xref: /linux/arch/riscv/kernel/cacheinfo.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2017 SiFive
4  */
5 
6 #include <linux/acpi.h>
7 #include <linux/cpu.h>
8 #include <linux/of.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,
68 			 enum cache_type type, unsigned int level)
69 {
70 	this_leaf->level = level;
71 	this_leaf->type = type;
72 }
73 
74 int init_cache_level(unsigned int cpu)
75 {
76 	return init_of_cache_level(cpu);
77 }
78 
79 int populate_cache_leaves(unsigned int cpu)
80 {
81 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
82 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
83 	struct device_node *np, *prev;
84 	int levels = 1, level = 1;
85 
86 	if (!acpi_disabled) {
87 		int ret, fw_levels, split_levels;
88 
89 		ret = acpi_get_cache_info(cpu, &fw_levels, &split_levels);
90 		if (ret)
91 			return ret;
92 
93 		BUG_ON((split_levels > fw_levels) ||
94 		       (split_levels + fw_levels > this_cpu_ci->num_leaves));
95 
96 		for (; level <= this_cpu_ci->num_levels; level++) {
97 			if (level <= split_levels) {
98 				ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
99 				ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
100 			} else {
101 				ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
102 			}
103 		}
104 		return 0;
105 	}
106 
107 	np = of_cpu_device_node_get(cpu);
108 	if (!np)
109 		return -ENOENT;
110 
111 	if (of_property_read_bool(np, "cache-size"))
112 		ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
113 	if (of_property_read_bool(np, "i-cache-size"))
114 		ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
115 	if (of_property_read_bool(np, "d-cache-size"))
116 		ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
117 
118 	prev = np;
119 	while ((np = of_find_next_cache_node(np))) {
120 		of_node_put(prev);
121 		prev = np;
122 		if (!of_device_is_compatible(np, "cache"))
123 			break;
124 		if (of_property_read_u32(np, "cache-level", &level))
125 			break;
126 		if (level <= levels)
127 			break;
128 		if (of_property_read_bool(np, "cache-size"))
129 			ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
130 		if (of_property_read_bool(np, "i-cache-size"))
131 			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
132 		if (of_property_read_bool(np, "d-cache-size"))
133 			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
134 		levels = level;
135 	}
136 	of_node_put(np);
137 
138 	return 0;
139 }
140