diff mbox

[05/17] drm/i915: Support for GuC interrupts

Message ID 1468158084-22028-6-git-send-email-akash.goel@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

akash.goel@intel.com July 10, 2016, 1:41 p.m. UTC
From: Sagar Arun Kamble <sagar.a.kamble@intel.com>

There are certain types of interrupts which Host can recieve from GuC.
GuC ukernel sends an interrupt to Host for certain events, like for
example retrieve/consume the logs generated by ukernel.
This patch adds support to receive interrupts from GuC but currently
enables & partially handles only the interrupt sent by GuC ukernel.
Future patches will add support for handling other interrupt types.

v2:
- Use common low level routines for PM IER/IIR programming (Chris)
- Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
- Replace disabling of wake ref asserts with rpm get/put (Chris)

v3:
- Update comments for more clarity. (Tvrtko)
- Remove the masking of GuC interrupt, which was kept masked till the
  start of bottom half, its not really needed as there is only a
  single instance of work item & wq is ordered. (Tvrtko)

v4:
- Rebase.
- Rename guc_events to pm_guc_events so as to be indicative of the
  register/control block it is associated with. (Chris)
- Add handling for back to back log buffer flush interrupts.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Akash Goel <akash.goel@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h            |  1 +
 drivers/gpu/drm/i915/i915_guc_submission.c |  5 ++
 drivers/gpu/drm/i915/i915_irq.c            | 98 ++++++++++++++++++++++++++++--
 drivers/gpu/drm/i915/i915_reg.h            | 11 ++++
 drivers/gpu/drm/i915/intel_drv.h           |  3 +
 drivers/gpu/drm/i915/intel_guc.h           |  4 ++
 drivers/gpu/drm/i915/intel_guc_loader.c    |  4 ++
 7 files changed, 122 insertions(+), 4 deletions(-)

Comments

Tvrtko Ursulin July 11, 2016, 10:30 a.m. UTC | #1
On 10/07/16 14:41, akash.goel@intel.com wrote:
> From: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>
> There are certain types of interrupts which Host can recieve from GuC.
> GuC ukernel sends an interrupt to Host for certain events, like for
> example retrieve/consume the logs generated by ukernel.
> This patch adds support to receive interrupts from GuC but currently
> enables & partially handles only the interrupt sent by GuC ukernel.
> Future patches will add support for handling other interrupt types.
>
> v2:
> - Use common low level routines for PM IER/IIR programming (Chris)
> - Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
> - Replace disabling of wake ref asserts with rpm get/put (Chris)
>
> v3:
> - Update comments for more clarity. (Tvrtko)
> - Remove the masking of GuC interrupt, which was kept masked till the
>    start of bottom half, its not really needed as there is only a
>    single instance of work item & wq is ordered. (Tvrtko)
>
> v4:
> - Rebase.
> - Rename guc_events to pm_guc_events so as to be indicative of the
>    register/control block it is associated with. (Chris)
> - Add handling for back to back log buffer flush interrupts.
>
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
> Signed-off-by: Akash Goel <akash.goel@intel.com>
> ---
>   drivers/gpu/drm/i915/i915_drv.h            |  1 +
>   drivers/gpu/drm/i915/i915_guc_submission.c |  5 ++
>   drivers/gpu/drm/i915/i915_irq.c            | 98 ++++++++++++++++++++++++++++--
>   drivers/gpu/drm/i915/i915_reg.h            | 11 ++++
>   drivers/gpu/drm/i915/intel_drv.h           |  3 +
>   drivers/gpu/drm/i915/intel_guc.h           |  4 ++
>   drivers/gpu/drm/i915/intel_guc_loader.c    |  4 ++
>   7 files changed, 122 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index c3a579f..6e2ddfa 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1794,6 +1794,7 @@ struct drm_i915_private {
>   	u32 pm_imr;
>   	u32 pm_ier;
>   	u32 pm_rps_events;
> +	u32 pm_guc_events;
>   	u32 pipestat_irq_mask[I915_MAX_PIPES];
>
>   	struct i915_hotplug hotplug;
> diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
> index 0fb00ab..0bac172 100644
> --- a/drivers/gpu/drm/i915/i915_guc_submission.c
> +++ b/drivers/gpu/drm/i915/i915_guc_submission.c
> @@ -1044,6 +1044,8 @@ int intel_guc_suspend(struct drm_device *dev)
>   	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
>   		return 0;
>
> +	gen9_disable_guc_interrupts(dev_priv);
> +
>   	ctx = dev_priv->kernel_context;
>
>   	data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
> @@ -1070,6 +1072,9 @@ int intel_guc_resume(struct drm_device *dev)
>   	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
>   		return 0;
>
> +	if (i915.guc_log_level >= 0)
> +		gen9_enable_guc_interrupts(dev_priv);
> +
>   	ctx = dev_priv->kernel_context;
>
>   	data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 24bbaf7..fd73c94 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -170,6 +170,7 @@ static void gen5_assert_iir_is_zero(struct drm_i915_private *dev_priv,
>   } while (0)
>
>   static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir);
> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir);
>
>   /* For display hotplug interrupt */
>   static inline void
> @@ -411,6 +412,39 @@ void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv)
>   	gen6_reset_rps_interrupts(dev_priv);
>   }
>
> +void gen9_reset_guc_interrupts(struct drm_i915_private *dev_priv)
> +{
> +	spin_lock_irq(&dev_priv->irq_lock);
> +	gen6_reset_pm_iir(dev_priv, dev_priv->pm_guc_events);
> +	spin_unlock_irq(&dev_priv->irq_lock);
> +}
> +
> +void gen9_enable_guc_interrupts(struct drm_i915_private *dev_priv)
> +{
> +	spin_lock_irq(&dev_priv->irq_lock);
> +	if (!dev_priv->guc.interrupts_enabled) {
> +		WARN_ON_ONCE(I915_READ(gen6_pm_iir(dev_priv)) &
> +						dev_priv->pm_guc_events);
> +		dev_priv->guc.interrupts_enabled = true;
> +		gen6_enable_pm_irq(dev_priv, dev_priv->pm_guc_events);
> +	}
> +	spin_unlock_irq(&dev_priv->irq_lock);
> +}
> +
> +void gen9_disable_guc_interrupts(struct drm_i915_private *dev_priv)
> +{
> +	spin_lock_irq(&dev_priv->irq_lock);
> +	dev_priv->guc.interrupts_enabled = false;
> +
> +	gen6_disable_pm_irq(dev_priv, dev_priv->pm_guc_events);
> +
> +	spin_unlock_irq(&dev_priv->irq_lock);
> +	synchronize_irq(dev_priv->drm.irq);
> +
> +	cancel_work_sync(&dev_priv->guc.events_work);
> +	gen9_reset_guc_interrupts(dev_priv);
> +}
> +
>   /**
>    * bdw_update_port_irq - update DE port interrupt
>    * @dev_priv: driver private
> @@ -1174,6 +1208,21 @@ static void gen6_pm_rps_work(struct work_struct *work)
>   	mutex_unlock(&dev_priv->rps.hw_lock);
>   }
>
> +static void gen9_guc2host_events_work(struct work_struct *work)
> +{
> +	struct drm_i915_private *dev_priv =
> +		container_of(work, struct drm_i915_private, guc.events_work);
> +
> +	spin_lock_irq(&dev_priv->irq_lock);
> +	/* Speed up work cancellation during disabling guc interrupts. */
> +	if (!dev_priv->guc.interrupts_enabled) {
> +		spin_unlock_irq(&dev_priv->irq_lock);
> +		return;
> +	}
> +	spin_unlock_irq(&dev_priv->irq_lock);
> +
> +	/* TODO: Handle the events for which GuC interrupted host */
> +}
>
>   /**
>    * ivybridge_parity_work - Workqueue called when a parity error interrupt
> @@ -1346,11 +1395,13 @@ static irqreturn_t gen8_gt_irq_ack(struct drm_i915_private *dev_priv,
>   			DRM_ERROR("The master control interrupt lied (GT3)!\n");
>   	}
>
> -	if (master_ctl & GEN8_GT_PM_IRQ) {
> +	if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
>   		gt_iir[2] = I915_READ_FW(GEN8_GT_IIR(2));
> -		if (gt_iir[2] & dev_priv->pm_rps_events) {
> +		if (gt_iir[2] & (dev_priv->pm_rps_events |
> +				 dev_priv->pm_guc_events)) {
>   			I915_WRITE_FW(GEN8_GT_IIR(2),
> -				      gt_iir[2] & dev_priv->pm_rps_events);
> +				      gt_iir[2] & (dev_priv->pm_rps_events |
> +						   dev_priv->pm_guc_events));
>   			ret = IRQ_HANDLED;
>   		} else
>   			DRM_ERROR("The master control interrupt lied (PM)!\n");
> @@ -1382,6 +1433,9 @@ static void gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
>
>   	if (gt_iir[2] & dev_priv->pm_rps_events)
>   		gen6_rps_irq_handler(dev_priv, gt_iir[2]);
> +
> +	if (gt_iir[2] & dev_priv->pm_guc_events)
> +		gen9_guc_irq_handler(dev_priv, gt_iir[2]);
>   }
>
>   static bool bxt_port_hotplug_long_detect(enum port port, u32 val)
> @@ -1628,6 +1682,38 @@ static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
>   	}
>   }
>
> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv, u32 gt_iir)
> +{
> +	if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
> +		spin_lock(&dev_priv->irq_lock);
> +		if (dev_priv->guc.interrupts_enabled) {
> +			/* Sample the log buffer flush related bits & clear them
> +			 * out now itself from the message identity register to
> +			 * minimize the probability of losing a flush interrupt,
> +			 * when there are back to back flush interrupts.
> +			 * There can be a new flush interrupt, for different log
> +			 * buffer type (like for ISR), whilst Host is handling
> +			 * one (for DPC). Since same bit is used in message
> +			 * register for ISR & DPC, it could happen that GuC
> +			 * sets the bit for 2nd interrupt but Host clears out
> +			 * the bit on handling the 1st interrupt.
> +			 */
> +			u32 msg = I915_READ(SOFT_SCRATCH(15)) &
> +					(GUC2HOST_MSG_CRASH_DUMP_POSTED |
> +					 GUC2HOST_MSG_FLUSH_LOG_BUFFER);
> +			if (msg) {
> +				/* Clear the message bits that are handled */
> +				I915_WRITE(SOFT_SCRATCH(15),
> +					I915_READ(SOFT_SCRATCH(15)) & ~msg);
> +
> +				/* Handle flush interrupt event in bottom half */
> +				queue_work(dev_priv->wq, &dev_priv->guc.events_work);

Since the later patch is changing this to use a thread, since you have 
established worker is too slow - especially the shared one - I would 
really recommend you start with the kthread straight away. Not have the 
worker for a while in the same series and then later change it to a thread.

> +			}
> +		}
> +		spin_unlock(&dev_priv->irq_lock);

Why does the above needs to be done under the irq_lock ?

> +	}
> +}
> +
>   static bool intel_pipe_handle_vblank(struct drm_i915_private *dev_priv,
>   				     enum pipe pipe)
>   {
> @@ -3754,7 +3840,7 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
>   	GEN8_IRQ_INIT_NDX(GT, 1, ~gt_interrupts[1], gt_interrupts[1]);
>   	/*
>   	 * RPS interrupts will get enabled/disabled on demand when RPS itself
> -	 * is enabled/disabled.
> +	 * is enabled/disabled. Same wil be the case for GuC interrupts.
>   	 */
>   	GEN8_IRQ_INIT_NDX(GT, 2, dev_priv->pm_imr, dev_priv->pm_ier);
>   	GEN8_IRQ_INIT_NDX(GT, 3, ~gt_interrupts[3], gt_interrupts[3]);
> @@ -4539,6 +4625,10 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
>
>   	INIT_WORK(&dev_priv->rps.work, gen6_pm_rps_work);
>   	INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);
> +	INIT_WORK(&dev_priv->guc.events_work, gen9_guc2host_events_work);
> +
> +	if (HAS_GUC_UCODE(dev))
> +		dev_priv->pm_guc_events = GEN9_GUC_TO_HOST_INT_EVENT;
>
>   	/* Let's track the enabled rps events */
>   	if (IS_VALLEYVIEW(dev_priv))
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 8bfde75..d0d13a2 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5963,6 +5963,7 @@ enum {
>   #define  GEN8_DE_PIPE_A_IRQ		(1<<16)
>   #define  GEN8_DE_PIPE_IRQ(pipe)		(1<<(16+(pipe)))
>   #define  GEN8_GT_VECS_IRQ		(1<<6)
> +#define  GEN8_GT_GUC_IRQ		(1<<5)
>   #define  GEN8_GT_PM_IRQ			(1<<4)
>   #define  GEN8_GT_VCS2_IRQ		(1<<3)
>   #define  GEN8_GT_VCS1_IRQ		(1<<2)
> @@ -5974,6 +5975,16 @@ enum {
>   #define GEN8_GT_IIR(which) _MMIO(0x44308 + (0x10 * (which)))
>   #define GEN8_GT_IER(which) _MMIO(0x4430c + (0x10 * (which)))
>
> +#define GEN9_GUC_TO_HOST_INT_EVENT	(1<<31)
> +#define GEN9_GUC_EXEC_ERROR_EVENT	(1<<30)
> +#define GEN9_GUC_DISPLAY_EVENT		(1<<29)
> +#define GEN9_GUC_SEMA_SIGNAL_EVENT	(1<<28)
> +#define GEN9_GUC_IOMMU_MSG_EVENT	(1<<27)
> +#define GEN9_GUC_DB_RING_EVENT		(1<<26)
> +#define GEN9_GUC_DMA_DONE_EVENT		(1<<25)
> +#define GEN9_GUC_FATAL_ERROR_EVENT	(1<<24)
> +#define GEN9_GUC_NOTIFICATION_EVENT	(1<<23)
> +
>   #define GEN8_RCS_IRQ_SHIFT 0
>   #define GEN8_BCS_IRQ_SHIFT 16
>   #define GEN8_VCS1_IRQ_SHIFT 0
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index ae6c535..6868f31 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1102,6 +1102,9 @@ void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
>   				     unsigned int pipe_mask);
>   void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
>   				     unsigned int pipe_mask);
> +void gen9_reset_guc_interrupts(struct drm_i915_private *dev_priv);
> +void gen9_enable_guc_interrupts(struct drm_i915_private *dev_priv);
> +void gen9_disable_guc_interrupts(struct drm_i915_private *dev_priv);
>
>   /* intel_crt.c */
>   void intel_crt_init(struct drm_device *dev);
> diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
> index d52eca3..2663b41 100644
> --- a/drivers/gpu/drm/i915/intel_guc.h
> +++ b/drivers/gpu/drm/i915/intel_guc.h
> @@ -131,6 +131,10 @@ struct intel_guc {
>   	struct intel_guc_fw guc_fw;
>   	struct intel_guc_log log;
>
> +	/* GuC2Host interrupt related state */
> +	struct work_struct events_work;
> +	bool interrupts_enabled;
> +
>   	struct drm_i915_gem_object *ads_obj;
>
>   	struct drm_i915_gem_object *ctx_pool_obj;
> diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
> index 4882f17..d74d7a5 100644
> --- a/drivers/gpu/drm/i915/intel_guc_loader.c
> +++ b/drivers/gpu/drm/i915/intel_guc_loader.c
> @@ -450,6 +450,7 @@ int intel_guc_setup(struct drm_device *dev)
>   	}
>
>   	direct_interrupts_to_host(dev_priv);
> +	gen9_reset_guc_interrupts(dev_priv);
>
>   	guc_fw->guc_fw_load_status = GUC_FIRMWARE_PENDING;
>
> @@ -496,6 +497,9 @@ int intel_guc_setup(struct drm_device *dev)
>   		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
>
>   	if (i915.enable_guc_submission) {
> +		if (i915.guc_log_level >= 0)
> +			gen9_enable_guc_interrupts(dev_priv);
> +
>   		err = i915_guc_submission_enable(dev_priv);
>   		if (err)
>   			goto fail;
>

Regards,

Tvrtko
akash.goel@intel.com July 11, 2016, 1:15 p.m. UTC | #2
On 7/11/2016 4:00 PM, Tvrtko Ursulin wrote:
>
> On 10/07/16 14:41, akash.goel@intel.com wrote:
>> From: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>>
>> There are certain types of interrupts which Host can recieve from GuC.
>> GuC ukernel sends an interrupt to Host for certain events, like for
>> example retrieve/consume the logs generated by ukernel.
>> This patch adds support to receive interrupts from GuC but currently
>> enables & partially handles only the interrupt sent by GuC ukernel.
>> Future patches will add support for handling other interrupt types.
>>
>> v2:
>> - Use common low level routines for PM IER/IIR programming (Chris)
>> - Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
>> - Replace disabling of wake ref asserts with rpm get/put (Chris)
>>
>> v3:
>> - Update comments for more clarity. (Tvrtko)
>> - Remove the masking of GuC interrupt, which was kept masked till the
>>    start of bottom half, its not really needed as there is only a
>>    single instance of work item & wq is ordered. (Tvrtko)
>>
>> v4:
>> - Rebase.
>> - Rename guc_events to pm_guc_events so as to be indicative of the
>>    register/control block it is associated with. (Chris)
>> - Add handling for back to back log buffer flush interrupts.
>>
>> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>> Signed-off-by: Akash Goel <akash.goel@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h            |  1 +
>>   drivers/gpu/drm/i915/i915_guc_submission.c |  5 ++
>>   drivers/gpu/drm/i915/i915_irq.c            | 98
>> ++++++++++++++++++++++++++++--
>>   drivers/gpu/drm/i915/i915_reg.h            | 11 ++++
>>   drivers/gpu/drm/i915/intel_drv.h           |  3 +
>>   drivers/gpu/drm/i915/intel_guc.h           |  4 ++
>>   drivers/gpu/drm/i915/intel_guc_loader.c    |  4 ++
>>   7 files changed, 122 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h
>> b/drivers/gpu/drm/i915/i915_drv.h
>> index c3a579f..6e2ddfa 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1794,6 +1794,7 @@ struct drm_i915_private {
>>       u32 pm_imr;
>>       u32 pm_ier;
>>       u32 pm_rps_events;
>> +    u32 pm_guc_events;
>>       u32 pipestat_irq_mask[I915_MAX_PIPES];
>>
>>       struct i915_hotplug hotplug;
>>
>> +
>>   /**
>>    * bdw_update_port_irq - update DE port interrupt
>>    * @dev_priv: driver private
>> @@ -1174,6 +1208,21 @@ static void gen6_pm_rps_work(struct work_struct
>> *work)
>>       mutex_unlock(&dev_priv->rps.hw_lock);
>>   }
>>
>> +static void gen9_guc2host_events_work(struct work_struct *work)
>> +{
>> +    struct drm_i915_private *dev_priv =
>> +        container_of(work, struct drm_i915_private, guc.events_work);
>> +
>> +    spin_lock_irq(&dev_priv->irq_lock);
>> +    /* Speed up work cancellation during disabling guc interrupts. */
>> +    if (!dev_priv->guc.interrupts_enabled) {
>> +        spin_unlock_irq(&dev_priv->irq_lock);
>> +        return;
>> +    }
>> +    spin_unlock_irq(&dev_priv->irq_lock);
>> +
>> +    /* TODO: Handle the events for which GuC interrupted host */
>> +}
>>
>>   /**
>>    * ivybridge_parity_work - Workqueue called when a parity error
>> interrupt
>> @@ -1346,11 +1395,13 @@ static irqreturn_t gen8_gt_irq_ack(struct
>> drm_i915_private *dev_priv,
>>               DRM_ERROR("The master control interrupt lied (GT3)!\n");
>>       }
>>
>> -    if (master_ctl & GEN8_GT_PM_IRQ) {
>> +    if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
>>           gt_iir[2] = I915_READ_FW(GEN8_GT_IIR(2));
>> -        if (gt_iir[2] & dev_priv->pm_rps_events) {
>> +        if (gt_iir[2] & (dev_priv->pm_rps_events |
>> +                 dev_priv->pm_guc_events)) {
>>               I915_WRITE_FW(GEN8_GT_IIR(2),
>> -                      gt_iir[2] & dev_priv->pm_rps_events);
>> +                      gt_iir[2] & (dev_priv->pm_rps_events |
>> +                           dev_priv->pm_guc_events));
>>               ret = IRQ_HANDLED;
>>           } else
>>               DRM_ERROR("The master control interrupt lied (PM)!\n");
>> @@ -1382,6 +1433,9 @@ static void gen8_gt_irq_handler(struct
>> drm_i915_private *dev_priv,
>>
>>       if (gt_iir[2] & dev_priv->pm_rps_events)
>>           gen6_rps_irq_handler(dev_priv, gt_iir[2]);
>> +
>> +    if (gt_iir[2] & dev_priv->pm_guc_events)
>> +        gen9_guc_irq_handler(dev_priv, gt_iir[2]);
>>   }
>>
>>   static bool bxt_port_hotplug_long_detect(enum port port, u32 val)
>> @@ -1628,6 +1682,38 @@ static void gen6_rps_irq_handler(struct
>> drm_i915_private *dev_priv, u32 pm_iir)
>>       }
>>   }
>>
>> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv,
>> u32 gt_iir)
>> +{
>> +    if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
>> +        spin_lock(&dev_priv->irq_lock);
>> +        if (dev_priv->guc.interrupts_enabled) {
>> +            /* Sample the log buffer flush related bits & clear them
>> +             * out now itself from the message identity register to
>> +             * minimize the probability of losing a flush interrupt,
>> +             * when there are back to back flush interrupts.
>> +             * There can be a new flush interrupt, for different log
>> +             * buffer type (like for ISR), whilst Host is handling
>> +             * one (for DPC). Since same bit is used in message
>> +             * register for ISR & DPC, it could happen that GuC
>> +             * sets the bit for 2nd interrupt but Host clears out
>> +             * the bit on handling the 1st interrupt.
>> +             */
>> +            u32 msg = I915_READ(SOFT_SCRATCH(15)) &
>> +                    (GUC2HOST_MSG_CRASH_DUMP_POSTED |
>> +                     GUC2HOST_MSG_FLUSH_LOG_BUFFER);
>> +            if (msg) {
>> +                /* Clear the message bits that are handled */
>> +                I915_WRITE(SOFT_SCRATCH(15),
>> +                    I915_READ(SOFT_SCRATCH(15)) & ~msg);
>> +
>> +                /* Handle flush interrupt event in bottom half */
>> +                queue_work(dev_priv->wq, &dev_priv->guc.events_work);
>
> Since the later patch is changing this to use a thread, since you have
> established worker is too slow - especially the shared one - I would
> really recommend you start with the kthread straight away. Not have the
> worker for a while in the same series and then later change it to a thread.
>
Actually it won't be appropriate to say that shared worker thread is too 
slow, but having a dedicated kthread definitely helps.

I kept the kthread patch at the last so that as per the response,
review comments can drop it also.

>> +            }
>> +        }
>> +        spin_unlock(&dev_priv->irq_lock);
>
> Why does the above needs to be done under the irq_lock ?
>
Using the irq_lock for 'guc.interrupts_enabled', especially useful
while disabling the interrupt.

Best regards
Akash

>> +    }
>> +}
>> +
>>   static bool intel_pipe_handle_vblank(struct drm_i915_private *dev_priv,
>>                        enum pipe pipe)
>>   {
>> @@ -3754,7 +3840,7 @@ static void gen8_gt_irq_postinstall(struct
>> drm_i915_private *dev_priv)
>>       GEN8_IRQ_INIT_NDX(GT, 1, ~gt_interrupts[1], gt_interrupts[1]);
>>       /*
>>        * RPS interrupts will get enabled/disabled on demand when RPS
>> itself
>> -     * is enabled/disabled.
>> +     * is enabled/disabled. Same wil be the case for GuC interrupts.
>>        */
>>       GEN8_IRQ_INIT_NDX(GT, 2, dev_priv->pm_imr, dev_priv->pm_ier);
>>       GEN8_IRQ_INIT_NDX(GT, 3, ~gt_interrupts[3], gt_interrupts[3]);
>> @@ -4539,6 +4625,10 @@ void intel_irq_init(struct drm_i915_private
>> *dev_priv)
>>
>>       INIT_WORK(&dev_priv->rps.work, gen6_pm_rps_work);
>>       INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);
>> +    INIT_WORK(&dev_priv->guc.events_work, gen9_guc2host_events_work);
>> +
>> +    if (HAS_GUC_UCODE(dev))
>> +        dev_priv->pm_guc_events = GEN9_GUC_TO_HOST_INT_EVENT;
>>
>>       /* Let's track the enabled rps events */
>>       if (IS_VALLEYVIEW(dev_priv))
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index 8bfde75..d0d13a2 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -5963,6 +5963,7 @@ enum {
>>   #define  GEN8_DE_PIPE_A_IRQ        (1<<16)
>>   #define  GEN8_DE_PIPE_IRQ(pipe)        (1<<(16+(pipe)))
>>   #define  GEN8_GT_VECS_IRQ        (1<<6)
>> +#define  GEN8_GT_GUC_IRQ        (1<<5)
>>   #define  GEN8_GT_PM_IRQ            (1<<4)
>>   #define  GEN8_GT_VCS2_IRQ        (1<<3)
>>   #define  GEN8_GT_VCS1_IRQ        (1<<2)
>> @@ -5974,6 +5975,16 @@ enum {
>>   #define GEN8_GT_IIR(which) _MMIO(0x44308 + (0x10 * (which)))
>>   #define GEN8_GT_IER(which) _MMIO(0x4430c + (0x10 * (which)))
>>
>> +#define GEN9_GUC_TO_HOST_INT_EVENT    (1<<31)
>> +#define GEN9_GUC_EXEC_ERROR_EVENT    (1<<30)
>> +#define GEN9_GUC_DISPLAY_EVENT        (1<<29)
>> +#define GEN9_GUC_SEMA_SIGNAL_EVENT    (1<<28)
>> +#define GEN9_GUC_IOMMU_MSG_EVENT    (1<<27)
>> +#define GEN9_GUC_DB_RING_EVENT        (1<<26)
>> +#define GEN9_GUC_DMA_DONE_EVENT        (1<<25)
>> +#define GEN9_GUC_FATAL_ERROR_EVENT    (1<<24)
>> +#define GEN9_GUC_NOTIFICATION_EVENT    (1<<23)
>> +
>>   #define GEN8_RCS_IRQ_SHIFT 0
>>   #define GEN8_BCS_IRQ_SHIFT 16
>>   #define GEN8_VCS1_IRQ_SHIFT 0
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> b/drivers/gpu/drm/i915/intel_drv.h
>> index ae6c535..6868f31 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -1102,6 +1102,9 @@ void gen8_irq_power_well_post_enable(struct
>> drm_i915_private *dev_priv,
>>                        unsigned int pipe_mask);
>>   void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
>>                        unsigned int pipe_mask);
>> +void gen9_reset_guc_interrupts(struct drm_i915_private *dev_priv);
>> +void gen9_enable_guc_interrupts(struct drm_i915_private *dev_priv);
>> +void gen9_disable_guc_interrupts(struct drm_i915_private *dev_priv);
>>
>>   /* intel_crt.c */
>>   void intel_crt_init(struct drm_device *dev);
>> diff --git a/drivers/gpu/drm/i915/intel_guc.h
>> b/drivers/gpu/drm/i915/intel_guc.h
>> index d52eca3..2663b41 100644
>> --- a/drivers/gpu/drm/i915/intel_guc.h
>> +++ b/drivers/gpu/drm/i915/intel_guc.h
>> @@ -131,6 +131,10 @@ struct intel_guc {
>>       struct intel_guc_fw guc_fw;
>>       struct intel_guc_log log;
>>
>> +    /* GuC2Host interrupt related state */
>> +    struct work_struct events_work;
>> +    bool interrupts_enabled;
>> +
>>       struct drm_i915_gem_object *ads_obj;
>>
>>       struct drm_i915_gem_object *ctx_pool_obj;
>> diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c
>> b/drivers/gpu/drm/i915/intel_guc_loader.c
>> index 4882f17..d74d7a5 100644
>> --- a/drivers/gpu/drm/i915/intel_guc_loader.c
>> +++ b/drivers/gpu/drm/i915/intel_guc_loader.c
>> @@ -450,6 +450,7 @@ int intel_guc_setup(struct drm_device *dev)
>>       }
>>
>>       direct_interrupts_to_host(dev_priv);
>> +    gen9_reset_guc_interrupts(dev_priv);
>>
>>       guc_fw->guc_fw_load_status = GUC_FIRMWARE_PENDING;
>>
>> @@ -496,6 +497,9 @@ int intel_guc_setup(struct drm_device *dev)
>>           intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
>>
>>       if (i915.enable_guc_submission) {
>> +        if (i915.guc_log_level >= 0)
>> +            gen9_enable_guc_interrupts(dev_priv);
>> +
>>           err = i915_guc_submission_enable(dev_priv);
>>           if (err)
>>               goto fail;
>>
>
> Regards,
>
> Tvrtko
>
Tvrtko Ursulin July 11, 2016, 1:23 p.m. UTC | #3
On 11/07/16 14:15, Goel, Akash wrote:
> On 7/11/2016 4:00 PM, Tvrtko Ursulin wrote:
>>
>> On 10/07/16 14:41, akash.goel@intel.com wrote:
>>> From: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>>>
>>> There are certain types of interrupts which Host can recieve from GuC.
>>> GuC ukernel sends an interrupt to Host for certain events, like for
>>> example retrieve/consume the logs generated by ukernel.
>>> This patch adds support to receive interrupts from GuC but currently
>>> enables & partially handles only the interrupt sent by GuC ukernel.
>>> Future patches will add support for handling other interrupt types.
>>>
>>> v2:
>>> - Use common low level routines for PM IER/IIR programming (Chris)
>>> - Rename interrupt functions to gen9_xxx from gen8_xxx (Chris)
>>> - Replace disabling of wake ref asserts with rpm get/put (Chris)
>>>
>>> v3:
>>> - Update comments for more clarity. (Tvrtko)
>>> - Remove the masking of GuC interrupt, which was kept masked till the
>>>    start of bottom half, its not really needed as there is only a
>>>    single instance of work item & wq is ordered. (Tvrtko)
>>>
>>> v4:
>>> - Rebase.
>>> - Rename guc_events to pm_guc_events so as to be indicative of the
>>>    register/control block it is associated with. (Chris)
>>> - Add handling for back to back log buffer flush interrupts.
>>>
>>> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>>> Signed-off-by: Akash Goel <akash.goel@intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/i915_drv.h            |  1 +
>>>   drivers/gpu/drm/i915/i915_guc_submission.c |  5 ++
>>>   drivers/gpu/drm/i915/i915_irq.c            | 98
>>> ++++++++++++++++++++++++++++--
>>>   drivers/gpu/drm/i915/i915_reg.h            | 11 ++++
>>>   drivers/gpu/drm/i915/intel_drv.h           |  3 +
>>>   drivers/gpu/drm/i915/intel_guc.h           |  4 ++
>>>   drivers/gpu/drm/i915/intel_guc_loader.c    |  4 ++
>>>   7 files changed, 122 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_drv.h
>>> b/drivers/gpu/drm/i915/i915_drv.h
>>> index c3a579f..6e2ddfa 100644
>>> --- a/drivers/gpu/drm/i915/i915_drv.h
>>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>>> @@ -1794,6 +1794,7 @@ struct drm_i915_private {
>>>       u32 pm_imr;
>>>       u32 pm_ier;
>>>       u32 pm_rps_events;
>>> +    u32 pm_guc_events;
>>>       u32 pipestat_irq_mask[I915_MAX_PIPES];
>>>
>>>       struct i915_hotplug hotplug;
>>>
>>> +
>>>   /**
>>>    * bdw_update_port_irq - update DE port interrupt
>>>    * @dev_priv: driver private
>>> @@ -1174,6 +1208,21 @@ static void gen6_pm_rps_work(struct work_struct
>>> *work)
>>>       mutex_unlock(&dev_priv->rps.hw_lock);
>>>   }
>>>
>>> +static void gen9_guc2host_events_work(struct work_struct *work)
>>> +{
>>> +    struct drm_i915_private *dev_priv =
>>> +        container_of(work, struct drm_i915_private, guc.events_work);
>>> +
>>> +    spin_lock_irq(&dev_priv->irq_lock);
>>> +    /* Speed up work cancellation during disabling guc interrupts. */
>>> +    if (!dev_priv->guc.interrupts_enabled) {
>>> +        spin_unlock_irq(&dev_priv->irq_lock);
>>> +        return;
>>> +    }
>>> +    spin_unlock_irq(&dev_priv->irq_lock);
>>> +
>>> +    /* TODO: Handle the events for which GuC interrupted host */
>>> +}
>>>
>>>   /**
>>>    * ivybridge_parity_work - Workqueue called when a parity error
>>> interrupt
>>> @@ -1346,11 +1395,13 @@ static irqreturn_t gen8_gt_irq_ack(struct
>>> drm_i915_private *dev_priv,
>>>               DRM_ERROR("The master control interrupt lied (GT3)!\n");
>>>       }
>>>
>>> -    if (master_ctl & GEN8_GT_PM_IRQ) {
>>> +    if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
>>>           gt_iir[2] = I915_READ_FW(GEN8_GT_IIR(2));
>>> -        if (gt_iir[2] & dev_priv->pm_rps_events) {
>>> +        if (gt_iir[2] & (dev_priv->pm_rps_events |
>>> +                 dev_priv->pm_guc_events)) {
>>>               I915_WRITE_FW(GEN8_GT_IIR(2),
>>> -                      gt_iir[2] & dev_priv->pm_rps_events);
>>> +                      gt_iir[2] & (dev_priv->pm_rps_events |
>>> +                           dev_priv->pm_guc_events));
>>>               ret = IRQ_HANDLED;
>>>           } else
>>>               DRM_ERROR("The master control interrupt lied (PM)!\n");
>>> @@ -1382,6 +1433,9 @@ static void gen8_gt_irq_handler(struct
>>> drm_i915_private *dev_priv,
>>>
>>>       if (gt_iir[2] & dev_priv->pm_rps_events)
>>>           gen6_rps_irq_handler(dev_priv, gt_iir[2]);
>>> +
>>> +    if (gt_iir[2] & dev_priv->pm_guc_events)
>>> +        gen9_guc_irq_handler(dev_priv, gt_iir[2]);
>>>   }
>>>
>>>   static bool bxt_port_hotplug_long_detect(enum port port, u32 val)
>>> @@ -1628,6 +1682,38 @@ static void gen6_rps_irq_handler(struct
>>> drm_i915_private *dev_priv, u32 pm_iir)
>>>       }
>>>   }
>>>
>>> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv,
>>> u32 gt_iir)
>>> +{
>>> +    if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
>>> +        spin_lock(&dev_priv->irq_lock);
>>> +        if (dev_priv->guc.interrupts_enabled) {
>>> +            /* Sample the log buffer flush related bits & clear them
>>> +             * out now itself from the message identity register to
>>> +             * minimize the probability of losing a flush interrupt,
>>> +             * when there are back to back flush interrupts.
>>> +             * There can be a new flush interrupt, for different log
>>> +             * buffer type (like for ISR), whilst Host is handling
>>> +             * one (for DPC). Since same bit is used in message
>>> +             * register for ISR & DPC, it could happen that GuC
>>> +             * sets the bit for 2nd interrupt but Host clears out
>>> +             * the bit on handling the 1st interrupt.
>>> +             */
>>> +            u32 msg = I915_READ(SOFT_SCRATCH(15)) &
>>> +                    (GUC2HOST_MSG_CRASH_DUMP_POSTED |
>>> +                     GUC2HOST_MSG_FLUSH_LOG_BUFFER);
>>> +            if (msg) {
>>> +                /* Clear the message bits that are handled */
>>> +                I915_WRITE(SOFT_SCRATCH(15),
>>> +                    I915_READ(SOFT_SCRATCH(15)) & ~msg);
>>> +
>>> +                /* Handle flush interrupt event in bottom half */
>>> +                queue_work(dev_priv->wq, &dev_priv->guc.events_work);
>>
>> Since the later patch is changing this to use a thread, since you have
>> established worker is too slow - especially the shared one - I would
>> really recommend you start with the kthread straight away. Not have the
>> worker for a while in the same series and then later change it to a
>> thread.
>>
> Actually it won't be appropriate to say that shared worker thread is too
> slow, but having a dedicated kthread definitely helps.
>
> I kept the kthread patch at the last so that as per the response,
> review comments can drop it also.

I think it should only be one implementation in the patch series. If we 
agreed on a kthread make it so from the start.

And describe in the commit message why it was selected etc.

>>> +            }
>>> +        }
>>> +        spin_unlock(&dev_priv->irq_lock);
>>
>> Why does the above needs to be done under the irq_lock ?
>>
> Using the irq_lock for 'guc.interrupts_enabled', especially useful
> while disabling the interrupt.

Why? I don't see how it gains you anything and so it seems preferable 
not to hold it over mmio accesses.

Regards,

Tvrtko
akash.goel@intel.com July 11, 2016, 1:38 p.m. UTC | #4
On 7/11/2016 6:53 PM, Tvrtko Ursulin wrote:
>
> On 11/07/16 14:15, Goel, Akash wrote:
>> On 7/11/2016 4:00 PM, Tvrtko Ursulin wrote:
>>>

>>>> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv,
>>>> u32 gt_iir)
>>>> +{
>>>> +    if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
>>>> +        spin_lock(&dev_priv->irq_lock);
>>>> +        if (dev_priv->guc.interrupts_enabled) {
>>>> +            /* Sample the log buffer flush related bits & clear them
>>>> +             * out now itself from the message identity register to
>>>> +             * minimize the probability of losing a flush interrupt,
>>>> +             * when there are back to back flush interrupts.
>>>> +             * There can be a new flush interrupt, for different log
>>>> +             * buffer type (like for ISR), whilst Host is handling
>>>> +             * one (for DPC). Since same bit is used in message
>>>> +             * register for ISR & DPC, it could happen that GuC
>>>> +             * sets the bit for 2nd interrupt but Host clears out
>>>> +             * the bit on handling the 1st interrupt.
>>>> +             */
>>>> +            u32 msg = I915_READ(SOFT_SCRATCH(15)) &
>>>> +                    (GUC2HOST_MSG_CRASH_DUMP_POSTED |
>>>> +                     GUC2HOST_MSG_FLUSH_LOG_BUFFER);
>>>> +            if (msg) {
>>>> +                /* Clear the message bits that are handled */
>>>> +                I915_WRITE(SOFT_SCRATCH(15),
>>>> +                    I915_READ(SOFT_SCRATCH(15)) & ~msg);
>>>> +
>>>> +                /* Handle flush interrupt event in bottom half */
>>>> +                queue_work(dev_priv->wq, &dev_priv->guc.events_work);
>>>
>>> Since the later patch is changing this to use a thread, since you have
>>> established worker is too slow - especially the shared one - I would
>>> really recommend you start with the kthread straight away. Not have the
>>> worker for a while in the same series and then later change it to a
>>> thread.
>>>
>> Actually it won't be appropriate to say that shared worker thread is too
>> slow, but having a dedicated kthread definitely helps.
>>
>> I kept the kthread patch at the last so that as per the response,
>> review comments can drop it also.
>
> I think it should only be one implementation in the patch series. If we
> agreed on a kthread make it so from the start.
>
Agree but actually right now, added the kthread patch more as a RFC and
presumed this won't be the final version of the series.
Will do the needful, as per the review comments, in the next version.

> And describe in the commit message why it was selected etc.
>
>>>> +            }
>>>> +        }
>>>> +        spin_unlock(&dev_priv->irq_lock);
>>>
>>> Why does the above needs to be done under the irq_lock ?
>>>
>> Using the irq_lock for 'guc.interrupts_enabled', especially useful
>> while disabling the interrupt.
>
> Why? I don't see how it gains you anything and so it seems preferable
> not to hold it over mmio accesses.
>
Yes not needed for the mmio access part.
Just needed for the inspection of 'guc.interrupts_enabled' value.
Will reorder the code.

Best regards
Akash

> Regards,
>
> Tvrtko
>
>
Tvrtko Ursulin July 11, 2016, 1:43 p.m. UTC | #5
On 11/07/16 14:38, Goel, Akash wrote:
> On 7/11/2016 6:53 PM, Tvrtko Ursulin wrote:
>>
>> On 11/07/16 14:15, Goel, Akash wrote:
>>> On 7/11/2016 4:00 PM, Tvrtko Ursulin wrote:
>>>>
>
>>>>> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv,
>>>>> u32 gt_iir)
>>>>> +{
>>>>> +    if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
>>>>> +        spin_lock(&dev_priv->irq_lock);
>>>>> +        if (dev_priv->guc.interrupts_enabled) {
>>>>> +            /* Sample the log buffer flush related bits & clear them
>>>>> +             * out now itself from the message identity register to
>>>>> +             * minimize the probability of losing a flush interrupt,
>>>>> +             * when there are back to back flush interrupts.
>>>>> +             * There can be a new flush interrupt, for different log
>>>>> +             * buffer type (like for ISR), whilst Host is handling
>>>>> +             * one (for DPC). Since same bit is used in message
>>>>> +             * register for ISR & DPC, it could happen that GuC
>>>>> +             * sets the bit for 2nd interrupt but Host clears out
>>>>> +             * the bit on handling the 1st interrupt.
>>>>> +             */
>>>>> +            u32 msg = I915_READ(SOFT_SCRATCH(15)) &
>>>>> +                    (GUC2HOST_MSG_CRASH_DUMP_POSTED |
>>>>> +                     GUC2HOST_MSG_FLUSH_LOG_BUFFER);
>>>>> +            if (msg) {
>>>>> +                /* Clear the message bits that are handled */
>>>>> +                I915_WRITE(SOFT_SCRATCH(15),
>>>>> +                    I915_READ(SOFT_SCRATCH(15)) & ~msg);
>>>>> +
>>>>> +                /* Handle flush interrupt event in bottom half */
>>>>> +                queue_work(dev_priv->wq, &dev_priv->guc.events_work);
>>>>
>>>> Since the later patch is changing this to use a thread, since you have
>>>> established worker is too slow - especially the shared one - I would
>>>> really recommend you start with the kthread straight away. Not have the
>>>> worker for a while in the same series and then later change it to a
>>>> thread.
>>>>
>>> Actually it won't be appropriate to say that shared worker thread is too
>>> slow, but having a dedicated kthread definitely helps.
>>>
>>> I kept the kthread patch at the last so that as per the response,
>>> review comments can drop it also.
>>
>> I think it should only be one implementation in the patch series. If we
>> agreed on a kthread make it so from the start.
>>
> Agree but actually right now, added the kthread patch more as a RFC and
> presumed this won't be the final version of the series.
> Will do the needful, as per the review comments, in the next version.

Ack.

>> And describe in the commit message why it was selected etc.
>>
>>>>> +            }
>>>>> +        }
>>>>> +        spin_unlock(&dev_priv->irq_lock);
>>>>
>>>> Why does the above needs to be done under the irq_lock ?
>>>>
>>> Using the irq_lock for 'guc.interrupts_enabled', especially useful
>>> while disabling the interrupt.
>>
>> Why? I don't see how it gains you anything and so it seems preferable
>> not to hold it over mmio accesses.
>>
> Yes not needed for the mmio access part.
> Just needed for the inspection of 'guc.interrupts_enabled' value.
> Will reorder the code.

You don't need it just for reading that value, you can just drop it.

Regards,

Tvrtko
akash.goel@intel.com July 11, 2016, 2:20 p.m. UTC | #6
On 7/11/2016 7:13 PM, Tvrtko Ursulin wrote:
>
> On 11/07/16 14:38, Goel, Akash wrote:
>> On 7/11/2016 6:53 PM, Tvrtko Ursulin wrote:
>>>
>>> On 11/07/16 14:15, Goel, Akash wrote:
>>>> On 7/11/2016 4:00 PM, Tvrtko Ursulin wrote:
>>>>>
>>
>>>>>> +static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv,
>>>>>> u32 gt_iir)
>>>>>> +{
>>>>>> +    if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
>>>>>> +        spin_lock(&dev_priv->irq_lock);
>>>>>> +        if (dev_priv->guc.interrupts_enabled) {
>>>>>> +            /* Sample the log buffer flush related bits & clear them
>>>>>> +             * out now itself from the message identity register to
>>>>>> +             * minimize the probability of losing a flush interrupt,
>>>>>> +             * when there are back to back flush interrupts.
>>>>>> +             * There can be a new flush interrupt, for different log
>>>>>> +             * buffer type (like for ISR), whilst Host is handling
>>>>>> +             * one (for DPC). Since same bit is used in message
>>>>>> +             * register for ISR & DPC, it could happen that GuC
>>>>>> +             * sets the bit for 2nd interrupt but Host clears out
>>>>>> +             * the bit on handling the 1st interrupt.
>>>>>> +             */
>>>>>> +            u32 msg = I915_READ(SOFT_SCRATCH(15)) &
>>>>>> +                    (GUC2HOST_MSG_CRASH_DUMP_POSTED |
>>>>>> +                     GUC2HOST_MSG_FLUSH_LOG_BUFFER);
>>>>>> +            if (msg) {
>>>>>> +                /* Clear the message bits that are handled */
>>>>>> +                I915_WRITE(SOFT_SCRATCH(15),
>>>>>> +                    I915_READ(SOFT_SCRATCH(15)) & ~msg);
>>>>>> +
>>>>>> +                /* Handle flush interrupt event in bottom half */
>>>>>> +                queue_work(dev_priv->wq,
>>>>>> &dev_priv->guc.events_work);
>>>>>
>>>>> Since the later patch is changing this to use a thread, since you have
>>>>> established worker is too slow - especially the shared one - I would
>>>>> really recommend you start with the kthread straight away. Not have
>>>>> the
>>>>> worker for a while in the same series and then later change it to a
>>>>> thread.
>>>>>
>>>> Actually it won't be appropriate to say that shared worker thread is
>>>> too
>>>> slow, but having a dedicated kthread definitely helps.
>>>>
>>>> I kept the kthread patch at the last so that as per the response,
>>>> review comments can drop it also.
>>>
>>> I think it should only be one implementation in the patch series. If we
>>> agreed on a kthread make it so from the start.
>>>
>> Agree but actually right now, added the kthread patch more as a RFC and
>> presumed this won't be the final version of the series.
>> Will do the needful, as per the review comments, in the next version.
>
> Ack.
>
>>> And describe in the commit message why it was selected etc.
>>>
>>>>>> +            }
>>>>>> +        }
>>>>>> +        spin_unlock(&dev_priv->irq_lock);
>>>>>
>>>>> Why does the above needs to be done under the irq_lock ?
>>>>>
>>>> Using the irq_lock for 'guc.interrupts_enabled', especially useful
>>>> while disabling the interrupt.
>>>
>>> Why? I don't see how it gains you anything and so it seems preferable
>>> not to hold it over mmio accesses.
>>>
>> Yes not needed for the mmio access part.
>> Just needed for the inspection of 'guc.interrupts_enabled' value.
>> Will reorder the code.
>
> You don't need it just for reading that value, you can just drop it.
>

Its not strictly needed as its a mere read. But as per my limited
understanding, without the spinlock (which provides an implicit barrier
also) ISR might miss the reset of 'interrupts_enabled' flag, from a
thread on other CPU, and queue the new work. The update will be
visible eventually though. And same applies to the case when
'interrupts_enabled' flag is set from other CPU.
Good practice to use locks for accessing shared variables ?.

Best regards
Akash


> Regards,
>
> Tvrtko
>
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c3a579f..6e2ddfa 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1794,6 +1794,7 @@  struct drm_i915_private {
 	u32 pm_imr;
 	u32 pm_ier;
 	u32 pm_rps_events;
+	u32 pm_guc_events;
 	u32 pipestat_irq_mask[I915_MAX_PIPES];
 
 	struct i915_hotplug hotplug;
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 0fb00ab..0bac172 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -1044,6 +1044,8 @@  int intel_guc_suspend(struct drm_device *dev)
 	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
 		return 0;
 
+	gen9_disable_guc_interrupts(dev_priv);
+
 	ctx = dev_priv->kernel_context;
 
 	data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
@@ -1070,6 +1072,9 @@  int intel_guc_resume(struct drm_device *dev)
 	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
 		return 0;
 
+	if (i915.guc_log_level >= 0)
+		gen9_enable_guc_interrupts(dev_priv);
+
 	ctx = dev_priv->kernel_context;
 
 	data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 24bbaf7..fd73c94 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -170,6 +170,7 @@  static void gen5_assert_iir_is_zero(struct drm_i915_private *dev_priv,
 } while (0)
 
 static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir);
+static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir);
 
 /* For display hotplug interrupt */
 static inline void
@@ -411,6 +412,39 @@  void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv)
 	gen6_reset_rps_interrupts(dev_priv);
 }
 
+void gen9_reset_guc_interrupts(struct drm_i915_private *dev_priv)
+{
+	spin_lock_irq(&dev_priv->irq_lock);
+	gen6_reset_pm_iir(dev_priv, dev_priv->pm_guc_events);
+	spin_unlock_irq(&dev_priv->irq_lock);
+}
+
+void gen9_enable_guc_interrupts(struct drm_i915_private *dev_priv)
+{
+	spin_lock_irq(&dev_priv->irq_lock);
+	if (!dev_priv->guc.interrupts_enabled) {
+		WARN_ON_ONCE(I915_READ(gen6_pm_iir(dev_priv)) &
+						dev_priv->pm_guc_events);
+		dev_priv->guc.interrupts_enabled = true;
+		gen6_enable_pm_irq(dev_priv, dev_priv->pm_guc_events);
+	}
+	spin_unlock_irq(&dev_priv->irq_lock);
+}
+
+void gen9_disable_guc_interrupts(struct drm_i915_private *dev_priv)
+{
+	spin_lock_irq(&dev_priv->irq_lock);
+	dev_priv->guc.interrupts_enabled = false;
+
+	gen6_disable_pm_irq(dev_priv, dev_priv->pm_guc_events);
+
+	spin_unlock_irq(&dev_priv->irq_lock);
+	synchronize_irq(dev_priv->drm.irq);
+
+	cancel_work_sync(&dev_priv->guc.events_work);
+	gen9_reset_guc_interrupts(dev_priv);
+}
+
 /**
  * bdw_update_port_irq - update DE port interrupt
  * @dev_priv: driver private
@@ -1174,6 +1208,21 @@  static void gen6_pm_rps_work(struct work_struct *work)
 	mutex_unlock(&dev_priv->rps.hw_lock);
 }
 
+static void gen9_guc2host_events_work(struct work_struct *work)
+{
+	struct drm_i915_private *dev_priv =
+		container_of(work, struct drm_i915_private, guc.events_work);
+
+	spin_lock_irq(&dev_priv->irq_lock);
+	/* Speed up work cancellation during disabling guc interrupts. */
+	if (!dev_priv->guc.interrupts_enabled) {
+		spin_unlock_irq(&dev_priv->irq_lock);
+		return;
+	}
+	spin_unlock_irq(&dev_priv->irq_lock);
+
+	/* TODO: Handle the events for which GuC interrupted host */
+}
 
 /**
  * ivybridge_parity_work - Workqueue called when a parity error interrupt
@@ -1346,11 +1395,13 @@  static irqreturn_t gen8_gt_irq_ack(struct drm_i915_private *dev_priv,
 			DRM_ERROR("The master control interrupt lied (GT3)!\n");
 	}
 
-	if (master_ctl & GEN8_GT_PM_IRQ) {
+	if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
 		gt_iir[2] = I915_READ_FW(GEN8_GT_IIR(2));
-		if (gt_iir[2] & dev_priv->pm_rps_events) {
+		if (gt_iir[2] & (dev_priv->pm_rps_events |
+				 dev_priv->pm_guc_events)) {
 			I915_WRITE_FW(GEN8_GT_IIR(2),
-				      gt_iir[2] & dev_priv->pm_rps_events);
+				      gt_iir[2] & (dev_priv->pm_rps_events |
+						   dev_priv->pm_guc_events));
 			ret = IRQ_HANDLED;
 		} else
 			DRM_ERROR("The master control interrupt lied (PM)!\n");
@@ -1382,6 +1433,9 @@  static void gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
 
 	if (gt_iir[2] & dev_priv->pm_rps_events)
 		gen6_rps_irq_handler(dev_priv, gt_iir[2]);
+
+	if (gt_iir[2] & dev_priv->pm_guc_events)
+		gen9_guc_irq_handler(dev_priv, gt_iir[2]);
 }
 
 static bool bxt_port_hotplug_long_detect(enum port port, u32 val)
@@ -1628,6 +1682,38 @@  static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
 	}
 }
 
+static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv, u32 gt_iir)
+{
+	if (gt_iir & GEN9_GUC_TO_HOST_INT_EVENT) {
+		spin_lock(&dev_priv->irq_lock);
+		if (dev_priv->guc.interrupts_enabled) {
+			/* Sample the log buffer flush related bits & clear them
+			 * out now itself from the message identity register to
+			 * minimize the probability of losing a flush interrupt,
+			 * when there are back to back flush interrupts.
+			 * There can be a new flush interrupt, for different log
+			 * buffer type (like for ISR), whilst Host is handling
+			 * one (for DPC). Since same bit is used in message
+			 * register for ISR & DPC, it could happen that GuC
+			 * sets the bit for 2nd interrupt but Host clears out
+			 * the bit on handling the 1st interrupt.
+			 */
+			u32 msg = I915_READ(SOFT_SCRATCH(15)) &
+					(GUC2HOST_MSG_CRASH_DUMP_POSTED |
+					 GUC2HOST_MSG_FLUSH_LOG_BUFFER);
+			if (msg) {
+				/* Clear the message bits that are handled */
+				I915_WRITE(SOFT_SCRATCH(15),
+					I915_READ(SOFT_SCRATCH(15)) & ~msg);
+
+				/* Handle flush interrupt event in bottom half */
+				queue_work(dev_priv->wq, &dev_priv->guc.events_work);
+			}
+		}
+		spin_unlock(&dev_priv->irq_lock);
+	}
+}
+
 static bool intel_pipe_handle_vblank(struct drm_i915_private *dev_priv,
 				     enum pipe pipe)
 {
@@ -3754,7 +3840,7 @@  static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
 	GEN8_IRQ_INIT_NDX(GT, 1, ~gt_interrupts[1], gt_interrupts[1]);
 	/*
 	 * RPS interrupts will get enabled/disabled on demand when RPS itself
-	 * is enabled/disabled.
+	 * is enabled/disabled. Same wil be the case for GuC interrupts.
 	 */
 	GEN8_IRQ_INIT_NDX(GT, 2, dev_priv->pm_imr, dev_priv->pm_ier);
 	GEN8_IRQ_INIT_NDX(GT, 3, ~gt_interrupts[3], gt_interrupts[3]);
@@ -4539,6 +4625,10 @@  void intel_irq_init(struct drm_i915_private *dev_priv)
 
 	INIT_WORK(&dev_priv->rps.work, gen6_pm_rps_work);
 	INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);
+	INIT_WORK(&dev_priv->guc.events_work, gen9_guc2host_events_work);
+
+	if (HAS_GUC_UCODE(dev))
+		dev_priv->pm_guc_events = GEN9_GUC_TO_HOST_INT_EVENT;
 
 	/* Let's track the enabled rps events */
 	if (IS_VALLEYVIEW(dev_priv))
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8bfde75..d0d13a2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5963,6 +5963,7 @@  enum {
 #define  GEN8_DE_PIPE_A_IRQ		(1<<16)
 #define  GEN8_DE_PIPE_IRQ(pipe)		(1<<(16+(pipe)))
 #define  GEN8_GT_VECS_IRQ		(1<<6)
+#define  GEN8_GT_GUC_IRQ		(1<<5)
 #define  GEN8_GT_PM_IRQ			(1<<4)
 #define  GEN8_GT_VCS2_IRQ		(1<<3)
 #define  GEN8_GT_VCS1_IRQ		(1<<2)
@@ -5974,6 +5975,16 @@  enum {
 #define GEN8_GT_IIR(which) _MMIO(0x44308 + (0x10 * (which)))
 #define GEN8_GT_IER(which) _MMIO(0x4430c + (0x10 * (which)))
 
+#define GEN9_GUC_TO_HOST_INT_EVENT	(1<<31)
+#define GEN9_GUC_EXEC_ERROR_EVENT	(1<<30)
+#define GEN9_GUC_DISPLAY_EVENT		(1<<29)
+#define GEN9_GUC_SEMA_SIGNAL_EVENT	(1<<28)
+#define GEN9_GUC_IOMMU_MSG_EVENT	(1<<27)
+#define GEN9_GUC_DB_RING_EVENT		(1<<26)
+#define GEN9_GUC_DMA_DONE_EVENT		(1<<25)
+#define GEN9_GUC_FATAL_ERROR_EVENT	(1<<24)
+#define GEN9_GUC_NOTIFICATION_EVENT	(1<<23)
+
 #define GEN8_RCS_IRQ_SHIFT 0
 #define GEN8_BCS_IRQ_SHIFT 16
 #define GEN8_VCS1_IRQ_SHIFT 0
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index ae6c535..6868f31 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1102,6 +1102,9 @@  void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
 				     unsigned int pipe_mask);
 void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv,
 				     unsigned int pipe_mask);
+void gen9_reset_guc_interrupts(struct drm_i915_private *dev_priv);
+void gen9_enable_guc_interrupts(struct drm_i915_private *dev_priv);
+void gen9_disable_guc_interrupts(struct drm_i915_private *dev_priv);
 
 /* intel_crt.c */
 void intel_crt_init(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index d52eca3..2663b41 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -131,6 +131,10 @@  struct intel_guc {
 	struct intel_guc_fw guc_fw;
 	struct intel_guc_log log;
 
+	/* GuC2Host interrupt related state */
+	struct work_struct events_work;
+	bool interrupts_enabled;
+
 	struct drm_i915_gem_object *ads_obj;
 
 	struct drm_i915_gem_object *ctx_pool_obj;
diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index 4882f17..d74d7a5 100644
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -450,6 +450,7 @@  int intel_guc_setup(struct drm_device *dev)
 	}
 
 	direct_interrupts_to_host(dev_priv);
+	gen9_reset_guc_interrupts(dev_priv);
 
 	guc_fw->guc_fw_load_status = GUC_FIRMWARE_PENDING;
 
@@ -496,6 +497,9 @@  int intel_guc_setup(struct drm_device *dev)
 		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
 
 	if (i915.enable_guc_submission) {
+		if (i915.guc_log_level >= 0)
+			gen9_enable_guc_interrupts(dev_priv);
+
 		err = i915_guc_submission_enable(dev_priv);
 		if (err)
 			goto fail;