/*
* Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Authors:
* Anhua Xu
* Kevin Tian <[email protected]>
*
* Contributors:
* Min He <[email protected]>
* Bing Niu <[email protected]>
* Zhi Wang <[email protected]>
*
*/
#include "i915_drv.h"
#include "gvt.h"
static bool vgpu_has_pending_workload(struct intel_vgpu *vgpu)
{
enum intel_engine_id i;
struct intel_engine_cs *engine;
for_each_engine(engine, vgpu->gvt->gt, i) {
if (!list_empty(workload_q_head(vgpu, engine)))
return true;
}
return false;
}
/* We give 2 seconds higher prio for vGPU during start */
#define GVT_SCHED_VGPU_PRI_TIME 2
struct vgpu_sched_data {
struct list_head lru_list;
struct intel_vgpu *vgpu;
bool active;
bool pri_sched;
ktime_t pri_time;
ktime_t sched_in_time;
ktime_t sched_time;
ktime_t left_ts;
ktime_t allocated_ts;
struct vgpu_sched_ctl sched_ctl;
};
struct gvt_sched_data {
struct intel_gvt *gvt;
struct hrtimer timer;
unsigned long period;
struct list_head lru_runq_head;
ktime_t expire_time;
};
static void vgpu_update_timeslice(struct intel_vgpu *vgpu, ktime_t cur_time)
{
ktime_t delta_ts;
struct vgpu_sched_data *vgpu_data;
if (!vgpu || vgpu == vgpu->gvt->idle_vgpu)
return;
vgpu_data = vgpu->sched_data;
delta_ts = ktime_sub(cur_time, vgpu_data->sched_in_time);
vgpu_data->sched_time = ktime_add(vgpu_data->sched_time, delta_ts);
vgpu_data->left_ts = ktime_sub(vgpu_data->left_ts, delta_ts);
vgpu_data->sched_in_time = cur_time;
}
#define GVT_TS_BALANCE_PERIOD_MS 100
#define GVT_TS_BALANCE_STAGE_NUM 10
static void gvt_balance_timeslice(struct gvt_sched_data *sched_data)
{
struct vgpu_sched_data *vgpu_data;
struct list_head *pos;
static u64 stage_check;
int stage = stage_check++ % GVT_TS_BALANCE_STAGE_NUM;
/* The timeslice accumulation reset at stage 0, which is
* allocated again without adding previous debt.
*/
if (stage == 0) {
int total_weight = 0;
ktime_t fair_timeslice;
list_for_each(pos, &sched_data->lru_runq_head) {
vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
total_weight += vgpu_data->sched_ctl.weight;
}
list_for_each(pos, &sched_data->lru_runq_head) {
vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
fair_timeslice = ktime_divns(ms_to_ktime(GVT_TS_BALANCE_PERIOD_MS),
total_weight) * vgpu_data->sched_ctl.weight;
vgpu_data->allocated_ts = fair_timeslice;
vgpu_data->left_ts = vgpu_data->allocated_ts;
}
} else {
list_for_each(pos, &sched_data->lru_runq_head) {
vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
/* timeslice for next 100ms should add the left/debt
* slice of previous stages.
*/
vgpu_data->left_ts += vgpu_data->allocated_ts;
}
}
}
static void try_to_schedule_next_vgpu(struct intel_gvt *gvt)
{
struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
enum intel_engine_id i;
struct intel_engine_cs *engine;
struct vgpu_sched_data *vgpu_data;
ktime_t cur_time;
/* no need to schedule if next_vgpu is the same with current_vgpu,
* let scheduler chose next_vgpu again by setting it to NULL.
*/
if (scheduler->next_vgpu == scheduler->current_vgpu) {
scheduler->next_vgpu = NULL;
return;
}
/*
* after the flag is set, workload dispatch thread will
* stop dispatching workload for current vgpu
*/
scheduler->need_reschedule = true;
/* still have uncompleted workload? */
for_each_engine(engine, gvt->gt, i) {
if (scheduler->current_workload[engine->id])
return;
}
cur_time = ktime_get();
vgpu_update_timeslice(scheduler->current_vgpu, cur_time);
vgpu_data = scheduler->next_vgpu->sched_data;
vgpu_data->sched_in_time = cur_time;
/* switch current vgpu */
scheduler->current_vgpu = scheduler->next_vgpu;
scheduler->next_vgpu = NULL;
scheduler->need_reschedule = false;
/* wake up workload dispatch thread */
for_each_engine(engine, gvt->gt, i)
wake_up(&scheduler->waitq[engine->id]);
}
static struct intel_vgpu *find_busy_vgpu(struct gvt_sched_data *sched_data)
{
struct vgpu_sched_data *vgpu_data;
struct intel_vgpu *vgpu = NULL;
struct list_head *head = &sched_data->lru_runq_head;
struct list_head *pos;
/* search a vgpu with pending workload */
list_for_each(pos, head) {
vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
if (!vgpu_has_pending_workload(vgpu_data->vgpu))
continue;
if (vgpu_data->pri_sched) {
if (ktime_before(ktime_get(), vgpu_data->pri_time)) {
vgpu = vgpu_data->vgpu;
break;
} else
vgpu_data->pri_sched = false;
}
/* Return the vGPU only if it has time slice left */
if (vgpu_data->left_ts > 0) {
vgpu = vgpu_data->vgpu;
break;
}
}
return vgpu;
}
/* in nanosecond */
#define GVT_DEFAULT_TIME_SLICE 1000000
static void tbs_sched_func(struct gvt_sched_data *sched_data)
{
struct intel_gvt *gvt = sched_data->gvt;
struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
struct vgpu_sched_data *vgpu_data;
struct intel_vgpu *vgpu = NULL;
/* no active vgpu or has already had a target */
if (list_empty(&sched_data->lru_runq_head) || scheduler->next_vgpu)
goto out;
vgpu = find_busy_vgpu(sched_data);
if (vgpu) {
scheduler->next_vgpu = vgpu;
vgpu_data = vgpu->sched_data;
if (!vgpu_data->pri_sched) {
/* Move the last used vGPU to the tail of lru_list */
list_del_init(&vgpu_data->lru_list);
list_add_tail(&vgpu_data->lru_list,
&sched_data->lru_runq_head);
}
} else {
scheduler->next_vgpu = gvt->idle_vgpu;
}
out:
if (scheduler->next_vgpu)
try_to_schedule_next_vgpu(gvt);
}
void intel_gvt_schedule(struct intel_gvt *gvt)
{
struct gvt_sched_data *sched_data = gvt->scheduler.sched_data;
ktime_t cur_time;
mutex_lock(&gvt->sched_lock);
cur_time = ktime_get();
if (test_and_clear_bit(INTEL_GVT_REQUEST_SCHED,
(void *)&gvt->service_request)) {
if (cur_time >= sched_data->expire_time) {
gvt_balance_timeslice(sched_data);
sched_data->expire_time = ktime_add_ms(
cur_time, GVT_TS_BALANCE_PERIOD_MS);
}
}
clear_bit(INTEL_GVT_REQUEST_EVENT_SCHED, (void *)&gvt->service_request);
vgpu_update_timeslice(gvt->scheduler.current_vgpu, cur_time);
tbs_sched_func(sched_data);
mutex_unlock(&gvt->sched_lock);
}
static enum hrtimer_restart tbs_timer_fn(struct hrtimer *timer_data)
{
struct gvt_sched_data *data;
data = container_of(timer_data, struct gvt_sched_data, timer);
intel_gvt_request_service(data->gvt, INTEL_GVT_REQUEST_SCHED);
hrtimer_add_expires_ns(&data->timer, data->period);
return HRTIMER_RESTART;
}
static int tbs_sched_init(struct intel_gvt *gvt)
{
struct intel_gvt_workload_scheduler *scheduler =
&gvt->scheduler;
struct gvt_sched_data *data;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
INIT_LIST_HEAD(&data->lru_runq_head);
hrtimer_init(&data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
data->timer.function = tbs_timer_fn;
data->period = GVT_DEFAULT_TIME_SLICE;
data->gvt = gvt;
scheduler->sched_data = data;
return 0;
}
static void tbs_sched_clean(struct intel_gvt *gvt)
{
struct intel_gvt_workload_scheduler *scheduler =
&gvt->scheduler;
struct gvt_sched_data *data = scheduler->sched_data;
hrtimer_cancel(&data->timer);
kfree(data);
scheduler->sched_data = NULL;
}
static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu)
{
struct vgpu_sched_data *data;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->sched_ctl.weight = vgpu->sched_ctl.weight;
data->vgpu = vgpu;
INIT_LIST_HEAD(&data->lru_list);
vgpu->sched_data = data;
return 0;
}
static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu)
{
struct intel_gvt *gvt = vgpu->gvt;
struct gvt_sched_data *sched_data = gvt->scheduler.sched_data;
kfree(vgpu->sched_data);
vgpu->sched_data = NULL;
/* this vgpu id has been removed */
if (idr_is_empty(&gvt->vgpu_idr))
hrtimer_cancel(&sched_data->timer);
}
static void tbs_sched_start_schedule(struct intel_vgpu *vgpu)
{
struct gvt_sched_data *sched_data = vgpu->gvt->scheduler.sched_data;
struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
ktime_t now;
if (!list_empty(&vgpu_data->lru_list))
return;
now = ktime_get();
vgpu_data->pri_time = ktime_add(now,
ktime_set(GVT_SCHED_VGPU_PRI_TIME, 0));
vgpu_data->pri_sched = true;
list_add(&vgpu_data->lru_list, &sched_data->lru_runq_head);
if (!hrtimer_active(&sched_data->timer))
hrtimer_start(&sched_data->timer, ktime_add_ns(ktime_get(),
sched_data->period), HRTIMER_MODE_ABS);
vgpu_data->active = true;
}
static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu)
{
struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
list_del_init(&vgpu_data->lru_list);
vgpu_data->active = false;
}
static const struct intel_gvt_sched_policy_ops tbs_schedule_ops = {
.init = tbs_sched_init,
.clean = tbs_sched_clean,
.init_vgpu = tbs_sched_init_vgpu,
.clean_vgpu = tbs_sched_clean_vgpu,
.start_schedule = tbs_sched_start_schedule,
.stop_schedule = tbs_sched_stop_schedule,
};
int intel_gvt_init_sched_policy(struct intel_gvt *gvt)
{
int ret;
mutex_lock(&gvt->sched_lock);
gvt->scheduler.sched_ops = &tbs_schedule_ops;
ret = gvt->scheduler.sched_ops->init(gvt);
mutex_unlock(&gvt->sched_lock);
return ret;
}
void intel_gvt_clean_sched_policy(struct intel_gvt *gvt)
{
mutex_lock(&gvt->sched_lock);
gvt->scheduler.sched_ops->clean(gvt);
mutex_unlock(&gvt->sched_lock);
}
/* for per-vgpu scheduler policy, there are 2 per-vgpu data:
* sched_data, and sched_ctl. We see these 2 data as part of
* the global scheduler which are proteced by gvt->sched_lock.
* Caller should make their decision if the vgpu_lock should
* be hold outside.
*/
int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu)
{
int ret;
mutex_lock(&vgpu->gvt->sched_lock);
ret = vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu);
mutex_unlock(&vgpu->gvt->sched_lock);
return ret;
}
void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu)
{
mutex_lock(&vgpu->gvt->sched_lock);
vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu);
mutex_unlock(&vgpu->gvt->sched_lock);
}
void intel_vgpu_start_schedule(struct intel_vgpu *vgpu)
{
struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
mutex_lock(&vgpu->gvt->sched_lock);
if (!vgpu_data->active) {
gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id);
vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
}
mutex_unlock(&vgpu->gvt->sched_lock);
}
void intel_gvt_kick_schedule(struct intel_gvt *gvt)
{
mutex_lock(&gvt->sched_lock);
intel_gvt_request_service(gvt, INTEL_GVT_REQUEST_EVENT_SCHED);
mutex_unlock(&gvt->sched_lock);
}
void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
{
struct intel_gvt_workload_scheduler *scheduler =
&vgpu->gvt->scheduler;
struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
struct drm_i915_private *dev_priv = vgpu->gvt->gt->i915;
struct intel_engine_cs *engine;
enum intel_engine_id id;
if (!vgpu_data->active)
return;
gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id);
mutex_lock(&vgpu->gvt->sched_lock);
scheduler->sched_ops->stop_schedule(vgpu);
if (scheduler->next_vgpu == vgpu)
scheduler->next_vgpu = NULL;
if (scheduler->current_vgpu == vgpu) {
/* stop workload dispatching */
scheduler->need_reschedule = true;
scheduler->current_vgpu = NULL;
}
intel_runtime_pm_get(&dev_priv->runtime_pm);
spin_lock_bh(&scheduler->mmio_context_lock);
for_each_engine(engine, vgpu->gvt->gt, id) {
if (scheduler->engine_owner[engine->id] == vgpu) {
intel_gvt_switch_mmio(vgpu, NULL, engine);
scheduler->engine_owner[engine->id] = NULL;
}
}
spin_unlock_bh(&scheduler->mmio_context_lock);
intel_runtime_pm_put_unchecked(&dev_priv->runtime_pm);
mutex_unlock(&vgpu->gvt->sched_lock);
}
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