1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Cache-handling routined for MIPS CPUs
5 * Copyright (c) 2003 Wolfgang Denk <wd@denx.de>
8 #include <asm-offsets.h>
11 #include <asm/regdef.h>
12 #include <asm/mipsregs.h>
13 #include <asm/addrspace.h>
14 #include <asm/cacheops.h>
17 #ifndef CONFIG_SYS_MIPS_CACHE_MODE
18 #define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
21 .macro f_fill64 dst, offset, val
22 LONG_S \val, (\offset + 0 * LONGSIZE)(\dst)
23 LONG_S \val, (\offset + 1 * LONGSIZE)(\dst)
24 LONG_S \val, (\offset + 2 * LONGSIZE)(\dst)
25 LONG_S \val, (\offset + 3 * LONGSIZE)(\dst)
26 LONG_S \val, (\offset + 4 * LONGSIZE)(\dst)
27 LONG_S \val, (\offset + 5 * LONGSIZE)(\dst)
28 LONG_S \val, (\offset + 6 * LONGSIZE)(\dst)
29 LONG_S \val, (\offset + 7 * LONGSIZE)(\dst)
31 LONG_S \val, (\offset + 8 * LONGSIZE)(\dst)
32 LONG_S \val, (\offset + 9 * LONGSIZE)(\dst)
33 LONG_S \val, (\offset + 10 * LONGSIZE)(\dst)
34 LONG_S \val, (\offset + 11 * LONGSIZE)(\dst)
35 LONG_S \val, (\offset + 12 * LONGSIZE)(\dst)
36 LONG_S \val, (\offset + 13 * LONGSIZE)(\dst)
37 LONG_S \val, (\offset + 14 * LONGSIZE)(\dst)
38 LONG_S \val, (\offset + 15 * LONGSIZE)(\dst)
42 .macro cache_loop curr, end, line_sz, op
43 10: cache \op, 0(\curr)
44 PTR_ADDU \curr, \curr, \line_sz
48 .macro l1_info sz, line_sz, off
52 mfc0 $1, CP0_CONFIG, 1
54 /* detect line size */
55 srl \line_sz, $1, \off + MIPS_CONF1_DL_SHF - MIPS_CONF1_DA_SHF
56 andi \line_sz, \line_sz, (MIPS_CONF1_DL >> MIPS_CONF1_DL_SHF)
60 sllv \line_sz, \sz, \line_sz
62 /* detect associativity */
63 srl \sz, $1, \off + MIPS_CONF1_DA_SHF - MIPS_CONF1_DA_SHF
64 andi \sz, \sz, (MIPS_CONF1_DA >> MIPS_CONF1_DA_SHF)
68 mul \sz, \sz, \line_sz
70 /* detect log32(sets) */
71 srl $1, $1, \off + MIPS_CONF1_DS_SHF - MIPS_CONF1_DA_SHF
72 andi $1, $1, (MIPS_CONF1_DS >> MIPS_CONF1_DS_SHF)
76 /* sz <<= log32(sets) */
87 * mips_cache_reset - low level initialisation of the primary caches
89 * This routine initialises the primary caches to ensure that they have good
90 * parity. It must be called by the ROM before any cached locations are used
91 * to prevent the possibility of data with bad parity being written to memory.
93 * To initialise the instruction cache it is essential that a source of data
94 * with good parity is available. This routine will initialise an area of
95 * memory starting at location zero to be used as a source of parity.
97 * Note that this function does not follow the standard calling convention &
98 * may clobber typically callee-saved registers.
110 #define R_L2_BYPASSED s7
112 LEAF(mips_cache_reset)
115 #ifdef CONFIG_MIPS_L2_CACHE
117 * For there to be an L2 present, Config2 must be present. If it isn't
118 * then we proceed knowing there's no L2 cache.
122 move R_L2_BYPASSED, zero
124 mfc0 t0, CP0_CONFIG, 1
125 bgez t0, l2_probe_done
128 * From MIPSr6 onwards the L2 cache configuration might not be reported
129 * by Config2. The Config5.L2C bit indicates whether this is the case,
130 * and if it is then we need knowledge of where else to look. For cores
131 * from Imagination Technologies this is a CM GCR.
133 # if __mips_isa_rev >= 6
134 /* Check that Config5 exists */
135 mfc0 t0, CP0_CONFIG, 2
136 bgez t0, l2_probe_cop0
137 mfc0 t0, CP0_CONFIG, 3
138 bgez t0, l2_probe_cop0
139 mfc0 t0, CP0_CONFIG, 4
140 bgez t0, l2_probe_cop0
142 /* Check Config5.L2C is set */
143 mfc0 t0, CP0_CONFIG, 5
144 and R_L2_L2C, t0, MIPS_CONF5_L2C
145 beqz R_L2_L2C, l2_probe_cop0
147 /* Config5.L2C is set */
148 # ifdef CONFIG_MIPS_CM
149 /* The CM will provide L2 configuration */
150 PTR_LI t0, CKSEG1ADDR(CONFIG_MIPS_CM_BASE)
151 lw t1, GCR_L2_CONFIG(t0)
152 bgez t1, l2_probe_done
155 GCR_L2_CONFIG_LINESZ_SHIFT, GCR_L2_CONFIG_LINESZ_BITS
156 beqz R_L2_LINE, l2_probe_done
158 sllv R_L2_LINE, t2, R_L2_LINE
160 ext t2, t1, GCR_L2_CONFIG_ASSOC_SHIFT, GCR_L2_CONFIG_ASSOC_BITS
162 mul R_L2_SIZE, R_L2_LINE, t2
164 ext t2, t1, GCR_L2_CONFIG_SETSZ_SHIFT, GCR_L2_CONFIG_SETSZ_BITS
165 sllv R_L2_SIZE, R_L2_SIZE, t2
167 mul R_L2_SIZE, R_L2_SIZE, t2
169 /* Bypass the L2 cache so that we can init the L1s early */
170 or t1, t1, GCR_L2_CONFIG_BYPASS
171 sw t1, GCR_L2_CONFIG(t0)
175 /* Zero the L2 tag registers */
176 sw zero, GCR_L2_TAG_ADDR(t0)
177 sw zero, GCR_L2_TAG_ADDR_UPPER(t0)
178 sw zero, GCR_L2_TAG_STATE(t0)
179 sw zero, GCR_L2_TAG_STATE_UPPER(t0)
180 sw zero, GCR_L2_DATA(t0)
181 sw zero, GCR_L2_DATA_UPPER(t0)
184 /* We don't know how to retrieve L2 configuration on this system */
190 * For pre-r6 systems, or r6 systems with Config5.L2C==0, probe the L2
191 * cache configuration from the cop0 Config2 register.
194 mfc0 t0, CP0_CONFIG, 2
196 srl R_L2_LINE, t0, MIPS_CONF2_SL_SHF
197 andi R_L2_LINE, R_L2_LINE, MIPS_CONF2_SL >> MIPS_CONF2_SL_SHF
198 beqz R_L2_LINE, l2_probe_done
200 sllv R_L2_LINE, t1, R_L2_LINE
202 srl t1, t0, MIPS_CONF2_SA_SHF
203 andi t1, t1, MIPS_CONF2_SA >> MIPS_CONF2_SA_SHF
205 mul R_L2_SIZE, R_L2_LINE, t1
207 srl t1, t0, MIPS_CONF2_SS_SHF
208 andi t1, t1, MIPS_CONF2_SS >> MIPS_CONF2_SS_SHF
209 sllv R_L2_SIZE, R_L2_SIZE, t1
211 mul R_L2_SIZE, R_L2_SIZE, t1
213 /* Attempt to bypass the L2 so that we can init the L1s early */
214 or t0, t0, MIPS_CONF2_L2B
215 mtc0 t0, CP0_CONFIG, 2
217 mfc0 t0, CP0_CONFIG, 2
218 and R_L2_BYPASSED, t0, MIPS_CONF2_L2B
220 /* Zero the L2 tag registers */
221 mtc0 zero, CP0_TAGLO, 4
226 #ifndef CONFIG_SYS_CACHE_SIZE_AUTO
227 li R_IC_SIZE, CONFIG_SYS_ICACHE_SIZE
228 li R_IC_LINE, CONFIG_SYS_ICACHE_LINE_SIZE
230 l1_info R_IC_SIZE, R_IC_LINE, MIPS_CONF1_IA_SHF
233 #ifndef CONFIG_SYS_CACHE_SIZE_AUTO
234 li R_DC_SIZE, CONFIG_SYS_DCACHE_SIZE
235 li R_DC_LINE, CONFIG_SYS_DCACHE_LINE_SIZE
237 l1_info R_DC_SIZE, R_DC_LINE, MIPS_CONF1_DA_SHF
240 #ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD
242 /* Determine the largest L1 cache size */
243 #ifndef CONFIG_SYS_CACHE_SIZE_AUTO
244 #if CONFIG_SYS_ICACHE_SIZE > CONFIG_SYS_DCACHE_SIZE
245 li v0, CONFIG_SYS_ICACHE_SIZE
247 li v0, CONFIG_SYS_DCACHE_SIZE
251 sltu t1, R_IC_SIZE, R_DC_SIZE
252 movn v0, R_DC_SIZE, t1
255 * Now clear that much memory starting from zero.
257 PTR_LI a0, CKSEG1ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
260 f_fill64 a0, -64, zero
263 #endif /* CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD */
265 #ifdef CONFIG_MIPS_L2_CACHE
267 * If the L2 is bypassed, init the L1 first so that we can execute the
268 * rest of the cache initialisation using the L1 instruction cache.
270 bnez R_L2_BYPASSED, l1_init
273 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
274 PTR_ADDU t1, t0, R_L2_SIZE
275 1: cache INDEX_STORE_TAG_SD, 0(t0)
276 PTR_ADDU t0, t0, R_L2_LINE
280 * If the L2 was bypassed then we already initialised the L1s before
281 * the L2, so we are now done.
283 bnez R_L2_BYPASSED, l2_unbypass
287 * The TagLo registers used depend upon the CPU implementation, but the
288 * architecture requires that it is safe for software to write to both
289 * TagLo selects 0 & 2 covering supported cases.
293 mtc0 zero, CP0_TAGLO, 2
297 * The caches are probably in an indeterminate state, so we force good
298 * parity into them by doing an invalidate for each line. If
299 * CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD is set then we'll proceed to
300 * perform a load/fill & a further invalidate for each line, assuming
301 * that the bottom of RAM (having just been cleared) will generate good
302 * parity for the cache.
306 * Initialize the I-cache first,
309 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
310 PTR_ADDU t1, t0, R_IC_SIZE
311 /* clear tag to invalidate */
312 cache_loop t0, t1, R_IC_LINE, INDEX_STORE_TAG_I
313 #ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD
314 /* fill once, so data field parity is correct */
315 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
316 cache_loop t0, t1, R_IC_LINE, FILL
317 /* invalidate again - prudent but not strictly neccessary */
318 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
319 cache_loop t0, t1, R_IC_LINE, INDEX_STORE_TAG_I
324 * Enable use of the I-cache by setting Config.K0. The code for this
325 * must be executed from KSEG1. Jump from KSEG0 to KSEG1 to do this.
326 * Jump back to KSEG0 after caches are enabled and insert an
327 * instruction hazard barrier.
329 PTR_LA t0, change_k0_cca
334 li a0, CONFIG_SYS_MIPS_CACHE_MODE
338 * then initialize D-cache.
340 1: blez R_DC_SIZE, 3f
341 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
342 PTR_ADDU t1, t0, R_DC_SIZE
344 cache_loop t0, t1, R_DC_LINE, INDEX_STORE_TAG_D
345 #ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD
346 /* load from each line (in cached space) */
347 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
348 2: LONG_L zero, 0(t0)
349 PTR_ADDU t0, R_DC_LINE
352 PTR_LI t0, CKSEG0ADDR(CONFIG_MIPS_CACHE_INDEX_BASE)
353 cache_loop t0, t1, R_DC_LINE, INDEX_STORE_TAG_D
357 #ifdef CONFIG_MIPS_L2_CACHE
358 /* If the L2 isn't bypassed then we're done */
359 beqz R_L2_BYPASSED, return
361 /* The L2 is bypassed - go initialise it */
365 # if __mips_isa_rev >= 6
368 li t0, CKSEG1ADDR(CONFIG_MIPS_CM_BASE)
369 lw t1, GCR_L2_CONFIG(t0)
370 xor t1, t1, GCR_L2_CONFIG_BYPASS
371 sw t1, GCR_L2_CONFIG(t0)
376 1: mfc0 t0, CP0_CONFIG, 2
377 xor t0, t0, MIPS_CONF2_L2B
378 mtc0 t0, CP0_CONFIG, 2
382 # ifdef CONFIG_MIPS_CM
383 /* Config3 must exist for a CM to be present */
384 mfc0 t0, CP0_CONFIG, 1
386 mfc0 t0, CP0_CONFIG, 2
389 /* Check Config3.CMGCR to determine CM presence */
390 mfc0 t0, CP0_CONFIG, 3
391 and t0, t0, MIPS_CONF3_CMGCR
394 /* Change Config.K0 to a coherent CCA */
395 PTR_LA t0, change_k0_cca
396 li a0, CONF_CM_CACHABLE_COW
400 * Join the coherent domain such that the caches of this core are kept
401 * coherent with those of other cores.
403 PTR_LI t0, CKSEG1ADDR(CONFIG_MIPS_CM_BASE)
406 li t3, GCR_Cx_COHERENCE_EN
408 li t3, GCR_Cx_COHERENCE_DOM_EN
409 1: sw t3, GCR_Cx_COHERENCE(t0)
416 /* Ensure all cache operations complete before returning */
419 END(mips_cache_reset)
423 #if __mips_isa_rev >= 2
427 andi a0, a0, CONF_CM_CMASK