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drm/i915: Split out parking from the idle worker for reuse

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We will want to park GEM before disengaging the drive^W^W^W unwedging.
Since we already do the work for idling, expose the guts as a new
function that we can then reuse.

v2: Just skip if already parked; makes it more forgiving to use by
future callers.
v3: Extract mark_busy, rename it to i915_gem_unpark and place it next to
i915_gem_park so that we can evaluate it for symmetry more easily.
Calling GEM from inside i915_request looks to be a bit of a layering
violation, for the moment I am imaging them as being notify_cb.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> #v1
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180406155144.27791-1-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2018-04-06 16:51:44 +01:00
parent 29991d533f
commit e4d2006f8f
3 changed files with 103 additions and 77 deletions
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123
drivers/gpu/drm/i915/i915_gem.c
View file

@ -136,6 +136,100 @@ int i915_mutex_lock_interruptible(struct drm_device *dev)
return 0;
}
static u32 __i915_gem_park(struct drm_i915_private *i915)
{
lockdep_assert_held(&i915->drm.struct_mutex);
GEM_BUG_ON(i915->gt.active_requests);
if (!i915->gt.awake)
return I915_EPOCH_INVALID;
GEM_BUG_ON(i915->gt.epoch == I915_EPOCH_INVALID);
/*
* Be paranoid and flush a concurrent interrupt to make sure
* we don't reactivate any irq tasklets after parking.
*
* FIXME: Note that even though we have waited for execlists to be idle,
* there may still be an in-flight interrupt even though the CSB
* is now empty. synchronize_irq() makes sure that a residual interrupt
* is completed before we continue, but it doesn't prevent the HW from
* raising a spurious interrupt later. To complete the shield we should
* coordinate disabling the CS irq with flushing the interrupts.
*/
synchronize_irq(i915->drm.irq);
intel_engines_park(i915);
i915_gem_timelines_park(i915);
i915_pmu_gt_parked(i915);
i915->gt.awake = false;
if (INTEL_GEN(i915) >= 6)
gen6_rps_idle(i915);
intel_display_power_put(i915, POWER_DOMAIN_GT_IRQ);
intel_runtime_pm_put(i915);
return i915->gt.epoch;
}
void i915_gem_park(struct drm_i915_private *i915)
{
lockdep_assert_held(&i915->drm.struct_mutex);
GEM_BUG_ON(i915->gt.active_requests);
if (!i915->gt.awake)
return;
/* Defer the actual call to __i915_gem_park() to prevent ping-pongs */
mod_delayed_work(i915->wq, &i915->gt.idle_work, msecs_to_jiffies(100));
}
void i915_gem_unpark(struct drm_i915_private *i915)
{
lockdep_assert_held(&i915->drm.struct_mutex);
GEM_BUG_ON(!i915->gt.active_requests);
if (i915->gt.awake)
return;
intel_runtime_pm_get_noresume(i915);
/*
* It seems that the DMC likes to transition between the DC states a lot
* when there are no connected displays (no active power domains) during
* command submission.
*
* This activity has negative impact on the performance of the chip with
* huge latencies observed in the interrupt handler and elsewhere.
*
* Work around it by grabbing a GT IRQ power domain whilst there is any
* GT activity, preventing any DC state transitions.
*/
intel_display_power_get(i915, POWER_DOMAIN_GT_IRQ);
i915->gt.awake = true;
if (unlikely(++i915->gt.epoch == 0)) /* keep 0 as invalid */
i915->gt.epoch = 1;
intel_enable_gt_powersave(i915);
i915_update_gfx_val(i915);
if (INTEL_GEN(i915) >= 6)
gen6_rps_busy(i915);
i915_pmu_gt_unparked(i915);
intel_engines_unpark(i915);
i915_queue_hangcheck(i915);
queue_delayed_work(i915->wq,
&i915->gt.retire_work,
round_jiffies_up_relative(HZ));
}
int
i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
@ -3496,36 +3590,9 @@ i915_gem_idle_work_handler(struct work_struct *work)
if (new_requests_since_last_retire(dev_priv))
goto out_unlock;
/*
* Be paranoid and flush a concurrent interrupt to make sure
* we don't reactivate any irq tasklets after parking.
*
* FIXME: Note that even though we have waited for execlists to be idle,
* there may still be an in-flight interrupt even though the CSB
* is now empty. synchronize_irq() makes sure that a residual interrupt
* is completed before we continue, but it doesn't prevent the HW from
* raising a spurious interrupt later. To complete the shield we should
* coordinate disabling the CS irq with flushing the interrupts.
*/
synchronize_irq(dev_priv->drm.irq);
epoch = __i915_gem_park(dev_priv);
intel_engines_park(dev_priv);
i915_gem_timelines_park(dev_priv);
i915_pmu_gt_parked(dev_priv);
GEM_BUG_ON(!dev_priv->gt.awake);
dev_priv->gt.awake = false;
epoch = dev_priv->gt.epoch;
GEM_BUG_ON(epoch == I915_EPOCH_INVALID);
rearm_hangcheck = false;
if (INTEL_GEN(dev_priv) >= 6)
gen6_rps_idle(dev_priv);
intel_display_power_put(dev_priv, POWER_DOMAIN_GT_IRQ);
intel_runtime_pm_put(dev_priv);
out_unlock:
mutex_unlock(&dev_priv->drm.struct_mutex);

5
drivers/gpu/drm/i915/i915_gem.h
View file

@ -27,6 +27,8 @@
#include <linux/bug.h>
struct drm_i915_private;
#ifdef CONFIG_DRM_I915_DEBUG_GEM
#define GEM_BUG_ON(condition) do { if (unlikely((condition))) { \
pr_err("%s:%d GEM_BUG_ON(%s)\n", \
@ -61,4 +63,7 @@
#define I915_NUM_ENGINES 8
void i915_gem_park(struct drm_i915_private *i915);
void i915_gem_unpark(struct drm_i915_private *i915);
#endif /* __I915_GEM_H__ */

52
drivers/gpu/drm/i915/i915_request.c
View file

@ -255,47 +255,6 @@ int i915_gem_set_global_seqno(struct drm_device *dev, u32 seqno)
return reset_all_global_seqno(i915, seqno - 1);
}
static void mark_busy(struct drm_i915_private *i915)
{
if (i915->gt.awake)
return;
GEM_BUG_ON(!i915->gt.active_requests);
intel_runtime_pm_get_noresume(i915);
/*
* It seems that the DMC likes to transition between the DC states a lot
* when there are no connected displays (no active power domains) during
* command submission.
*
* This activity has negative impact on the performance of the chip with
* huge latencies observed in the interrupt handler and elsewhere.
*
* Work around it by grabbing a GT IRQ power domain whilst there is any
* GT activity, preventing any DC state transitions.
*/
intel_display_power_get(i915, POWER_DOMAIN_GT_IRQ);
i915->gt.awake = true;
if (unlikely(++i915->gt.epoch == 0)) /* keep 0 as invalid */
i915->gt.epoch = 1;
intel_enable_gt_powersave(i915);
i915_update_gfx_val(i915);
if (INTEL_GEN(i915) >= 6)
gen6_rps_busy(i915);
i915_pmu_gt_unparked(i915);
intel_engines_unpark(i915);
i915_queue_hangcheck(i915);
queue_delayed_work(i915->wq,
&i915->gt.retire_work,
round_jiffies_up_relative(HZ));
}
static int reserve_engine(struct intel_engine_cs *engine)
{
struct drm_i915_private *i915 = engine->i915;
@ -313,7 +272,7 @@ static int reserve_engine(struct intel_engine_cs *engine)
}
if (!i915->gt.active_requests++)
mark_busy(i915);
i915_gem_unpark(i915);
return 0;
}
@ -322,13 +281,8 @@ static void unreserve_engine(struct intel_engine_cs *engine)
{
struct drm_i915_private *i915 = engine->i915;
if (!--i915->gt.active_requests) {
/* Cancel the mark_busy() from our reserve_engine() */
GEM_BUG_ON(!i915->gt.awake);
mod_delayed_work(i915->wq,
&i915->gt.idle_work,
msecs_to_jiffies(100));
}
if (!--i915->gt.active_requests)
i915_gem_park(i915);
GEM_BUG_ON(!engine->timeline->inflight_seqnos);
engine->timeline->inflight_seqnos--;