xref: /openbmc/linux/arch/arm64/kernel/cacheinfo.c (revision 3213486f)
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/acpi.h>
21 #include <linux/cacheinfo.h>
22 #include <linux/of.h>
23 
24 #define MAX_CACHE_LEVEL			7	/* Max 7 level supported */
25 /* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */
26 #define CLIDR_CTYPE_SHIFT(level)	(3 * (level - 1))
27 #define CLIDR_CTYPE_MASK(level)		(7 << CLIDR_CTYPE_SHIFT(level))
28 #define CLIDR_CTYPE(clidr, level)	\
29 	(((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
30 
31 static inline enum cache_type get_cache_type(int level)
32 {
33 	u64 clidr;
34 
35 	if (level > MAX_CACHE_LEVEL)
36 		return CACHE_TYPE_NOCACHE;
37 	clidr = read_sysreg(clidr_el1);
38 	return CLIDR_CTYPE(clidr, level);
39 }
40 
41 static void ci_leaf_init(struct cacheinfo *this_leaf,
42 			 enum cache_type type, unsigned int level)
43 {
44 	this_leaf->level = level;
45 	this_leaf->type = type;
46 }
47 
48 static int __init_cache_level(unsigned int cpu)
49 {
50 	unsigned int ctype, level, leaves, fw_level;
51 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
52 
53 	for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
54 		ctype = get_cache_type(level);
55 		if (ctype == CACHE_TYPE_NOCACHE) {
56 			level--;
57 			break;
58 		}
59 		/* Separate instruction and data caches */
60 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
61 	}
62 
63 	if (acpi_disabled)
64 		fw_level = of_find_last_cache_level(cpu);
65 	else
66 		fw_level = acpi_find_last_cache_level(cpu);
67 
68 	if (level < fw_level) {
69 		/*
70 		 * some external caches not specified in CLIDR_EL1
71 		 * the information may be available in the device tree
72 		 * only unified external caches are considered here
73 		 */
74 		leaves += (fw_level - level);
75 		level = fw_level;
76 	}
77 
78 	this_cpu_ci->num_levels = level;
79 	this_cpu_ci->num_leaves = leaves;
80 	return 0;
81 }
82 
83 static int __populate_cache_leaves(unsigned int cpu)
84 {
85 	unsigned int level, idx;
86 	enum cache_type type;
87 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
88 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
89 
90 	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
91 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
92 		type = get_cache_type(level);
93 		if (type == CACHE_TYPE_SEPARATE) {
94 			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
95 			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
96 		} else {
97 			ci_leaf_init(this_leaf++, type, level);
98 		}
99 	}
100 	return 0;
101 }
102 
103 DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level)
104 DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves)
105