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|
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <cpuinfo.h>
#include <arm/linux/api.h>
#if defined(__ANDROID__)
#include <arm/android/api.h>
#endif
#include <arm/api.h>
#include <arm/midr.h>
#include <linux/api.h>
#include <cpuinfo/internal-api.h>
#include <cpuinfo/log.h>
static inline bool bitmask_all(uint32_t bitfield, uint32_t mask) {
return (bitfield & mask) == mask;
}
/*
* Assigns logical processors to clusters of cores using heuristic based on the typical configuration of clusters for
* 5, 6, 8, and 10 cores:
* - 5 cores (ARM32 Android only): 2 clusters of 4+1 cores
* - 6 cores: 2 clusters of 4+2 cores
* - 8 cores: 2 clusters of 4+4 cores
* - 10 cores: 3 clusters of 4+4+2 cores
*
* The function must be called after parsing OS-provided information on core clusters.
* Its purpose is to detect clusters of cores when OS-provided information is lacking or incomplete, i.e.
* - Linux kernel is not configured to report information in sysfs topology leaf.
* - Linux kernel reports topology information only for online cores, and only cores on one cluster are online, e.g.:
* - Exynos 8890 has 8 cores in 4+4 clusters, but only the first cluster of 4 cores is reported, and cluster
* configuration of logical processors 4-7 is not reported (all remaining processors 4-7 form cluster 1)
* - MT6797 has 10 cores in 4+4+2, but only the first cluster of 4 cores is reported, and cluster configuration
* of logical processors 4-9 is not reported (processors 4-7 form cluster 1, and processors 8-9 form cluster 2).
*
* Heuristic assignment of processors to the above pre-defined clusters fails if such assignment would contradict
* information provided by the operating system:
* - Any of the OS-reported processor clusters is different than the corresponding heuristic cluster.
* - Processors in a heuristic cluster have no OS-provided cluster siblings information, but have known and different
* minimum/maximum frequency.
* - Processors in a heuristic cluster have no OS-provided cluster siblings information, but have known and different
* MIDR components.
*
* If the heuristic assignment of processors to clusters of cores fails, all processors' clusters are unchanged.
*
* @param usable_processors - number of processors in the @p processors array with CPUINFO_LINUX_FLAG_VALID flags.
* @param max_processors - number of elements in the @p processors array.
* @param[in,out] processors - processor descriptors with pre-parsed POSSIBLE and PRESENT flags, minimum/maximum
* frequency, MIDR information, and core cluster (package siblings list) information.
*
* @retval true if the heuristic successfully assigned all processors into clusters of cores.
* @retval false if known details about processors contradict the heuristic configuration of core clusters.
*/
bool cpuinfo_arm_linux_detect_core_clusters_by_heuristic(
uint32_t usable_processors,
uint32_t max_processors,
struct cpuinfo_arm_linux_processor processors[restrict static max_processors])
{
uint32_t cluster_processors[3];
switch (usable_processors) {
case 10:
cluster_processors[0] = 4;
cluster_processors[1] = 4;
cluster_processors[2] = 2;
break;
case 8:
cluster_processors[0] = 4;
cluster_processors[1] = 4;
break;
case 6:
cluster_processors[0] = 4;
cluster_processors[1] = 2;
break;
#if defined(__ANDROID__) && CPUINFO_ARCH_ARM
case 5:
/*
* The only processor with 5 cores is Leadcore L1860C (ARMv7, mobile),
* but this configuration is not too unreasonable for a virtualized ARM server.
*/
cluster_processors[0] = 4;
cluster_processors[1] = 1;
break;
#endif
default:
return false;
}
/*
* Assignment of processors to core clusters is done in two passes:
* 1. Verify that the clusters proposed by heuristic are compatible with known details about processors.
* 2. If verification passed, update core clusters for the processors.
*/
uint32_t cluster = 0;
uint32_t expected_cluster_processors = 0;
uint32_t cluster_start, cluster_flags, cluster_midr, cluster_max_frequency, cluster_min_frequency;
bool expected_cluster_exists;
for (uint32_t i = 0; i < max_processors; i++) {
if (bitmask_all(processors[i].flags, CPUINFO_LINUX_FLAG_VALID)) {
if (expected_cluster_processors == 0) {
/* Expect this processor to start a new cluster */
expected_cluster_exists = !!(processors[i].flags & CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER);
if (expected_cluster_exists) {
if (processors[i].package_leader_id != i) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"processor %"PRIu32" is expected to start a new cluster #%"PRIu32" with %"PRIu32" cores, "
"but system siblings lists reported it as a sibling of processor %"PRIu32,
i, cluster, cluster_processors[cluster], processors[i].package_leader_id);
return false;
}
} else {
cluster_flags = 0;
}
cluster_start = i;
expected_cluster_processors = cluster_processors[cluster++];
} else {
/* Expect this processor to belong to the same cluster as processor */
if (expected_cluster_exists) {
/*
* The cluster suggested by the heuristic was already parsed from system siblings lists.
* For all processors we expect in the cluster, check that:
* - They have pre-assigned cluster from siblings lists (CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER flag).
* - They were assigned to the same cluster based on siblings lists
* (package_leader_id points to the first processor in the cluster).
*/
if ((processors[i].flags & CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER) == 0) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"processor %"PRIu32" is expected to belong to the cluster of processor %"PRIu32", "
"but system siblings lists did not report it as a sibling of processor %"PRIu32,
i, cluster_start, cluster_start);
return false;
}
if (processors[i].package_leader_id != cluster_start) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"processor %"PRIu32" is expected to belong to the cluster of processor %"PRIu32", "
"but system siblings lists reported it to belong to the cluster of processor %"PRIu32,
i, cluster_start, cluster_start);
return false;
}
} else {
/*
* The cluster suggest by the heuristic was not parsed from system siblings lists.
* For all processors we expect in the cluster, check that:
* - They have no pre-assigned cluster from siblings lists.
* - If their min/max CPU frequency is known, it is the same.
* - If any part of their MIDR (Implementer, Variant, Part, Revision) is known, it is the same.
*/
if (processors[i].flags & CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"processor %"PRIu32" is expected to be unassigned to any cluster, "
"but system siblings lists reported it to belong to the cluster of processor %"PRIu32,
i, processors[i].package_leader_id);
return false;
}
if (processors[i].flags & CPUINFO_LINUX_FLAG_MIN_FREQUENCY) {
if (cluster_flags & CPUINFO_LINUX_FLAG_MIN_FREQUENCY) {
if (cluster_min_frequency != processors[i].min_frequency) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"minimum frequency of processor %"PRIu32" (%"PRIu32" KHz) is different than of its expected cluster (%"PRIu32" KHz)",
i, processors[i].min_frequency, cluster_min_frequency);
return false;
}
} else {
cluster_min_frequency = processors[i].min_frequency;
cluster_flags |= CPUINFO_LINUX_FLAG_MIN_FREQUENCY;
}
}
if (processors[i].flags & CPUINFO_LINUX_FLAG_MAX_FREQUENCY) {
if (cluster_flags & CPUINFO_LINUX_FLAG_MAX_FREQUENCY) {
if (cluster_max_frequency != processors[i].max_frequency) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"maximum frequency of processor %"PRIu32" (%"PRIu32" KHz) is different than of its expected cluster (%"PRIu32" KHz)",
i, processors[i].max_frequency, cluster_max_frequency);
return false;
}
} else {
cluster_max_frequency = processors[i].max_frequency;
cluster_flags |= CPUINFO_LINUX_FLAG_MAX_FREQUENCY;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_IMPLEMENTER) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_IMPLEMENTER) {
if ((cluster_midr & CPUINFO_ARM_MIDR_IMPLEMENTER_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_IMPLEMENTER_MASK)) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"CPU Implementer of processor %"PRIu32" (0x%02"PRIx32") is different than of its expected cluster (0x%02"PRIx32")",
i, midr_get_implementer(processors[i].midr), midr_get_implementer(cluster_midr));
return false;
}
} else {
cluster_midr = midr_copy_implementer(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_IMPLEMENTER;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_VARIANT) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_VARIANT) {
if ((cluster_midr & CPUINFO_ARM_MIDR_VARIANT_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_VARIANT_MASK)) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"CPU Variant of processor %"PRIu32" (0x%"PRIx32") is different than of its expected cluster (0x%"PRIx32")",
i, midr_get_variant(processors[i].midr), midr_get_variant(cluster_midr));
return false;
}
} else {
cluster_midr = midr_copy_variant(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_VARIANT;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_PART) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_PART) {
if ((cluster_midr & CPUINFO_ARM_MIDR_PART_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_PART_MASK)) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"CPU Part of processor %"PRIu32" (0x%03"PRIx32") is different than of its expected cluster (0x%03"PRIx32")",
i, midr_get_part(processors[i].midr), midr_get_part(cluster_midr));
return false;
}
} else {
cluster_midr = midr_copy_part(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_PART;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_REVISION) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_REVISION) {
if ((cluster_midr & CPUINFO_ARM_MIDR_REVISION_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_REVISION_MASK)) {
cpuinfo_log_debug(
"heuristic detection of core clusters failed: "
"CPU Revision of processor %"PRIu32" (0x%"PRIx32") is different than of its expected cluster (0x%"PRIx32")",
i, midr_get_revision(cluster_midr), midr_get_revision(processors[i].midr));
return false;
}
} else {
cluster_midr = midr_copy_revision(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_REVISION;
}
}
}
}
expected_cluster_processors--;
}
}
/* Verification passed, assign all processors to new clusters */
cluster = 0;
expected_cluster_processors = 0;
for (uint32_t i = 0; i < max_processors; i++) {
if (bitmask_all(processors[i].flags, CPUINFO_LINUX_FLAG_VALID)) {
if (expected_cluster_processors == 0) {
/* Expect this processor to start a new cluster */
cluster_start = i;
expected_cluster_processors = cluster_processors[cluster++];
} else {
/* Expect this processor to belong to the same cluster as processor */
if (!(processors[i].flags & CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER)) {
cpuinfo_log_debug("assigned processor %"PRIu32" to cluster of processor %"PRIu32" based on heuristic",
i, cluster_start);
}
processors[i].package_leader_id = cluster_start;
processors[i].flags |= CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER;
}
expected_cluster_processors--;
}
}
return true;
}
/*
* Assigns logical processors to clusters of cores in sequential manner:
* - Clusters detected from OS-provided information are unchanged:
* - Processors assigned to these clusters stay assigned to the same clusters
* - No new processors are added to these clusters
* - Processors without pre-assigned cluster are clustered in one sequential scan:
* - If known details (min/max frequency, MIDR components) of a processor are compatible with a preceding
* processor, without pre-assigned cluster, the processor is assigned to the cluster of the preceding processor.
* - If known details (min/max frequency, MIDR components) of a processor are not compatible with a preceding
* processor, the processor is assigned to a newly created cluster.
*
* The function must be called after parsing OS-provided information on core clusters, and usually is called only
* if heuristic assignment of processors to clusters (cpuinfo_arm_linux_cluster_processors_by_heuristic) failed.
*
* Its purpose is to detect clusters of cores when OS-provided information is lacking or incomplete, i.e.
* - Linux kernel is not configured to report information in sysfs topology leaf.
* - Linux kernel reports topology information only for online cores, and all cores on some of the clusters are offline.
*
* Sequential assignment of processors to clusters always succeeds, and upon exit, all usable processors in the
* @p processors array have cluster information.
*
* @param max_processors - number of elements in the @p processors array.
* @param[in,out] processors - processor descriptors with pre-parsed POSSIBLE and PRESENT flags, minimum/maximum
* frequency, MIDR information, and core cluster (package siblings list) information.
*
* @retval true if the heuristic successfully assigned all processors into clusters of cores.
* @retval false if known details about processors contradict the heuristic configuration of core clusters.
*/
void cpuinfo_arm_linux_detect_core_clusters_by_sequential_scan(
uint32_t max_processors,
struct cpuinfo_arm_linux_processor processors[restrict static max_processors])
{
uint32_t cluster_flags = 0;
uint32_t cluster_processors = 0;
uint32_t cluster_start, cluster_midr, cluster_max_frequency, cluster_min_frequency;
for (uint32_t i = 0; i < max_processors; i++) {
if ((processors[i].flags & (CPUINFO_LINUX_FLAG_VALID | CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER)) == CPUINFO_LINUX_FLAG_VALID) {
if (cluster_processors == 0) {
goto new_cluster;
}
if (processors[i].flags & CPUINFO_LINUX_FLAG_MIN_FREQUENCY) {
if (cluster_flags & CPUINFO_LINUX_FLAG_MIN_FREQUENCY) {
if (cluster_min_frequency != processors[i].min_frequency) {
cpuinfo_log_info(
"minimum frequency of processor %"PRIu32" (%"PRIu32" KHz) is different than of preceding cluster (%"PRIu32" KHz); "
"processor %"PRIu32" starts to a new cluster",
i, processors[i].min_frequency, cluster_min_frequency, i);
goto new_cluster;
}
} else {
cluster_min_frequency = processors[i].min_frequency;
cluster_flags |= CPUINFO_LINUX_FLAG_MIN_FREQUENCY;
}
}
if (processors[i].flags & CPUINFO_LINUX_FLAG_MAX_FREQUENCY) {
if (cluster_flags & CPUINFO_LINUX_FLAG_MAX_FREQUENCY) {
if (cluster_max_frequency != processors[i].max_frequency) {
cpuinfo_log_debug(
"maximum frequency of processor %"PRIu32" (%"PRIu32" KHz) is different than of preceding cluster (%"PRIu32" KHz); "
"processor %"PRIu32" starts a new cluster",
i, processors[i].max_frequency, cluster_max_frequency, i);
goto new_cluster;
}
} else {
cluster_max_frequency = processors[i].max_frequency;
cluster_flags |= CPUINFO_LINUX_FLAG_MAX_FREQUENCY;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_IMPLEMENTER) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_IMPLEMENTER) {
if ((cluster_midr & CPUINFO_ARM_MIDR_IMPLEMENTER_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_IMPLEMENTER_MASK)) {
cpuinfo_log_debug(
"CPU Implementer of processor %"PRIu32" (0x%02"PRIx32") is different than of preceding cluster (0x%02"PRIx32"); "
"processor %"PRIu32" starts to a new cluster",
i, midr_get_implementer(processors[i].midr), midr_get_implementer(cluster_midr), i);
goto new_cluster;
}
} else {
cluster_midr = midr_copy_implementer(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_IMPLEMENTER;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_VARIANT) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_VARIANT) {
if ((cluster_midr & CPUINFO_ARM_MIDR_VARIANT_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_VARIANT_MASK)) {
cpuinfo_log_debug(
"CPU Variant of processor %"PRIu32" (0x%"PRIx32") is different than of its expected cluster (0x%"PRIx32")"
"processor %"PRIu32" starts to a new cluster",
i, midr_get_variant(processors[i].midr), midr_get_variant(cluster_midr), i);
goto new_cluster;
}
} else {
cluster_midr = midr_copy_variant(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_VARIANT;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_PART) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_PART) {
if ((cluster_midr & CPUINFO_ARM_MIDR_PART_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_PART_MASK)) {
cpuinfo_log_debug(
"CPU Part of processor %"PRIu32" (0x%03"PRIx32") is different than of its expected cluster (0x%03"PRIx32")"
"processor %"PRIu32" starts to a new cluster",
i, midr_get_part(processors[i].midr), midr_get_part(cluster_midr), i);
goto new_cluster;
}
} else {
cluster_midr = midr_copy_part(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_PART;
}
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_REVISION) {
if (cluster_flags & CPUINFO_ARM_LINUX_VALID_REVISION) {
if ((cluster_midr & CPUINFO_ARM_MIDR_REVISION_MASK) != (processors[i].midr & CPUINFO_ARM_MIDR_REVISION_MASK)) {
cpuinfo_log_debug(
"CPU Revision of processor %"PRIu32" (0x%"PRIx32") is different than of its expected cluster (0x%"PRIx32")"
"processor %"PRIu32" starts to a new cluster",
i, midr_get_revision(cluster_midr), midr_get_revision(processors[i].midr), i);
goto new_cluster;
}
} else {
cluster_midr = midr_copy_revision(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_REVISION;
}
}
/* All checks passed, attach processor to the preceding cluster */
cluster_processors++;
processors[i].package_leader_id = cluster_start;
processors[i].flags |= CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER;
cpuinfo_log_debug("assigned processor %"PRIu32" to preceding cluster of processor %"PRIu32, i, cluster_start);
continue;
new_cluster:
/* Create a new cluster starting with processor i */
cluster_start = i;
processors[i].package_leader_id = i;
processors[i].flags |= CPUINFO_LINUX_FLAG_PACKAGE_CLUSTER;
cluster_processors = 1;
/* Copy known information from processor to cluster, and set the flags accordingly */
cluster_flags = 0;
if (processors[i].flags & CPUINFO_LINUX_FLAG_MIN_FREQUENCY) {
cluster_min_frequency = processors[i].min_frequency;
cluster_flags |= CPUINFO_LINUX_FLAG_MIN_FREQUENCY;
}
if (processors[i].flags & CPUINFO_LINUX_FLAG_MAX_FREQUENCY) {
cluster_max_frequency = processors[i].max_frequency;
cluster_flags |= CPUINFO_LINUX_FLAG_MAX_FREQUENCY;
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_IMPLEMENTER) {
cluster_midr = midr_copy_implementer(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_IMPLEMENTER;
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_VARIANT) {
cluster_midr = midr_copy_variant(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_VARIANT;
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_PART) {
cluster_midr = midr_copy_part(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_PART;
}
if (processors[i].flags & CPUINFO_ARM_LINUX_VALID_REVISION) {
cluster_midr = midr_copy_revision(cluster_midr, processors[i].midr);
cluster_flags |= CPUINFO_ARM_LINUX_VALID_REVISION;
}
}
}
}
/*
* Counts the number of logical processors in each core cluster.
* This function should be called after all processors are assigned to core clusters.
*
* @param max_processors - number of elements in the @p processors array.
* @param[in,out] processors - processor descriptors with pre-parsed POSSIBLE and PRESENT flags,
* and decoded core cluster (package_leader_id) information.
* The function expects the value of processors[i].package_processor_count to be zero.
* Upon return, processors[i].package_processor_count will contain the number of logical
* processors in the respective core cluster.
*/
void cpuinfo_arm_linux_count_cluster_processors(
uint32_t max_processors,
struct cpuinfo_arm_linux_processor processors[restrict static max_processors])
{
/* First pass: accumulate the number of processors at the group leader's package_processor_count */
for (uint32_t i = 0; i < max_processors; i++) {
if (bitmask_all(processors[i].flags, CPUINFO_LINUX_FLAG_VALID)) {
const uint32_t package_leader_id = processors[i].package_leader_id;
processors[package_leader_id].package_processor_count += 1;
}
}
/* Second pass: copy the package_processor_count from the group leader processor */
for (uint32_t i = 0; i < max_processors; i++) {
if (bitmask_all(processors[i].flags, CPUINFO_LINUX_FLAG_VALID)) {
const uint32_t package_leader_id = processors[i].package_leader_id;
processors[i].package_processor_count = processors[package_leader_id].package_processor_count;
}
}
}
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