1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2006 Chris Dearman (chris@mips.com),
4 */
5 #include <linux/init.h>
6 #include <linux/kernel.h>
7 #include <linux/sched.h>
8 #include <linux/mm.h>
9
10 #include <asm/cpu-type.h>
11 #include <asm/mipsregs.h>
12 #include <asm/bcache.h>
13 #include <asm/cacheops.h>
14 #include <asm/page.h>
15 #include <asm/mmu_context.h>
16 #include <asm/r4kcache.h>
17 #include <asm/mips-cps.h>
18 #include <asm/bootinfo.h>
19
20 /*
21 * MIPS32/MIPS64 L2 cache handling
22 */
23
24 /*
25 * Writeback and invalidate the secondary cache before DMA.
26 */
27 static void mips_sc_wback_inv(unsigned long addr, unsigned long size)
28 {
29 blast_scache_range(addr, addr + size);
30 }
31
32 /*
33 * Invalidate the secondary cache before DMA.
34 */
35 static void mips_sc_inv(unsigned long addr, unsigned long size)
36 {
37 unsigned long lsize = cpu_scache_line_size();
38 unsigned long almask = ~(lsize - 1);
39
40 cache_op(Hit_Writeback_Inv_SD, addr & almask);
41 cache_op(Hit_Writeback_Inv_SD, (addr + size - 1) & almask);
42 blast_inv_scache_range(addr, addr + size);
43 }
44
45 static void mips_sc_enable(void)
46 {
47 /* L2 cache is permanently enabled */
48 }
49
50 static void mips_sc_disable(void)
51 {
52 /* L2 cache is permanently enabled */
53 }
54
55 static void mips_sc_prefetch_enable(void)
56 {
57 unsigned long pftctl;
58
59 if (mips_cm_revision() < CM_REV_CM2_5)
60 return;
61
62 /*
63 * If there is one or more L2 prefetch unit present then enable
64 * prefetching for both code & data, for all ports.
65 */
66 pftctl = read_gcr_l2_pft_control();
67 if (pftctl & CM_GCR_L2_PFT_CONTROL_NPFT) {
68 pftctl &= ~CM_GCR_L2_PFT_CONTROL_PAGEMASK;
69 pftctl |= PAGE_MASK & CM_GCR_L2_PFT_CONTROL_PAGEMASK;
70 pftctl |= CM_GCR_L2_PFT_CONTROL_PFTEN;
71 write_gcr_l2_pft_control(pftctl);
72
73 set_gcr_l2_pft_control_b(CM_GCR_L2_PFT_CONTROL_B_PORTID |
74 CM_GCR_L2_PFT_CONTROL_B_CEN);
75 }
76 }
77
78 static void mips_sc_prefetch_disable(void)
79 {
80 if (mips_cm_revision() < CM_REV_CM2_5)
81 return;
82
83 clear_gcr_l2_pft_control(CM_GCR_L2_PFT_CONTROL_PFTEN);
84 clear_gcr_l2_pft_control_b(CM_GCR_L2_PFT_CONTROL_B_PORTID |
85 CM_GCR_L2_PFT_CONTROL_B_CEN);
86 }
87
88 static bool mips_sc_prefetch_is_enabled(void)
89 {
90 unsigned long pftctl;
91
92 if (mips_cm_revision() < CM_REV_CM2_5)
93 return false;
94
95 pftctl = read_gcr_l2_pft_control();
96 if (!(pftctl & CM_GCR_L2_PFT_CONTROL_NPFT))
97 return false;
98 return !!(pftctl & CM_GCR_L2_PFT_CONTROL_PFTEN);
99 }
100
101 static struct bcache_ops mips_sc_ops = {
102 .bc_enable = mips_sc_enable,
103 .bc_disable = mips_sc_disable,
104 .bc_wback_inv = mips_sc_wback_inv,
105 .bc_inv = mips_sc_inv,
106 .bc_prefetch_enable = mips_sc_prefetch_enable,
107 .bc_prefetch_disable = mips_sc_prefetch_disable,
108 .bc_prefetch_is_enabled = mips_sc_prefetch_is_enabled,
109 };
110
111 /*
112 * Check if the L2 cache controller is activated on a particular platform.
113 * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS
114 * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the
115 * cache being disabled. However there is no guarantee for this to be
116 * true on all platforms. In an act of stupidity the spec defined bits
117 * 12..15 as implementation defined so below function will eventually have
118 * to be replaced by a platform specific probe.
119 */
120 static inline int mips_sc_is_activated(struct cpuinfo_mips *c)
121 {
122 unsigned int config2 = read_c0_config2();
123 unsigned int tmp;
124
125 /* Check the bypass bit (L2B) */
126 switch (current_cpu_type()) {
127 case CPU_34K:
128 case CPU_74K:
129 case CPU_1004K:
130 case CPU_1074K:
131 case CPU_INTERAPTIV:
132 case CPU_PROAPTIV:
133 case CPU_P5600:
134 case CPU_BMIPS5000:
135 case CPU_QEMU_GENERIC:
136 case CPU_P6600:
137 if (config2 & (1 << 12))
138 return 0;
139 }
140
141 tmp = (config2 >> 4) & 0x0f;
142 if (0 < tmp && tmp <= 7)
143 c->scache.linesz = 2 << tmp;
144 else
145 return 0;
146 return 1;
147 }
148
149 static int mips_sc_probe_cm3(void)
150 {
151 struct cpuinfo_mips *c = ¤t_cpu_data;
152 unsigned long cfg = read_gcr_l2_config();
153 unsigned long sets, line_sz, assoc;
154
155 if (cfg & CM_GCR_L2_CONFIG_BYPASS)
156 return 0;
157
158 sets = cfg & CM_GCR_L2_CONFIG_SET_SIZE;
159 sets >>= __ffs(CM_GCR_L2_CONFIG_SET_SIZE);
160 if (sets)
161 c->scache.sets = 64 << sets;
162
163 line_sz = cfg & CM_GCR_L2_CONFIG_LINE_SIZE;
164 line_sz >>= __ffs(CM_GCR_L2_CONFIG_LINE_SIZE);
165 if (line_sz)
166 c->scache.linesz = 2 << line_sz;
167
168 assoc = cfg & CM_GCR_L2_CONFIG_ASSOC;
169 assoc >>= __ffs(CM_GCR_L2_CONFIG_ASSOC);
170 c->scache.ways = assoc + 1;
171 c->scache.waysize = c->scache.sets * c->scache.linesz;
172 c->scache.waybit = __ffs(c->scache.waysize);
173
174 if (c->scache.linesz) {
175 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
176 c->options |= MIPS_CPU_INCLUSIVE_CACHES;
177 return 1;
178 }
179
180 return 0;
181 }
182
183 static inline int mips_sc_probe(void)
184 {
185 struct cpuinfo_mips *c = ¤t_cpu_data;
186 unsigned int config1, config2;
187 unsigned int tmp;
188
189 /* Mark as not present until probe completed */
190 c->scache.flags |= MIPS_CACHE_NOT_PRESENT;
191
192 if (mips_cm_revision() >= CM_REV_CM3)
193 return mips_sc_probe_cm3();
194
195 /* Ignore anything but MIPSxx processors */
196 if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
197 MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
198 MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
199 MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)))
200 return 0;
201
202 /* Does this MIPS32/MIPS64 CPU have a config2 register? */
203 config1 = read_c0_config1();
204 if (!(config1 & MIPS_CONF_M))
205 return 0;
206
207 config2 = read_c0_config2();
208
209 if (!mips_sc_is_activated(c))
210 return 0;
211
212 tmp = (config2 >> 8) & 0x0f;
213 if (tmp <= 7)
214 c->scache.sets = 64 << tmp;
215 else
216 return 0;
217
218 tmp = (config2 >> 0) & 0x0f;
219 if (tmp <= 7)
220 c->scache.ways = tmp + 1;
221 else
222 return 0;
223
224 if (current_cpu_type() == CPU_XBURST) {
225 switch (mips_machtype) {
226 /*
227 * According to config2 it would be 5-ways, but that is
228 * contradicted by all documentation.
229 */
230 case MACH_INGENIC_JZ4770:
231 case MACH_INGENIC_JZ4775:
232 c->scache.ways = 4;
233 break;
234
235 /*
236 * According to config2 it would be 5-ways and 512-sets,
237 * but that is contradicted by all documentation.
238 */
239 case MACH_INGENIC_X1000:
240 case MACH_INGENIC_X1000E:
241 c->scache.sets = 256;
242 c->scache.ways = 4;
243 break;
244 }
245 }
246
247 c->scache.waysize = c->scache.sets * c->scache.linesz;
248 c->scache.waybit = __ffs(c->scache.waysize);
249
250 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
251
252 return 1;
253 }
254
255 int mips_sc_init(void)
256 {
257 int found = mips_sc_probe();
258 if (found) {
259 mips_sc_enable();
260 mips_sc_prefetch_enable();
261 bcops = &mips_sc_ops;
262 }
263 return found;
264 }
265
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