Re: [PATCH v4 13/17] drm/i915/pxp: Enable PXP power management

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

On 6/2/2021 9:20 AM, Rodrigo Vivi wrote:
> On Mon, May 24, 2021 at 10:47:59PM -0700, Daniele Ceraolo Spurio wrote:
>> From: "Huang, Sean Z" <sean.z.huang@intel.com>
>>
>> During the power event S3+ sleep/resume, hardware will lose all the
>> encryption keys for every hardware session, even though the
>> session state might still be marked as alive after resume. Therefore,
>> we should consider the session as dead on suspend and invalidate all the
>> objects. The session will be automatically restarted on the first
>> protected submission on resume.
>>
>> v2: runtime suspend also invalidates the keys
>> v3: fix return codes, simplify rpm ops (Chris), use the new worker func
>> v4: invalidate the objects on suspend, don't re-create the arb sesson on
>> resume (delayed to first submission).
>>
>> Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
>> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
>> ---
>>   drivers/gpu/drm/i915/Makefile                |  1 +
>>   drivers/gpu/drm/i915/gt/intel_gt_pm.c        | 15 +++++++-
>>   drivers/gpu/drm/i915/i915_drv.c              |  2 +
>>   drivers/gpu/drm/i915/pxp/intel_pxp_irq.c     | 11 ++++--
>>   drivers/gpu/drm/i915/pxp/intel_pxp_pm.c      | 40 ++++++++++++++++++++
>>   drivers/gpu/drm/i915/pxp/intel_pxp_pm.h      | 23 +++++++++++
>>   drivers/gpu/drm/i915/pxp/intel_pxp_session.c | 38 ++++++++++++++-----
>>   drivers/gpu/drm/i915/pxp/intel_pxp_tee.c     |  9 +++++
>>   8 files changed, 124 insertions(+), 15 deletions(-)
>>   create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_pm.c
>>   create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_pm.h
>>
>> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
>> index 29331bbb3e98..9cce0bf9a50f 100644
>> --- a/drivers/gpu/drm/i915/Makefile
>> +++ b/drivers/gpu/drm/i915/Makefile
>> @@ -278,6 +278,7 @@ i915-$(CONFIG_DRM_I915_PXP) += \
>>   	pxp/intel_pxp.o \
>>   	pxp/intel_pxp_cmd.o \
>>   	pxp/intel_pxp_irq.o \
>> +	pxp/intel_pxp_pm.o \
>>   	pxp/intel_pxp_session.o \
>>   	pxp/intel_pxp_tee.o
>>   
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
>> index aef3084e8b16..91151a02f7a2 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gt_pm.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
>> @@ -19,6 +19,7 @@
>>   #include "intel_rc6.h"
>>   #include "intel_rps.h"
>>   #include "intel_wakeref.h"
>> +#include "pxp/intel_pxp_pm.h"
>>   
>>   static void user_forcewake(struct intel_gt *gt, bool suspend)
>>   {
>> @@ -265,6 +266,8 @@ int intel_gt_resume(struct intel_gt *gt)
>>   
>>   	intel_uc_resume(&gt->uc);
>>   
>> +	intel_pxp_resume(&gt->pxp);
>> +
>>   	user_forcewake(gt, false);
>>   
>>   out_fw:
>> @@ -299,6 +302,7 @@ void intel_gt_suspend_prepare(struct intel_gt *gt)
>>   	user_forcewake(gt, true);
>>   	wait_for_suspend(gt);
>>   
>> +	intel_pxp_suspend(&gt->pxp);
>>   	intel_uc_suspend(&gt->uc);
>>   }
>>   
>> @@ -349,6 +353,7 @@ void intel_gt_suspend_late(struct intel_gt *gt)
>>   
>>   void intel_gt_runtime_suspend(struct intel_gt *gt)
>>   {
>> +	intel_pxp_suspend(&gt->pxp);
>>   	intel_uc_runtime_suspend(&gt->uc);
>>   
>>   	GT_TRACE(gt, "\n");
>> @@ -356,11 +361,19 @@ void intel_gt_runtime_suspend(struct intel_gt *gt)
>>   
>>   int intel_gt_runtime_resume(struct intel_gt *gt)
>>   {
>> +	int ret;
>> +
>>   	GT_TRACE(gt, "\n");
>>   	intel_gt_init_swizzling(gt);
>>   	intel_ggtt_restore_fences(gt->ggtt);
>>   
>> -	return intel_uc_runtime_resume(&gt->uc);
>> +	ret = intel_uc_runtime_resume(&gt->uc);
>> +	if (ret)
>> +		return ret;
>> +
>> +	intel_pxp_resume(&gt->pxp);
>> +
>> +	return 0;
>>   }
>>   
>>   static ktime_t __intel_gt_get_awake_time(const struct intel_gt *gt)
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index 2f06bb7b3ed2..6543e5577709 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -68,6 +68,8 @@
>>   #include "gt/intel_gt_pm.h"
>>   #include "gt/intel_rc6.h"
>>   
>> +#include "pxp/intel_pxp_pm.h"
>> +
>>   #include "i915_debugfs.h"
>>   #include "i915_drv.h"
>>   #include "i915_ioc32.h"
>> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
>> index a230d0034e50..9e5847c653f2 100644
>> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
>> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
>> @@ -9,6 +9,7 @@
>>   #include "gt/intel_gt_irq.h"
>>   #include "i915_irq.h"
>>   #include "i915_reg.h"
>> +#include "intel_runtime_pm.h"
>>   
>>   /**
>>    * intel_pxp_irq_handler - Handles PXP interrupts.
>> @@ -62,11 +63,13 @@ void intel_pxp_irq_enable(struct intel_pxp *pxp)
>>   	struct intel_gt *gt = pxp_to_gt(pxp);
>>   
>>   	spin_lock_irq(&gt->irq_lock);
>> -	if (!pxp->irq_enabled) {
>> +
>> +	if (!pxp->irq_enabled)
>>   		WARN_ON_ONCE(gen11_gt_reset_one_iir(gt, 0, GEN11_KCR));
>> -		__pxp_set_interrupts(gt, GEN12_PXP_INTERRUPTS);
>> -		pxp->irq_enabled = true;
>> -	}
>> +
>> +	__pxp_set_interrupts(gt, GEN12_PXP_INTERRUPTS);
>> +	pxp->irq_enabled = true;
> why?
> and if we really need this maybe worth a squash on the other patch or a separated new one?

I had some troubles with the driver resetting all interrupts on S3 exit 
behind the PXP code, so wanted to make sure we always enabled them when 
we entered this function.  I can squash this change in the patch that 
adds the irq logic if you think that's better.

>
>> +
>>   	spin_unlock_irq(&gt->irq_lock);
>>   }
>>   
>> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_pm.c b/drivers/gpu/drm/i915/pxp/intel_pxp_pm.c
>> new file mode 100644
>> index 000000000000..400b3a9944c8
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_pm.c
>> @@ -0,0 +1,40 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright(c) 2020 Intel Corporation.
>> + */
>> +
>> +#include "intel_pxp.h"
>> +#include "intel_pxp_irq.h"
>> +#include "intel_pxp_pm.h"
>> +#include "intel_pxp_session.h"
>> +
>> +void intel_pxp_suspend(struct intel_pxp *pxp)
>> +{
>> +	if (!intel_pxp_is_enabled(pxp))
>> +		return;
>> +
>> +	pxp->arb_is_valid = false;
>> +
>> +	/* invalidate protected objects */
>> +	intel_pxp_invalidate(pxp);
>> +
>> +	intel_pxp_fini_hw(pxp);
>> +
>> +	pxp->global_state_attacked = false;
> this attacked var name is really bad :)

pxp->hw_state_invalidated?

>
> and if we are setting this any time we disable, maybe the it would deserve to be in the fini function...
> but not sure...

I'd prefer to keep it out of the fini_hw, but I'll double check if I can 
wrap it up more nicely.

>
>> +}
>> +
>> +void intel_pxp_resume(struct intel_pxp *pxp)
>> +{
>> +	if (!intel_pxp_is_enabled(pxp))
>> +		return;
>> +
>> +	/*
>> +	 * The PXP component gets automatically unbound when we go into S3 and
>> +	 * re-bound after we come out, so in that scenario we can defer the
>> +	 * hw init to the bind call.
>> +	 */
>> +	if (!pxp->pxp_component)
>> +		return;
>> +
>> +	intel_pxp_init_hw(pxp);
>> +}
>> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_pm.h b/drivers/gpu/drm/i915/pxp/intel_pxp_pm.h
>> new file mode 100644
>> index 000000000000..6f488789db6a
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_pm.h
>> @@ -0,0 +1,23 @@
>> +/* SPDX-License-Identifier: MIT */
> // SPDX-License-Identifier: MIT

Don't we use /* for SPDX in headers?

Daniele

>> +/*
>> + * Copyright(c) 2020, Intel Corporation. All rights reserved.
>> + */
>> +
>> +#ifndef __INTEL_PXP_PM_H__
>> +#define __INTEL_PXP_PM_H__
>> +
>> +#include "i915_drv.h"
>> +
>> +#ifdef CONFIG_DRM_I915_PXP
>> +void intel_pxp_suspend(struct intel_pxp *pxp);
>> +void intel_pxp_resume(struct intel_pxp *pxp);
>> +#else
>> +static inline void intel_pxp_suspend(struct intel_pxp *pxp)
>> +{
>> +}
>> +static inline void intel_pxp_resume(struct intel_pxp *pxp)
>> +{
>> +}
>> +#endif
>> +
>> +#endif /* __INTEL_PXP_PM_H__ */
>> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
>> index c21620916710..893a2bf61b5c 100644
>> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
>> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
>> @@ -21,29 +21,36 @@
>>   
>>   static bool intel_pxp_session_is_in_play(struct intel_pxp *pxp, u32 id)
>>   {
>> -	struct intel_gt *gt = pxp_to_gt(pxp);
>> +	struct intel_uncore *uncore = pxp_to_gt(pxp)->uncore;
>>   	intel_wakeref_t wakeref;
>>   	u32 sip = 0;
>>   
>> -	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
>> -		sip = intel_uncore_read(gt->uncore, GEN12_KCR_SIP);
>> +	/* if we're suspended the session is considered off */
>> +	with_intel_runtime_pm_if_in_use(uncore->rpm, wakeref)
>> +		sip = intel_uncore_read(uncore, GEN12_KCR_SIP);
>>   
>>   	return sip & BIT(id);
>>   }
>>   
>>   static int pxp_wait_for_session_state(struct intel_pxp *pxp, u32 id, bool in_play)
>>   {
>> -	struct intel_gt *gt = pxp_to_gt(pxp);
>> +	struct intel_uncore *uncore = pxp_to_gt(pxp)->uncore;
>>   	intel_wakeref_t wakeref;
>>   	u32 mask = BIT(id);
>>   	int ret;
>>   
>> -	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
>> -		ret = intel_wait_for_register(gt->uncore,
>> -					      GEN12_KCR_SIP,
>> -					      mask,
>> -					      in_play ? mask : 0,
>> -					      100);
>> +	/* if we're suspended the session is considered off */
>> +	wakeref = intel_runtime_pm_get_if_in_use(uncore->rpm);
>> +	if (!wakeref)
>> +		return in_play ? -ENODEV : 0;
>> +
>> +	ret = intel_wait_for_register(uncore,
>> +				      GEN12_KCR_SIP,
>> +				      mask,
>> +				      in_play ? mask : 0,
>> +				      100);
>> +
>> +	intel_runtime_pm_put(uncore->rpm, wakeref);
>>   
>>   	return ret;
>>   }
>> @@ -132,6 +139,7 @@ void intel_pxp_session_work(struct work_struct *work)
>>   {
>>   	struct intel_pxp *pxp = container_of(work, typeof(*pxp), session_work);
>>   	struct intel_gt *gt = pxp_to_gt(pxp);
>> +	intel_wakeref_t wakeref;
>>   	u32 events = 0;
>>   
>>   	spin_lock_irq(&gt->irq_lock);
>> @@ -144,6 +152,14 @@ void intel_pxp_session_work(struct work_struct *work)
>>   	if (events & PXP_INVAL_REQUIRED)
>>   		intel_pxp_invalidate(pxp);
>>   
>> +	/*
>> +	 * If we're processing an event while suspending then don't bother,
>> +	 * we're going to re-init everything on resume anyway.
>> +	 */
>> +	wakeref = intel_runtime_pm_get_if_in_use(gt->uncore->rpm);
>> +	if (!wakeref)
>> +		return;
>> +
>>   	if (events & PXP_TERMINATION_REQUEST) {
>>   		events &= ~PXP_TERMINATION_COMPLETE;
>>   		pxp_terminate(pxp);
>> @@ -151,4 +167,6 @@ void intel_pxp_session_work(struct work_struct *work)
>>   
>>   	if (events & PXP_TERMINATION_COMPLETE)
>>   		pxp_terminate_complete(pxp);
>> +
>> +	intel_runtime_pm_put(gt->uncore->rpm, wakeref);
>>   }
>> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
>> index 35b3fed4ca2f..0b6098a7b75c 100644
>> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
>> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
>> @@ -63,14 +63,23 @@ static int intel_pxp_tee_io_message(struct intel_pxp *pxp,
>>   static int i915_pxp_tee_component_bind(struct device *i915_kdev,
>>   				       struct device *tee_kdev, void *data)
>>   {
>> +	struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
>>   	struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
>> +	intel_wakeref_t wakeref;
>>   
>>   	pxp->pxp_component = data;
>>   	pxp->pxp_component->tee_dev = tee_kdev;
>>   
>> +	/* if we are suspended, the HW will be re-initialized on resume */
>> +	wakeref = intel_runtime_pm_get_if_in_use(&i915->runtime_pm);
>> +	if (!wakeref)
>> +		return 0;
>> +
>>   	/* the component is required to fully start the PXP HW */
>>   	intel_pxp_init_hw(pxp);
>>   
>> +	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
>> +
>>   	return 0;
>>   }
>>   
>> -- 
>> 2.29.2
>>