xref: /openbmc/linux/arch/arc/mm/cache.c (revision 6c33a6f4)
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 void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr,
32 			       unsigned long sz, const int op, const int full_page);
33 
34 void (*__dma_cache_wback_inv)(phys_addr_t start, unsigned long sz);
35 void (*__dma_cache_inv)(phys_addr_t start, unsigned long sz);
36 void (*__dma_cache_wback)(phys_addr_t start, unsigned long sz);
37 
38 char *arc_cache_mumbojumbo(int c, char *buf, int len)
39 {
40 	int n = 0;
41 	struct cpuinfo_arc_cache *p;
42 
43 #define PR_CACHE(p, cfg, str)						\
44 	if (!(p)->line_len)						\
45 		n += scnprintf(buf + n, len - n, str"\t\t: N/A\n");	\
46 	else								\
47 		n += scnprintf(buf + n, len - n,			\
48 			str"\t\t: %uK, %dway/set, %uB Line, %s%s%s\n",	\
49 			(p)->sz_k, (p)->assoc, (p)->line_len,		\
50 			(p)->vipt ? "VIPT" : "PIPT",			\
51 			(p)->alias ? " aliasing" : "",			\
52 			IS_USED_CFG(cfg));
53 
54 	PR_CACHE(&cpuinfo_arc700[c].icache, CONFIG_ARC_HAS_ICACHE, "I-Cache");
55 	PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache");
56 
57 	p = &cpuinfo_arc700[c].slc;
58 	if (p->line_len)
59 		n += scnprintf(buf + n, len - n,
60 			       "SLC\t\t: %uK, %uB Line%s\n",
61 			       p->sz_k, p->line_len, IS_USED_RUN(slc_enable));
62 
63 	n += scnprintf(buf + n, len - n, "Peripherals\t: %#lx%s%s\n",
64 		       perip_base,
65 		       IS_AVAIL3(ioc_exists, ioc_enable, ", IO-Coherency (per-device) "));
66 
67 	return buf;
68 }
69 
70 /*
71  * Read the Cache Build Confuration Registers, Decode them and save into
72  * the cpuinfo structure for later use.
73  * No Validation done here, simply read/convert the BCRs
74  */
75 static void read_decode_cache_bcr_arcv2(int cpu)
76 {
77 	struct cpuinfo_arc_cache *p_slc = &cpuinfo_arc700[cpu].slc;
78 	struct bcr_generic sbcr;
79 
80 	struct bcr_slc_cfg {
81 #ifdef CONFIG_CPU_BIG_ENDIAN
82 		unsigned int pad:24, way:2, lsz:2, sz:4;
83 #else
84 		unsigned int sz:4, lsz:2, way:2, pad:24;
85 #endif
86 	} slc_cfg;
87 
88 	struct bcr_clust_cfg {
89 #ifdef CONFIG_CPU_BIG_ENDIAN
90 		unsigned int pad:7, c:1, num_entries:8, num_cores:8, ver:8;
91 #else
92 		unsigned int ver:8, num_cores:8, num_entries:8, c:1, pad:7;
93 #endif
94 	} cbcr;
95 
96 	struct bcr_volatile {
97 #ifdef CONFIG_CPU_BIG_ENDIAN
98 		unsigned int start:4, limit:4, pad:22, order:1, disable:1;
99 #else
100 		unsigned int disable:1, order:1, pad:22, limit:4, start:4;
101 #endif
102 	} vol;
103 
104 
105 	READ_BCR(ARC_REG_SLC_BCR, sbcr);
106 	if (sbcr.ver) {
107 		READ_BCR(ARC_REG_SLC_CFG, slc_cfg);
108 		p_slc->sz_k = 128 << slc_cfg.sz;
109 		l2_line_sz = p_slc->line_len = (slc_cfg.lsz == 0) ? 128 : 64;
110 	}
111 
112 	READ_BCR(ARC_REG_CLUSTER_BCR, cbcr);
113 	if (cbcr.c) {
114 		ioc_exists = 1;
115 
116 		/*
117 		 * As for today we don't support both IOC and ZONE_HIGHMEM enabled
118 		 * simultaneously. This happens because as of today IOC aperture covers
119 		 * only ZONE_NORMAL (low mem) and any dma transactions outside this
120 		 * region won't be HW coherent.
121 		 * If we want to use both IOC and ZONE_HIGHMEM we can use
122 		 * bounce_buffer to handle dma transactions to HIGHMEM.
123 		 * Also it is possible to modify dma_direct cache ops or increase IOC
124 		 * aperture size if we are planning to use HIGHMEM without PAE.
125 		 */
126 		if (IS_ENABLED(CONFIG_HIGHMEM) || is_pae40_enabled())
127 			ioc_enable = 0;
128 	} else {
129 		ioc_enable = 0;
130 	}
131 
132 	/* HS 2.0 didn't have AUX_VOL */
133 	if (cpuinfo_arc700[cpu].core.family > 0x51) {
134 		READ_BCR(AUX_VOL, vol);
135 		perip_base = vol.start << 28;
136 		/* HS 3.0 has limit and strict-ordering fields */
137 		if (cpuinfo_arc700[cpu].core.family > 0x52)
138 			perip_end = (vol.limit << 28) - 1;
139 	}
140 }
141 
142 void read_decode_cache_bcr(void)
143 {
144 	struct cpuinfo_arc_cache *p_ic, *p_dc;
145 	unsigned int cpu = smp_processor_id();
146 	struct bcr_cache {
147 #ifdef CONFIG_CPU_BIG_ENDIAN
148 		unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
149 #else
150 		unsigned int ver:8, config:4, sz:4, line_len:4, pad:12;
151 #endif
152 	} ibcr, dbcr;
153 
154 	p_ic = &cpuinfo_arc700[cpu].icache;
155 	READ_BCR(ARC_REG_IC_BCR, ibcr);
156 
157 	if (!ibcr.ver)
158 		goto dc_chk;
159 
160 	if (ibcr.ver <= 3) {
161 		BUG_ON(ibcr.config != 3);
162 		p_ic->assoc = 2;		/* Fixed to 2w set assoc */
163 	} else if (ibcr.ver >= 4) {
164 		p_ic->assoc = 1 << ibcr.config;	/* 1,2,4,8 */
165 	}
166 
167 	p_ic->line_len = 8 << ibcr.line_len;
168 	p_ic->sz_k = 1 << (ibcr.sz - 1);
169 	p_ic->vipt = 1;
170 	p_ic->alias = p_ic->sz_k/p_ic->assoc/TO_KB(PAGE_SIZE) > 1;
171 
172 dc_chk:
173 	p_dc = &cpuinfo_arc700[cpu].dcache;
174 	READ_BCR(ARC_REG_DC_BCR, dbcr);
175 
176 	if (!dbcr.ver)
177 		goto slc_chk;
178 
179 	if (dbcr.ver <= 3) {
180 		BUG_ON(dbcr.config != 2);
181 		p_dc->assoc = 4;		/* Fixed to 4w set assoc */
182 		p_dc->vipt = 1;
183 		p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1;
184 	} else if (dbcr.ver >= 4) {
185 		p_dc->assoc = 1 << dbcr.config;	/* 1,2,4,8 */
186 		p_dc->vipt = 0;
187 		p_dc->alias = 0;		/* PIPT so can't VIPT alias */
188 	}
189 
190 	p_dc->line_len = 16 << dbcr.line_len;
191 	p_dc->sz_k = 1 << (dbcr.sz - 1);
192 
193 slc_chk:
194 	if (is_isa_arcv2())
195                 read_decode_cache_bcr_arcv2(cpu);
196 }
197 
198 /*
199  * Line Operation on {I,D}-Cache
200  */
201 
202 #define OP_INV		0x1
203 #define OP_FLUSH	0x2
204 #define OP_FLUSH_N_INV	0x3
205 #define OP_INV_IC	0x4
206 
207 /*
208  *		I-Cache Aliasing in ARC700 VIPT caches (MMU v1-v3)
209  *
210  * ARC VIPT I-cache uses vaddr to index into cache and paddr to match the tag.
211  * The orig Cache Management Module "CDU" only required paddr to invalidate a
212  * certain line since it sufficed as index in Non-Aliasing VIPT cache-geometry.
213  * Infact for distinct V1,V2,P: all of {V1-P},{V2-P},{P-P} would end up fetching
214  * the exact same line.
215  *
216  * However for larger Caches (way-size > page-size) - i.e. in Aliasing config,
217  * paddr alone could not be used to correctly index the cache.
218  *
219  * ------------------
220  * MMU v1/v2 (Fixed Page Size 8k)
221  * ------------------
222  * The solution was to provide CDU with these additonal vaddr bits. These
223  * would be bits [x:13], x would depend on cache-geometry, 13 comes from
224  * standard page size of 8k.
225  * H/w folks chose [17:13] to be a future safe range, and moreso these 5 bits
226  * of vaddr could easily be "stuffed" in the paddr as bits [4:0] since the
227  * orig 5 bits of paddr were anyways ignored by CDU line ops, as they
228  * represent the offset within cache-line. The adv of using this "clumsy"
229  * interface for additional info was no new reg was needed in CDU programming
230  * model.
231  *
232  * 17:13 represented the max num of bits passable, actual bits needed were
233  * fewer, based on the num-of-aliases possible.
234  * -for 2 alias possibility, only bit 13 needed (32K cache)
235  * -for 4 alias possibility, bits 14:13 needed (64K cache)
236  *
237  * ------------------
238  * MMU v3
239  * ------------------
240  * This ver of MMU supports variable page sizes (1k-16k): although Linux will
241  * only support 8k (default), 16k and 4k.
242  * However from hardware perspective, smaller page sizes aggravate aliasing
243  * meaning more vaddr bits needed to disambiguate the cache-line-op ;
244  * the existing scheme of piggybacking won't work for certain configurations.
245  * Two new registers IC_PTAG and DC_PTAG inttoduced.
246  * "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
247  */
248 
249 static inline
250 void __cache_line_loop_v2(phys_addr_t paddr, unsigned long vaddr,
251 			  unsigned long sz, const int op, const int full_page)
252 {
253 	unsigned int aux_cmd;
254 	int num_lines;
255 
256 	if (op == OP_INV_IC) {
257 		aux_cmd = ARC_REG_IC_IVIL;
258 	} else {
259 		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
260 		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
261 	}
262 
263 	/* Ensure we properly floor/ceil the non-line aligned/sized requests
264 	 * and have @paddr - aligned to cache line and integral @num_lines.
265 	 * This however can be avoided for page sized since:
266 	 *  -@paddr will be cache-line aligned already (being page aligned)
267 	 *  -@sz will be integral multiple of line size (being page sized).
268 	 */
269 	if (!full_page) {
270 		sz += paddr & ~CACHE_LINE_MASK;
271 		paddr &= CACHE_LINE_MASK;
272 		vaddr &= CACHE_LINE_MASK;
273 	}
274 
275 	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
276 
277 	/* MMUv2 and before: paddr contains stuffed vaddrs bits */
278 	paddr |= (vaddr >> PAGE_SHIFT) & 0x1F;
279 
280 	while (num_lines-- > 0) {
281 		write_aux_reg(aux_cmd, paddr);
282 		paddr += L1_CACHE_BYTES;
283 	}
284 }
285 
286 /*
287  * For ARC700 MMUv3 I-cache and D-cache flushes
288  *  - ARC700 programming model requires paddr and vaddr be passed in seperate
289  *    AUX registers (*_IV*L and *_PTAG respectively) irrespective of whether the
290  *    caches actually alias or not.
291  * -  For HS38, only the aliasing I-cache configuration uses the PTAG reg
292  *    (non aliasing I-cache version doesn't; while D-cache can't possibly alias)
293  */
294 static inline
295 void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
296 			  unsigned long sz, const int op, const int full_page)
297 {
298 	unsigned int aux_cmd, aux_tag;
299 	int num_lines;
300 
301 	if (op == OP_INV_IC) {
302 		aux_cmd = ARC_REG_IC_IVIL;
303 		aux_tag = ARC_REG_IC_PTAG;
304 	} else {
305 		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
306 		aux_tag = ARC_REG_DC_PTAG;
307 	}
308 
309 	/* Ensure we properly floor/ceil the non-line aligned/sized requests
310 	 * and have @paddr - aligned to cache line and integral @num_lines.
311 	 * This however can be avoided for page sized since:
312 	 *  -@paddr will be cache-line aligned already (being page aligned)
313 	 *  -@sz will be integral multiple of line size (being page sized).
314 	 */
315 	if (!full_page) {
316 		sz += paddr & ~CACHE_LINE_MASK;
317 		paddr &= CACHE_LINE_MASK;
318 		vaddr &= CACHE_LINE_MASK;
319 	}
320 	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
321 
322 	/*
323 	 * MMUv3, cache ops require paddr in PTAG reg
324 	 * if V-P const for loop, PTAG can be written once outside loop
325 	 */
326 	if (full_page)
327 		write_aux_reg(aux_tag, paddr);
328 
329 	/*
330 	 * This is technically for MMU v4, using the MMU v3 programming model
331 	 * Special work for HS38 aliasing I-cache configuration with PAE40
332 	 *   - upper 8 bits of paddr need to be written into PTAG_HI
333 	 *   - (and needs to be written before the lower 32 bits)
334 	 * Note that PTAG_HI is hoisted outside the line loop
335 	 */
336 	if (is_pae40_enabled() && op == OP_INV_IC)
337 		write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
338 
339 	while (num_lines-- > 0) {
340 		if (!full_page) {
341 			write_aux_reg(aux_tag, paddr);
342 			paddr += L1_CACHE_BYTES;
343 		}
344 
345 		write_aux_reg(aux_cmd, vaddr);
346 		vaddr += L1_CACHE_BYTES;
347 	}
348 }
349 
350 #ifndef USE_RGN_FLSH
351 
352 /*
353  * In HS38x (MMU v4), I-cache is VIPT (can alias), D-cache is PIPT
354  * Here's how cache ops are implemented
355  *
356  *  - D-cache: only paddr needed (in DC_IVDL/DC_FLDL)
357  *  - I-cache Non Aliasing: Despite VIPT, only paddr needed (in IC_IVIL)
358  *  - I-cache Aliasing: Both vaddr and paddr needed (in IC_IVIL, IC_PTAG
359  *    respectively, similar to MMU v3 programming model, hence
360  *    __cache_line_loop_v3() is used)
361  *
362  * If PAE40 is enabled, independent of aliasing considerations, the higher bits
363  * needs to be written into PTAG_HI
364  */
365 static inline
366 void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
367 			  unsigned long sz, const int op, const int full_page)
368 {
369 	unsigned int aux_cmd;
370 	int num_lines;
371 
372 	if (op == OP_INV_IC) {
373 		aux_cmd = ARC_REG_IC_IVIL;
374 	} else {
375 		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
376 		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
377 	}
378 
379 	/* Ensure we properly floor/ceil the non-line aligned/sized requests
380 	 * and have @paddr - aligned to cache line and integral @num_lines.
381 	 * This however can be avoided for page sized since:
382 	 *  -@paddr will be cache-line aligned already (being page aligned)
383 	 *  -@sz will be integral multiple of line size (being page sized).
384 	 */
385 	if (!full_page) {
386 		sz += paddr & ~CACHE_LINE_MASK;
387 		paddr &= CACHE_LINE_MASK;
388 	}
389 
390 	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
391 
392 	/*
393 	 * For HS38 PAE40 configuration
394 	 *   - upper 8 bits of paddr need to be written into PTAG_HI
395 	 *   - (and needs to be written before the lower 32 bits)
396 	 */
397 	if (is_pae40_enabled()) {
398 		if (op == OP_INV_IC)
399 			/*
400 			 * Non aliasing I-cache in HS38,
401 			 * aliasing I-cache handled in __cache_line_loop_v3()
402 			 */
403 			write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
404 		else
405 			write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
406 	}
407 
408 	while (num_lines-- > 0) {
409 		write_aux_reg(aux_cmd, paddr);
410 		paddr += L1_CACHE_BYTES;
411 	}
412 }
413 
414 #else
415 
416 /*
417  * optimized flush operation which takes a region as opposed to iterating per line
418  */
419 static inline
420 void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
421 			  unsigned long sz, const int op, const int full_page)
422 {
423 	unsigned int s, e;
424 
425 	/* Only for Non aliasing I-cache in HS38 */
426 	if (op == OP_INV_IC) {
427 		s = ARC_REG_IC_IVIR;
428 		e = ARC_REG_IC_ENDR;
429 	} else {
430 		s = ARC_REG_DC_STARTR;
431 		e = ARC_REG_DC_ENDR;
432 	}
433 
434 	if (!full_page) {
435 		/* for any leading gap between @paddr and start of cache line */
436 		sz += paddr & ~CACHE_LINE_MASK;
437 		paddr &= CACHE_LINE_MASK;
438 
439 		/*
440 		 *  account for any trailing gap to end of cache line
441 		 *  this is equivalent to DIV_ROUND_UP() in line ops above
442 		 */
443 		sz += L1_CACHE_BYTES - 1;
444 	}
445 
446 	if (is_pae40_enabled()) {
447 		/* TBD: check if crossing 4TB boundary */
448 		if (op == OP_INV_IC)
449 			write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
450 		else
451 			write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
452 	}
453 
454 	/* ENDR needs to be set ahead of START */
455 	write_aux_reg(e, paddr + sz);	/* ENDR is exclusive */
456 	write_aux_reg(s, paddr);
457 
458 	/* caller waits on DC_CTRL.FS */
459 }
460 
461 #endif
462 
463 #if (CONFIG_ARC_MMU_VER < 3)
464 #define __cache_line_loop	__cache_line_loop_v2
465 #elif (CONFIG_ARC_MMU_VER == 3)
466 #define __cache_line_loop	__cache_line_loop_v3
467 #elif (CONFIG_ARC_MMU_VER > 3)
468 #define __cache_line_loop	__cache_line_loop_v4
469 #endif
470 
471 #ifdef CONFIG_ARC_HAS_DCACHE
472 
473 /***************************************************************
474  * Machine specific helpers for Entire D-Cache or Per Line ops
475  */
476 
477 #ifndef USE_RGN_FLSH
478 /*
479  * this version avoids extra read/write of DC_CTRL for flush or invalid ops
480  * in the non region flush regime (such as for ARCompact)
481  */
482 static inline void __before_dc_op(const int op)
483 {
484 	if (op == OP_FLUSH_N_INV) {
485 		/* Dcache provides 2 cmd: FLUSH or INV
486 		 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
487 		 * flush-n-inv is achieved by INV cmd but with IM=1
488 		 * So toggle INV sub-mode depending on op request and default
489 		 */
490 		const unsigned int ctl = ARC_REG_DC_CTRL;
491 		write_aux_reg(ctl, read_aux_reg(ctl) | DC_CTRL_INV_MODE_FLUSH);
492 	}
493 }
494 
495 #else
496 
497 static inline void __before_dc_op(const int op)
498 {
499 	const unsigned int ctl = ARC_REG_DC_CTRL;
500 	unsigned int val = read_aux_reg(ctl);
501 
502 	if (op == OP_FLUSH_N_INV) {
503 		val |= DC_CTRL_INV_MODE_FLUSH;
504 	}
505 
506 	if (op != OP_INV_IC) {
507 		/*
508 		 * Flush / Invalidate is provided by DC_CTRL.RNG_OP 0 or 1
509 		 * combined Flush-n-invalidate uses DC_CTRL.IM = 1 set above
510 		 */
511 		val &= ~DC_CTRL_RGN_OP_MSK;
512 		if (op & OP_INV)
513 			val |= DC_CTRL_RGN_OP_INV;
514 	}
515 	write_aux_reg(ctl, val);
516 }
517 
518 #endif
519 
520 
521 static inline void __after_dc_op(const int op)
522 {
523 	if (op & OP_FLUSH) {
524 		const unsigned int ctl = ARC_REG_DC_CTRL;
525 		unsigned int reg;
526 
527 		/* flush / flush-n-inv both wait */
528 		while ((reg = read_aux_reg(ctl)) & DC_CTRL_FLUSH_STATUS)
529 			;
530 
531 		/* Switch back to default Invalidate mode */
532 		if (op == OP_FLUSH_N_INV)
533 			write_aux_reg(ctl, reg & ~DC_CTRL_INV_MODE_FLUSH);
534 	}
535 }
536 
537 /*
538  * Operation on Entire D-Cache
539  * @op = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
540  * Note that constant propagation ensures all the checks are gone
541  * in generated code
542  */
543 static inline void __dc_entire_op(const int op)
544 {
545 	int aux;
546 
547 	__before_dc_op(op);
548 
549 	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
550 		aux = ARC_REG_DC_IVDC;
551 	else
552 		aux = ARC_REG_DC_FLSH;
553 
554 	write_aux_reg(aux, 0x1);
555 
556 	__after_dc_op(op);
557 }
558 
559 static inline void __dc_disable(void)
560 {
561 	const int r = ARC_REG_DC_CTRL;
562 
563 	__dc_entire_op(OP_FLUSH_N_INV);
564 	write_aux_reg(r, read_aux_reg(r) | DC_CTRL_DIS);
565 }
566 
567 static void __dc_enable(void)
568 {
569 	const int r = ARC_REG_DC_CTRL;
570 
571 	write_aux_reg(r, read_aux_reg(r) & ~DC_CTRL_DIS);
572 }
573 
574 /* For kernel mappings cache operation: index is same as paddr */
575 #define __dc_line_op_k(p, sz, op)	__dc_line_op(p, p, sz, op)
576 
577 /*
578  * D-Cache Line ops: Per Line INV (discard or wback+discard) or FLUSH (wback)
579  */
580 static inline void __dc_line_op(phys_addr_t paddr, unsigned long vaddr,
581 				unsigned long sz, const int op)
582 {
583 	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
584 	unsigned long flags;
585 
586 	local_irq_save(flags);
587 
588 	__before_dc_op(op);
589 
590 	__cache_line_loop(paddr, vaddr, sz, op, full_page);
591 
592 	__after_dc_op(op);
593 
594 	local_irq_restore(flags);
595 }
596 
597 #else
598 
599 #define __dc_entire_op(op)
600 #define __dc_disable()
601 #define __dc_enable()
602 #define __dc_line_op(paddr, vaddr, sz, op)
603 #define __dc_line_op_k(paddr, sz, op)
604 
605 #endif /* CONFIG_ARC_HAS_DCACHE */
606 
607 #ifdef CONFIG_ARC_HAS_ICACHE
608 
609 static inline void __ic_entire_inv(void)
610 {
611 	write_aux_reg(ARC_REG_IC_IVIC, 1);
612 	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
613 }
614 
615 static inline void
616 __ic_line_inv_vaddr_local(phys_addr_t paddr, unsigned long vaddr,
617 			  unsigned long sz)
618 {
619 	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
620 	unsigned long flags;
621 
622 	local_irq_save(flags);
623 	(*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC, full_page);
624 	local_irq_restore(flags);
625 }
626 
627 #ifndef CONFIG_SMP
628 
629 #define __ic_line_inv_vaddr(p, v, s)	__ic_line_inv_vaddr_local(p, v, s)
630 
631 #else
632 
633 struct ic_inv_args {
634 	phys_addr_t paddr, vaddr;
635 	int sz;
636 };
637 
638 static void __ic_line_inv_vaddr_helper(void *info)
639 {
640         struct ic_inv_args *ic_inv = info;
641 
642         __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
643 }
644 
645 static void __ic_line_inv_vaddr(phys_addr_t paddr, unsigned long vaddr,
646 				unsigned long sz)
647 {
648 	struct ic_inv_args ic_inv = {
649 		.paddr = paddr,
650 		.vaddr = vaddr,
651 		.sz    = sz
652 	};
653 
654 	on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
655 }
656 
657 #endif	/* CONFIG_SMP */
658 
659 #else	/* !CONFIG_ARC_HAS_ICACHE */
660 
661 #define __ic_entire_inv()
662 #define __ic_line_inv_vaddr(pstart, vstart, sz)
663 
664 #endif /* CONFIG_ARC_HAS_ICACHE */
665 
666 noinline void slc_op_rgn(phys_addr_t paddr, unsigned long sz, const int op)
667 {
668 #ifdef CONFIG_ISA_ARCV2
669 	/*
670 	 * SLC is shared between all cores and concurrent aux operations from
671 	 * multiple cores need to be serialized using a spinlock
672 	 * A concurrent operation can be silently ignored and/or the old/new
673 	 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
674 	 * below)
675 	 */
676 	static DEFINE_SPINLOCK(lock);
677 	unsigned long flags;
678 	unsigned int ctrl;
679 	phys_addr_t end;
680 
681 	spin_lock_irqsave(&lock, flags);
682 
683 	/*
684 	 * The Region Flush operation is specified by CTRL.RGN_OP[11..9]
685 	 *  - b'000 (default) is Flush,
686 	 *  - b'001 is Invalidate if CTRL.IM == 0
687 	 *  - b'001 is Flush-n-Invalidate if CTRL.IM == 1
688 	 */
689 	ctrl = read_aux_reg(ARC_REG_SLC_CTRL);
690 
691 	/* Don't rely on default value of IM bit */
692 	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
693 		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
694 	else
695 		ctrl |= SLC_CTRL_IM;
696 
697 	if (op & OP_INV)
698 		ctrl |= SLC_CTRL_RGN_OP_INV;	/* Inv or flush-n-inv */
699 	else
700 		ctrl &= ~SLC_CTRL_RGN_OP_INV;
701 
702 	write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
703 
704 	/*
705 	 * Lower bits are ignored, no need to clip
706 	 * END needs to be setup before START (latter triggers the operation)
707 	 * END can't be same as START, so add (l2_line_sz - 1) to sz
708 	 */
709 	end = paddr + sz + l2_line_sz - 1;
710 	if (is_pae40_enabled())
711 		write_aux_reg(ARC_REG_SLC_RGN_END1, upper_32_bits(end));
712 
713 	write_aux_reg(ARC_REG_SLC_RGN_END, lower_32_bits(end));
714 
715 	if (is_pae40_enabled())
716 		write_aux_reg(ARC_REG_SLC_RGN_START1, upper_32_bits(paddr));
717 
718 	write_aux_reg(ARC_REG_SLC_RGN_START, lower_32_bits(paddr));
719 
720 	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
721 	read_aux_reg(ARC_REG_SLC_CTRL);
722 
723 	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
724 
725 	spin_unlock_irqrestore(&lock, flags);
726 #endif
727 }
728 
729 noinline void slc_op_line(phys_addr_t paddr, unsigned long sz, const int op)
730 {
731 #ifdef CONFIG_ISA_ARCV2
732 	/*
733 	 * SLC is shared between all cores and concurrent aux operations from
734 	 * multiple cores need to be serialized using a spinlock
735 	 * A concurrent operation can be silently ignored and/or the old/new
736 	 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop
737 	 * below)
738 	 */
739 	static DEFINE_SPINLOCK(lock);
740 
741 	const unsigned long SLC_LINE_MASK = ~(l2_line_sz - 1);
742 	unsigned int ctrl, cmd;
743 	unsigned long flags;
744 	int num_lines;
745 
746 	spin_lock_irqsave(&lock, flags);
747 
748 	ctrl = read_aux_reg(ARC_REG_SLC_CTRL);
749 
750 	/* Don't rely on default value of IM bit */
751 	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
752 		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
753 	else
754 		ctrl |= SLC_CTRL_IM;
755 
756 	write_aux_reg(ARC_REG_SLC_CTRL, ctrl);
757 
758 	cmd = op & OP_INV ? ARC_AUX_SLC_IVDL : ARC_AUX_SLC_FLDL;
759 
760 	sz += paddr & ~SLC_LINE_MASK;
761 	paddr &= SLC_LINE_MASK;
762 
763 	num_lines = DIV_ROUND_UP(sz, l2_line_sz);
764 
765 	while (num_lines-- > 0) {
766 		write_aux_reg(cmd, paddr);
767 		paddr += l2_line_sz;
768 	}
769 
770 	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
771 	read_aux_reg(ARC_REG_SLC_CTRL);
772 
773 	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
774 
775 	spin_unlock_irqrestore(&lock, flags);
776 #endif
777 }
778 
779 #define slc_op(paddr, sz, op)	slc_op_rgn(paddr, sz, op)
780 
781 noinline static void slc_entire_op(const int op)
782 {
783 	unsigned int ctrl, r = ARC_REG_SLC_CTRL;
784 
785 	ctrl = read_aux_reg(r);
786 
787 	if (!(op & OP_FLUSH))		/* i.e. OP_INV */
788 		ctrl &= ~SLC_CTRL_IM;	/* clear IM: Disable flush before Inv */
789 	else
790 		ctrl |= SLC_CTRL_IM;
791 
792 	write_aux_reg(r, ctrl);
793 
794 	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
795 		write_aux_reg(ARC_REG_SLC_INVALIDATE, 0x1);
796 	else
797 		write_aux_reg(ARC_REG_SLC_FLUSH, 0x1);
798 
799 	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
800 	read_aux_reg(r);
801 
802 	/* Important to wait for flush to complete */
803 	while (read_aux_reg(r) & SLC_CTRL_BUSY);
804 }
805 
806 static inline void arc_slc_disable(void)
807 {
808 	const int r = ARC_REG_SLC_CTRL;
809 
810 	slc_entire_op(OP_FLUSH_N_INV);
811 	write_aux_reg(r, read_aux_reg(r) | SLC_CTRL_DIS);
812 }
813 
814 static inline void arc_slc_enable(void)
815 {
816 	const int r = ARC_REG_SLC_CTRL;
817 
818 	write_aux_reg(r, read_aux_reg(r) & ~SLC_CTRL_DIS);
819 }
820 
821 /***********************************************************
822  * Exported APIs
823  */
824 
825 /*
826  * Handle cache congruency of kernel and userspace mappings of page when kernel
827  * writes-to/reads-from
828  *
829  * The idea is to defer flushing of kernel mapping after a WRITE, possible if:
830  *  -dcache is NOT aliasing, hence any U/K-mappings of page are congruent
831  *  -U-mapping doesn't exist yet for page (finalised in update_mmu_cache)
832  *  -In SMP, if hardware caches are coherent
833  *
834  * There's a corollary case, where kernel READs from a userspace mapped page.
835  * If the U-mapping is not congruent to to K-mapping, former needs flushing.
836  */
837 void flush_dcache_page(struct page *page)
838 {
839 	struct address_space *mapping;
840 
841 	if (!cache_is_vipt_aliasing()) {
842 		clear_bit(PG_dc_clean, &page->flags);
843 		return;
844 	}
845 
846 	/* don't handle anon pages here */
847 	mapping = page_mapping_file(page);
848 	if (!mapping)
849 		return;
850 
851 	/*
852 	 * pagecache page, file not yet mapped to userspace
853 	 * Make a note that K-mapping is dirty
854 	 */
855 	if (!mapping_mapped(mapping)) {
856 		clear_bit(PG_dc_clean, &page->flags);
857 	} else if (page_mapcount(page)) {
858 
859 		/* kernel reading from page with U-mapping */
860 		phys_addr_t paddr = (unsigned long)page_address(page);
861 		unsigned long vaddr = page->index << PAGE_SHIFT;
862 
863 		if (addr_not_cache_congruent(paddr, vaddr))
864 			__flush_dcache_page(paddr, vaddr);
865 	}
866 }
867 EXPORT_SYMBOL(flush_dcache_page);
868 
869 /*
870  * DMA ops for systems with L1 cache only
871  * Make memory coherent with L1 cache by flushing/invalidating L1 lines
872  */
873 static void __dma_cache_wback_inv_l1(phys_addr_t start, unsigned long sz)
874 {
875 	__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
876 }
877 
878 static void __dma_cache_inv_l1(phys_addr_t start, unsigned long sz)
879 {
880 	__dc_line_op_k(start, sz, OP_INV);
881 }
882 
883 static void __dma_cache_wback_l1(phys_addr_t start, unsigned long sz)
884 {
885 	__dc_line_op_k(start, sz, OP_FLUSH);
886 }
887 
888 /*
889  * DMA ops for systems with both L1 and L2 caches, but without IOC
890  * Both L1 and L2 lines need to be explicitly flushed/invalidated
891  */
892 static void __dma_cache_wback_inv_slc(phys_addr_t start, unsigned long sz)
893 {
894 	__dc_line_op_k(start, sz, OP_FLUSH_N_INV);
895 	slc_op(start, sz, OP_FLUSH_N_INV);
896 }
897 
898 static void __dma_cache_inv_slc(phys_addr_t start, unsigned long sz)
899 {
900 	__dc_line_op_k(start, sz, OP_INV);
901 	slc_op(start, sz, OP_INV);
902 }
903 
904 static void __dma_cache_wback_slc(phys_addr_t start, unsigned long sz)
905 {
906 	__dc_line_op_k(start, sz, OP_FLUSH);
907 	slc_op(start, sz, OP_FLUSH);
908 }
909 
910 /*
911  * Exported DMA API
912  */
913 void dma_cache_wback_inv(phys_addr_t start, unsigned long sz)
914 {
915 	__dma_cache_wback_inv(start, sz);
916 }
917 EXPORT_SYMBOL(dma_cache_wback_inv);
918 
919 void dma_cache_inv(phys_addr_t start, unsigned long sz)
920 {
921 	__dma_cache_inv(start, sz);
922 }
923 EXPORT_SYMBOL(dma_cache_inv);
924 
925 void dma_cache_wback(phys_addr_t start, unsigned long sz)
926 {
927 	__dma_cache_wback(start, sz);
928 }
929 EXPORT_SYMBOL(dma_cache_wback);
930 
931 /*
932  * This is API for making I/D Caches consistent when modifying
933  * kernel code (loadable modules, kprobes, kgdb...)
934  * This is called on insmod, with kernel virtual address for CODE of
935  * the module. ARC cache maintenance ops require PHY address thus we
936  * need to convert vmalloc addr to PHY addr
937  */
938 void flush_icache_range(unsigned long kstart, unsigned long kend)
939 {
940 	unsigned int tot_sz;
941 
942 	WARN(kstart < TASK_SIZE, "%s() can't handle user vaddr", __func__);
943 
944 	/* Shortcut for bigger flush ranges.
945 	 * Here we don't care if this was kernel virtual or phy addr
946 	 */
947 	tot_sz = kend - kstart;
948 	if (tot_sz > PAGE_SIZE) {
949 		flush_cache_all();
950 		return;
951 	}
952 
953 	/* Case: Kernel Phy addr (0x8000_0000 onwards) */
954 	if (likely(kstart > PAGE_OFFSET)) {
955 		/*
956 		 * The 2nd arg despite being paddr will be used to index icache
957 		 * This is OK since no alternate virtual mappings will exist
958 		 * given the callers for this case: kprobe/kgdb in built-in
959 		 * kernel code only.
960 		 */
961 		__sync_icache_dcache(kstart, kstart, kend - kstart);
962 		return;
963 	}
964 
965 	/*
966 	 * Case: Kernel Vaddr (0x7000_0000 to 0x7fff_ffff)
967 	 * (1) ARC Cache Maintenance ops only take Phy addr, hence special
968 	 *     handling of kernel vaddr.
969 	 *
970 	 * (2) Despite @tot_sz being < PAGE_SIZE (bigger cases handled already),
971 	 *     it still needs to handle  a 2 page scenario, where the range
972 	 *     straddles across 2 virtual pages and hence need for loop
973 	 */
974 	while (tot_sz > 0) {
975 		unsigned int off, sz;
976 		unsigned long phy, pfn;
977 
978 		off = kstart % PAGE_SIZE;
979 		pfn = vmalloc_to_pfn((void *)kstart);
980 		phy = (pfn << PAGE_SHIFT) + off;
981 		sz = min_t(unsigned int, tot_sz, PAGE_SIZE - off);
982 		__sync_icache_dcache(phy, kstart, sz);
983 		kstart += sz;
984 		tot_sz -= sz;
985 	}
986 }
987 EXPORT_SYMBOL(flush_icache_range);
988 
989 /*
990  * General purpose helper to make I and D cache lines consistent.
991  * @paddr is phy addr of region
992  * @vaddr is typically user vaddr (breakpoint) or kernel vaddr (vmalloc)
993  *    However in one instance, when called by kprobe (for a breakpt in
994  *    builtin kernel code) @vaddr will be paddr only, meaning CDU operation will
995  *    use a paddr to index the cache (despite VIPT). This is fine since since a
996  *    builtin kernel page will not have any virtual mappings.
997  *    kprobe on loadable module will be kernel vaddr.
998  */
999 void __sync_icache_dcache(phys_addr_t paddr, unsigned long vaddr, int len)
1000 {
1001 	__dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
1002 	__ic_line_inv_vaddr(paddr, vaddr, len);
1003 }
1004 
1005 /* wrapper to compile time eliminate alignment checks in flush loop */
1006 void __inv_icache_page(phys_addr_t paddr, unsigned long vaddr)
1007 {
1008 	__ic_line_inv_vaddr(paddr, vaddr, PAGE_SIZE);
1009 }
1010 
1011 /*
1012  * wrapper to clearout kernel or userspace mappings of a page
1013  * For kernel mappings @vaddr == @paddr
1014  */
1015 void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr)
1016 {
1017 	__dc_line_op(paddr, vaddr & PAGE_MASK, PAGE_SIZE, OP_FLUSH_N_INV);
1018 }
1019 
1020 noinline void flush_cache_all(void)
1021 {
1022 	unsigned long flags;
1023 
1024 	local_irq_save(flags);
1025 
1026 	__ic_entire_inv();
1027 	__dc_entire_op(OP_FLUSH_N_INV);
1028 
1029 	local_irq_restore(flags);
1030 
1031 }
1032 
1033 #ifdef CONFIG_ARC_CACHE_VIPT_ALIASING
1034 
1035 void flush_cache_mm(struct mm_struct *mm)
1036 {
1037 	flush_cache_all();
1038 }
1039 
1040 void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
1041 		      unsigned long pfn)
1042 {
1043 	phys_addr_t paddr = pfn << PAGE_SHIFT;
1044 
1045 	u_vaddr &= PAGE_MASK;
1046 
1047 	__flush_dcache_page(paddr, u_vaddr);
1048 
1049 	if (vma->vm_flags & VM_EXEC)
1050 		__inv_icache_page(paddr, u_vaddr);
1051 }
1052 
1053 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
1054 		       unsigned long end)
1055 {
1056 	flush_cache_all();
1057 }
1058 
1059 void flush_anon_page(struct vm_area_struct *vma, struct page *page,
1060 		     unsigned long u_vaddr)
1061 {
1062 	/* TBD: do we really need to clear the kernel mapping */
1063 	__flush_dcache_page((phys_addr_t)page_address(page), u_vaddr);
1064 	__flush_dcache_page((phys_addr_t)page_address(page),
1065 			    (phys_addr_t)page_address(page));
1066 
1067 }
1068 
1069 #endif
1070 
1071 void copy_user_highpage(struct page *to, struct page *from,
1072 	unsigned long u_vaddr, struct vm_area_struct *vma)
1073 {
1074 	void *kfrom = kmap_atomic(from);
1075 	void *kto = kmap_atomic(to);
1076 	int clean_src_k_mappings = 0;
1077 
1078 	/*
1079 	 * If SRC page was already mapped in userspace AND it's U-mapping is
1080 	 * not congruent with K-mapping, sync former to physical page so that
1081 	 * K-mapping in memcpy below, sees the right data
1082 	 *
1083 	 * Note that while @u_vaddr refers to DST page's userspace vaddr, it is
1084 	 * equally valid for SRC page as well
1085 	 *
1086 	 * For !VIPT cache, all of this gets compiled out as
1087 	 * addr_not_cache_congruent() is 0
1088 	 */
1089 	if (page_mapcount(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {
1090 		__flush_dcache_page((unsigned long)kfrom, u_vaddr);
1091 		clean_src_k_mappings = 1;
1092 	}
1093 
1094 	copy_page(kto, kfrom);
1095 
1096 	/*
1097 	 * Mark DST page K-mapping as dirty for a later finalization by
1098 	 * update_mmu_cache(). Although the finalization could have been done
1099 	 * here as well (given that both vaddr/paddr are available).
1100 	 * But update_mmu_cache() already has code to do that for other
1101 	 * non copied user pages (e.g. read faults which wire in pagecache page
1102 	 * directly).
1103 	 */
1104 	clear_bit(PG_dc_clean, &to->flags);
1105 
1106 	/*
1107 	 * if SRC was already usermapped and non-congruent to kernel mapping
1108 	 * sync the kernel mapping back to physical page
1109 	 */
1110 	if (clean_src_k_mappings) {
1111 		__flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom);
1112 		set_bit(PG_dc_clean, &from->flags);
1113 	} else {
1114 		clear_bit(PG_dc_clean, &from->flags);
1115 	}
1116 
1117 	kunmap_atomic(kto);
1118 	kunmap_atomic(kfrom);
1119 }
1120 
1121 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
1122 {
1123 	clear_page(to);
1124 	clear_bit(PG_dc_clean, &page->flags);
1125 }
1126 
1127 
1128 /**********************************************************************
1129  * Explicit Cache flush request from user space via syscall
1130  * Needed for JITs which generate code on the fly
1131  */
1132 SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags)
1133 {
1134 	/* TBD: optimize this */
1135 	flush_cache_all();
1136 	return 0;
1137 }
1138 
1139 /*
1140  * IO-Coherency (IOC) setup rules:
1141  *
1142  * 1. Needs to be at system level, so only once by Master core
1143  *    Non-Masters need not be accessing caches at that time
1144  *    - They are either HALT_ON_RESET and kick started much later or
1145  *    - if run on reset, need to ensure that arc_platform_smp_wait_to_boot()
1146  *      doesn't perturb caches or coherency unit
1147  *
1148  * 2. caches (L1 and SLC) need to be purged (flush+inv) before setting up IOC,
1149  *    otherwise any straggler data might behave strangely post IOC enabling
1150  *
1151  * 3. All Caches need to be disabled when setting up IOC to elide any in-flight
1152  *    Coherency transactions
1153  */
1154 noinline void __init arc_ioc_setup(void)
1155 {
1156 	unsigned int ioc_base, mem_sz;
1157 
1158 	/*
1159 	 * If IOC was already enabled (due to bootloader) it technically needs to
1160 	 * be reconfigured with aperture base,size corresponding to Linux memory map
1161 	 * which will certainly be different than uboot's. But disabling and
1162 	 * reenabling IOC when DMA might be potentially active is tricky business.
1163 	 * To avoid random memory issues later, just panic here and ask user to
1164 	 * upgrade bootloader to one which doesn't enable IOC
1165 	 */
1166 	if (read_aux_reg(ARC_REG_IO_COH_ENABLE) & ARC_IO_COH_ENABLE_BIT)
1167 		panic("IOC already enabled, please upgrade bootloader!\n");
1168 
1169 	if (!ioc_enable)
1170 		return;
1171 
1172 	/* Flush + invalidate + disable L1 dcache */
1173 	__dc_disable();
1174 
1175 	/* Flush + invalidate SLC */
1176 	if (read_aux_reg(ARC_REG_SLC_BCR))
1177 		slc_entire_op(OP_FLUSH_N_INV);
1178 
1179 	/*
1180 	 * currently IOC Aperture covers entire DDR
1181 	 * TBD: fix for PGU + 1GB of low mem
1182 	 * TBD: fix for PAE
1183 	 */
1184 	mem_sz = arc_get_mem_sz();
1185 
1186 	if (!is_power_of_2(mem_sz) || mem_sz < 4096)
1187 		panic("IOC Aperture size must be power of 2 larger than 4KB");
1188 
1189 	/*
1190 	 * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
1191 	 * so setting 0x11 implies 512MB, 0x12 implies 1GB...
1192 	 */
1193 	write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2);
1194 
1195 	/* for now assume kernel base is start of IOC aperture */
1196 	ioc_base = CONFIG_LINUX_RAM_BASE;
1197 
1198 	if (ioc_base % mem_sz != 0)
1199 		panic("IOC Aperture start must be aligned to the size of the aperture");
1200 
1201 	write_aux_reg(ARC_REG_IO_COH_AP0_BASE, ioc_base >> 12);
1202 	write_aux_reg(ARC_REG_IO_COH_PARTIAL, ARC_IO_COH_PARTIAL_BIT);
1203 	write_aux_reg(ARC_REG_IO_COH_ENABLE, ARC_IO_COH_ENABLE_BIT);
1204 
1205 	/* Re-enable L1 dcache */
1206 	__dc_enable();
1207 }
1208 
1209 /*
1210  * Cache related boot time checks/setups only needed on master CPU:
1211  *  - Geometry checks (kernel build and hardware agree: e.g. L1_CACHE_BYTES)
1212  *    Assume SMP only, so all cores will have same cache config. A check on
1213  *    one core suffices for all
1214  *  - IOC setup / dma callbacks only need to be done once
1215  */
1216 void __init arc_cache_init_master(void)
1217 {
1218 	unsigned int __maybe_unused cpu = smp_processor_id();
1219 
1220 	if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
1221 		struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
1222 
1223 		if (!ic->line_len)
1224 			panic("cache support enabled but non-existent cache\n");
1225 
1226 		if (ic->line_len != L1_CACHE_BYTES)
1227 			panic("ICache line [%d] != kernel Config [%d]",
1228 			      ic->line_len, L1_CACHE_BYTES);
1229 
1230 		/*
1231 		 * In MMU v4 (HS38x) the aliasing icache config uses IVIL/PTAG
1232 		 * pair to provide vaddr/paddr respectively, just as in MMU v3
1233 		 */
1234 		if (is_isa_arcv2() && ic->alias)
1235 			_cache_line_loop_ic_fn = __cache_line_loop_v3;
1236 		else
1237 			_cache_line_loop_ic_fn = __cache_line_loop;
1238 	}
1239 
1240 	if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
1241 		struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
1242 
1243 		if (!dc->line_len)
1244 			panic("cache support enabled but non-existent cache\n");
1245 
1246 		if (dc->line_len != L1_CACHE_BYTES)
1247 			panic("DCache line [%d] != kernel Config [%d]",
1248 			      dc->line_len, L1_CACHE_BYTES);
1249 
1250 		/* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */
1251 		if (is_isa_arcompact()) {
1252 			int handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
1253 			int num_colors = dc->sz_k/dc->assoc/TO_KB(PAGE_SIZE);
1254 
1255 			if (dc->alias) {
1256 				if (!handled)
1257 					panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
1258 				if (CACHE_COLORS_NUM != num_colors)
1259 					panic("CACHE_COLORS_NUM not optimized for config\n");
1260 			} else if (!dc->alias && handled) {
1261 				panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
1262 			}
1263 		}
1264 	}
1265 
1266 	/*
1267 	 * Check that SMP_CACHE_BYTES (and hence ARCH_DMA_MINALIGN) is larger
1268 	 * or equal to any cache line length.
1269 	 */
1270 	BUILD_BUG_ON_MSG(L1_CACHE_BYTES > SMP_CACHE_BYTES,
1271 			 "SMP_CACHE_BYTES must be >= any cache line length");
1272 	if (is_isa_arcv2() && (l2_line_sz > SMP_CACHE_BYTES))
1273 		panic("L2 Cache line [%d] > kernel Config [%d]\n",
1274 		      l2_line_sz, SMP_CACHE_BYTES);
1275 
1276 	/* Note that SLC disable not formally supported till HS 3.0 */
1277 	if (is_isa_arcv2() && l2_line_sz && !slc_enable)
1278 		arc_slc_disable();
1279 
1280 	if (is_isa_arcv2() && ioc_exists)
1281 		arc_ioc_setup();
1282 
1283 	if (is_isa_arcv2() && l2_line_sz && slc_enable) {
1284 		__dma_cache_wback_inv = __dma_cache_wback_inv_slc;
1285 		__dma_cache_inv = __dma_cache_inv_slc;
1286 		__dma_cache_wback = __dma_cache_wback_slc;
1287 	} else {
1288 		__dma_cache_wback_inv = __dma_cache_wback_inv_l1;
1289 		__dma_cache_inv = __dma_cache_inv_l1;
1290 		__dma_cache_wback = __dma_cache_wback_l1;
1291 	}
1292 	/*
1293 	 * In case of IOC (say IOC+SLC case), pointers above could still be set
1294 	 * but end up not being relevant as the first function in chain is not
1295 	 * called at all for devices using coherent DMA.
1296 	 *     arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*()
1297 	 */
1298 }
1299 
1300 void __ref arc_cache_init(void)
1301 {
1302 	unsigned int __maybe_unused cpu = smp_processor_id();
1303 	char str[256];
1304 
1305 	pr_info("%s", arc_cache_mumbojumbo(0, str, sizeof(str)));
1306 
1307 	if (!cpu)
1308 		arc_cache_init_master();
1309 
1310 	/*
1311 	 * In PAE regime, TLB and cache maintenance ops take wider addresses
1312 	 * And even if PAE is not enabled in kernel, the upper 32-bits still need
1313 	 * to be zeroed to keep the ops sane.
1314 	 * As an optimization for more common !PAE enabled case, zero them out
1315 	 * once at init, rather than checking/setting to 0 for every runtime op
1316 	 */
1317 	if (is_isa_arcv2() && pae40_exist_but_not_enab()) {
1318 
1319 		if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE))
1320 			write_aux_reg(ARC_REG_IC_PTAG_HI, 0);
1321 
1322 		if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE))
1323 			write_aux_reg(ARC_REG_DC_PTAG_HI, 0);
1324 
1325 		if (l2_line_sz) {
1326 			write_aux_reg(ARC_REG_SLC_RGN_END1, 0);
1327 			write_aux_reg(ARC_REG_SLC_RGN_START1, 0);
1328 		}
1329 	}
1330 }
1331