| /* 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 { |
| u32 head; |
| u32 tail; |
| u32 status; |
| #define GUC_CTB_STATUS_NO_ERROR 0 |
| #define GUC_CTB_STATUS_OVERFLOW (1 << 0) |
| #define GUC_CTB_STATUS_UNDERFLOW (1 << 1) |
| #define GUC_CTB_STATUS_MISMATCH (1 << 2) |
| u32 reserved[13]; |
| } __packed; |
| static_assert(sizeof(struct guc_ct_buffer_desc) == 64); |
| |
| /** |
| * 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 1u |
| #define GUC_CTB_MSG_MIN_LEN GUC_CTB_HDR_LEN |
| #define GUC_CTB_MSG_MAX_LEN (GUC_CTB_MSG_MIN_LEN + GUC_CTB_MAX_DWORDS) |
| #define GUC_CTB_MSG_0_FENCE (0xffffu << 16) |
| #define GUC_CTB_MSG_0_FORMAT (0xfu << 12) |
| #define GUC_CTB_FORMAT_HXG 0u |
| #define GUC_CTB_MSG_0_RESERVED (0xfu << 8) |
| #define GUC_CTB_MSG_0_NUM_DWORDS (0xffu << 0) |
| #define GUC_CTB_MAX_DWORDS 255 |
| |
| /** |
| * 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 (GUC_CTB_MSG_MIN_LEN + GUC_HXG_MSG_MIN_LEN) |
| #define GUC_CTB_HXG_MSG_MAX_LEN GUC_CTB_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 |
