xref: /openbmc/linux/arch/arm64/kernel/cacheinfo.c (revision 9fabdbe8)
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;
49 	int fw_level;
50 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
51 
52 	for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
53 		ctype = get_cache_type(level);
54 		if (ctype == CACHE_TYPE_NOCACHE) {
55 			level--;
56 			break;
57 		}
58 		/* Separate instruction and data caches */
59 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
60 	}
61 
62 	if (acpi_disabled)
63 		fw_level = of_find_last_cache_level(cpu);
64 	else
65 		fw_level = acpi_find_last_cache_level(cpu);
66 
67 	if (fw_level < 0)
68 		return fw_level;
69 
70 	if (level < fw_level) {
71 		/*
72 		 * some external caches not specified in CLIDR_EL1
73 		 * the information may be available in the device tree
74 		 * only unified external caches are considered here
75 		 */
76 		leaves += (fw_level - level);
77 		level = fw_level;
78 	}
79 
80 	this_cpu_ci->num_levels = level;
81 	this_cpu_ci->num_leaves = leaves;
82 	return 0;
83 }
84 
85 int populate_cache_leaves(unsigned int cpu)
86 {
87 	unsigned int level, idx;
88 	enum cache_type type;
89 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
90 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
91 
92 	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
93 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
94 		type = get_cache_type(level);
95 		if (type == CACHE_TYPE_SEPARATE) {
96 			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
97 			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
98 		} else {
99 			ci_leaf_init(this_leaf++, type, level);
100 		}
101 	}
102 	return 0;
103 }
104