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 /* Bit values in IC_CTRL */
91 #define IC_CTRL_CACHE_DISABLE BIT(0)
93 /* Bit values in DC_CTRL */
94 #define DC_CTRL_CACHE_DISABLE BIT(0)
95 #define DC_CTRL_INV_MODE_FLUSH BIT(6)
96 #define DC_CTRL_FLUSH_STATUS BIT(8)
99 #define OP_FLUSH BIT(1)
100 #define OP_FLUSH_N_INV (OP_FLUSH | OP_INV)
102 /* Bit val in SLC_CONTROL */
103 #define SLC_CTRL_DIS 0x001
104 #define SLC_CTRL_IM 0x040
105 #define SLC_CTRL_BUSY 0x100
106 #define SLC_CTRL_RGN_OP_INV 0x200
109 * By default that variable will fall into .bss section.
110 * But .bss section is not relocated and so it will be initilized before
111 * relocation but will be used after being zeroed.
113 int l1_line_sz __section(".data");
115 #define CACHE_LINE_MASK (~(l1_line_sz - 1))
117 int slc_line_sz __section(".data");
118 bool ioc_exists __section(".data") = false;
120 /* To force enable IOC set ioc_enable to 'true' */
121 bool ioc_enable __section(".data") = false;
123 static inline bool pae_exists(void)
125 /* TODO: should we compare mmu version from BCR and from CONFIG? */
126 #if (CONFIG_ARC_MMU_VER >= 4)
127 union bcr_mmu_4 mmu4;
129 mmu4.word = read_aux_reg(ARC_AUX_MMU_BCR);
133 #endif /* (CONFIG_ARC_MMU_VER >= 4) */
138 static inline bool icache_exists(void)
140 union bcr_di_cache ibcr;
142 ibcr.word = read_aux_reg(ARC_BCR_IC_BUILD);
143 return !!ibcr.fields.ver;
146 static inline bool dcache_exists(void)
148 union bcr_di_cache dbcr;
150 dbcr.word = read_aux_reg(ARC_BCR_DC_BUILD);
151 return !!dbcr.fields.ver;
154 static inline bool slc_exists(void)
156 if (is_isa_arcv2()) {
157 union bcr_generic sbcr;
159 sbcr.word = read_aux_reg(ARC_BCR_SLC);
160 return !!sbcr.fields.ver;
166 static void __slc_entire_op(const int op)
173 ctrl = read_aux_reg(ARC_AUX_SLC_CTRL);
175 if (!(op & OP_FLUSH)) /* i.e. OP_INV */
176 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */
180 write_aux_reg(ARC_AUX_SLC_CTRL, ctrl);
182 if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */
183 write_aux_reg(ARC_AUX_SLC_INVALIDATE, 0x1);
185 write_aux_reg(ARC_AUX_SLC_FLUSH, 0x1);
187 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
188 read_aux_reg(ARC_AUX_SLC_CTRL);
190 /* Important to wait for flush to complete */
191 while (read_aux_reg(ARC_AUX_SLC_CTRL) & SLC_CTRL_BUSY);
194 static void slc_upper_region_init(void)
197 * ARC_AUX_SLC_RGN_END1 and ARC_AUX_SLC_RGN_START1 are always == 0
198 * as we don't use PAE40.
200 write_aux_reg(ARC_AUX_SLC_RGN_END1, 0);
201 write_aux_reg(ARC_AUX_SLC_RGN_START1, 0);
204 static void __slc_rgn_op(unsigned long paddr, unsigned long sz, const int op)
206 #ifdef CONFIG_ISA_ARCV2
215 * The Region Flush operation is specified by CTRL.RGN_OP[11..9]
216 * - b'000 (default) is Flush,
217 * - b'001 is Invalidate if CTRL.IM == 0
218 * - b'001 is Flush-n-Invalidate if CTRL.IM == 1
220 ctrl = read_aux_reg(ARC_AUX_SLC_CTRL);
222 /* Don't rely on default value of IM bit */
223 if (!(op & OP_FLUSH)) /* i.e. OP_INV */
224 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */
229 ctrl |= SLC_CTRL_RGN_OP_INV; /* Inv or flush-n-inv */
231 ctrl &= ~SLC_CTRL_RGN_OP_INV;
233 write_aux_reg(ARC_AUX_SLC_CTRL, ctrl);
236 * Lower bits are ignored, no need to clip
237 * END needs to be setup before START (latter triggers the operation)
238 * END can't be same as START, so add (l2_line_sz - 1) to sz
240 end = paddr + sz + slc_line_sz - 1;
243 * Upper addresses (ARC_AUX_SLC_RGN_END1 and ARC_AUX_SLC_RGN_START1)
244 * are always == 0 as we don't use PAE40, so we only setup lower ones
245 * (ARC_AUX_SLC_RGN_END and ARC_AUX_SLC_RGN_START)
247 write_aux_reg(ARC_AUX_SLC_RGN_END, end);
248 write_aux_reg(ARC_AUX_SLC_RGN_START, paddr);
250 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
251 read_aux_reg(ARC_AUX_SLC_CTRL);
253 while (read_aux_reg(ARC_AUX_SLC_CTRL) & SLC_CTRL_BUSY);
255 #endif /* CONFIG_ISA_ARCV2 */
258 static void arc_ioc_setup(void)
260 /* IOC Aperture start is equal to DDR start */
261 unsigned int ap_base = CONFIG_SYS_SDRAM_BASE;
262 /* IOC Aperture size is equal to DDR size */
263 long ap_size = CONFIG_SYS_SDRAM_SIZE;
265 flush_n_invalidate_dcache_all();
267 if (!is_power_of_2(ap_size) || ap_size < 4096)
268 panic("IOC Aperture size must be power of 2 and bigger 4Kib");
271 * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB,
272 * so setting 0x11 implies 512M, 0x12 implies 1G...
274 write_aux_reg(ARC_AUX_IO_COH_AP0_SIZE,
275 order_base_2(ap_size / 1024) - 2);
277 /* IOC Aperture start must be aligned to the size of the aperture */
278 if (ap_base % ap_size != 0)
279 panic("IOC Aperture start must be aligned to the size of the aperture");
281 write_aux_reg(ARC_AUX_IO_COH_AP0_BASE, ap_base >> 12);
282 write_aux_reg(ARC_AUX_IO_COH_PARTIAL, 1);
283 write_aux_reg(ARC_AUX_IO_COH_ENABLE, 1);
286 static void read_decode_cache_bcr_arcv2(void)
288 #ifdef CONFIG_ISA_ARCV2
290 union bcr_slc_cfg slc_cfg;
291 union bcr_clust_cfg cbcr;
294 slc_cfg.word = read_aux_reg(ARC_AUX_SLC_CONFIG);
295 slc_line_sz = (slc_cfg.fields.lsz == 0) ? 128 : 64;
298 cbcr.word = read_aux_reg(ARC_BCR_CLUSTER);
299 if (cbcr.fields.c && ioc_enable)
302 #endif /* CONFIG_ISA_ARCV2 */
305 void read_decode_cache_bcr(void)
307 int dc_line_sz = 0, ic_line_sz = 0;
308 union bcr_di_cache ibcr, dbcr;
310 ibcr.word = read_aux_reg(ARC_BCR_IC_BUILD);
311 if (ibcr.fields.ver) {
312 l1_line_sz = ic_line_sz = 8 << ibcr.fields.line_len;
314 panic("Instruction exists but line length is 0\n");
317 dbcr.word = read_aux_reg(ARC_BCR_DC_BUILD);
318 if (dbcr.fields.ver) {
319 l1_line_sz = dc_line_sz = 16 << dbcr.fields.line_len;
321 panic("Data cache exists but line length is 0\n");
324 if (ic_line_sz && dc_line_sz && (ic_line_sz != dc_line_sz))
325 panic("Instruction and data cache line lengths differ\n");
328 void cache_init(void)
330 read_decode_cache_bcr();
333 read_decode_cache_bcr_arcv2();
335 if (is_isa_arcv2() && ioc_exists)
339 * ARC_AUX_SLC_RGN_START1 and ARC_AUX_SLC_RGN_END1 register exist
340 * only if PAE exists in current HW. So we had to check pae_exist
343 if (is_isa_arcv2() && slc_exists() && pae_exists())
344 slc_upper_region_init();
347 int icache_status(void)
349 if (!icache_exists())
352 if (read_aux_reg(ARC_AUX_IC_CTRL) & IC_CTRL_CACHE_DISABLE)
358 void icache_enable(void)
361 write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) &
362 ~IC_CTRL_CACHE_DISABLE);
365 void icache_disable(void)
368 write_aux_reg(ARC_AUX_IC_CTRL, read_aux_reg(ARC_AUX_IC_CTRL) |
369 IC_CTRL_CACHE_DISABLE);
372 /* IC supports only invalidation */
373 static inline void __ic_entire_invalidate(void)
375 if (!icache_status())
378 /* Any write to IC_IVIC register triggers invalidation of entire I$ */
379 write_aux_reg(ARC_AUX_IC_IVIC, 1);
381 * As per ARC HS databook (see chapter 5.3.3.2)
382 * it is required to add 3 NOPs after each write to IC_IVIC.
387 read_aux_reg(ARC_AUX_IC_CTRL); /* blocks */
390 void invalidate_icache_all(void)
392 __ic_entire_invalidate();
395 __slc_entire_op(OP_INV);
398 int dcache_status(void)
400 if (!dcache_exists())
403 if (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_CACHE_DISABLE)
409 void dcache_enable(void)
411 if (!dcache_exists())
414 write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) &
415 ~(DC_CTRL_INV_MODE_FLUSH | DC_CTRL_CACHE_DISABLE));
418 void dcache_disable(void)
420 if (!dcache_exists())
423 write_aux_reg(ARC_AUX_DC_CTRL, read_aux_reg(ARC_AUX_DC_CTRL) |
424 DC_CTRL_CACHE_DISABLE);
427 /* Common Helper for Line Operations on D-cache */
428 static inline void __dcache_line_loop(unsigned long paddr, unsigned long sz,
431 unsigned int aux_cmd;
434 /* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
435 aux_cmd = cacheop & OP_INV ? ARC_AUX_DC_IVDL : ARC_AUX_DC_FLDL;
437 sz += paddr & ~CACHE_LINE_MASK;
438 paddr &= CACHE_LINE_MASK;
440 num_lines = DIV_ROUND_UP(sz, l1_line_sz);
442 while (num_lines-- > 0) {
443 #if (CONFIG_ARC_MMU_VER == 3)
444 write_aux_reg(ARC_AUX_DC_PTAG, paddr);
446 write_aux_reg(aux_cmd, paddr);
451 static void __before_dc_op(const int op)
455 ctrl = read_aux_reg(ARC_AUX_DC_CTRL);
457 /* IM bit implies flush-n-inv, instead of vanilla inv */
459 ctrl &= ~DC_CTRL_INV_MODE_FLUSH;
461 ctrl |= DC_CTRL_INV_MODE_FLUSH;
463 write_aux_reg(ARC_AUX_DC_CTRL, ctrl);
466 static void __after_dc_op(const int op)
468 if (op & OP_FLUSH) /* flush / flush-n-inv both wait */
469 while (read_aux_reg(ARC_AUX_DC_CTRL) & DC_CTRL_FLUSH_STATUS);
472 static inline void __dc_entire_op(const int cacheop)
476 if (!dcache_status())
479 __before_dc_op(cacheop);
481 if (cacheop & OP_INV) /* Inv or flush-n-inv use same cmd reg */
482 aux = ARC_AUX_DC_IVDC;
484 aux = ARC_AUX_DC_FLSH;
486 write_aux_reg(aux, 0x1);
488 __after_dc_op(cacheop);
491 static inline void __dc_line_op(unsigned long paddr, unsigned long sz,
494 if (!dcache_status())
497 __before_dc_op(cacheop);
498 __dcache_line_loop(paddr, sz, cacheop);
499 __after_dc_op(cacheop);
502 void invalidate_dcache_range(unsigned long start, unsigned long end)
508 * ARCv1 -> call __dc_line_op
509 * ARCv2 && no IOC -> call __dc_line_op; call __slc_rgn_op
510 * ARCv2 && IOC enabled -> nothing
512 if (!is_isa_arcv2() || !ioc_exists)
513 __dc_line_op(start, end - start, OP_INV);
515 if (is_isa_arcv2() && !ioc_exists)
516 __slc_rgn_op(start, end - start, OP_INV);
519 void flush_dcache_range(unsigned long start, unsigned long end)
525 * ARCv1 -> call __dc_line_op
526 * ARCv2 && no IOC -> call __dc_line_op; call __slc_rgn_op
527 * ARCv2 && IOC enabled -> nothing
529 if (!is_isa_arcv2() || !ioc_exists)
530 __dc_line_op(start, end - start, OP_FLUSH);
532 if (is_isa_arcv2() && !ioc_exists)
533 __slc_rgn_op(start, end - start, OP_FLUSH);
536 void flush_cache(unsigned long start, unsigned long size)
538 flush_dcache_range(start, start + size);
542 * As invalidate_dcache_all() is not used in generic U-Boot code and as we
543 * don't need it in arch/arc code alone (invalidate without flush) we implement
544 * flush_n_invalidate_dcache_all (flush and invalidate in 1 operation) because
545 * it's much safer. See [ NOTE 1 ] for more details.
547 void flush_n_invalidate_dcache_all(void)
549 __dc_entire_op(OP_FLUSH_N_INV);
552 __slc_entire_op(OP_FLUSH_N_INV);
555 void flush_dcache_all(void)
557 __dc_entire_op(OP_FLUSH);
560 __slc_entire_op(OP_FLUSH);