1 /*
2  *  (C) 2010,2011       Thomas Renninger <trenn@suse.de>, Novell Inc.
3  *
4  *  Licensed under the terms of the GNU GPL License version 2.
5  *
6  * ToDo: Needs to be done more properly for AMD/Intel specifics
7  */
8 
9 /* Helper struct for qsort, must be in sync with cpupower_topology.cpu_info */
10 /* Be careful: Need to pass unsigned to the sort, so that offlined cores are
11    in the end, but double check for -1 for offlined cpus at other places */
12 
13 #include <stdlib.h>
14 #include <stdio.h>
15 #include <unistd.h>
16 #include <errno.h>
17 #include <fcntl.h>
18 
19 #include <helpers/helpers.h>
20 #include <helpers/sysfs.h>
21 
22 /* returns -1 on failure, 0 on success */
23 static int sysfs_topology_read_file(unsigned int cpu, const char *fname, int *result)
24 {
25 	char linebuf[MAX_LINE_LEN];
26 	char *endp;
27 	char path[SYSFS_PATH_MAX];
28 
29 	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s",
30 			 cpu, fname);
31 	if (sysfs_read_file(path, linebuf, MAX_LINE_LEN) == 0)
32 		return -1;
33 	*result = strtol(linebuf, &endp, 0);
34 	if (endp == linebuf || errno == ERANGE)
35 		return -1;
36 	return 0;
37 }
38 
39 static int __compare(const void *t1, const void *t2)
40 {
41 	struct cpuid_core_info *top1 = (struct cpuid_core_info *)t1;
42 	struct cpuid_core_info *top2 = (struct cpuid_core_info *)t2;
43 	if (top1->pkg < top2->pkg)
44 		return -1;
45 	else if (top1->pkg > top2->pkg)
46 		return 1;
47 	else if (top1->core < top2->core)
48 		return -1;
49 	else if (top1->core > top2->core)
50 		return 1;
51 	else if (top1->cpu < top2->cpu)
52 		return -1;
53 	else if (top1->cpu > top2->cpu)
54 		return 1;
55 	else
56 		return 0;
57 }
58 
59 /*
60  * Returns amount of cpus, negative on error, cpu_top must be
61  * passed to cpu_topology_release to free resources
62  *
63  * Array is sorted after ->pkg, ->core, then ->cpu
64  */
65 int get_cpu_topology(struct cpupower_topology *cpu_top)
66 {
67 	int cpu, last_pkg, cpus = sysconf(_SC_NPROCESSORS_CONF);
68 
69 	cpu_top->core_info = malloc(sizeof(struct cpuid_core_info) * cpus);
70 	if (cpu_top->core_info == NULL)
71 		return -ENOMEM;
72 	cpu_top->pkgs = cpu_top->cores = 0;
73 	for (cpu = 0; cpu < cpus; cpu++) {
74 		cpu_top->core_info[cpu].cpu = cpu;
75 		cpu_top->core_info[cpu].is_online = sysfs_is_cpu_online(cpu);
76 		if(sysfs_topology_read_file(
77 			cpu,
78 			"physical_package_id",
79 			&(cpu_top->core_info[cpu].pkg)) < 0)
80 			return -1;
81 		if(sysfs_topology_read_file(
82 			cpu,
83 			"core_id",
84 			&(cpu_top->core_info[cpu].core)) < 0)
85 			return -1;
86 	}
87 
88 	qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info),
89 	      __compare);
90 
91 	/* Count the number of distinct pkgs values. This works
92 	   because the primary sort of the core_info struct was just
93 	   done by pkg value. */
94 	last_pkg = cpu_top->core_info[0].pkg;
95 	for(cpu = 1; cpu < cpus; cpu++) {
96 		if(cpu_top->core_info[cpu].pkg != last_pkg) {
97 			last_pkg = cpu_top->core_info[cpu].pkg;
98 			cpu_top->pkgs++;
99 		}
100 	}
101 	cpu_top->pkgs++;
102 
103 	/* Intel's cores count is not consecutively numbered, there may
104 	 * be a core_id of 3, but none of 2. Assume there always is 0
105 	 * Get amount of cores by counting duplicates in a package
106 	for (cpu = 0; cpu_top->core_info[cpu].pkg = 0 && cpu < cpus; cpu++) {
107 		if (cpu_top->core_info[cpu].core == 0)
108 	cpu_top->cores++;
109 	*/
110 	return cpus;
111 }
112 
113 void cpu_topology_release(struct cpupower_topology cpu_top)
114 {
115 	free(cpu_top.core_info);
116 }
117