diff options
author | Mark Brown <broonie@kernel.org> | 2016-02-09 18:20:39 +0000 |
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committer | Mark Brown <broonie@kernel.org> | 2016-02-09 18:20:39 +0000 |
commit | fcdcc79628a1919bde9acf239e364f65bab6327c (patch) | |
tree | 5499be387cf3028c90ac083b1cf866ebed7bf7e0 /tools/testing/selftests/powerpc/utils.c | |
parent | 7a8d44bc89e5cddcd5c0704a11a90484d36ba6ba (diff) | |
parent | a0a90718f18264dc904d34a580f332006f5561e9 (diff) |
Merge branch 'topic/acpi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-pxa2xx
Diffstat (limited to 'tools/testing/selftests/powerpc/utils.c')
-rw-r--r-- | tools/testing/selftests/powerpc/utils.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c new file mode 100644 index 000000000000..dcf74184bfd0 --- /dev/null +++ b/tools/testing/selftests/powerpc/utils.c @@ -0,0 +1,87 @@ +/* + * Copyright 2013-2015, Michael Ellerman, IBM Corp. + * Licensed under GPLv2. + */ + +#define _GNU_SOURCE /* For CPU_ZERO etc. */ + +#include <elf.h> +#include <errno.h> +#include <fcntl.h> +#include <link.h> +#include <sched.h> +#include <stdio.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include "utils.h" + +static char auxv[4096]; + +void *get_auxv_entry(int type) +{ + ElfW(auxv_t) *p; + void *result; + ssize_t num; + int fd; + + fd = open("/proc/self/auxv", O_RDONLY); + if (fd == -1) { + perror("open"); + return NULL; + } + + result = NULL; + + num = read(fd, auxv, sizeof(auxv)); + if (num < 0) { + perror("read"); + goto out; + } + + if (num > sizeof(auxv)) { + printf("Overflowed auxv buffer\n"); + goto out; + } + + p = (ElfW(auxv_t) *)auxv; + + while (p->a_type != AT_NULL) { + if (p->a_type == type) { + result = (void *)p->a_un.a_val; + break; + } + + p++; + } +out: + close(fd); + return result; +} + +int pick_online_cpu(void) +{ + cpu_set_t mask; + int cpu; + + CPU_ZERO(&mask); + + if (sched_getaffinity(0, sizeof(mask), &mask)) { + perror("sched_getaffinity"); + return -1; + } + + /* We prefer a primary thread, but skip 0 */ + for (cpu = 8; cpu < CPU_SETSIZE; cpu += 8) + if (CPU_ISSET(cpu, &mask)) + return cpu; + + /* Search for anything, but in reverse */ + for (cpu = CPU_SETSIZE - 1; cpu >= 0; cpu--) + if (CPU_ISSET(cpu, &mask)) + return cpu; + + printf("No cpus in affinity mask?!\n"); + return -1; +} |