xref: /linux/arch/riscv/kernel/cacheinfo.c (revision 7fa8a8ee9400fe8ec188426e40e481717bc5e924)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2017 SiFive
4  */
5 
6 #include <linux/cpu.h>
7 #include <linux/of.h>
8 #include <asm/cacheinfo.h>
9 
10 static struct riscv_cacheinfo_ops *rv_cache_ops;
11 
12 void riscv_set_cacheinfo_ops(struct riscv_cacheinfo_ops *ops)
13 {
14 	rv_cache_ops = ops;
15 }
16 EXPORT_SYMBOL_GPL(riscv_set_cacheinfo_ops);
17 
18 const struct attribute_group *
19 cache_get_priv_group(struct cacheinfo *this_leaf)
20 {
21 	if (rv_cache_ops && rv_cache_ops->get_priv_group)
22 		return rv_cache_ops->get_priv_group(this_leaf);
23 	return NULL;
24 }
25 
26 static struct cacheinfo *get_cacheinfo(u32 level, enum cache_type type)
27 {
28 	/*
29 	 * Using raw_smp_processor_id() elides a preemptability check, but this
30 	 * is really indicative of a larger problem: the cacheinfo UABI assumes
31 	 * that cores have a homonogenous view of the cache hierarchy.  That
32 	 * happens to be the case for the current set of RISC-V systems, but
33 	 * likely won't be true in general.  Since there's no way to provide
34 	 * correct information for these systems via the current UABI we're
35 	 * just eliding the check for now.
36 	 */
37 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(raw_smp_processor_id());
38 	struct cacheinfo *this_leaf;
39 	int index;
40 
41 	for (index = 0; index < this_cpu_ci->num_leaves; index++) {
42 		this_leaf = this_cpu_ci->info_list + index;
43 		if (this_leaf->level == level && this_leaf->type == type)
44 			return this_leaf;
45 	}
46 
47 	return NULL;
48 }
49 
50 uintptr_t get_cache_size(u32 level, enum cache_type type)
51 {
52 	struct cacheinfo *this_leaf = get_cacheinfo(level, type);
53 
54 	return this_leaf ? this_leaf->size : 0;
55 }
56 
57 uintptr_t get_cache_geometry(u32 level, enum cache_type type)
58 {
59 	struct cacheinfo *this_leaf = get_cacheinfo(level, type);
60 
61 	return this_leaf ? (this_leaf->ways_of_associativity << 16 |
62 			    this_leaf->coherency_line_size) :
63 			   0;
64 }
65 
66 static void ci_leaf_init(struct cacheinfo *this_leaf, enum cache_type type,
67 			 unsigned int level, unsigned int size,
68 			 unsigned int sets, unsigned int line_size)
69 {
70 	this_leaf->level = level;
71 	this_leaf->type = type;
72 	this_leaf->size = size;
73 	this_leaf->number_of_sets = sets;
74 	this_leaf->coherency_line_size = line_size;
75 
76 	/*
77 	 * If the cache is fully associative, there is no need to
78 	 * check the other properties.
79 	 */
80 	if (sets == 1)
81 		return;
82 
83 	/*
84 	 * Set the ways number for n-ways associative, make sure
85 	 * all properties are big than zero.
86 	 */
87 	if (sets > 0 && size > 0 && line_size > 0)
88 		this_leaf->ways_of_associativity = (size / sets) / line_size;
89 }
90 
91 static void fill_cacheinfo(struct cacheinfo **this_leaf,
92 			   struct device_node *node, unsigned int level)
93 {
94 	unsigned int size, sets, line_size;
95 
96 	if (!of_property_read_u32(node, "cache-size", &size) &&
97 	    !of_property_read_u32(node, "cache-block-size", &line_size) &&
98 	    !of_property_read_u32(node, "cache-sets", &sets)) {
99 		ci_leaf_init((*this_leaf)++, CACHE_TYPE_UNIFIED, level, size, sets, line_size);
100 	}
101 
102 	if (!of_property_read_u32(node, "i-cache-size", &size) &&
103 	    !of_property_read_u32(node, "i-cache-sets", &sets) &&
104 	    !of_property_read_u32(node, "i-cache-block-size", &line_size)) {
105 		ci_leaf_init((*this_leaf)++, CACHE_TYPE_INST, level, size, sets, line_size);
106 	}
107 
108 	if (!of_property_read_u32(node, "d-cache-size", &size) &&
109 	    !of_property_read_u32(node, "d-cache-sets", &sets) &&
110 	    !of_property_read_u32(node, "d-cache-block-size", &line_size)) {
111 		ci_leaf_init((*this_leaf)++, CACHE_TYPE_DATA, level, size, sets, line_size);
112 	}
113 }
114 
115 int populate_cache_leaves(unsigned int cpu)
116 {
117 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
118 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
119 	struct device_node *np = of_cpu_device_node_get(cpu);
120 	struct device_node *prev = NULL;
121 	int levels = 1, level = 1;
122 
123 	/* Level 1 caches in cpu node */
124 	fill_cacheinfo(&this_leaf, np, level);
125 
126 	/* Next level caches in cache nodes */
127 	prev = np;
128 	while ((np = of_find_next_cache_node(np))) {
129 		of_node_put(prev);
130 		prev = np;
131 
132 		if (!of_device_is_compatible(np, "cache"))
133 			break;
134 		if (of_property_read_u32(np, "cache-level", &level))
135 			break;
136 		if (level <= levels)
137 			break;
138 
139 		fill_cacheinfo(&this_leaf, np, level);
140 
141 		levels = level;
142 	}
143 	of_node_put(np);
144 
145 	return 0;
146 }
147