[PATCH v2 6/9] drm/i915/pxp: Add ARB session creation with new PXP API Ver4.3

[Alan Previn]

Add MTL's function for ARB session creation using PXP firmware
version 4.3 ABI structure format.

Before checking the return status, look at the GSC-CS-Mem-Header's
pending-bit which means the GSC firmware is busy and we should
resubmit.

Signed-off-by: Alan Previn <alan.previn.teres.alexis at intel.com>
---
 .../drm/i915/pxp/intel_pxp_cmd_interface_43.h | 21 +++++++
 drivers/gpu/drm/i915/pxp/intel_pxp_gsccs.c    | 56 ++++++++++++++++++-
 2 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_cmd_interface_43.h b/drivers/gpu/drm/i915/pxp/intel_pxp_cmd_interface_43.h
index 52b9a61bcdd4..ee78c0817ba1 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_cmd_interface_43.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_cmd_interface_43.h
@@ -11,6 +11,7 @@
 
 /* PXP-Cmd-Op definitions */
 #define PXP43_CMDID_START_HUC_AUTH	0x0000003A
+#define PXP43_CMDID_INIT_SESSION	0x00000036
 
 /* PXP-Packet sizes for MTL's GSCCS-HECI instruction */
 #define PXP43_MAX_HECI_IN_SIZE		(SZ_32K)
@@ -27,4 +28,24 @@ struct pxp43_start_huc_auth_out {
 	struct pxp_cmd_header header;
 } __packed;
 
+/* PXP-Input-Packet: Init PXP session */
+struct pxp43_create_arb_in {
+	struct pxp_cmd_header header;
+		/* header.stream_id fields for vesion 4.3 of Init PXP session: */
+		#define PXP43_INIT_SESSION_VALID GENMASK(0, 0)
+		#define PXP43_INIT_SESSION_APPTYPE GENMASK(1, 1)
+		#define PXP43_INIT_SESSION_APPID GENMASK(17, 2)
+	u32 protection_mode;
+		#define PXP43_INIT_SESSION_PROTECTION_ARB 0x2
+	u32 sub_session_id;
+	u32 init_flags;
+	u32 rsvd[12];
+} __packed;
+
+/* PXP-Input-Packet: Init PXP session */
+struct pxp43_create_arb_out {
+	struct pxp_cmd_header header;
+	u32 rsvd[8];
+} __packed;
+
 #endif /* __INTEL_PXP_FW_INTERFACE_43_H__ */
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_gsccs.c b/drivers/gpu/drm/i915/pxp/intel_pxp_gsccs.c
index ff235822743e..1b06629ac16e 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_gsccs.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_gsccs.c
@@ -43,7 +43,8 @@ static inline struct gsccs_teelink_priv *pxp_to_gsccs_priv(struct intel_pxp *pxp
 static int gsccs_send_message(struct intel_pxp *pxp,
 			      void *msg_in, size_t msg_in_size,
 			      void *msg_out, size_t msg_out_size_max,
-			      size_t *msg_out_len)
+			      size_t *msg_out_len,
+			      u64 *gsc_msg_handle_retry)
 {
 	struct intel_gt *gt = pxp->ctrl_gt;
 	struct drm_i915_private *i915 = gt->i915;
@@ -75,6 +76,9 @@ static int gsccs_send_message(struct intel_pxp *pxp,
 					      msg_in_size + sizeof(*header),
 					      exec->host_session_handle);
 
+	/* copy caller provided gsc message handle if this is polling for a prior msg completion */
+	header->gsc_message_handle = *gsc_msg_handle_retry;
+
 	memcpy(exec->pkt_vaddr + sizeof(*header), msg_in, msg_in_size);
 
 	pkt.addr_in = i915_vma_offset(exec->pkt_vma);
@@ -91,7 +95,7 @@ static int gsccs_send_message(struct intel_pxp *pxp,
 		goto unlock;
 	}
 
-	/* we keep separate location for reply, so get the response header loc first */
+	/* we keep separate location for reply, so go to the response header now */
 	header = exec->pkt_vaddr + PXP43_MAX_HECI_IN_SIZE;
 
 	/* Response validity marker, status and busyness */
@@ -108,6 +112,13 @@ static int gsccs_send_message(struct intel_pxp *pxp,
 	}
 	if (header->flags & GSC_HECI_FLAG_MSG_PENDING) {
 		drm_dbg(&i915->drm, "gsc PXP reply is busy\n");
+		/*
+		 * When the GSC firmware replies with pending bit, it means that the requested
+		 * operation has begun but the completion is pending and the caller needs
+		 * to re-request with the gsc_message_handle that was returned by the firmware.
+		 * until the pending bit is turned off.
+		 */
+		*gsc_msg_handle_retry = header->gsc_message_handle;
 		ret = -EAGAIN;
 		goto unlock;
 	}
@@ -135,7 +146,46 @@ static int gsccs_send_message(struct intel_pxp *pxp,
 int intel_pxp_gsccs_create_session(struct intel_pxp *pxp,
 				   int arb_session_id)
 {
-	return -ENODEV;
+	struct gsccs_session_resources *exec = &pxp_to_gsccs_priv(pxp)->arb_exec_res;
+	struct pxp43_create_arb_in msg_in = {0};
+	struct pxp43_create_arb_out msg_out = {0};
+	u64 gsc_session_retry = 0;
+	int insize, outsize, ret, tries = 0;
+	void *inptr, *outptr;
+
+	/* get a unique host-session-handle (used later in HW cmds) at time of session creation */
+	get_random_bytes(&exec->host_session_handle, sizeof(exec->host_session_handle));
+
+	msg_in.header.api_version = PXP_APIVER(4, 3);
+	msg_in.header.command_id = PXP43_CMDID_INIT_SESSION;
+	msg_in.header.stream_id = (FIELD_PREP(PXP43_INIT_SESSION_APPID, arb_session_id) |
+				   FIELD_PREP(PXP43_INIT_SESSION_VALID, 1) |
+				   FIELD_PREP(PXP43_INIT_SESSION_APPTYPE, 0));
+	msg_in.header.buffer_len = sizeof(msg_in) - sizeof(msg_in.header);
+	msg_in.protection_mode = PXP43_INIT_SESSION_PROTECTION_ARB;
+
+	inptr = &msg_in;
+	outptr = &msg_out;
+	insize = sizeof(msg_in);
+	outsize = sizeof(msg_out);
+
+	/*
+	 * Keep sending request if GSC firmware was busy.
+	 * Based on test data, we expects a worst case delay of 250 milisecs.
+	 */
+	do {
+		ret = gsccs_send_message(pxp,
+					 inptr, insize,
+					 outptr, outsize, NULL,
+					 &gsc_session_retry);
+		/* Only try again if gsc says so */
+		if (ret != -EAGAIN)
+			break;
+
+		msleep(20);
+	} while (++tries < 12);
+
+	return ret;
 }
 
 static void
-- 
2.39.0