xref: /openbmc/linux/arch/arm64/kernel/cacheinfo.c (revision c4e78957)
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 /* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */
15 #define CLIDR_CTYPE_SHIFT(level)	(3 * (level - 1))
16 #define CLIDR_CTYPE_MASK(level)		(7 << CLIDR_CTYPE_SHIFT(level))
17 #define CLIDR_CTYPE(clidr, level)	\
18 	(((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
19 
20 int cache_line_size(void)
21 {
22 	if (coherency_max_size != 0)
23 		return coherency_max_size;
24 
25 	return cache_line_size_of_cpu();
26 }
27 EXPORT_SYMBOL_GPL(cache_line_size);
28 
29 static inline enum cache_type get_cache_type(int level)
30 {
31 	u64 clidr;
32 
33 	if (level > MAX_CACHE_LEVEL)
34 		return CACHE_TYPE_NOCACHE;
35 	clidr = read_sysreg(clidr_el1);
36 	return CLIDR_CTYPE(clidr, level);
37 }
38 
39 static void ci_leaf_init(struct cacheinfo *this_leaf,
40 			 enum cache_type type, unsigned int level)
41 {
42 	this_leaf->level = level;
43 	this_leaf->type = type;
44 }
45 
46 int init_cache_level(unsigned int cpu)
47 {
48 	unsigned int ctype, level, leaves, fw_level;
49 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
50 
51 	for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
52 		ctype = get_cache_type(level);
53 		if (ctype == CACHE_TYPE_NOCACHE) {
54 			level--;
55 			break;
56 		}
57 		/* Separate instruction and data caches */
58 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
59 	}
60 
61 	if (acpi_disabled)
62 		fw_level = of_find_last_cache_level(cpu);
63 	else
64 		fw_level = acpi_find_last_cache_level(cpu);
65 
66 	if (level < fw_level) {
67 		/*
68 		 * some external caches not specified in CLIDR_EL1
69 		 * the information may be available in the device tree
70 		 * only unified external caches are considered here
71 		 */
72 		leaves += (fw_level - level);
73 		level = fw_level;
74 	}
75 
76 	this_cpu_ci->num_levels = level;
77 	this_cpu_ci->num_leaves = leaves;
78 	return 0;
79 }
80 
81 int populate_cache_leaves(unsigned int cpu)
82 {
83 	unsigned int level, idx;
84 	enum cache_type type;
85 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
86 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
87 
88 	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
89 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
90 		type = get_cache_type(level);
91 		if (type == CACHE_TYPE_SEPARATE) {
92 			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
93 			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
94 		} else {
95 			ci_leaf_init(this_leaf++, type, level);
96 		}
97 	}
98 	return 0;
99 }
100