Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  kernel/sched/cpudl.c
 *
 *  Global CPU deadline management
 *
 *  Author: Juri Lelli <j.lelli@sssup.it>
 */
#include "sched.h"
 
static inline int parent(int i)
{
<------>return (i - 1) >> 1;
}
 
static inline int left_child(int i)
{
<------>return (i << 1) + 1;
}
 
static inline int right_child(int i)
{
<------>return (i << 1) + 2;
}
 
static void cpudl_heapify_down(struct cpudl *cp, int idx)
{
<------>int l, r, largest;
 
<------>int orig_cpu = cp->elements[idx].cpu;
<------>u64 orig_dl = cp->elements[idx].dl;
 
<------>if (left_child(idx) >= cp->size)
<------><------>return;
 
<------>/* adapted from lib/prio_heap.c */
<------>while (1) {
<------><------>u64 largest_dl;
 
<------><------>l = left_child(idx);
<------><------>r = right_child(idx);
<------><------>largest = idx;
<------><------>largest_dl = orig_dl;
 
<------><------>if ((l < cp->size) && dl_time_before(orig_dl,
<------><------><------><------><------><------>cp->elements[l].dl)) {
<------><------><------>largest = l;
<------><------><------>largest_dl = cp->elements[l].dl;
<------><------>}
<------><------>if ((r < cp->size) && dl_time_before(largest_dl,
<------><------><------><------><------><------>cp->elements[r].dl))
<------><------><------>largest = r;
 
<------><------>if (largest == idx)
<------><------><------>break;
 
<------><------>/* pull largest child onto idx */
<------><------>cp->elements[idx].cpu = cp->elements[largest].cpu;
<------><------>cp->elements[idx].dl = cp->elements[largest].dl;
<------><------>cp->elements[cp->elements[idx].cpu].idx = idx;
<------><------>idx = largest;
<------>}
<------>/* actual push down of saved original values orig_* */
<------>cp->elements[idx].cpu = orig_cpu;
<------>cp->elements[idx].dl = orig_dl;
<------>cp->elements[cp->elements[idx].cpu].idx = idx;
}
 
static void cpudl_heapify_up(struct cpudl *cp, int idx)
{
<------>int p;
 
<------>int orig_cpu = cp->elements[idx].cpu;
<------>u64 orig_dl = cp->elements[idx].dl;
 
<------>if (idx == 0)
<------><------>return;
 
<------>do {
<------><------>p = parent(idx);
<------><------>if (dl_time_before(orig_dl, cp->elements[p].dl))
<------><------><------>break;
<------><------>/* pull parent onto idx */
<------><------>cp->elements[idx].cpu = cp->elements[p].cpu;
<------><------>cp->elements[idx].dl = cp->elements[p].dl;
<------><------>cp->elements[cp->elements[idx].cpu].idx = idx;
<------><------>idx = p;
<------>} while (idx != 0);
<------>/* actual push up of saved original values orig_* */
<------>cp->elements[idx].cpu = orig_cpu;
<------>cp->elements[idx].dl = orig_dl;
<------>cp->elements[cp->elements[idx].cpu].idx = idx;
}
 
static void cpudl_heapify(struct cpudl *cp, int idx)
{
<------>if (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
<------><------><------><------>cp->elements[idx].dl))
<------><------>cpudl_heapify_up(cp, idx);
<------>else
<------><------>cpudl_heapify_down(cp, idx);
}
 
static inline int cpudl_maximum(struct cpudl *cp)
{
<------>return cp->elements[0].cpu;
}
 
/*
 * cpudl_find - find the best (later-dl) CPU in the system
 * @cp: the cpudl max-heap context
 * @p: the task
 * @later_mask: a mask to fill in with the selected CPUs (or NULL)
 *
 * Returns: int - CPUs were found
 */
int cpudl_find(struct cpudl *cp, struct task_struct *p,
<------>       struct cpumask *later_mask)
{
<------>const struct sched_dl_entity *dl_se = &p->dl;
 
<------>if (later_mask &&
<------>    cpumask_and(later_mask, cp->free_cpus, p->cpus_ptr)) {
<------><------>unsigned long cap, max_cap = 0;
<------><------>int cpu, max_cpu = -1;
 
<------><------>if (!static_branch_unlikely(&sched_asym_cpucapacity))
<------><------><------>return 1;
 
<------><------>/* Ensure the capacity of the CPUs fits the task. */
<------><------>for_each_cpu(cpu, later_mask) {
<------><------><------>if (!dl_task_fits_capacity(p, cpu)) {
<------><------><------><------>cpumask_clear_cpu(cpu, later_mask);
 
<------><------><------><------>cap = capacity_orig_of(cpu);
 
<------><------><------><------>if (cap > max_cap ||
<------><------><------><------>    (cpu == task_cpu(p) && cap == max_cap)) {
<------><------><------><------><------>max_cap = cap;
<------><------><------><------><------>max_cpu = cpu;
<------><------><------><------>}
<------><------><------>}
<------><------>}
 
<------><------>if (cpumask_empty(later_mask))
<------><------><------>cpumask_set_cpu(max_cpu, later_mask);
 
<------><------>return 1;
<------>} else {
<------><------>int best_cpu = cpudl_maximum(cp);
 
<------><------>WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
<------><------>if (cpumask_test_cpu(best_cpu, p->cpus_ptr) &&
<------><------>    dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
<------><------><------>if (later_mask)
<------><------><------><------>cpumask_set_cpu(best_cpu, later_mask);
 
<------><------><------>return 1;
<------><------>}
<------>}
<------>return 0;
}
 
/*
 * cpudl_clear - remove a CPU from the cpudl max-heap
 * @cp: the cpudl max-heap context
 * @cpu: the target CPU
 *
 * Notes: assumes cpu_rq(cpu)->lock is locked
 *
 * Returns: (void)
 */
void cpudl_clear(struct cpudl *cp, int cpu)
{
<------>int old_idx, new_cpu;
<------>unsigned long flags;
 
<------>WARN_ON(!cpu_present(cpu));
 
<------>raw_spin_lock_irqsave(&cp->lock, flags);
 
<------>old_idx = cp->elements[cpu].idx;
<------>if (old_idx == IDX_INVALID) {
<------><------>/*
<------><------> * Nothing to remove if old_idx was invalid.
<------><------> * This could happen if a rq_offline_dl is
<------><------> * called for a CPU without -dl tasks running.
<------><------> */
<------>} else {
<------><------>new_cpu = cp->elements[cp->size - 1].cpu;
<------><------>cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl;
<------><------>cp->elements[old_idx].cpu = new_cpu;
<------><------>cp->size--;
<------><------>cp->elements[new_cpu].idx = old_idx;
<------><------>cp->elements[cpu].idx = IDX_INVALID;
<------><------>cpudl_heapify(cp, old_idx);
 
<------><------>cpumask_set_cpu(cpu, cp->free_cpus);
<------>}
<------>raw_spin_unlock_irqrestore(&cp->lock, flags);
}
 
/*
 * cpudl_set - update the cpudl max-heap
 * @cp: the cpudl max-heap context
 * @cpu: the target CPU
 * @dl: the new earliest deadline for this CPU
 *
 * Notes: assumes cpu_rq(cpu)->lock is locked
 *
 * Returns: (void)
 */
void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
{
<------>int old_idx;
<------>unsigned long flags;
 
<------>WARN_ON(!cpu_present(cpu));
 
<------>raw_spin_lock_irqsave(&cp->lock, flags);
 
<------>old_idx = cp->elements[cpu].idx;
<------>if (old_idx == IDX_INVALID) {
<------><------>int new_idx = cp->size++;
 
<------><------>cp->elements[new_idx].dl = dl;
<------><------>cp->elements[new_idx].cpu = cpu;
<------><------>cp->elements[cpu].idx = new_idx;
<------><------>cpudl_heapify_up(cp, new_idx);
<------><------>cpumask_clear_cpu(cpu, cp->free_cpus);
<------>} else {
<------><------>cp->elements[old_idx].dl = dl;
<------><------>cpudl_heapify(cp, old_idx);
<------>}
 
<------>raw_spin_unlock_irqrestore(&cp->lock, flags);
}
 
/*
 * cpudl_set_freecpu - Set the cpudl.free_cpus
 * @cp: the cpudl max-heap context
 * @cpu: rd attached CPU
 */
void cpudl_set_freecpu(struct cpudl *cp, int cpu)
{
<------>cpumask_set_cpu(cpu, cp->free_cpus);
}
 
/*
 * cpudl_clear_freecpu - Clear the cpudl.free_cpus
 * @cp: the cpudl max-heap context
 * @cpu: rd attached CPU
 */
void cpudl_clear_freecpu(struct cpudl *cp, int cpu)
{
<------>cpumask_clear_cpu(cpu, cp->free_cpus);
}
 
/*
 * cpudl_init - initialize the cpudl structure
 * @cp: the cpudl max-heap context
 */
int cpudl_init(struct cpudl *cp)
{
<------>int i;
 
<------>raw_spin_lock_init(&cp->lock);
<------>cp->size = 0;
 
<------>cp->elements = kcalloc(nr_cpu_ids,
<------><------><------>       sizeof(struct cpudl_item),
<------><------><------>       GFP_KERNEL);
<------>if (!cp->elements)
<------><------>return -ENOMEM;
 
<------>if (!zalloc_cpumask_var(&cp->free_cpus, GFP_KERNEL)) {
<------><------>kfree(cp->elements);
<------><------>return -ENOMEM;
<------>}
 
<------>for_each_possible_cpu(i)
<------><------>cp->elements[i].idx = IDX_INVALID;
 
<------>return 0;
}
 
/*
 * cpudl_cleanup - clean up the cpudl structure
 * @cp: the cpudl max-heap context
 */
void cpudl_cleanup(struct cpudl *cp)
{
<------>free_cpumask_var(cp->free_cpus);
<------>kfree(cp->elements);
}