2 * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
4 * SPDX-License-Identifier: GPL-2.0+
9 #include <linux/compiler.h>
10 #include <linux/kernel.h>
11 #include <linux/log2.h>
12 #include <asm/arcregs.h>
13 #include <asm/arc-bcr.h>
14 #include <asm/cache.h>
18 * Data cache (L1 D$ or SL$) entire invalidate operation or data cache disable
19 * operation may result in unexpected behavior and data loss even if we flush
20 * data cache right before invalidation. That may happens if we store any context
21 * on stack (like we store BLINK register on stack before function call).
22 * BLINK register is the register where return address is automatically saved
23 * when we do function call with instructions like 'bl'.
25 * There is the real example:
26 * We may hang in the next code as we store any BLINK register on stack in
27 * invalidate_dcache_all() function.
29 * void flush_dcache_all() {
30 * __dc_entire_op(OP_FLUSH);
34 * void invalidate_dcache_all() {
35 * __dc_entire_op(OP_INV);
41 * invalidate_dcache_all();
44 * Now let's see what really happens during that code execution:
47 * |->> call flush_dcache_all
48 * [return address is saved to BLINK register]
49 * [push BLINK] (save to stack) ![point 1]
50 * |->> call __dc_entire_op(OP_FLUSH)
51 * [return address is saved to BLINK register]
53 * return [jump to BLINK]
55 * [other flush_dcache_all code]
56 * [pop BLINK] (get from stack)
57 * return [jump to BLINK]
59 * |->> call invalidate_dcache_all
60 * [return address is saved to BLINK register]
61 * [push BLINK] (save to stack) ![point 2]
62 * |->> call __dc_entire_op(OP_FLUSH)
63 * [return address is saved to BLINK register]
64 * [invalidate L1 D$] ![point 3]
66 * // We lose return address from invalidate_dcache_all function:
67 * // we save it to stack and invalidate L1 D$ after that!
68 * return [jump to BLINK]
70 * [other invalidate_dcache_all code]
71 * [pop BLINK] (get from stack)
72 * // we don't have this data in L1 dcache as we invalidated it in [point 3]
73 * // so we get it from next memory level (for example DDR memory)
74 * // but in the memory we have value which we save in [point 1], which
75 * // is return address from flush_dcache_all function (instead of
76 * // address from current invalidate_dcache_all function which we
77 * // saved in [point 2] !)
78 * return [jump to BLINK]
80 * // As BLINK points to invalidate_dcache_all, we call it again and
83 * Fortunately we may fix that by using flush & invalidation of D$ with a single
84 * one instruction (instead of flush and invalidation instructions pair) and
85 * enabling force function inline with '__attribute__((always_inline))' gcc
86 * attribute to avoid any function call (and BLINK store) between cache flush
90 DECLARE_GLOBAL_DATA_PTR;
92 /* Bit values in IC_CTRL */
93 #define IC_CTRL_CACHE_DISABLE BIT(0)
95 /* Bit values in DC_CTRL */
96 #define DC_CTRL_CACHE_DISABLE BIT(0)
97 #define DC_CTRL_INV_MODE_FLUSH BIT(6)
98 #define DC_CTRL_FLUSH_STATUS BIT(8)
100 #define OP_INV BIT(0)
101 #define OP_FLUSH BIT(1)
102 #define OP_FLUSH_N_INV (OP_FLUSH | OP_INV)
104 /* Bit val in SLC_CONTROL */
105 #define SLC_CTRL_DIS 0x001
106 #define SLC_CTRL_IM 0x040
107 #define SLC_CTRL_BUSY 0x100
108 #define SLC_CTRL_RGN_OP_INV 0x200
111 * By default that variable will fall into .bss section.
112 * But .bss section is not relocated and so it will be initilized before
113 * relocation but will be used after being zeroed.
115 #define CACHE_LINE_MASK (~(gd->arch.l1_line_sz - 1))
117 bool ioc_exists __section(".data") = false;
119 /* To force enable IOC set ioc_enable to 'true' */
120 bool ioc_enable __section(".data") = false;
122 static inline bool pae_exists(void)
124 /* TODO: should we compare mmu version from BCR and from CONFIG? */
125 #if (CONFIG_ARC_MMU_VER >= 4)
126 union bcr_mmu_4 mmu4;
128 mmu4.word = read_aux_reg(ARC_AUX_MMU_BCR);
132 #endif /* (CONFIG_ARC_MMU_VER >= 4) */
137 static inline bool icache_exists(void)
139 union bcr_di_cache ibcr;
141 ibcr.word = read_aux_reg(ARC_BCR_IC_BUILD);
142 return !!ibcr.fields.ver;
145 static inline bool dcache_exists(void)
147 union bcr_di_cache dbcr;
149 dbcr.word = read_aux_reg(ARC_BCR_DC_BUILD);
150 return !!dbcr.fields.ver;
153 static inline bool slc_exists(void)
155 if (is_isa_arcv2()) {
156 union bcr_generic sbcr;
158 sbcr.word = read_aux_reg(ARC_BCR_SLC);
159 return !!sbcr.fields.ver;
165 static void __slc_entire_op(const int op)
172 ctrl = read_aux_reg(ARC_AUX_SLC_CTRL);
174 if (!(op & OP_FLUSH)) /* i.e. OP_INV */
175 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */
179 write_aux_reg(ARC_AUX_SLC_CTRL, ctrl);
181 if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */
182 write_aux_reg(ARC_AUX_SLC_INVALIDATE, 0x1);
184 write_aux_reg(ARC_AUX_SLC_FLUSH, 0x1);
186 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
187 read_aux_reg(ARC_AUX_SLC_CTRL);
189 /* Important to wait for flush to complete */
190 while (read_aux_reg(ARC_AUX_SLC_CTRL) & SLC_CTRL_BUSY);
193 static void slc_upper_region_init(void)
196 * ARC_AUX_SLC_RGN_START1 and ARC_AUX_SLC_RGN_END1 register exist
197 * only if PAE exists in current HW. So we had to check pae_exist
204 * ARC_AUX_SLC_RGN_END1 and ARC_AUX_SLC_RGN_START1 are always == 0
205 * as we don't use PAE40.
207 write_aux_reg(ARC_AUX_SLC_RGN_END1, 0);
208 write_aux_reg(ARC_AUX_SLC_RGN_START1, 0);
211 static void __slc_rgn_op(unsigned long paddr, unsigned long sz, const int op)
213 #ifdef CONFIG_ISA_ARCV2
222 * The Region Flush operation is specified by CTRL.RGN_OP[11..9]
223 * - b'000 (default) is Flush,
224 * - b'001 is Invalidate if CTRL.IM == 0
225 * - b'001 is Flush-n-Invalidate if CTRL.IM == 1
227 ctrl = read_aux_reg(ARC_AUX_SLC_CTRL);
229 /* Don't rely on default value of IM bit */
230 if (!(op & OP_FLUSH)) /* i.e. OP_INV */
231 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */
236 ctrl |= SLC_CTRL_RGN_OP_INV; /* Inv or flush-n-inv */
238 ctrl &= ~SLC_CTRL_RGN_OP_INV;
240 write_aux_reg(ARC_AUX_SLC_CTRL, ctrl);
243 * Lower bits are ignored, no need to clip
244 * END needs to be setup before START (latter triggers the operation)
245 * END can't be same as START, so add (l2_line_sz - 1) to sz
247 end = paddr + sz + gd->arch.slc_line_sz - 1;
250 * Upper addresses (ARC_AUX_SLC_RGN_END1 and ARC_AUX_SLC_RGN_START1)
251 * are always == 0 as we don't use PAE40, so we only setup lower ones
252 * (ARC_AUX_SLC_RGN_END and ARC_AUX_SLC_RGN_START)
254 write_aux_reg(ARC_AUX_SLC_RGN_END, end);
255 write_aux_reg(ARC_AUX_SLC_RGN_START, paddr);
257 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
258 read_aux_reg(ARC_AUX_SLC_CTRL);
260 while (read_aux_reg(ARC_AUX_SLC_CTRL) & SLC_CTRL_BUSY);
262 #endif /* CONFIG_ISA_ARCV2 */
265 static void arc_ioc_setup(void)
267 /* IOC Aperture start is equal to DDR start */
268 unsigned int ap_base = CONFIG_SYS_SDRAM_BASE;
269 /* IOC Aperture size is equal to DDR size */
270 long ap_size = CONFIG_SYS_SDRAM_SIZE;
272 flush_n_invalidate_dcache_all();
274 if (!is_power_of_2(ap_size) || ap_size < 4096)
275 panic("IOC Aperture size must be power of 2 and bigger 4Kib");
278 * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
279 * so setting 0x11 implies 512M, 0x12 implies 1G...
281 write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE,
282 order_base_2(ap_size / 1024) - 2);
284 /* IOC Aperture start must be aligned to the size of the aperture */
285 if (ap_base % ap_size != 0)
286 panic("IOC Aperture start must be aligned to the size of the aperture");
288 write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, ap_base >> 12);
289 write_aux_reg(ARC_AUX_IO_COH_PARTIAL, 1);
290 write_aux_reg(ARC_AUX_IO_COH_ENABLE, 1);
293 static void read_decode_cache_bcr_arcv2(void)
295 #ifdef CONFIG_ISA_ARCV2
297 union bcr_slc_cfg slc_cfg;
298 union bcr_clust_cfg cbcr;
301 slc_cfg.word = read_aux_reg(ARC_AUX_SLC_CONFIG);
302 gd->arch.slc_line_sz = (slc_cfg.fields.lsz == 0) ? 128 : 64;
305 cbcr.word = read_aux_reg(ARC_BCR_CLUSTER);
306 if (cbcr.fields.c && ioc_enable)
309 #endif /* CONFIG_ISA_ARCV2 */
312 void read_decode_cache_bcr(void)
314 int dc_line_sz = 0, ic_line_sz = 0;
315 union bcr_di_cache ibcr, dbcr;
317 ibcr.word = read_aux_reg(ARC_BCR_IC_BUILD);
318 if (ibcr.fields.ver) {
319 gd->arch.l1_line_sz = ic_line_sz = 8 << ibcr.fields.line_len;
321 panic("Instruction exists but line length is 0\n");
324 dbcr.word = read_aux_reg(ARC_BCR_DC_BUILD);
325 if (dbcr.fields.ver) {
326 gd->arch.l1_line_sz = dc_line_sz = 16 << dbcr.fields.line_len;
328 panic("Data cache exists but line length is 0\n");
331 if (ic_line_sz && dc_line_sz && (ic_line_sz != dc_line_sz))
332 panic("Instruction and data cache line lengths differ\n");
335 void cache_init(void)
337 read_decode_cache_bcr();
340 read_decode_cache_bcr_arcv2();
342 if (is_isa_arcv2() && ioc_exists)
345 if (is_isa_arcv2() && slc_exists())
346 slc_upper_region_init();
349 int icache_status(void)
351 if (!icache_exists())
354 if (read_aux_reg(ARC_AUX_IC_CTRL) & IC_CTRL_CACHE_DISABLE)
360 void icache_enable(void)
363 write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) &
364 ~IC_CTRL_CACHE_DISABLE);
367 void icache_disable(void)
370 write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) |
371 IC_CTRL_CACHE_DISABLE);
374 /* IC supports only invalidation */
375 static inline void __ic_entire_invalidate(void)
377 if (!icache_status())
380 /* Any write to IC_IVIC register triggers invalidation of entire I$ */
381 write_aux_reg(ARC_AUX_IC_IVIC, 1);
383 * As per ARC HS databook (see chapter 5.3.3.2)
384 * it is required to add 3 NOPs after each write to IC_IVIC.
389 read_aux_reg(ARC_AUX_IC_CTRL); /* blocks */
392 void invalidate_icache_all(void)
394 __ic_entire_invalidate();
397 __slc_entire_op(OP_INV);
400 int dcache_status(void)
402 if (!dcache_exists())
405 if (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_CACHE_DISABLE)
411 void dcache_enable(void)
413 if (!dcache_exists())
416 write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) &
417 ~(DC_CTRL_INV_MODE_FLUSH | DC_CTRL_CACHE_DISABLE));
420 void dcache_disable(void)
422 if (!dcache_exists())
425 write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) |
426 DC_CTRL_CACHE_DISABLE);
429 /* Common Helper for Line Operations on D-cache */
430 static inline void __dcache_line_loop(unsigned long paddr, unsigned long sz,
433 unsigned int aux_cmd;
436 /* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
437 aux_cmd = cacheop & OP_INV ? ARC_AUX_DC_IVDL : ARC_AUX_DC_FLDL;
439 sz += paddr & ~CACHE_LINE_MASK;
440 paddr &= CACHE_LINE_MASK;
442 num_lines = DIV_ROUND_UP(sz, gd->arch.l1_line_sz);
444 while (num_lines-- > 0) {
445 #if (CONFIG_ARC_MMU_VER == 3)
446 write_aux_reg(ARC_AUX_DC_PTAG, paddr);
448 write_aux_reg(aux_cmd, paddr);
449 paddr += gd->arch.l1_line_sz;
453 static void __before_dc_op(const int op)
457 ctrl = read_aux_reg(ARC_AUX_DC_CTRL);
459 /* IM bit implies flush-n-inv, instead of vanilla inv */
461 ctrl &= ~DC_CTRL_INV_MODE_FLUSH;
463 ctrl |= DC_CTRL_INV_MODE_FLUSH;
465 write_aux_reg(ARC_AUX_DC_CTRL, ctrl);
468 static void __after_dc_op(const int op)
470 if (op & OP_FLUSH) /* flush / flush-n-inv both wait */
471 while (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_FLUSH_STATUS);
474 static inline void __dc_entire_op(const int cacheop)
478 if (!dcache_status())
481 __before_dc_op(cacheop);
483 if (cacheop & OP_INV) /* Inv or flush-n-inv use same cmd reg */
484 aux = ARC_AUX_DC_IVDC;
486 aux = ARC_AUX_DC_FLSH;
488 write_aux_reg(aux, 0x1);
490 __after_dc_op(cacheop);
493 static inline void __dc_line_op(unsigned long paddr, unsigned long sz,
496 if (!dcache_status())
499 __before_dc_op(cacheop);
500 __dcache_line_loop(paddr, sz, cacheop);
501 __after_dc_op(cacheop);
504 void invalidate_dcache_range(unsigned long start, unsigned long end)
510 * ARCv1 -> call __dc_line_op
511 * ARCv2 && no IOC -> call __dc_line_op; call __slc_rgn_op
512 * ARCv2 && IOC enabled -> nothing
514 if (!is_isa_arcv2() || !ioc_exists)
515 __dc_line_op(start, end - start, OP_INV);
517 if (is_isa_arcv2() && !ioc_exists)
518 __slc_rgn_op(start, end - start, OP_INV);
521 void flush_dcache_range(unsigned long start, unsigned long end)
527 * ARCv1 -> call __dc_line_op
528 * ARCv2 && no IOC -> call __dc_line_op; call __slc_rgn_op
529 * ARCv2 && IOC enabled -> nothing
531 if (!is_isa_arcv2() || !ioc_exists)
532 __dc_line_op(start, end - start, OP_FLUSH);
534 if (is_isa_arcv2() && !ioc_exists)
535 __slc_rgn_op(start, end - start, OP_FLUSH);
538 void flush_cache(unsigned long start, unsigned long size)
540 flush_dcache_range(start, start + size);
544 * As invalidate_dcache_all() is not used in generic U-Boot code and as we
545 * don't need it in arch/arc code alone (invalidate without flush) we implement
546 * flush_n_invalidate_dcache_all (flush and invalidate in 1 operation) because
547 * it's much safer. See [ NOTE 1 ] for more details.
549 void flush_n_invalidate_dcache_all(void)
551 __dc_entire_op(OP_FLUSH_N_INV);
554 __slc_entire_op(OP_FLUSH_N_INV);
557 void flush_dcache_all(void)
559 __dc_entire_op(OP_FLUSH);
562 __slc_entire_op(OP_FLUSH);