[Intel-gfx] [PATCH 7/8] drm/i915: Defer enabling rc6 til after we submit the first batch/context
Mika Kuoppala
mika.kuoppala at linux.intel.com
Thu Jul 14 13:56:50 UTC 2016
Chris Wilson <chris at chris-wilson.co.uk> writes:
> Some hardware requires a valid render context before it can initiate
> rc6 power gating of the GPU; the default state of the GPU is not
> sufficient and may lead to undefined behaviour. The first execution of
> any batch will load the "golden render state", at which point it is safe
> to enable rc6. As we do not forcibly load the kernel context at resume,
> we have to hook into the batch submission to be sure that the render
> state is setup before enabling rc6.
>
> However, since we don't enable powersaving until that first batch, we
> queued a delayed task in order to guarantee that the batch is indeed
> submitted.
>
> v2: Rearrange intel_disable_gt_powersave() to match.
> v3: Apply user specified cur_freq (or idle_freq if not set).
> v4: Give in, and supply a delayed work to autoenable rc6
> v5: Mika suggested a couple of better names for delayed_resume_work
> v6: Rebalance rpm_put around the autoenable task
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Ta for splitting stuff out from this patch(set) to smaller
bits. I think it's all done now.
Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com
> ---
> drivers/gpu/drm/i915/i915_drv.c | 11 +--
> drivers/gpu/drm/i915/i915_drv.h | 2 +-
> drivers/gpu/drm/i915/i915_gem.c | 3 +
> drivers/gpu/drm/i915/intel_display.c | 1 -
> drivers/gpu/drm/i915/intel_drv.h | 3 +-
> drivers/gpu/drm/i915/intel_pm.c | 136 +++++++++++++++++++++--------------
> drivers/gpu/drm/i915/intel_uncore.c | 2 +-
> 7 files changed, 94 insertions(+), 64 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index b9a811750ca8..c6cc01faaa36 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1343,7 +1343,7 @@ void i915_driver_unload(struct drm_device *dev)
> i915_destroy_error_state(dev);
>
> /* Flush any outstanding unpin_work. */
> - flush_workqueue(dev_priv->wq);
> + drain_workqueue(dev_priv->wq);
>
> intel_guc_fini(dev);
> i915_gem_fini(dev);
> @@ -1458,8 +1458,6 @@ static int i915_drm_suspend(struct drm_device *dev)
>
> intel_guc_suspend(dev);
>
> - intel_suspend_gt_powersave(dev_priv);
> -
> intel_display_suspend(dev);
>
> intel_dp_mst_suspend(dev);
> @@ -1652,6 +1650,7 @@ static int i915_drm_resume(struct drm_device *dev)
>
> intel_opregion_notify_adapter(dev_priv, PCI_D0);
>
> + intel_autoenable_gt_powersave(dev_priv);
> drm_kms_helper_poll_enable(dev);
>
> enable_rpm_wakeref_asserts(dev_priv);
> @@ -1778,8 +1777,6 @@ int i915_reset(struct drm_i915_private *dev_priv)
> unsigned reset_counter;
> int ret;
>
> - intel_reset_gt_powersave(dev_priv);
> -
> mutex_lock(&dev->struct_mutex);
>
> /* Clear any previous failed attempts at recovery. Time to try again. */
> @@ -1835,8 +1832,7 @@ int i915_reset(struct drm_i915_private *dev_priv)
> * previous concerns that it doesn't respond well to some forms
> * of re-init after reset.
> */
> - if (INTEL_INFO(dev)->gen > 5)
> - intel_enable_gt_powersave(dev_priv);
> + intel_autoenable_gt_powersave(dev_priv);
>
> return 0;
>
> @@ -2459,7 +2455,6 @@ static int intel_runtime_resume(struct device *device)
> * we can do is to hope that things will still work (and disable RPM).
> */
> i915_gem_init_swizzling(dev);
> - gen6_update_ring_freq(dev_priv);
>
> intel_runtime_pm_enable_interrupts(dev_priv);
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index fe85235367be..1fdca3bb7f33 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1188,7 +1188,7 @@ struct intel_gen6_power_mgmt {
> bool client_boost;
>
> bool enabled;
> - struct delayed_work delayed_resume_work;
> + struct delayed_work autoenable_work;
> unsigned boosts;
>
> struct intel_rps_client semaphores, mmioflips;
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 9d8c26f42dee..67c3bffb700d 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2842,6 +2842,7 @@ static void i915_gem_mark_busy(const struct intel_engine_cs *engine)
> intel_runtime_pm_get_noresume(dev_priv);
> dev_priv->gt.awake = true;
>
> + intel_enable_gt_powersave(dev_priv);
> i915_update_gfx_val(dev_priv);
> if (INTEL_GEN(dev_priv) >= 6)
> gen6_rps_busy(dev_priv);
> @@ -4980,6 +4981,8 @@ i915_gem_suspend(struct drm_device *dev)
> struct drm_i915_private *dev_priv = to_i915(dev);
> int ret = 0;
>
> + intel_suspend_gt_powersave(dev_priv);
> +
> mutex_lock(&dev->struct_mutex);
> ret = i915_gem_wait_for_idle(dev_priv);
> if (ret)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index be3b2cab2640..88589b5bde25 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -15456,7 +15456,6 @@ void intel_modeset_init_hw(struct drm_device *dev)
> dev_priv->atomic_cdclk_freq = dev_priv->cdclk_freq;
>
> intel_init_clock_gating(dev);
> - intel_enable_gt_powersave(dev_priv);
> }
>
> /*
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 6c8485c3a44f..c036dfdffe0d 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1690,10 +1690,11 @@ void intel_gpu_ips_init(struct drm_i915_private *dev_priv);
> void intel_gpu_ips_teardown(void);
> void intel_init_gt_powersave(struct drm_i915_private *dev_priv);
> void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv);
> +void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv);
> void intel_enable_gt_powersave(struct drm_i915_private *dev_priv);
> +void intel_autoenable_gt_powersave(struct drm_i915_private *dev_priv);
> void intel_disable_gt_powersave(struct drm_i915_private *dev_priv);
> void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv);
> -void intel_reset_gt_powersave(struct drm_i915_private *dev_priv);
> void gen6_update_ring_freq(struct drm_i915_private *dev_priv);
> void gen6_rps_busy(struct drm_i915_private *dev_priv);
> void gen6_rps_reset_ei(struct drm_i915_private *dev_priv);
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index aab1e0b5d2eb..c77ec106a93c 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -6536,6 +6536,8 @@ void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
> dev_priv->rps.boost_freq = dev_priv->rps.max_freq;
>
> mutex_unlock(&dev_priv->rps.hw_lock);
> +
> + intel_autoenable_gt_powersave(dev_priv);
> }
>
> void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
> @@ -6549,13 +6551,6 @@ void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
> intel_runtime_pm_put(dev_priv);
> }
>
> -static void gen6_suspend_rps(struct drm_i915_private *dev_priv)
> -{
> - flush_delayed_work(&dev_priv->rps.delayed_resume_work);
> -
> - gen6_disable_rps_interrupts(dev_priv);
> -}
> -
> /**
> * intel_suspend_gt_powersave - suspend PM work and helper threads
> * @dev_priv: i915 device
> @@ -6569,50 +6564,63 @@ void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv)
> if (INTEL_GEN(dev_priv) < 6)
> return;
>
> - gen6_suspend_rps(dev_priv);
> + if (cancel_delayed_work_sync(&dev_priv->rps.autoenable_work))
> + intel_runtime_pm_put(dev_priv);
>
> - /* Force GPU to min freq during suspend */
> - gen6_rps_idle(dev_priv);
> + /* gen6_rps_idle() will be called later to disable interrupts */
> +}
> +
> +void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv)
> +{
> + dev_priv->rps.enabled = true; /* force disabling */
> + intel_disable_gt_powersave(dev_priv);
> +
> + gen6_reset_rps_interrupts(dev_priv);
> }
>
> void intel_disable_gt_powersave(struct drm_i915_private *dev_priv)
> {
> - if (IS_IRONLAKE_M(dev_priv)) {
> - ironlake_disable_drps(dev_priv);
> - } else if (INTEL_INFO(dev_priv)->gen >= 6) {
> - intel_suspend_gt_powersave(dev_priv);
> + if (!READ_ONCE(dev_priv->rps.enabled))
> + return;
>
> - mutex_lock(&dev_priv->rps.hw_lock);
> - if (INTEL_INFO(dev_priv)->gen >= 9) {
> - gen9_disable_rc6(dev_priv);
> - gen9_disable_rps(dev_priv);
> - } else if (IS_CHERRYVIEW(dev_priv))
> - cherryview_disable_rps(dev_priv);
> - else if (IS_VALLEYVIEW(dev_priv))
> - valleyview_disable_rps(dev_priv);
> - else
> - gen6_disable_rps(dev_priv);
> + mutex_lock(&dev_priv->rps.hw_lock);
>
> - dev_priv->rps.enabled = false;
> - mutex_unlock(&dev_priv->rps.hw_lock);
> + if (INTEL_GEN(dev_priv) >= 9) {
> + gen9_disable_rc6(dev_priv);
> + gen9_disable_rps(dev_priv);
> + } else if (IS_CHERRYVIEW(dev_priv)) {
> + cherryview_disable_rps(dev_priv);
> + } else if (IS_VALLEYVIEW(dev_priv)) {
> + valleyview_disable_rps(dev_priv);
> + } else if (INTEL_GEN(dev_priv) >= 6) {
> + gen6_disable_rps(dev_priv);
> + } else if (IS_IRONLAKE_M(dev_priv)) {
> + ironlake_disable_drps(dev_priv);
> }
> +
> + dev_priv->rps.enabled = false;
> + mutex_unlock(&dev_priv->rps.hw_lock);
> }
>
> -static void intel_gen6_powersave_work(struct work_struct *work)
> +void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
> {
> - struct drm_i915_private *dev_priv =
> - container_of(work, struct drm_i915_private,
> - rps.delayed_resume_work.work);
> + /* We shouldn't be disabling as we submit, so this should be less
> + * racy than it appears!
> + */
> + if (READ_ONCE(dev_priv->rps.enabled))
> + return;
>
> - mutex_lock(&dev_priv->rps.hw_lock);
> + /* Powersaving is controlled by the host when inside a VM */
> + if (intel_vgpu_active(dev_priv))
> + return;
>
> - gen6_reset_rps_interrupts(dev_priv);
> + mutex_lock(&dev_priv->rps.hw_lock);
>
> if (IS_CHERRYVIEW(dev_priv)) {
> cherryview_enable_rps(dev_priv);
> } else if (IS_VALLEYVIEW(dev_priv)) {
> valleyview_enable_rps(dev_priv);
> - } else if (INTEL_INFO(dev_priv)->gen >= 9) {
> + } else if (INTEL_GEN(dev_priv) >= 9) {
> gen9_enable_rc6(dev_priv);
> gen9_enable_rps(dev_priv);
> if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
> @@ -6620,9 +6628,12 @@ static void intel_gen6_powersave_work(struct work_struct *work)
> } else if (IS_BROADWELL(dev_priv)) {
> gen8_enable_rps(dev_priv);
> __gen6_update_ring_freq(dev_priv);
> - } else {
> + } else if (INTEL_GEN(dev_priv) >= 6) {
> gen6_enable_rps(dev_priv);
> __gen6_update_ring_freq(dev_priv);
> + } else if (IS_IRONLAKE_M(dev_priv)) {
> + ironlake_enable_drps(dev_priv);
> + intel_init_emon(dev_priv);
> }
>
> WARN_ON(dev_priv->rps.max_freq < dev_priv->rps.min_freq);
> @@ -6632,18 +6643,47 @@ static void intel_gen6_powersave_work(struct work_struct *work)
> WARN_ON(dev_priv->rps.efficient_freq > dev_priv->rps.max_freq);
>
> dev_priv->rps.enabled = true;
> + mutex_unlock(&dev_priv->rps.hw_lock);
> +}
>
> - gen6_enable_rps_interrupts(dev_priv);
> +static void __intel_autoenable_gt_powersave(struct work_struct *work)
> +{
> + struct drm_i915_private *dev_priv =
> + container_of(work, typeof(*dev_priv), rps.autoenable_work.work);
> + struct intel_engine_cs *rcs;
> + struct drm_i915_gem_request *req;
>
> - mutex_unlock(&dev_priv->rps.hw_lock);
> + if (READ_ONCE(dev_priv->rps.enabled))
> + goto out;
> +
> + rcs = &dev_priv->engine[RCS];
> + if (rcs->last_context)
> + goto out;
> +
> + if (!rcs->init_context)
> + goto out;
>
> + mutex_lock(&dev_priv->drm.struct_mutex);
> +
> + req = i915_gem_request_alloc(rcs, dev_priv->kernel_context);
> + if (IS_ERR(req))
> + goto unlock;
> +
> + if (!i915.enable_execlists && i915_switch_context(req) == 0)
> + rcs->init_context(req);
> +
> + /* Mark the device busy, calling intel_enable_gt_powersave() */
> + i915_add_request_no_flush(req);
> +
> +unlock:
> + mutex_unlock(&dev_priv->drm.struct_mutex);
> +out:
> intel_runtime_pm_put(dev_priv);
> }
>
> -void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
> +void intel_autoenable_gt_powersave(struct drm_i915_private *dev_priv)
> {
> - /* Powersaving is controlled by the host when inside a VM */
> - if (intel_vgpu_active(dev_priv))
> + if (READ_ONCE(dev_priv->rps.enabled))
> return;
>
> if (IS_IRONLAKE_M(dev_priv)) {
> @@ -6664,21 +6704,13 @@ void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
> * paths, so the _noresume version is enough (and in case of
> * runtime resume it's necessary).
> */
> - if (schedule_delayed_work(&dev_priv->rps.delayed_resume_work,
> - round_jiffies_up_relative(HZ)))
> + if (queue_delayed_work(dev_priv->wq,
> + &dev_priv->rps.autoenable_work,
> + round_jiffies_up_relative(HZ)))
> intel_runtime_pm_get_noresume(dev_priv);
> }
> }
>
> -void intel_reset_gt_powersave(struct drm_i915_private *dev_priv)
> -{
> - if (INTEL_INFO(dev_priv)->gen < 6)
> - return;
> -
> - gen6_suspend_rps(dev_priv);
> - dev_priv->rps.enabled = false;
> -}
> -
> static void ibx_init_clock_gating(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = to_i915(dev);
> @@ -7785,8 +7817,8 @@ void intel_pm_setup(struct drm_device *dev)
> mutex_init(&dev_priv->rps.hw_lock);
> spin_lock_init(&dev_priv->rps.client_lock);
>
> - INIT_DELAYED_WORK(&dev_priv->rps.delayed_resume_work,
> - intel_gen6_powersave_work);
> + INIT_DELAYED_WORK(&dev_priv->rps.autoenable_work,
> + __intel_autoenable_gt_powersave);
> INIT_LIST_HEAD(&dev_priv->rps.clients);
> INIT_LIST_HEAD(&dev_priv->rps.semaphores.link);
> INIT_LIST_HEAD(&dev_priv->rps.mmioflips.link);
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index ff80a81b1a84..eeb4cbce19ff 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -435,7 +435,7 @@ void intel_uncore_sanitize(struct drm_i915_private *dev_priv)
> i915.enable_rc6 = sanitize_rc6_option(dev_priv, i915.enable_rc6);
>
> /* BIOS often leaves RC6 enabled, but disable it for hw init */
> - intel_disable_gt_powersave(dev_priv);
> + intel_sanitize_gt_powersave(dev_priv);
> }
>
> static void __intel_uncore_forcewake_get(struct drm_i915_private *dev_priv,
> --
> 2.8.1
>
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