xref: /openbmc/linux/arch/arm64/kernel/cacheinfo.c (revision 020c5260)
1 /*
2  *  ARM64 cacheinfo support
3  *
4  *  Copyright (C) 2015 ARM Ltd.
5  *  All Rights Reserved
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
12  * kind, whether express or implied; without even the implied warranty
13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/cacheinfo.h>
21 #include <linux/of.h>
22 
23 #define MAX_CACHE_LEVEL			7	/* Max 7 level supported */
24 /* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */
25 #define CLIDR_CTYPE_SHIFT(level)	(3 * (level - 1))
26 #define CLIDR_CTYPE_MASK(level)		(7 << CLIDR_CTYPE_SHIFT(level))
27 #define CLIDR_CTYPE(clidr, level)	\
28 	(((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
29 
30 static inline enum cache_type get_cache_type(int level)
31 {
32 	u64 clidr;
33 
34 	if (level > MAX_CACHE_LEVEL)
35 		return CACHE_TYPE_NOCACHE;
36 	clidr = read_sysreg(clidr_el1);
37 	return CLIDR_CTYPE(clidr, level);
38 }
39 
40 static void ci_leaf_init(struct cacheinfo *this_leaf,
41 			 enum cache_type type, unsigned int level)
42 {
43 	this_leaf->level = level;
44 	this_leaf->type = type;
45 }
46 
47 static int __init_cache_level(unsigned int cpu)
48 {
49 	unsigned int ctype, level, leaves, of_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 	of_level = of_find_last_cache_level(cpu);
63 	if (level < of_level) {
64 		/*
65 		 * some external caches not specified in CLIDR_EL1
66 		 * the information may be available in the device tree
67 		 * only unified external caches are considered here
68 		 */
69 		leaves += (of_level - level);
70 		level = of_level;
71 	}
72 
73 	this_cpu_ci->num_levels = level;
74 	this_cpu_ci->num_leaves = leaves;
75 	return 0;
76 }
77 
78 static int __populate_cache_leaves(unsigned int cpu)
79 {
80 	unsigned int level, idx;
81 	enum cache_type type;
82 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
83 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
84 
85 	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
86 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
87 		type = get_cache_type(level);
88 		if (type == CACHE_TYPE_SEPARATE) {
89 			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
90 			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
91 		} else {
92 			ci_leaf_init(this_leaf++, type, level);
93 		}
94 	}
95 	return 0;
96 }
97 
98 DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level)
99 DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves)
100