("L2 Cache line [%d] > kernel Config [%d]\n",
1041 		      l2_line_sz, SMP_CACHE_BYTES);
1042 
1043 	/* Note that SLC disable not formally supported till HS 3.0 */
1044 	if (is_isa_arcv2() && l2_line_sz && !slc_enable)
1045 		arc_slc_disable();
1046 
1047 	if (is_isa_arcv2() && ioc_exists)
1048 		arc_ioc_setup();
1049 
1050 	if (is_isa_arcv2() && l2_line_sz && slc_enable) {
1051 		__dma_cache_wback_inv = __dma_cache_wback_inv_slc;
1052 		__dma_cache_inv = __dma_cache_inv_slc;
1053 		__dma_cache_wback = __dma_cache_wback_slc;
1054 	} else {
1055 		__dma_cache_wback_inv = __dma_cache_wback_inv_l1;
1056 		__dma_cache_inv = __dma_cache_inv_l1;
1057 		__dma_cache_wback = __dma_cache_wback_l1;
1058 	}
1059 	/*
1060 	 * In case of IOC (say IOC+SLC case), pointers above could still be set
1061 	 * but end up not being relevant as the first function in chain is not
1062 	 * called at all for devices using coherent DMA.
1063 	 *     arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*()
1064 	 */
1065 }
1066 
1067 void __ref arc_cache_init(void)
1068 {
1069 	unsigned int __maybe_unused cpu = smp_processor_id();
1070 
1071 	if (!cpu)
1072 		arc_cache_init_master();
1073 
1074 	/*
1075 	 * In PAE regime, TLB and cache maintenance ops take wider addresses
1076 	 * And even if PAE is not enabled in kernel, the upper 32-bits still need
1077 	 * to be zeroed to keep the ops sane.
1078 	 * As an optimization for more common !PAE enabled case, zero them out
1079 	 * once at init, rather than checking/setting to 0 for every runtime op
1080 	 */
1081 	if (is_isa_arcv2() && pae40_exist_but_not_enab()) {
1082 
1083 		if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE))
1084 			write_aux_reg(ARC_REG_IC_PTAG_HI, 0);
1085 
1086 		if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE))
1087 			write_aux_reg(ARC_REG_DC_PTAG_HI, 0);
1088 
1089 		if (l2_line_sz) {
1090 			write_aux_reg(ARC_REG_SLC_RGN_END1, 0);
1091 			write_aux_reg(ARC_REG_SLC_RGN_START1, 0);
1092 		}
1093 	}
1094 }
1095