xref: /openbmc/u-boot/arch/mips/lib/cache_init.S (revision ad3098f7)
1/*
2 *  Cache-handling routined for MIPS CPUs
3 *
4 *  Copyright (c) 2003	Wolfgang Denk <wd@denx.de>
5 *
6 * SPDX-License-Identifier:	GPL-2.0+
7 */
8
9#include <asm-offsets.h>
10#include <config.h>
11#include <asm/asm.h>
12#include <asm/regdef.h>
13#include <asm/mipsregs.h>
14#include <asm/addrspace.h>
15#include <asm/cacheops.h>
16
17#ifndef CONFIG_SYS_MIPS_CACHE_MODE
18#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
19#endif
20
21#define INDEX_BASE	CKSEG0
22
23	.macro	f_fill64 dst, offset, val
24	LONG_S	\val, (\offset +  0 * LONGSIZE)(\dst)
25	LONG_S	\val, (\offset +  1 * LONGSIZE)(\dst)
26	LONG_S	\val, (\offset +  2 * LONGSIZE)(\dst)
27	LONG_S	\val, (\offset +  3 * LONGSIZE)(\dst)
28	LONG_S	\val, (\offset +  4 * LONGSIZE)(\dst)
29	LONG_S	\val, (\offset +  5 * LONGSIZE)(\dst)
30	LONG_S	\val, (\offset +  6 * LONGSIZE)(\dst)
31	LONG_S	\val, (\offset +  7 * LONGSIZE)(\dst)
32#if LONGSIZE == 4
33	LONG_S	\val, (\offset +  8 * LONGSIZE)(\dst)
34	LONG_S	\val, (\offset +  9 * LONGSIZE)(\dst)
35	LONG_S	\val, (\offset + 10 * LONGSIZE)(\dst)
36	LONG_S	\val, (\offset + 11 * LONGSIZE)(\dst)
37	LONG_S	\val, (\offset + 12 * LONGSIZE)(\dst)
38	LONG_S	\val, (\offset + 13 * LONGSIZE)(\dst)
39	LONG_S	\val, (\offset + 14 * LONGSIZE)(\dst)
40	LONG_S	\val, (\offset + 15 * LONGSIZE)(\dst)
41#endif
42	.endm
43
44	.macro cache_loop	curr, end, line_sz, op
4510:	cache		\op, 0(\curr)
46	PTR_ADDU	\curr, \curr, \line_sz
47	bne		\curr, \end, 10b
48	.endm
49
50	.macro	l1_info		sz, line_sz, off
51	.set	push
52	.set	noat
53
54	mfc0	$1, CP0_CONFIG, 1
55
56	/* detect line size */
57	srl	\line_sz, $1, \off + MIPS_CONF1_DL_SHF - MIPS_CONF1_DA_SHF
58	andi	\line_sz, \line_sz, (MIPS_CONF1_DL >> MIPS_CONF1_DL_SHF)
59	move	\sz, zero
60	beqz	\line_sz, 10f
61	li	\sz, 2
62	sllv	\line_sz, \sz, \line_sz
63
64	/* detect associativity */
65	srl	\sz, $1, \off + MIPS_CONF1_DA_SHF - MIPS_CONF1_DA_SHF
66	andi	\sz, \sz, (MIPS_CONF1_DA >> MIPS_CONF1_DA_SHF)
67	addi	\sz, \sz, 1
68
69	/* sz *= line_sz */
70	mul	\sz, \sz, \line_sz
71
72	/* detect log32(sets) */
73	srl	$1, $1, \off + MIPS_CONF1_DS_SHF - MIPS_CONF1_DA_SHF
74	andi	$1, $1, (MIPS_CONF1_DS >> MIPS_CONF1_DS_SHF)
75	addiu	$1, $1, 1
76	andi	$1, $1, 0x7
77
78	/* sz <<= log32(sets) */
79	sllv	\sz, \sz, $1
80
81	/* sz *= 32 */
82	li	$1, 32
83	mul	\sz, \sz, $1
8410:
85	.set	pop
86	.endm
87/*
88 * mips_cache_reset - low level initialisation of the primary caches
89 *
90 * This routine initialises the primary caches to ensure that they have good
91 * parity.  It must be called by the ROM before any cached locations are used
92 * to prevent the possibility of data with bad parity being written to memory.
93 *
94 * To initialise the instruction cache it is essential that a source of data
95 * with good parity is available. This routine will initialise an area of
96 * memory starting at location zero to be used as a source of parity.
97 *
98 * RETURNS: N/A
99 *
100 */
101LEAF(mips_cache_reset)
102#ifdef CONFIG_SYS_ICACHE_SIZE
103	li	t2, CONFIG_SYS_ICACHE_SIZE
104	li	t8, CONFIG_SYS_CACHELINE_SIZE
105#else
106	l1_info	t2, t8, MIPS_CONF1_IA_SHF
107#endif
108
109#ifdef CONFIG_SYS_DCACHE_SIZE
110	li	t3, CONFIG_SYS_DCACHE_SIZE
111	li	t9, CONFIG_SYS_CACHELINE_SIZE
112#else
113	l1_info	t3, t9, MIPS_CONF1_DA_SHF
114#endif
115
116#ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD
117
118	/* Determine the largest L1 cache size */
119#if defined(CONFIG_SYS_ICACHE_SIZE) && defined(CONFIG_SYS_DCACHE_SIZE)
120#if CONFIG_SYS_ICACHE_SIZE > CONFIG_SYS_DCACHE_SIZE
121	li	v0, CONFIG_SYS_ICACHE_SIZE
122#else
123	li	v0, CONFIG_SYS_DCACHE_SIZE
124#endif
125#else
126	move	v0, t2
127	sltu	t1, t2, t3
128	movn	v0, t3, t1
129#endif
130	/*
131	 * Now clear that much memory starting from zero.
132	 */
133	PTR_LI		a0, CKSEG1
134	PTR_ADDU	a1, a0, v0
1352:	PTR_ADDIU	a0, 64
136	f_fill64	a0, -64, zero
137	bne		a0, a1, 2b
138
139#endif /* CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD */
140
141	/*
142	 * The TagLo registers used depend upon the CPU implementation, but the
143	 * architecture requires that it is safe for software to write to both
144	 * TagLo selects 0 & 2 covering supported cases.
145	 */
146	mtc0		zero, CP0_TAGLO
147	mtc0		zero, CP0_TAGLO, 2
148
149	/*
150	 * The caches are probably in an indeterminate state, so we force good
151	 * parity into them by doing an invalidate for each line. If
152	 * CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD is set then we'll proceed to
153	 * perform a load/fill & a further invalidate for each line, assuming
154	 * that the bottom of RAM (having just been cleared) will generate good
155	 * parity for the cache.
156	 */
157
158	/*
159	 * Initialize the I-cache first,
160	 */
161	blez		t2, 1f
162	PTR_LI		t0, INDEX_BASE
163	PTR_ADDU	t1, t0, t2
164	/* clear tag to invalidate */
165	cache_loop	t0, t1, t8, INDEX_STORE_TAG_I
166#ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD
167	/* fill once, so data field parity is correct */
168	PTR_LI		t0, INDEX_BASE
169	cache_loop	t0, t1, t8, FILL
170	/* invalidate again - prudent but not strictly neccessary */
171	PTR_LI		t0, INDEX_BASE
172	cache_loop	t0, t1, t8, INDEX_STORE_TAG_I
173#endif
174
175	/*
176	 * then initialize D-cache.
177	 */
1781:	blez		t3, 3f
179	PTR_LI		t0, INDEX_BASE
180	PTR_ADDU	t1, t0, t3
181	/* clear all tags */
182	cache_loop	t0, t1, t9, INDEX_STORE_TAG_D
183#ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD
184	/* load from each line (in cached space) */
185	PTR_LI		t0, INDEX_BASE
1862:	LONG_L		zero, 0(t0)
187	PTR_ADDU	t0, t9
188	bne		t0, t1, 2b
189	/* clear all tags */
190	PTR_LI		t0, INDEX_BASE
191	cache_loop	t0, t1, t9, INDEX_STORE_TAG_D
192#endif
193
1943:	jr	ra
195	END(mips_cache_reset)
196
197/*
198 * dcache_status - get cache status
199 *
200 * RETURNS: 0 - cache disabled; 1 - cache enabled
201 *
202 */
203LEAF(dcache_status)
204	mfc0	t0, CP0_CONFIG
205	li	t1, CONF_CM_UNCACHED
206	andi	t0, t0, CONF_CM_CMASK
207	move	v0, zero
208	beq	t0, t1, 2f
209	li	v0, 1
2102:	jr	ra
211	END(dcache_status)
212
213/*
214 * dcache_disable - disable cache
215 *
216 * RETURNS: N/A
217 *
218 */
219LEAF(dcache_disable)
220	mfc0	t0, CP0_CONFIG
221	li	t1, -8
222	and	t0, t0, t1
223	ori	t0, t0, CONF_CM_UNCACHED
224	mtc0	t0, CP0_CONFIG
225	jr	ra
226	END(dcache_disable)
227
228/*
229 * dcache_enable - enable cache
230 *
231 * RETURNS: N/A
232 *
233 */
234LEAF(dcache_enable)
235	mfc0	t0, CP0_CONFIG
236	ori	t0, CONF_CM_CMASK
237	xori	t0, CONF_CM_CMASK
238	ori	t0, CONFIG_SYS_MIPS_CACHE_MODE
239	mtc0	t0, CP0_CONFIG
240	jr	ra
241	END(dcache_enable)
242