xref: /linux/arch/s390/kernel/cache.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Extract CPU cache information and expose them via sysfs.
4  *
5  *    Copyright IBM Corp. 2012
6  */
7 
8 #include <linux/seq_file.h>
9 #include <linux/cpu.h>
10 #include <linux/cacheinfo.h>
11 #include <asm/facility.h>
12 
13 enum {
14 	CACHE_SCOPE_NOTEXISTS,
15 	CACHE_SCOPE_PRIVATE,
16 	CACHE_SCOPE_SHARED,
17 	CACHE_SCOPE_RESERVED,
18 };
19 
20 enum {
21 	CTYPE_SEPARATE,
22 	CTYPE_DATA,
23 	CTYPE_INSTRUCTION,
24 	CTYPE_UNIFIED,
25 };
26 
27 enum {
28 	EXTRACT_TOPOLOGY,
29 	EXTRACT_LINE_SIZE,
30 	EXTRACT_SIZE,
31 	EXTRACT_ASSOCIATIVITY,
32 };
33 
34 enum {
35 	CACHE_TI_UNIFIED = 0,
36 	CACHE_TI_DATA = 0,
37 	CACHE_TI_INSTRUCTION,
38 };
39 
40 struct cache_info {
41 	unsigned char	    : 4;
42 	unsigned char scope : 2;
43 	unsigned char type  : 2;
44 };
45 
46 #define CACHE_MAX_LEVEL 8
47 union cache_topology {
48 	struct cache_info ci[CACHE_MAX_LEVEL];
49 	unsigned long raw;
50 };
51 
52 static const char * const cache_type_string[] = {
53 	"",
54 	"Instruction",
55 	"Data",
56 	"",
57 	"Unified",
58 };
59 
60 static const enum cache_type cache_type_map[] = {
61 	[CTYPE_SEPARATE] = CACHE_TYPE_SEPARATE,
62 	[CTYPE_DATA] = CACHE_TYPE_DATA,
63 	[CTYPE_INSTRUCTION] = CACHE_TYPE_INST,
64 	[CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
65 };
66 
show_cacheinfo(struct seq_file * m)67 void show_cacheinfo(struct seq_file *m)
68 {
69 	struct cpu_cacheinfo *this_cpu_ci;
70 	struct cacheinfo *cache;
71 	int idx;
72 
73 	this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask));
74 	for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
75 		cache = this_cpu_ci->info_list + idx;
76 		seq_printf(m, "cache%-11d: ", idx);
77 		seq_printf(m, "level=%d ", cache->level);
78 		seq_printf(m, "type=%s ", cache_type_string[cache->type]);
79 		seq_printf(m, "scope=%s ",
80 			   cache->disable_sysfs ? "Shared" : "Private");
81 		seq_printf(m, "size=%dK ", cache->size >> 10);
82 		seq_printf(m, "line_size=%u ", cache->coherency_line_size);
83 		seq_printf(m, "associativity=%d", cache->ways_of_associativity);
84 		seq_puts(m, "\n");
85 	}
86 }
87 
get_cache_type(struct cache_info * ci,int level)88 static inline enum cache_type get_cache_type(struct cache_info *ci, int level)
89 {
90 	if (level >= CACHE_MAX_LEVEL)
91 		return CACHE_TYPE_NOCACHE;
92 	ci += level;
93 	if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE)
94 		return CACHE_TYPE_NOCACHE;
95 	return cache_type_map[ci->type];
96 }
97 
ecag(int ai,int li,int ti)98 static inline unsigned long ecag(int ai, int li, int ti)
99 {
100 	return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
101 }
102 
ci_leaf_init(struct cacheinfo * this_leaf,int private,enum cache_type type,unsigned int level,int cpu)103 static void ci_leaf_init(struct cacheinfo *this_leaf, int private,
104 			 enum cache_type type, unsigned int level, int cpu)
105 {
106 	int ti, num_sets;
107 
108 	if (type == CACHE_TYPE_INST)
109 		ti = CACHE_TI_INSTRUCTION;
110 	else
111 		ti = CACHE_TI_UNIFIED;
112 	this_leaf->level = level + 1;
113 	this_leaf->type = type;
114 	this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
115 	this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
116 	this_leaf->size = ecag(EXTRACT_SIZE, level, ti);
117 	num_sets = this_leaf->size / this_leaf->coherency_line_size;
118 	num_sets /= this_leaf->ways_of_associativity;
119 	this_leaf->number_of_sets = num_sets;
120 	cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
121 	if (!private)
122 		this_leaf->disable_sysfs = true;
123 }
124 
init_cache_level(unsigned int cpu)125 int init_cache_level(unsigned int cpu)
126 {
127 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
128 	unsigned int level = 0, leaves = 0;
129 	union cache_topology ct;
130 	enum cache_type ctype;
131 
132 	if (!this_cpu_ci)
133 		return -EINVAL;
134 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
135 	do {
136 		ctype = get_cache_type(&ct.ci[0], level);
137 		if (ctype == CACHE_TYPE_NOCACHE)
138 			break;
139 		/* Separate instruction and data caches */
140 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
141 	} while (++level < CACHE_MAX_LEVEL);
142 	this_cpu_ci->num_levels = level;
143 	this_cpu_ci->num_leaves = leaves;
144 	return 0;
145 }
146 
populate_cache_leaves(unsigned int cpu)147 int populate_cache_leaves(unsigned int cpu)
148 {
149 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
150 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
151 	unsigned int level, idx, pvt;
152 	union cache_topology ct;
153 	enum cache_type ctype;
154 
155 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
156 	for (idx = 0, level = 0; level < this_cpu_ci->num_levels &&
157 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
158 		if (!this_leaf)
159 			return -EINVAL;
160 		pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0;
161 		ctype = get_cache_type(&ct.ci[0], level);
162 		if (ctype == CACHE_TYPE_SEPARATE) {
163 			ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu);
164 			ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu);
165 		} else {
166 			ci_leaf_init(this_leaf++, pvt, ctype, level, cpu);
167 		}
168 	}
169 	this_cpu_ci->cpu_map_populated = true;
170 	return 0;
171 }
172