/* SPDX-License-Identifier: MIT */ /* * Copyright © 2014-2021 Intel Corporation */ #ifndef _ABI_GUC_COMMUNICATION_CTB_ABI_H #define _ABI_GUC_COMMUNICATION_CTB_ABI_H #include <linux/types.h> #include <linux/build_bug.h> #include "guc_messages_abi.h" /** * DOC: CT Buffer * * Circular buffer used to send `CTB Message`_ */ /** * DOC: CTB Descriptor * * +---+-------+--------------------------------------------------------------+ * | | Bits | Description | * +===+=======+==============================================================+ * | 0 | 31:0 | **HEAD** - offset (in dwords) to the last dword that was | * | | | read from the `CT Buffer`_. | * | | | It can only be updated by the receiver. | * +---+-------+--------------------------------------------------------------+ * | 1 | 31:0 | **TAIL** - offset (in dwords) to the last dword that was | * | | | written to the `CT Buffer`_. | * | | | It can only be updated by the sender. | * +---+-------+--------------------------------------------------------------+ * | 2 | 31:0 | **STATUS** - status of the CTB | * | | | | * | | | - _`GUC_CTB_STATUS_NO_ERROR` = 0 (normal operation) | * | | | - _`GUC_CTB_STATUS_OVERFLOW` = 1 (head/tail too large) | * | | | - _`GUC_CTB_STATUS_UNDERFLOW` = 2 (truncated message) | * | | | - _`GUC_CTB_STATUS_MISMATCH` = 4 (head/tail modified) | * +---+-------+--------------------------------------------------------------+ * |...| | RESERVED = MBZ | * +---+-------+--------------------------------------------------------------+ * | 15| 31:0 | RESERVED = MBZ | * +---+-------+--------------------------------------------------------------+ */ struct guc_ct_buffer_desc { … } __packed; static_assert(…); /** * DOC: CTB Message * * +---+-------+--------------------------------------------------------------+ * | | Bits | Description | * +===+=======+==============================================================+ * | 0 | 31:16 | **FENCE** - message identifier | * | +-------+--------------------------------------------------------------+ * | | 15:12 | **FORMAT** - format of the CTB message | * | | | - _`GUC_CTB_FORMAT_HXG` = 0 - see `CTB HXG Message`_ | * | +-------+--------------------------------------------------------------+ * | | 11:8 | **RESERVED** | * | +-------+--------------------------------------------------------------+ * | | 7:0 | **NUM_DWORDS** - length of the CTB message (w/o header) | * +---+-------+--------------------------------------------------------------+ * | 1 | 31:0 | optional (depends on FORMAT) | * +---+-------+ | * |...| | | * +---+-------+ | * | n | 31:0 | | * +---+-------+--------------------------------------------------------------+ */ #define GUC_CTB_HDR_LEN … #define GUC_CTB_MSG_MIN_LEN … #define GUC_CTB_MSG_MAX_LEN … #define GUC_CTB_MSG_0_FENCE … #define GUC_CTB_MSG_0_FORMAT … #define GUC_CTB_FORMAT_HXG … #define GUC_CTB_MSG_0_RESERVED … #define GUC_CTB_MSG_0_NUM_DWORDS … #define GUC_CTB_MAX_DWORDS … /** * DOC: CTB HXG Message * * +---+-------+--------------------------------------------------------------+ * | | Bits | Description | * +===+=======+==============================================================+ * | 0 | 31:16 | FENCE | * | +-------+--------------------------------------------------------------+ * | | 15:12 | FORMAT = GUC_CTB_FORMAT_HXG_ | * | +-------+--------------------------------------------------------------+ * | | 11:8 | RESERVED = MBZ | * | +-------+--------------------------------------------------------------+ * | | 7:0 | NUM_DWORDS = length (in dwords) of the embedded HXG message | * +---+-------+--------------------------------------------------------------+ * | 1 | 31:0 | | * +---+-------+ | * |...| | [Embedded `HXG Message`_] | * +---+-------+ | * | n | 31:0 | | * +---+-------+--------------------------------------------------------------+ */ #define GUC_CTB_HXG_MSG_MIN_LEN … #define GUC_CTB_HXG_MSG_MAX_LEN … /** * DOC: CTB based communication * * The CTB (command transport buffer) communication between Host and GuC * is based on u32 data stream written to the shared buffer. One buffer can * be used to transmit data only in one direction (one-directional channel). * * Current status of the each buffer is maintained in the `CTB Descriptor`_. * Each message in data stream is encoded as `CTB HXG Message`_. */ #endif
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