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 */
23static 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
39static 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 */
65int 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
113void cpu_topology_release(struct cpupower_topology cpu_top)
114{
115	free(cpu_top.core_info);
116}
117