/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2018 Intel Corporation
*/
#ifndef _I915_SCHEDULER_H_
#define _I915_SCHEDULER_H_
#include <linux/bitops.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include "i915_scheduler_types.h"
#define priolist_for_each_request(it, plist, idx) \
for (idx = 0; idx < ARRAY_SIZE((plist)->requests); idx++) \
list_for_each_entry(it, &(plist)->requests[idx], sched.link)
#define priolist_for_each_request_consume(it, n, plist, idx) \
for (; \
(plist)->used ? (idx = __ffs((plist)->used)), 1 : 0; \
(plist)->used &= ~BIT(idx)) \
list_for_each_entry_safe(it, n, \
&(plist)->requests[idx], \
sched.link)
void i915_sched_node_init(struct i915_sched_node *node);
bool __i915_sched_node_add_dependency(struct i915_sched_node *node,
struct i915_sched_node *signal,
struct i915_dependency *dep,
unsigned long flags);
int i915_sched_node_add_dependency(struct i915_sched_node *node,
struct i915_sched_node *signal);
void i915_sched_node_fini(struct i915_sched_node *node);
void i915_schedule(struct i915_request *request,
const struct i915_sched_attr *attr);
void i915_schedule_bump_priority(struct i915_request *rq, unsigned int bump);
struct list_head *
i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio);
void __i915_priolist_free(struct i915_priolist *p);
static inline void i915_priolist_free(struct i915_priolist *p)
{
if (p->priority != I915_PRIORITY_NORMAL)
__i915_priolist_free(p);
}
static inline bool i915_scheduler_need_preempt(int prio, int active)
{
/*
* Allow preemption of low -> normal -> high, but we do
* not allow low priority tasks to preempt other low priority
* tasks under the impression that latency for low priority
* tasks does not matter (as much as background throughput),
* so kiss.
*
* More naturally we would write
* prio >= max(0, last);
* except that we wish to prevent triggering preemption at the same
* priority level: the task that is running should remain running
* to preserve FIFO ordering of dependencies.
*/
return prio > max(I915_PRIORITY_NORMAL - 1, active);
}
#endif /* _I915_SCHEDULER_H_ */
