Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #include "api/fs/fs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include "smt.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) int smt_on(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 	static bool cached;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 	static int cached_result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 	int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 	int ncpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	if (cached)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 		return cached_result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 		goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	ncpu = sysconf(_SC_NPROCESSORS_CONF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	for (cpu = 0; cpu < ncpu; cpu++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 		unsigned long long siblings;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 		char *str;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 		size_t strlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 		char fn[256];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 		snprintf(fn, sizeof fn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 			"devices/system/cpu/cpu%d/topology/core_cpus", cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 		if (sysfs__read_str(fn, &str, &strlen) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 			snprintf(fn, sizeof fn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 				"devices/system/cpu/cpu%d/topology/thread_siblings",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 				cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 			if (sysfs__read_str(fn, &str, &strlen) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 				continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 		/* Entry is hex, but does not have 0x, so need custom parser */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 		siblings = strtoull(str, NULL, 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		free(str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		if (hweight64(siblings) > 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 			cached_result = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 			cached = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	if (!cached) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 		cached_result = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) done:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 		cached = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	return cached_result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }