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1 /*
2  * Extract CPU cache information and expose them via sysfs.
3  *
4  *    Copyright IBM Corp. 2012
5  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
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 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 	if (!test_facility(34))
74 		return;
75 	get_online_cpus();
76 	this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask));
77 	for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
78 		cache = this_cpu_ci->info_list + idx;
79 		seq_printf(m, "cache%-11d: ", idx);
80 		seq_printf(m, "level=%d ", cache->level);
81 		seq_printf(m, "type=%s ", cache_type_string[cache->type]);
82 		seq_printf(m, "scope=%s ",
83 			   cache->disable_sysfs ? "Shared" : "Private");
84 		seq_printf(m, "size=%dK ", cache->size >> 10);
85 		seq_printf(m, "line_size=%u ", cache->coherency_line_size);
86 		seq_printf(m, "associativity=%d", cache->ways_of_associativity);
87 		seq_puts(m, "\n");
88 	}
89 	put_online_cpus();
90 }
91 
get_cache_type(struct cache_info * ci,int level)92 static inline enum cache_type get_cache_type(struct cache_info *ci, int level)
93 {
94 	if (level >= CACHE_MAX_LEVEL)
95 		return CACHE_TYPE_NOCACHE;
96 	ci += level;
97 	if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE)
98 		return CACHE_TYPE_NOCACHE;
99 	return cache_type_map[ci->type];
100 }
101 
ecag(int ai,int li,int ti)102 static inline unsigned long ecag(int ai, int li, int ti)
103 {
104 	unsigned long cmd, val;
105 
106 	cmd = ai << 4 | li << 1 | ti;
107 	asm volatile(".insn	rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */
108 		     : "=d" (val) : "a" (cmd));
109 	return val;
110 }
111 
ci_leaf_init(struct cacheinfo * this_leaf,int private,enum cache_type type,unsigned int level,int cpu)112 static void ci_leaf_init(struct cacheinfo *this_leaf, int private,
113 			 enum cache_type type, unsigned int level, int cpu)
114 {
115 	int ti, num_sets;
116 
117 	if (type == CACHE_TYPE_INST)
118 		ti = CACHE_TI_INSTRUCTION;
119 	else
120 		ti = CACHE_TI_UNIFIED;
121 	this_leaf->level = level + 1;
122 	this_leaf->type = type;
123 	this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
124 	this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
125 	this_leaf->size = ecag(EXTRACT_SIZE, level, ti);
126 	num_sets = this_leaf->size / this_leaf->coherency_line_size;
127 	num_sets /= this_leaf->ways_of_associativity;
128 	this_leaf->number_of_sets = num_sets;
129 	cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
130 	if (!private)
131 		this_leaf->disable_sysfs = true;
132 }
133 
init_cache_level(unsigned int cpu)134 int init_cache_level(unsigned int cpu)
135 {
136 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
137 	unsigned int level = 0, leaves = 0;
138 	union cache_topology ct;
139 	enum cache_type ctype;
140 
141 	if (!test_facility(34))
142 		return -EOPNOTSUPP;
143 	if (!this_cpu_ci)
144 		return -EINVAL;
145 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
146 	do {
147 		ctype = get_cache_type(&ct.ci[0], level);
148 		if (ctype == CACHE_TYPE_NOCACHE)
149 			break;
150 		/* Separate instruction and data caches */
151 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
152 	} while (++level < CACHE_MAX_LEVEL);
153 	this_cpu_ci->num_levels = level;
154 	this_cpu_ci->num_leaves = leaves;
155 	return 0;
156 }
157 
populate_cache_leaves(unsigned int cpu)158 int populate_cache_leaves(unsigned int cpu)
159 {
160 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
161 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
162 	unsigned int level, idx, pvt;
163 	union cache_topology ct;
164 	enum cache_type ctype;
165 
166 	if (!test_facility(34))
167 		return -EOPNOTSUPP;
168 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
169 	for (idx = 0, level = 0; level < this_cpu_ci->num_levels &&
170 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
171 		if (!this_leaf)
172 			return -EINVAL;
173 		pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0;
174 		ctype = get_cache_type(&ct.ci[0], level);
175 		if (ctype == CACHE_TYPE_SEPARATE) {
176 			ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu);
177 			ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu);
178 		} else {
179 			ci_leaf_init(this_leaf++, pvt, ctype, level, cpu);
180 		}
181 	}
182 	return 0;
183 }
184