xref: /openbmc/linux/arch/riscv/kernel/cacheinfo.c (revision 0b656310)
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 <linux/of_device.h>
9 #include <asm/cacheinfo.h>
10 
11 static struct riscv_cacheinfo_ops *rv_cache_ops;
12 
13 void riscv_set_cacheinfo_ops(struct riscv_cacheinfo_ops *ops)
14 {
15 	rv_cache_ops = ops;
16 }
17 EXPORT_SYMBOL_GPL(riscv_set_cacheinfo_ops);
18 
19 const struct attribute_group *
20 cache_get_priv_group(struct cacheinfo *this_leaf)
21 {
22 	if (rv_cache_ops && rv_cache_ops->get_priv_group)
23 		return rv_cache_ops->get_priv_group(this_leaf);
24 	return NULL;
25 }
26 
27 static struct cacheinfo *get_cacheinfo(u32 level, enum cache_type type)
28 {
29 	/*
30 	 * Using raw_smp_processor_id() elides a preemptability check, but this
31 	 * is really indicative of a larger problem: the cacheinfo UABI assumes
32 	 * that cores have a homonogenous view of the cache hierarchy.  That
33 	 * happens to be the case for the current set of RISC-V systems, but
34 	 * likely won't be true in general.  Since there's no way to provide
35 	 * correct information for these systems via the current UABI we're
36 	 * just eliding the check for now.
37 	 */
38 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(raw_smp_processor_id());
39 	struct cacheinfo *this_leaf;
40 	int index;
41 
42 	for (index = 0; index < this_cpu_ci->num_leaves; index++) {
43 		this_leaf = this_cpu_ci->info_list + index;
44 		if (this_leaf->level == level && this_leaf->type == type)
45 			return this_leaf;
46 	}
47 
48 	return NULL;
49 }
50 
51 uintptr_t get_cache_size(u32 level, enum cache_type type)
52 {
53 	struct cacheinfo *this_leaf = get_cacheinfo(level, type);
54 
55 	return this_leaf ? this_leaf->size : 0;
56 }
57 
58 uintptr_t get_cache_geometry(u32 level, enum cache_type type)
59 {
60 	struct cacheinfo *this_leaf = get_cacheinfo(level, type);
61 
62 	return this_leaf ? (this_leaf->ways_of_associativity << 16 |
63 			    this_leaf->coherency_line_size) :
64 			   0;
65 }
66 
67 static void ci_leaf_init(struct cacheinfo *this_leaf, enum cache_type type,
68 			 unsigned int level, unsigned int size,
69 			 unsigned int sets, unsigned int line_size)
70 {
71 	this_leaf->level = level;
72 	this_leaf->type = type;
73 	this_leaf->size = size;
74 	this_leaf->number_of_sets = sets;
75 	this_leaf->coherency_line_size = line_size;
76 
77 	/*
78 	 * If the cache is fully associative, there is no need to
79 	 * check the other properties.
80 	 */
81 	if (sets == 1)
82 		return;
83 
84 	/*
85 	 * Set the ways number for n-ways associative, make sure
86 	 * all properties are big than zero.
87 	 */
88 	if (sets > 0 && size > 0 && line_size > 0)
89 		this_leaf->ways_of_associativity = (size / sets) / line_size;
90 }
91 
92 static void fill_cacheinfo(struct cacheinfo **this_leaf,
93 			   struct device_node *node, unsigned int level)
94 {
95 	unsigned int size, sets, line_size;
96 
97 	if (!of_property_read_u32(node, "cache-size", &size) &&
98 	    !of_property_read_u32(node, "cache-block-size", &line_size) &&
99 	    !of_property_read_u32(node, "cache-sets", &sets)) {
100 		ci_leaf_init((*this_leaf)++, CACHE_TYPE_UNIFIED, level, size, sets, line_size);
101 	}
102 
103 	if (!of_property_read_u32(node, "i-cache-size", &size) &&
104 	    !of_property_read_u32(node, "i-cache-sets", &sets) &&
105 	    !of_property_read_u32(node, "i-cache-block-size", &line_size)) {
106 		ci_leaf_init((*this_leaf)++, CACHE_TYPE_INST, level, size, sets, line_size);
107 	}
108 
109 	if (!of_property_read_u32(node, "d-cache-size", &size) &&
110 	    !of_property_read_u32(node, "d-cache-sets", &sets) &&
111 	    !of_property_read_u32(node, "d-cache-block-size", &line_size)) {
112 		ci_leaf_init((*this_leaf)++, CACHE_TYPE_DATA, level, size, sets, line_size);
113 	}
114 }
115 
116 int populate_cache_leaves(unsigned int cpu)
117 {
118 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
119 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
120 	struct device_node *np = of_cpu_device_node_get(cpu);
121 	struct device_node *prev = NULL;
122 	int levels = 1, level = 1;
123 
124 	/* Level 1 caches in cpu node */
125 	fill_cacheinfo(&this_leaf, np, level);
126 
127 	/* Next level caches in cache nodes */
128 	prev = np;
129 	while ((np = of_find_next_cache_node(np))) {
130 		of_node_put(prev);
131 		prev = np;
132 
133 		if (!of_device_is_compatible(np, "cache"))
134 			break;
135 		if (of_property_read_u32(np, "cache-level", &level))
136 			break;
137 		if (level <= levels)
138 			break;
139 
140 		fill_cacheinfo(&this_leaf, np, level);
141 
142 		levels = level;
143 	}
144 	of_node_put(np);
145 
146 	return 0;
147 }
148