1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SiFive composable cache controller Driver
4  *
5  * Copyright (C) 2018-2022 SiFive, Inc.
6  *
7  */
8 
9 #define pr_fmt(fmt) "CCACHE: " fmt
10 
11 #include <linux/debugfs.h>
12 #include <linux/interrupt.h>
13 #include <linux/of_irq.h>
14 #include <linux/of_address.h>
15 #include <linux/device.h>
16 #include <linux/bitfield.h>
17 #include <asm/cacheinfo.h>
18 #include <soc/sifive/sifive_ccache.h>
19 
20 #define SIFIVE_CCACHE_DIRECCFIX_LOW 0x100
21 #define SIFIVE_CCACHE_DIRECCFIX_HIGH 0x104
22 #define SIFIVE_CCACHE_DIRECCFIX_COUNT 0x108
23 
24 #define SIFIVE_CCACHE_DIRECCFAIL_LOW 0x120
25 #define SIFIVE_CCACHE_DIRECCFAIL_HIGH 0x124
26 #define SIFIVE_CCACHE_DIRECCFAIL_COUNT 0x128
27 
28 #define SIFIVE_CCACHE_DATECCFIX_LOW 0x140
29 #define SIFIVE_CCACHE_DATECCFIX_HIGH 0x144
30 #define SIFIVE_CCACHE_DATECCFIX_COUNT 0x148
31 
32 #define SIFIVE_CCACHE_DATECCFAIL_LOW 0x160
33 #define SIFIVE_CCACHE_DATECCFAIL_HIGH 0x164
34 #define SIFIVE_CCACHE_DATECCFAIL_COUNT 0x168
35 
36 #define SIFIVE_CCACHE_CONFIG 0x00
37 #define SIFIVE_CCACHE_CONFIG_BANK_MASK GENMASK_ULL(7, 0)
38 #define SIFIVE_CCACHE_CONFIG_WAYS_MASK GENMASK_ULL(15, 8)
39 #define SIFIVE_CCACHE_CONFIG_SETS_MASK GENMASK_ULL(23, 16)
40 #define SIFIVE_CCACHE_CONFIG_BLKS_MASK GENMASK_ULL(31, 24)
41 
42 #define SIFIVE_CCACHE_WAYENABLE 0x08
43 #define SIFIVE_CCACHE_ECCINJECTERR 0x40
44 
45 #define SIFIVE_CCACHE_MAX_ECCINTR 4
46 
47 static void __iomem *ccache_base;
48 static int g_irq[SIFIVE_CCACHE_MAX_ECCINTR];
49 static struct riscv_cacheinfo_ops ccache_cache_ops;
50 static int level;
51 
52 enum {
53 	DIR_CORR = 0,
54 	DATA_CORR,
55 	DATA_UNCORR,
56 	DIR_UNCORR,
57 };
58 
59 #ifdef CONFIG_DEBUG_FS
60 static struct dentry *sifive_test;
61 
62 static ssize_t ccache_write(struct file *file, const char __user *data,
63 			    size_t count, loff_t *ppos)
64 {
65 	unsigned int val;
66 
67 	if (kstrtouint_from_user(data, count, 0, &val))
68 		return -EINVAL;
69 	if ((val < 0xFF) || (val >= 0x10000 && val < 0x100FF))
70 		writel(val, ccache_base + SIFIVE_CCACHE_ECCINJECTERR);
71 	else
72 		return -EINVAL;
73 	return count;
74 }
75 
76 static const struct file_operations ccache_fops = {
77 	.owner = THIS_MODULE,
78 	.open = simple_open,
79 	.write = ccache_write
80 };
81 
82 static void setup_sifive_debug(void)
83 {
84 	sifive_test = debugfs_create_dir("sifive_ccache_cache", NULL);
85 
86 	debugfs_create_file("sifive_debug_inject_error", 0200,
87 			    sifive_test, NULL, &ccache_fops);
88 }
89 #endif
90 
91 static void ccache_config_read(void)
92 {
93 	u32 cfg;
94 
95 	cfg = readl(ccache_base + SIFIVE_CCACHE_CONFIG);
96 	pr_info("%llu banks, %llu ways, sets/bank=%llu, bytes/block=%llu\n",
97 		FIELD_GET(SIFIVE_CCACHE_CONFIG_BANK_MASK, cfg),
98 		FIELD_GET(SIFIVE_CCACHE_CONFIG_WAYS_MASK, cfg),
99 		BIT_ULL(FIELD_GET(SIFIVE_CCACHE_CONFIG_SETS_MASK, cfg)),
100 		BIT_ULL(FIELD_GET(SIFIVE_CCACHE_CONFIG_BLKS_MASK, cfg)));
101 
102 	cfg = readl(ccache_base + SIFIVE_CCACHE_WAYENABLE);
103 	pr_info("Index of the largest way enabled: %u\n", cfg);
104 }
105 
106 static const struct of_device_id sifive_ccache_ids[] = {
107 	{ .compatible = "sifive,fu540-c000-ccache" },
108 	{ .compatible = "sifive,fu740-c000-ccache" },
109 	{ .compatible = "sifive,ccache0" },
110 	{ /* end of table */ }
111 };
112 
113 static ATOMIC_NOTIFIER_HEAD(ccache_err_chain);
114 
115 int register_sifive_ccache_error_notifier(struct notifier_block *nb)
116 {
117 	return atomic_notifier_chain_register(&ccache_err_chain, nb);
118 }
119 EXPORT_SYMBOL_GPL(register_sifive_ccache_error_notifier);
120 
121 int unregister_sifive_ccache_error_notifier(struct notifier_block *nb)
122 {
123 	return atomic_notifier_chain_unregister(&ccache_err_chain, nb);
124 }
125 EXPORT_SYMBOL_GPL(unregister_sifive_ccache_error_notifier);
126 
127 static int ccache_largest_wayenabled(void)
128 {
129 	return readl(ccache_base + SIFIVE_CCACHE_WAYENABLE) & 0xFF;
130 }
131 
132 static ssize_t number_of_ways_enabled_show(struct device *dev,
133 					   struct device_attribute *attr,
134 					   char *buf)
135 {
136 	return sprintf(buf, "%u\n", ccache_largest_wayenabled());
137 }
138 
139 static DEVICE_ATTR_RO(number_of_ways_enabled);
140 
141 static struct attribute *priv_attrs[] = {
142 	&dev_attr_number_of_ways_enabled.attr,
143 	NULL,
144 };
145 
146 static const struct attribute_group priv_attr_group = {
147 	.attrs = priv_attrs,
148 };
149 
150 static const struct attribute_group *ccache_get_priv_group(struct cacheinfo
151 							   *this_leaf)
152 {
153 	/* We want to use private group for composable cache only */
154 	if (this_leaf->level == level)
155 		return &priv_attr_group;
156 	else
157 		return NULL;
158 }
159 
160 static irqreturn_t ccache_int_handler(int irq, void *device)
161 {
162 	unsigned int add_h, add_l;
163 
164 	if (irq == g_irq[DIR_CORR]) {
165 		add_h = readl(ccache_base + SIFIVE_CCACHE_DIRECCFIX_HIGH);
166 		add_l = readl(ccache_base + SIFIVE_CCACHE_DIRECCFIX_LOW);
167 		pr_err("DirError @ 0x%08X.%08X\n", add_h, add_l);
168 		/* Reading this register clears the DirError interrupt sig */
169 		readl(ccache_base + SIFIVE_CCACHE_DIRECCFIX_COUNT);
170 		atomic_notifier_call_chain(&ccache_err_chain,
171 					   SIFIVE_CCACHE_ERR_TYPE_CE,
172 					   "DirECCFix");
173 	}
174 	if (irq == g_irq[DIR_UNCORR]) {
175 		add_h = readl(ccache_base + SIFIVE_CCACHE_DIRECCFAIL_HIGH);
176 		add_l = readl(ccache_base + SIFIVE_CCACHE_DIRECCFAIL_LOW);
177 		/* Reading this register clears the DirFail interrupt sig */
178 		readl(ccache_base + SIFIVE_CCACHE_DIRECCFAIL_COUNT);
179 		atomic_notifier_call_chain(&ccache_err_chain,
180 					   SIFIVE_CCACHE_ERR_TYPE_UE,
181 					   "DirECCFail");
182 		panic("CCACHE: DirFail @ 0x%08X.%08X\n", add_h, add_l);
183 	}
184 	if (irq == g_irq[DATA_CORR]) {
185 		add_h = readl(ccache_base + SIFIVE_CCACHE_DATECCFIX_HIGH);
186 		add_l = readl(ccache_base + SIFIVE_CCACHE_DATECCFIX_LOW);
187 		pr_err("DataError @ 0x%08X.%08X\n", add_h, add_l);
188 		/* Reading this register clears the DataError interrupt sig */
189 		readl(ccache_base + SIFIVE_CCACHE_DATECCFIX_COUNT);
190 		atomic_notifier_call_chain(&ccache_err_chain,
191 					   SIFIVE_CCACHE_ERR_TYPE_CE,
192 					   "DatECCFix");
193 	}
194 	if (irq == g_irq[DATA_UNCORR]) {
195 		add_h = readl(ccache_base + SIFIVE_CCACHE_DATECCFAIL_HIGH);
196 		add_l = readl(ccache_base + SIFIVE_CCACHE_DATECCFAIL_LOW);
197 		pr_err("DataFail @ 0x%08X.%08X\n", add_h, add_l);
198 		/* Reading this register clears the DataFail interrupt sig */
199 		readl(ccache_base + SIFIVE_CCACHE_DATECCFAIL_COUNT);
200 		atomic_notifier_call_chain(&ccache_err_chain,
201 					   SIFIVE_CCACHE_ERR_TYPE_UE,
202 					   "DatECCFail");
203 	}
204 
205 	return IRQ_HANDLED;
206 }
207 
208 static int __init sifive_ccache_init(void)
209 {
210 	struct device_node *np;
211 	struct resource res;
212 	int i, rc, intr_num;
213 
214 	np = of_find_matching_node(NULL, sifive_ccache_ids);
215 	if (!np)
216 		return -ENODEV;
217 
218 	if (of_address_to_resource(np, 0, &res)) {
219 		rc = -ENODEV;
220 		goto err_node_put;
221 	}
222 
223 	ccache_base = ioremap(res.start, resource_size(&res));
224 	if (!ccache_base) {
225 		rc = -ENOMEM;
226 		goto err_node_put;
227 	}
228 
229 	if (of_property_read_u32(np, "cache-level", &level)) {
230 		rc = -ENOENT;
231 		goto err_unmap;
232 	}
233 
234 	intr_num = of_property_count_u32_elems(np, "interrupts");
235 	if (!intr_num) {
236 		pr_err("No interrupts property\n");
237 		rc = -ENODEV;
238 		goto err_unmap;
239 	}
240 
241 	for (i = 0; i < intr_num; i++) {
242 		g_irq[i] = irq_of_parse_and_map(np, i);
243 		rc = request_irq(g_irq[i], ccache_int_handler, 0, "ccache_ecc",
244 				 NULL);
245 		if (rc) {
246 			pr_err("Could not request IRQ %d\n", g_irq[i]);
247 			goto err_free_irq;
248 		}
249 	}
250 	of_node_put(np);
251 
252 	ccache_config_read();
253 
254 	ccache_cache_ops.get_priv_group = ccache_get_priv_group;
255 	riscv_set_cacheinfo_ops(&ccache_cache_ops);
256 
257 #ifdef CONFIG_DEBUG_FS
258 	setup_sifive_debug();
259 #endif
260 	return 0;
261 
262 err_free_irq:
263 	while (--i >= 0)
264 		free_irq(g_irq[i], NULL);
265 err_unmap:
266 	iounmap(ccache_base);
267 err_node_put:
268 	of_node_put(np);
269 	return rc;
270 }
271 
272 device_initcall(sifive_ccache_init);
273