diff mbox series

[10/27] drm/i915/pxp: Enable ioctl action to reserve session slot

Message ID 20201115210815.5272-10-sean.z.huang@intel.com (mailing list archive)
State New, archived
Headers show
Series [01/27] drm/i915/pxp: Introduce Intel PXP component | expand

Commit Message

Huang, Sean Z Nov. 15, 2020, 9:07 p.m. UTC
With this ioctl action, ring3 driver can reserve a specific
session slot/id assigned by ring0 PXP, as the first step of PXP
session establishment flow. Ring3 PXP stores the session info in
the session list structure.

Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
---
 drivers/gpu/drm/i915/pxp/intel_pxp.c    |  20 +++
 drivers/gpu/drm/i915/pxp/intel_pxp.h    |  24 +++-
 drivers/gpu/drm/i915/pxp/intel_pxp_sm.c | 168 ++++++++++++++++++++++++
 drivers/gpu/drm/i915/pxp/intel_pxp_sm.h |   3 +
 4 files changed, 213 insertions(+), 2 deletions(-)

Comments

Joonas Lahtinen Nov. 16, 2020, 11:01 a.m. UTC | #1
Quoting Huang, Sean Z (2020-11-15 23:07:58)
> With this ioctl action, ring3 driver can reserve a specific
> session slot/id assigned by ring0 PXP, as the first step of PXP
> session establishment flow. Ring3 PXP stores the session info in
> the session list structure.

The whole suggested userspace<->kernel API surface should be strictly
moved into i915_drm.h to make review easier. Now it's hard to tell
apart the suggested uAPI from the implementation.

Once the separation is in place, I'll be able to provide more review
comments on the rest of the patches.

Regards, Joonas
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index 8fa88ea17bc0..919ebe2405e3 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -40,6 +40,26 @@  int i915_pxp_ops_ioctl(struct drm_device *dev, void *data, struct drm_file *drmf
 	}
 
 	switch (pxp_info.action) {
+	case PXP_ACTION_SET_SESSION_STATUS:
+	{
+		struct pxp_sm_set_session_status_params *params = &pxp_info.set_session_status;
+
+		if (params->req_session_state == PXP_SM_REQ_SESSION_ID_INIT) {
+			ret = intel_pxp_sm_reserve_session(i915, drmfile, 0,
+							   params->session_type,
+							   params->session_mode,
+							   &params->pxp_tag);
+			if (ret == PXP_SM_STATUS_RETRY_REQUIRED ||
+			    ret == PXP_SM_STATUS_SESSION_NOT_AVAILABLE) {
+				pxp_info.sm_status = ret;
+				ret = 0;
+			}
+		} else {
+			ret = -EINVAL;
+			goto end;
+		}
+		break;
+	}
 	case PXP_ACTION_SET_R3_CONTEXT:
 	{
 		ret = intel_pxp_set_r3ctx(i915, pxp_info.set_r3ctx);
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
index 95d3deba7ade..cbaf25690596 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -15,6 +15,9 @@ 
 #define pxp_session_list(i915, session_type) (((session_type) == SESSION_TYPE_TYPE0) ? \
 	&(i915)->pxp.r0ctx->active_pxp_type0_sessions : &(i915)->pxp.r0ctx->active_pxp_type1_sessions)
 
+#define pxp_session_max(session_type) (((session_type) == SESSION_TYPE_TYPE0) ? \
+	MAX_TYPE0_SESSIONS : MAX_TYPE1_SESSIONS)
+
 #define MAX_TYPE0_SESSIONS 16
 #define MAX_TYPE1_SESSIONS 6
 
@@ -27,7 +30,10 @@  enum pxp_sm_session_req {
 	PXP_SM_REQ_SESSION_TERMINATE
 };
 
-#define PXP_ACTION_SET_R3_CONTEXT 5
+enum pxp_ioctl_action {
+	PXP_ACTION_SET_SESSION_STATUS = 1,
+	PXP_ACTION_SET_R3_CONTEXT = 5,
+};
 
 enum pxp_sm_status {
 	PXP_SM_STATUS_SUCCESS,
@@ -36,10 +42,24 @@  enum pxp_sm_status {
 	PXP_SM_STATUS_ERROR_UNKNOWN
 };
 
+struct pxp_sm_set_session_status_params {
+	/** @pxp_tag: in [optional], for Arbitrator session, out pxp tag */
+	u32 pxp_tag;
+	/** @session_type: in, session type */
+	u32 session_type;
+	/** @session_mode: in, session mode */
+	u32 session_mode;
+	/** @req_session_state: in, new session state */
+	u32 req_session_state;
+};
+
 struct pxp_info {
 	u32 action;
 	u32 sm_status;
-	u32 set_r3ctx;
+	union {
+		struct pxp_sm_set_session_status_params set_session_status;
+		u32 set_r3ctx;
+	};
 } __packed;
 
 struct pxp_context;
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
index f3223c9f71c7..3a22fb485cd8 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.c
@@ -307,6 +307,174 @@  static bool check_if_protected_type0_sessions_are_attacked(struct drm_i915_priva
 	return false;
 }
 
+/**
+ * create_new_session_entry - Create a new session entry with provided info.
+ * @i915: i915 device handle.
+ * @drmfile: pointer to drm_file
+ * @context_id: Numeric identifier of the context created by the caller.
+ * @session_type: Type of the session requested. One of enum pxp_session_types.
+ * @protection_mode: Type of protection requested for the session.
+ *                   One of the enum pxp_protection_modes.
+ * @session_index: Numeric session identifier.
+ *
+ * Return: status. 0 means creation is successful.
+ */
+static int create_new_session_entry(struct drm_i915_private *i915, struct drm_file *drmfile,
+				    int context_id, int session_type, int protection_mode,
+				    int session_index)
+{
+	int ret;
+	struct pxp_protected_session *new_session = NULL;
+	int pid = 0;
+
+	if (drmfile)
+		pid = pid_nr(drmfile->pid);
+
+	drm_dbg(&i915->drm, ">>> %s context_id=[%d] session_type=[%d] protection_mode=[%d] session_index=[%d] drmfile=[%p] pid=[%d]\n",
+		__func__, context_id, session_type, protection_mode, session_index,
+		drmfile, pid);
+
+	new_session = kzalloc(sizeof(*new_session), GFP_KERNEL);
+	if (!new_session) {
+		ret = -ENOMEM;
+		drm_dbg(&i915->drm, "Failed to kzalloc()\n");
+		goto end;
+	}
+
+	new_session->context_id = context_id;
+	new_session->session_type = session_type;
+	new_session->protection_mode = protection_mode;
+	new_session->session_index = session_index;
+	new_session->session_is_in_play = false;
+	new_session->drmfile = drmfile;
+	new_session->pid = pid;
+
+	switch (session_type) {
+	case SESSION_TYPE_TYPE0:
+		/* check to make sure the session id is within allowed range */
+		if (session_index < 0 || session_index >= MAX_TYPE0_SESSIONS) {
+			/* session id out of range.. free the new entry and return error */
+			kfree(new_session);
+			ret = -EINVAL;
+			drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+			goto end;
+		}
+
+		list_add(&new_session->session_list, &i915->pxp.r0ctx->active_pxp_type0_sessions);
+		break;
+
+	case SESSION_TYPE_TYPE1:
+		/* check to make sure the session id is within allowed range */
+		if (session_index < 0 || session_index >= MAX_TYPE1_SESSIONS) {
+			/* session id out of range.. free the new entry and return error */
+			kfree(new_session);
+			ret = -EINVAL;
+			drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+			goto end;
+		}
+
+		list_add(&new_session->session_list, &i915->pxp.r0ctx->active_pxp_type1_sessions);
+		break;
+
+	default:
+		/* session type is invalid... free new entry and return error. */
+		kfree(new_session);
+		ret = -EINVAL;
+		drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+		break;
+	}
+	ret = 0;
+end:
+	return ret;
+}
+
+/**
+ * intel_pxp_sm_reserve_session - To reserve an available protected session.
+ * @i915: i915 device handle.
+ * @drmfile: pointer to drm_file.
+ * @context_id: Numeric identifier of the context created by the caller.
+ * @session_type: Type of the session requested. One of enum pxp_session_types.
+ * @protection_mode: Type of protection requested for the session. One of the
+ *                   enum pxp_protection_modes.
+ * @pxp_tag: Numeric session identifier returned back to caller.
+ *
+ * Return: status. 0 means reserve is successful.
+ */
+int intel_pxp_sm_reserve_session(struct drm_i915_private *i915, struct drm_file *drmfile,
+				 int context_id, int session_type, int protection_mode,
+				 u32 *pxp_tag)
+{
+	int ret;
+	int session_index = 0;
+
+	drm_dbg(&i915->drm, ">>> %s session_type=[%d] protection_mode=[%d]\n", __func__,
+		session_type, protection_mode);
+
+	if (!pxp_tag || !i915) {
+		ret = -EINVAL;
+		drm_dbg(&i915->drm, "Failed to %s, bad params\n", __func__);
+		goto end;
+	}
+
+	if (protection_mode != PROTECTION_MODE_LM && protection_mode != PROTECTION_MODE_HM &&
+	    protection_mode != PROTECTION_MODE_SM) {
+		ret = -EINVAL;
+		drm_dbg(&i915->drm, "Failed to %s, invalid session mode=[%d]\n", __func__, protection_mode);
+		goto end;
+	}
+
+	lockdep_assert_held(&i915->pxp.r0ctx->ctx_mutex);
+
+	if (session_type == SESSION_TYPE_TYPE0) {
+		/*
+		 * check if sessions are under attack. if so, don't allow creation of
+		 * new session entries
+		 */
+		if (check_if_protected_type0_sessions_are_attacked(i915)) {
+			/** protected sessions are under attack. return failure... **/
+			ret = -EPERM;
+			goto end;
+		}
+	}
+
+	/*
+	 * iterate over the active sessions list to find next available open session id
+	 * Cannot assume that the session entries will be sorted in the linked list
+	 * as terminates are allowed at any time without re-sorting the linked list.
+	 * So, the linked list should be walked start to finish to ensure a session is
+	 * not already active
+	 */
+	for (session_index = 0; session_index < pxp_session_max(session_type); session_index++) {
+		if (!is_sw_session_active(i915, session_type, session_index, false, NULL)) {
+			ret = sync_hw_sw_state(i915, session_index, session_type);
+			if (unlikely(ret)) {
+				ret = PXP_SM_STATUS_RETRY_REQUIRED;
+				goto end;
+			}
+
+			/*
+			 * found an available session... create a new session entry
+			 * with this identifier and return success
+			 */
+			ret = create_new_session_entry(i915, drmfile, context_id, session_type,
+						       protection_mode, session_index);
+			if (unlikely(ret))
+				goto end;
+
+			ret = pxp_set_pxp_tag(i915, session_type, session_index, protection_mode);
+			goto end;
+		}
+	}
+
+	ret = PXP_SM_STATUS_SESSION_NOT_AVAILABLE;
+end:
+	if (ret == 0)
+		*pxp_tag = intel_pxp_get_pxp_tag(i915, session_index, session_type, NULL);
+
+	drm_dbg(&i915->drm, "<<< %s ret=[%d]\n", __func__, ret);
+	return ret;
+}
+
 int pxp_sm_set_kcr_init_reg(struct drm_i915_private *i915)
 {
 	int ret;
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
index b5012948f971..5fcf63f804f8 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_sm.h
@@ -84,6 +84,9 @@  struct pxp_protected_session {
 	bool session_is_in_play;
 };
 
+int intel_pxp_sm_reserve_session(struct drm_i915_private *i915, struct drm_file *drmfile,
+				 int context_id, int session_type, int protection_mode,
+				 u32 *pxp_tag);
 int pxp_sm_set_kcr_init_reg(struct drm_i915_private *i915);
 
 #endif /* __INTEL_PXP_SM_H__ */