[Intel-gfx] [PATCH v11 11/17] drm/i915/pxp: start the arb session on demand

Alan Previn
2021-09-22T00:15:35Z

From: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

Now that we can handle destruction and re-creation of the arb session,
we can postpone the start of the session to the first submission that
requires it, to avoid keeping it running with no user.

v10: increase timeout when waiting in intel_pxp_start as firmware
session startup is slower right after boot.

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 4 ++-
drivers/gpu/drm/i915/pxp/intel_pxp.c | 37 +++++++++++++-------
drivers/gpu/drm/i915/pxp/intel_pxp.h | 10 ++++--
drivers/gpu/drm/i915/pxp/intel_pxp_irq.c | 2 +-
drivers/gpu/drm/i915/pxp/intel_pxp_session.c | 6 ++--
drivers/gpu/drm/i915/pxp/intel_pxp_tee.c | 10 +-----
drivers/gpu/drm/i915/pxp/intel_pxp_types.h | 2 ++
7 files changed, 42 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 3efbfbfed0b9..abe74088afe4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -267,7 +267,9 @@ static int proto_context_set_protected(struct drm_i915_private *i915,
* which in turn requires the device to be active.
*/
pc->pxp_wakeref = intel_runtime_pm_get(&i915->runtime_pm);
- ret = intel_pxp_wait_for_arb_start(&i915->gt.pxp);
+
+ if (!intel_pxp_is_active(&i915->gt.pxp))
+ ret = intel_pxp_start(&i915->gt.pxp);
}

return ret;
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index 82f250d15e1e..77f58641f6de 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -90,6 +90,7 @@ void intel_pxp_init(struct intel_pxp *pxp)
init_completion(&pxp->termination);
complete_all(&pxp->termination);

+ mutex_init(&pxp->arb_mutex);
INIT_WORK(&pxp->session_work, intel_pxp_session_work);

ret = create_vcs_context(pxp);
@@ -126,7 +127,7 @@ void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp)
reinit_completion(&pxp->termination);
}

-static void intel_pxp_queue_termination(struct intel_pxp *pxp)
+static void pxp_queue_termination(struct intel_pxp *pxp)
{
struct intel_gt *gt = pxp_to_gt(pxp);

@@ -145,31 +146,41 @@ static void intel_pxp_queue_termination(struct intel_pxp *pxp)
* the arb session is restarted from the irq work when we receive the
* termination completion interrupt
*/
-int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
+int intel_pxp_start(struct intel_pxp *pxp)
{
+ int ret = 0;
+
if (!intel_pxp_is_enabled(pxp))
- return 0;
+ return -ENODEV;
+
+ mutex_lock(&pxp->arb_mutex);
+
+ if (pxp->arb_is_valid)
+ goto unlock;
+
+ pxp_queue_termination(pxp);

if (!wait_for_completion_timeout(&pxp->termination,
- msecs_to_jiffies(100)))
- return -ETIMEDOUT;
+ msecs_to_jiffies(200))) {
+ ret = -ETIMEDOUT;
+ goto unlock;
+ }
+
+ /* make sure the compiler doesn't optimize the double access */
+ barrier();

if (!pxp->arb_is_valid)
- return -EIO;
+ ret = -EIO;

- return 0;
+unlock:
+ mutex_unlock(&pxp->arb_mutex);
+ return ret;
}

void intel_pxp_init_hw(struct intel_pxp *pxp)
{
kcr_pxp_enable(pxp_to_gt(pxp));
intel_pxp_irq_enable(pxp);
-
- /*
- * the session could've been attacked while we weren't loaded, so
- * handle it as if it was and re-create it.
- */
- intel_pxp_queue_termination(pxp);
}

void intel_pxp_fini_hw(struct intel_pxp *pxp)
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
index 430f01ea9860..bce0014d9ff9 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -26,7 +26,8 @@ void intel_pxp_init_hw(struct intel_pxp *pxp);
void intel_pxp_fini_hw(struct intel_pxp *pxp);

void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp);
-int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp);
+
+int intel_pxp_start(struct intel_pxp *pxp);

int intel_pxp_key_check(struct intel_pxp *pxp, struct drm_i915_gem_object *obj);

@@ -40,11 +41,16 @@ static inline void intel_pxp_fini(struct intel_pxp *pxp)
{
}

-static inline int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
+static inline int intel_pxp_start(struct intel_pxp *pxp)
{
return -ENODEV;
}

+static inline bool intel_pxp_is_active(const struct intel_pxp *pxp)
+{
+ return false;
+}
+
static inline int intel_pxp_key_check(struct intel_pxp *pxp,
struct drm_i915_gem_object *obj)
{
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
index 300cf2b96fda..7b25efa82b76 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
@@ -32,7 +32,7 @@ void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir)
GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT)) {
/* immediately mark PXP as inactive on termination */
intel_pxp_mark_termination_in_progress(pxp);
- pxp->session_events |= PXP_TERMINATION_REQUEST;
+ pxp->session_events |= PXP_TERMINATION_REQUEST | PXP_INVAL_REQUIRED;
}

if (iir & GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT)
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
index c6a5e4197e40..a95cc443a48d 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
@@ -88,9 +88,6 @@ static int pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
/* must mark termination in progress calling this function */
GEM_WARN_ON(pxp->arb_is_valid);

- /* invalidate protected objects */
- intel_pxp_invalidate(pxp);
-
/* terminate the hw sessions */
ret = intel_pxp_terminate_session(pxp, ARB_SESSION);
if (ret) {
@@ -147,6 +144,9 @@ void intel_pxp_session_work(struct work_struct *work)
if (!events)
return;

+ if (events & PXP_INVAL_REQUIRED)
+ intel_pxp_invalidate(pxp);
+
if (events & PXP_TERMINATION_REQUEST) {
events &= ~PXP_TERMINATION_COMPLETE;
pxp_terminate(pxp);
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
index 494bd6b48514..3fc3ddfd02b3 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
@@ -78,9 +78,7 @@ 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);
- int ret;

mutex_lock(&pxp->tee_mutex);
pxp->pxp_component = data;
@@ -89,14 +87,8 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev,

/* the component is required to fully start the PXP HW */
intel_pxp_init_hw(pxp);
- ret = intel_pxp_wait_for_arb_start(pxp);
- if (ret) {
- drm_err(&i915->drm, "Failed to create arb session during bind\n");
- intel_pxp_fini_hw(pxp);
- pxp->pxp_component = NULL;
- }

- return ret;
+ return 0;
}

static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
index c394ab2e452b..ae24064bb57e 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
@@ -27,6 +27,7 @@ struct intel_pxp {
* even if the keys are gone, so we can't rely on the HW state of the
* session to know if it's valid and need to track the status in SW.
*/
+ struct mutex arb_mutex; /* protects arb session start */
bool arb_is_valid;

/*
@@ -53,6 +54,7 @@ struct intel_pxp {
u32 session_events; /* protected with gt->irq_lock */
#define PXP_TERMINATION_REQUEST BIT(0)
#define PXP_TERMINATION_COMPLETE BIT(1)
+#define PXP_INVAL_REQUIRED BIT(2)
};

#endif /* __INTEL_PXP_TYPES_H__ */
--
2.25.1