drm/xe/guc: Add Relay Communication ABI definitions

The communication between Virtual Function (VF) drivers and
Physical Function (PF) drivers is based on the GuC firmware
acting as a proxy (relay) agent.

Add related ABI definitions that we will be using in upcoming
patches with our GuC Relay implementation.
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://lore.kernel.org/r/20240104222031.277-7-michal.wajdeczko@intel.comSigned-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

drivers/gpu/drm/xe/abi/guc_relay_actions_abi.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef _ABI_GUC_RELAY_ACTIONS_ABI_H_
+#define _ABI_GUC_RELAY_ACTIONS_ABI_H_
+
+/**
+ * DOC: GuC Relay Debug Actions
+ *
+ * This range of action codes is reserved for debugging purposes only and should
+ * be used only on debug builds. These actions may not be supported by the
+ * production drivers. Their definitions could be changed in the future.
+ *
+ *  _`GUC_RELAY_ACTION_DEBUG_ONLY_START` = 0xDEB0
+ *  _`GUC_RELAY_ACTION_DEBUG_ONLY_END` = 0xDEFF
+ */
+
+#define GUC_RELAY_ACTION_DEBUG_ONLY_START	0xDEB0
+#define GUC_RELAY_ACTION_DEBUG_ONLY_END		0xDEFF
+
+/**
+ * DOC: VFXPF_TESTLOOP
+ *
+ * This `Relay Message`_ is used to selftest the `GuC Relay Communication`_.
+ *
+ * The following opcodes are defined:
+ * VFXPF_TESTLOOP_OPCODE_NOP_ will return no data.
+ * VFXPF_TESTLOOP_OPCODE_BUSY_ will reply with BUSY response first.
+ * VFXPF_TESTLOOP_OPCODE_RETRY_ will reply with RETRY response instead.
+ * VFXPF_TESTLOOP_OPCODE_ECHO_ will return same data as received.
+ * VFXPF_TESTLOOP_OPCODE_FAIL_ will always fail with error.
+ *
+ *  +---+-------+--------------------------------------------------------------+
+ *  |   | Bits  | Description                                                  |
+ *  +===+=======+==============================================================+
+ *  | 0 |    31 | ORIGIN = GUC_HXG_ORIGIN_HOST_                                |
+ *  |   +-------+--------------------------------------------------------------+
+ *  |   | 30:28 | TYPE = GUC_HXG_TYPE_REQUEST_ or GUC_HXG_TYPE_FAST_REQUEST_   |
+ *  |   |       | or GUC_HXG_TYPE_EVENT_                                       |
+ *  |   +-------+--------------------------------------------------------------+
+ *  |   | 27:16 | **OPCODE**                                                   |
+ *  |   |       |    - _`VFXPF_TESTLOOP_OPCODE_NOP` = 0x0                      |
+ *  |   |       |    - _`VFXPF_TESTLOOP_OPCODE_BUSY` = 0xB                     |
+ *  |   |       |    - _`VFXPF_TESTLOOP_OPCODE_RETRY` = 0xD                    |
+ *  |   |       |    - _`VFXPF_TESTLOOP_OPCODE_ECHO` = 0xE                     |
+ *  |   |       |    - _`VFXPF_TESTLOOP_OPCODE_FAIL` = 0xF                     |
+ *  |   +-------+--------------------------------------------------------------+
+ *  |   |  15:0 | ACTION = _`IOV_ACTION_SELFTEST_RELAY`                        |
+ *  +---+-------+--------------------------------------------------------------+
+ *  | 1 |  31:0 | **DATA1** = optional, depends on **OPCODE**:                 |
+ *  |   |       | for VFXPF_TESTLOOP_OPCODE_BUSY_: time in ms for reply        |
+ *  |   |       | for VFXPF_TESTLOOP_OPCODE_FAIL_: expected error              |
+ *  |   |       | for VFXPF_TESTLOOP_OPCODE_ECHO_: payload                     |
+ *  +---+-------+--------------------------------------------------------------+
+ *  |...|  31:0 | **DATAn** = only for **OPCODE** VFXPF_TESTLOOP_OPCODE_ECHO_  |
+ *  +---+-------+--------------------------------------------------------------+
+ *
+ *  +---+-------+--------------------------------------------------------------+
+ *  |   | Bits  | Description                                                  |
+ *  +===+=======+==============================================================+
+ *  | 0 |    31 | ORIGIN = GUC_HXG_ORIGIN_HOST_                                |
+ *  |   +-------+--------------------------------------------------------------+
+ *  |   | 30:28 | TYPE = GUC_HXG_TYPE_RESPONSE_SUCCESS_                        |
+ *  |   +-------+--------------------------------------------------------------+
+ *  |   |  27:0 | DATA0 = MBZ                                                  |
+ *  +---+-------+--------------------------------------------------------------+
+ *  |...|  31:0 | DATAn = only for **OPCODE** VFXPF_TESTLOOP_OPCODE_ECHO_      |
+ *  +---+-------+--------------------------------------------------------------+
+ */
+#define GUC_RELAY_ACTION_VFXPF_TESTLOOP		(GUC_RELAY_ACTION_DEBUG_ONLY_START + 1)
+#define   VFXPF_TESTLOOP_OPCODE_NOP		0x0
+#define   VFXPF_TESTLOOP_OPCODE_BUSY		0xB
+#define   VFXPF_TESTLOOP_OPCODE_RETRY		0xD
+#define   VFXPF_TESTLOOP_OPCODE_ECHO		0xE
+#define   VFXPF_TESTLOOP_OPCODE_FAIL		0xF
+
+#endif

drivers/gpu/drm/xe/abi/guc_relay_communication_abi.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef _ABI_GUC_RELAY_COMMUNICATION_ABI_H
+#define _ABI_GUC_RELAY_COMMUNICATION_ABI_H
+
+#include <linux/build_bug.h>
+
+#include "guc_actions_sriov_abi.h"
+#include "guc_communication_ctb_abi.h"
+#include "guc_messages_abi.h"
+
+/**
+ * DOC: GuC Relay Communication
+ *
+ * The communication between Virtual Function (VF) drivers and Physical Function
+ * (PF) drivers is based on the GuC firmware acting as a proxy (relay) agent.
+ *
+ * To communicate with the PF driver, VF's drivers use `VF2GUC_RELAY_TO_PF`_
+ * action that takes the `Relay Message`_ as opaque payload and requires the
+ * relay message identifier (RID) as additional parameter.
+ *
+ * This identifier is used by the drivers to match related messages.
+ *
+ * The GuC forwards this `Relay Message`_ and its identifier to the PF driver
+ * in `GUC2PF_RELAY_FROM_VF`_ action. This event message additionally contains
+ * the identifier of the origin VF (VFID).
+ *
+ * Likewise, to communicate with the VF drivers, PF driver use
+ * `VF2GUC_RELAY_TO_PF`_ action that in addition to the `Relay Message`_
+ * and the relay message identifier (RID) also takes the target VF identifier.
+ *
+ * The GuC uses this target VFID from the message to select where to send the
+ * `GUC2VF_RELAY_FROM_PF`_ with the embedded `Relay Message`_ with response::
+ *
+ *      VF                             GuC                              PF
+ *      |                               |                               |
+ *     [ ] VF2GUC_RELAY_TO_PF           |                               |
+ *     [ ]---------------------------> [ ]                              |
+ *     [ ] { rid, msg }                [ ]                              |
+ *     [ ]                             [ ] GUC2PF_RELAY_FROM_VF         |
+ *     [ ]                             [ ]---------------------------> [ ]
+ *     [ ]                              |  { VFID, rid, msg }          [ ]
+ *     [ ]                              |                              [ ]
+ *     [ ]                              |           PF2GUC_RELAY_TO_VF [ ]
+ *     [ ]                             [ ] <---------------------------[ ]
+ *     [ ]                             [ ]        { VFID, rid, reply }  |
+ *     [ ]        GUC2VF_RELAY_FROM_PF [ ]                              |
+ *     [ ] <---------------------------[ ]                              |
+ *      |               { rid, reply }  |                               |
+ *      |                               |                               |
+ *
+ * It is also possible that PF driver will initiate communication with the
+ * selected VF driver. The same GuC action messages will be used::
+ *
+ *      VF                             GuC                              PF
+ *      |                               |                               |
+ *      |                               |           PF2GUC_RELAY_TO_VF [ ]
+ *      |                              [ ] <---------------------------[ ]
+ *      |                              [ ]          { VFID, rid, msg } [ ]
+ *      |         GUC2VF_RELAY_FROM_PF [ ]                             [ ]
+ *     [ ] <---------------------------[ ]                             [ ]
+ *     [ ]                { rid, msg }  |                              [ ]
+ *     [ ]                              |                              [ ]
+ *     [ ] VF2GUC_RELAY_TO_PF           |                              [ ]
+ *     [ ]---------------------------> [ ]                             [ ]
+ *      |  { rid, reply }              [ ]                             [ ]
+ *      |                              [ ] GUC2PF_RELAY_FROM_VF        [ ]
+ *      |                              [ ]---------------------------> [ ]
+ *      |                               | { VFID, rid, reply }          |
+ *      |                               |                               |
+ */
+
+/**
+ * DOC: Relay Message
+ *
+ * The `Relay Message`_ is used by Physical Function (PF) driver and Virtual
+ * Function (VF) drivers to communicate using `GuC Relay Communication`_.
+ *
+ * Format of the `Relay Message`_ follows format of the generic `HXG Message`_.
+ *
+ *  +--------------------------------------------------------------------------+
+ *  |  `Relay Message`_                                                        |
+ *  +==========================================================================+
+ *  |  `HXG Message`_                                                          |
+ *  +--------------------------------------------------------------------------+
+ *
+ * Maximum length of the `Relay Message`_ is limited by the maximum length of
+ * the `CTB HXG Message`_ and format of the `GUC2PF_RELAY_FROM_VF`_ message.
+ */
+
+#define GUC_RELAY_MSG_MIN_LEN GUC_HXG_MSG_MIN_LEN
+#define GUC_RELAY_MSG_MAX_LEN \
+	(GUC_CTB_MAX_DWORDS - GUC2PF_RELAY_FROM_VF_EVENT_MSG_MIN_LEN)
+
+static_assert(PF2GUC_RELAY_TO_VF_REQUEST_MSG_MIN_LEN >
+	      VF2GUC_RELAY_TO_PF_REQUEST_MSG_MIN_LEN);
+
+/**
+ * DOC: Relay Error Codes
+ *
+ * The `GuC Relay Communication`_ can be used to pass `Relay Message`_ between
+ * drivers that run on different Operating Systems. To help in troubleshooting,
+ * `GuC Relay Communication`_ uses error codes that mostly match errno values.
+ */
+
+#define GUC_RELAY_ERROR_UNDISCLOSED			0
+#define GUC_RELAY_ERROR_OPERATION_NOT_PERMITTED		1	/* EPERM */
+#define GUC_RELAY_ERROR_PERMISSION_DENIED		13	/* EACCES */
+#define GUC_RELAY_ERROR_INVALID_ARGUMENT		22	/* EINVAL */
+#define GUC_RELAY_ERROR_INVALID_REQUEST_CODE		56	/* EBADRQC */
+#define GUC_RELAY_ERROR_NO_DATA_AVAILABLE		61	/* ENODATA */
+#define GUC_RELAY_ERROR_PROTOCOL_ERROR			71	/* EPROTO */
+#define GUC_RELAY_ERROR_MESSAGE_SIZE			90	/* EMSGSIZE */
+
+#endif