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 #include <linux/debugfs.h>
9 #include <linux/interrupt.h>
10 #include <linux/of_irq.h>
11 #include <linux/of_address.h>
12 #include <linux/device.h>
13 #include <asm/cacheinfo.h>
14 #include <soc/sifive/sifive_ccache.h>
15 
16 #define SIFIVE_CCACHE_DIRECCFIX_LOW 0x100
17 #define SIFIVE_CCACHE_DIRECCFIX_HIGH 0x104
18 #define SIFIVE_CCACHE_DIRECCFIX_COUNT 0x108
19 
20 #define SIFIVE_CCACHE_DIRECCFAIL_LOW 0x120
21 #define SIFIVE_CCACHE_DIRECCFAIL_HIGH 0x124
22 #define SIFIVE_CCACHE_DIRECCFAIL_COUNT 0x128
23 
24 #define SIFIVE_CCACHE_DATECCFIX_LOW 0x140
25 #define SIFIVE_CCACHE_DATECCFIX_HIGH 0x144
26 #define SIFIVE_CCACHE_DATECCFIX_COUNT 0x148
27 
28 #define SIFIVE_CCACHE_DATECCFAIL_LOW 0x160
29 #define SIFIVE_CCACHE_DATECCFAIL_HIGH 0x164
30 #define SIFIVE_CCACHE_DATECCFAIL_COUNT 0x168
31 
32 #define SIFIVE_CCACHE_CONFIG 0x00
33 #define SIFIVE_CCACHE_WAYENABLE 0x08
34 #define SIFIVE_CCACHE_ECCINJECTERR 0x40
35 
36 #define SIFIVE_CCACHE_MAX_ECCINTR 4
37 
38 static void __iomem *ccache_base;
39 static int g_irq[SIFIVE_CCACHE_MAX_ECCINTR];
40 static struct riscv_cacheinfo_ops ccache_cache_ops;
41 
42 enum {
43 	DIR_CORR = 0,
44 	DATA_CORR,
45 	DATA_UNCORR,
46 	DIR_UNCORR,
47 };
48 
49 #ifdef CONFIG_DEBUG_FS
50 static struct dentry *sifive_test;
51 
52 static ssize_t ccache_write(struct file *file, const char __user *data,
53 			    size_t count, loff_t *ppos)
54 {
55 	unsigned int val;
56 
57 	if (kstrtouint_from_user(data, count, 0, &val))
58 		return -EINVAL;
59 	if ((val < 0xFF) || (val >= 0x10000 && val < 0x100FF))
60 		writel(val, ccache_base + SIFIVE_CCACHE_ECCINJECTERR);
61 	else
62 		return -EINVAL;
63 	return count;
64 }
65 
66 static const struct file_operations ccache_fops = {
67 	.owner = THIS_MODULE,
68 	.open = simple_open,
69 	.write = ccache_write
70 };
71 
72 static void setup_sifive_debug(void)
73 {
74 	sifive_test = debugfs_create_dir("sifive_ccache_cache", NULL);
75 
76 	debugfs_create_file("sifive_debug_inject_error", 0200,
77 			    sifive_test, NULL, &ccache_fops);
78 }
79 #endif
80 
81 static void ccache_config_read(void)
82 {
83 	u32 regval, val;
84 
85 	regval = readl(ccache_base + SIFIVE_CCACHE_CONFIG);
86 	val = regval & 0xFF;
87 	pr_info("CCACHE: No. of Banks in the cache: %d\n", val);
88 	val = (regval & 0xFF00) >> 8;
89 	pr_info("CCACHE: No. of ways per bank: %d\n", val);
90 	val = (regval & 0xFF0000) >> 16;
91 	pr_info("CCACHE: Sets per bank: %llu\n", (uint64_t)1 << val);
92 	val = (regval & 0xFF000000) >> 24;
93 	pr_info("CCACHE: Bytes per cache block: %llu\n", (uint64_t)1 << val);
94 
95 	regval = readl(ccache_base + SIFIVE_CCACHE_WAYENABLE);
96 	pr_info("CCACHE: Index of the largest way enabled: %d\n", regval);
97 }
98 
99 static const struct of_device_id sifive_ccache_ids[] = {
100 	{ .compatible = "sifive,fu540-c000-ccache" },
101 	{ .compatible = "sifive,fu740-c000-ccache" },
102 	{ .compatible = "sifive,ccache0" },
103 	{ /* end of table */ }
104 };
105 
106 static ATOMIC_NOTIFIER_HEAD(ccache_err_chain);
107 
108 int register_sifive_ccache_error_notifier(struct notifier_block *nb)
109 {
110 	return atomic_notifier_chain_register(&ccache_err_chain, nb);
111 }
112 EXPORT_SYMBOL_GPL(register_sifive_ccache_error_notifier);
113 
114 int unregister_sifive_ccache_error_notifier(struct notifier_block *nb)
115 {
116 	return atomic_notifier_chain_unregister(&ccache_err_chain, nb);
117 }
118 EXPORT_SYMBOL_GPL(unregister_sifive_ccache_error_notifier);
119 
120 static int ccache_largest_wayenabled(void)
121 {
122 	return readl(ccache_base + SIFIVE_CCACHE_WAYENABLE) & 0xFF;
123 }
124 
125 static ssize_t number_of_ways_enabled_show(struct device *dev,
126 					   struct device_attribute *attr,
127 					   char *buf)
128 {
129 	return sprintf(buf, "%u\n", ccache_largest_wayenabled());
130 }
131 
132 static DEVICE_ATTR_RO(number_of_ways_enabled);
133 
134 static struct attribute *priv_attrs[] = {
135 	&dev_attr_number_of_ways_enabled.attr,
136 	NULL,
137 };
138 
139 static const struct attribute_group priv_attr_group = {
140 	.attrs = priv_attrs,
141 };
142 
143 static const struct attribute_group *ccache_get_priv_group(struct cacheinfo
144 							   *this_leaf)
145 {
146 	/* We want to use private group for composable cache only */
147 	if (this_leaf->level == 2)
148 		return &priv_attr_group;
149 	else
150 		return NULL;
151 }
152 
153 static irqreturn_t ccache_int_handler(int irq, void *device)
154 {
155 	unsigned int add_h, add_l;
156 
157 	if (irq == g_irq[DIR_CORR]) {
158 		add_h = readl(ccache_base + SIFIVE_CCACHE_DIRECCFIX_HIGH);
159 		add_l = readl(ccache_base + SIFIVE_CCACHE_DIRECCFIX_LOW);
160 		pr_err("CCACHE: DirError @ 0x%08X.%08X\n", add_h, add_l);
161 		/* Reading this register clears the DirError interrupt sig */
162 		readl(ccache_base + SIFIVE_CCACHE_DIRECCFIX_COUNT);
163 		atomic_notifier_call_chain(&ccache_err_chain,
164 					   SIFIVE_CCACHE_ERR_TYPE_CE,
165 					   "DirECCFix");
166 	}
167 	if (irq == g_irq[DIR_UNCORR]) {
168 		add_h = readl(ccache_base + SIFIVE_CCACHE_DIRECCFAIL_HIGH);
169 		add_l = readl(ccache_base + SIFIVE_CCACHE_DIRECCFAIL_LOW);
170 		/* Reading this register clears the DirFail interrupt sig */
171 		readl(ccache_base + SIFIVE_CCACHE_DIRECCFAIL_COUNT);
172 		atomic_notifier_call_chain(&ccache_err_chain,
173 					   SIFIVE_CCACHE_ERR_TYPE_UE,
174 					   "DirECCFail");
175 		panic("CCACHE: DirFail @ 0x%08X.%08X\n", add_h, add_l);
176 	}
177 	if (irq == g_irq[DATA_CORR]) {
178 		add_h = readl(ccache_base + SIFIVE_CCACHE_DATECCFIX_HIGH);
179 		add_l = readl(ccache_base + SIFIVE_CCACHE_DATECCFIX_LOW);
180 		pr_err("CCACHE: DataError @ 0x%08X.%08X\n", add_h, add_l);
181 		/* Reading this register clears the DataError interrupt sig */
182 		readl(ccache_base + SIFIVE_CCACHE_DATECCFIX_COUNT);
183 		atomic_notifier_call_chain(&ccache_err_chain,
184 					   SIFIVE_CCACHE_ERR_TYPE_CE,
185 					   "DatECCFix");
186 	}
187 	if (irq == g_irq[DATA_UNCORR]) {
188 		add_h = readl(ccache_base + SIFIVE_CCACHE_DATECCFAIL_HIGH);
189 		add_l = readl(ccache_base + SIFIVE_CCACHE_DATECCFAIL_LOW);
190 		pr_err("CCACHE: DataFail @ 0x%08X.%08X\n", add_h, add_l);
191 		/* Reading this register clears the DataFail interrupt sig */
192 		readl(ccache_base + SIFIVE_CCACHE_DATECCFAIL_COUNT);
193 		atomic_notifier_call_chain(&ccache_err_chain,
194 					   SIFIVE_CCACHE_ERR_TYPE_UE,
195 					   "DatECCFail");
196 	}
197 
198 	return IRQ_HANDLED;
199 }
200 
201 static int __init sifive_ccache_init(void)
202 {
203 	struct device_node *np;
204 	struct resource res;
205 	int i, rc, intr_num;
206 
207 	np = of_find_matching_node(NULL, sifive_ccache_ids);
208 	if (!np)
209 		return -ENODEV;
210 
211 	if (of_address_to_resource(np, 0, &res))
212 		return -ENODEV;
213 
214 	ccache_base = ioremap(res.start, resource_size(&res));
215 	if (!ccache_base)
216 		return -ENOMEM;
217 
218 	intr_num = of_property_count_u32_elems(np, "interrupts");
219 	if (!intr_num) {
220 		pr_err("CCACHE: no interrupts property\n");
221 		return -ENODEV;
222 	}
223 
224 	for (i = 0; i < intr_num; i++) {
225 		g_irq[i] = irq_of_parse_and_map(np, i);
226 		rc = request_irq(g_irq[i], ccache_int_handler, 0, "ccache_ecc",
227 				 NULL);
228 		if (rc) {
229 			pr_err("CCACHE: Could not request IRQ %d\n", g_irq[i]);
230 			return rc;
231 		}
232 	}
233 
234 	ccache_config_read();
235 
236 	ccache_cache_ops.get_priv_group = ccache_get_priv_group;
237 	riscv_set_cacheinfo_ops(&ccache_cache_ops);
238 
239 #ifdef CONFIG_DEBUG_FS
240 	setup_sifive_debug();
241 #endif
242 	return 0;
243 }
244 
245 device_initcall(sifive_ccache_init);
246