xref: /openbmc/linux/arch/arm64/kernel/cacheinfo.c (revision ecefa105)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  ARM64 cacheinfo support
4  *
5  *  Copyright (C) 2015 ARM Ltd.
6  *  All Rights Reserved
7  */
8 
9 #include <linux/acpi.h>
10 #include <linux/cacheinfo.h>
11 #include <linux/of.h>
12 
13 #define MAX_CACHE_LEVEL			7	/* Max 7 level supported */
14 
15 int cache_line_size(void)
16 {
17 	if (coherency_max_size != 0)
18 		return coherency_max_size;
19 
20 	return cache_line_size_of_cpu();
21 }
22 EXPORT_SYMBOL_GPL(cache_line_size);
23 
24 static inline enum cache_type get_cache_type(int level)
25 {
26 	u64 clidr;
27 
28 	if (level > MAX_CACHE_LEVEL)
29 		return CACHE_TYPE_NOCACHE;
30 	clidr = read_sysreg(clidr_el1);
31 	return CLIDR_CTYPE(clidr, level);
32 }
33 
34 static void ci_leaf_init(struct cacheinfo *this_leaf,
35 			 enum cache_type type, unsigned int level)
36 {
37 	this_leaf->level = level;
38 	this_leaf->type = type;
39 }
40 
41 int init_cache_level(unsigned int cpu)
42 {
43 	unsigned int ctype, level, leaves;
44 	int fw_level, ret;
45 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
46 
47 	for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
48 		ctype = get_cache_type(level);
49 		if (ctype == CACHE_TYPE_NOCACHE) {
50 			level--;
51 			break;
52 		}
53 		/* Separate instruction and data caches */
54 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
55 	}
56 
57 	if (acpi_disabled) {
58 		fw_level = of_find_last_cache_level(cpu);
59 	} else {
60 		ret = acpi_get_cache_info(cpu, &fw_level, NULL);
61 		if (ret < 0)
62 			fw_level = 0;
63 	}
64 
65 	if (level < fw_level) {
66 		/*
67 		 * some external caches not specified in CLIDR_EL1
68 		 * the information may be available in the device tree
69 		 * only unified external caches are considered here
70 		 */
71 		leaves += (fw_level - level);
72 		level = fw_level;
73 	}
74 
75 	this_cpu_ci->num_levels = level;
76 	this_cpu_ci->num_leaves = leaves;
77 	return 0;
78 }
79 
80 int populate_cache_leaves(unsigned int cpu)
81 {
82 	unsigned int level, idx;
83 	enum cache_type type;
84 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
85 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
86 
87 	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
88 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
89 		type = get_cache_type(level);
90 		if (type == CACHE_TYPE_SEPARATE) {
91 			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
92 			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
93 		} else {
94 			ci_leaf_init(this_leaf++, type, level);
95 		}
96 	}
97 	return 0;
98 }
99