[Intel-gfx] [PATCH v6 11/15] drm/i915/pxp: start the arb session on demand

Daniele Ceraolo Spurio
2021-07-29T02:03:02Z

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.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 8 ++--
drivers/gpu/drm/i915/pxp/intel_pxp.c | 37 ++++++++++++-------
drivers/gpu/drm/i915/pxp/intel_pxp.h | 5 ++-
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, 39 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 04f33d163340..862f887b1809 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2780,9 +2780,11 @@ eb_select_engine(struct i915_execbuffer *eb)
intel_gt_pm_get(ce->engine->gt);

if (i915_gem_context_uses_protected_content(eb->gem_context)) {
- err = intel_pxp_wait_for_arb_start(&ce->engine->gt->pxp);
- if (err)
- goto err;
+ if (!intel_pxp_is_active(&ce->engine->gt->pxp)) {
+ err = intel_pxp_start(&ce->engine->gt->pxp);
+ if (err)
+ goto err;
+ }

if (i915_gem_context_invalidated(eb->gem_context)) {
err = -EACCES;
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index f418281e8c10..31c8835eebb4 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -82,6 +82,7 @@ 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);
@@ -118,7 +119,7 @@ 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);

@@ -137,31 +138,41 @@ 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(100))) {
+ 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 4f7647f34153..382f7f069aca 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -34,7 +34,8 @@ 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_object_add(struct drm_i915_gem_object *obj);
void intel_pxp_object_remove(struct drm_i915_gem_object *obj);
@@ -49,7 +50,7 @@ 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 0;
}
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
index 46eca1e81b9b..340f20d130a8 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c
@@ -31,7 +31,7 @@ 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 0edd563a653d..1f13e58d47f9 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
@@ -85,9 +85,6 @@ 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) {
@@ -144,6 +141,9 @@ 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 7693540dc1f9..c0998047c1b6 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 be2bed3a2e4e..42601e6f51ee 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
@@ -26,6 +26,7 @@ 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;

struct mutex tee_mutex; /* protects the tee channel binding */
@@ -45,6 +46,7 @@ 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)

spinlock_t lock; /* protects the objects list */
struct list_head protected_objects;
--
2.32.0