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

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/xe/abi/guc_communication_ctb_abi.h

File Facts

System: Linux kernel
Corpus path: drivers/gpu/drm/xe/abi/guc_communication_ctb_abi.h
Extension: .h
Size: 6371 bytes
Lines: 130
Domain: Driver Families
Bucket: drivers/gpu
Inferred role: Driver Families: implementation source
Status: source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

linux/types.h
linux/build_bug.h
guc_messages_abi.h

Detected Declarations

struct guc_ct_buffer_desc

Annotated Snippet

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)
#define GUC_CTB_STATUS_DISABLED				(1 << 3)
	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

Annotation

Immediate include surface: `linux/types.h`, `linux/build_bug.h`, `guc_messages_abi.h`.
Detected declarations: `struct guc_ct_buffer_desc`.
Atlas domain: Driver Families / drivers/gpu.
Implementation status: source implementation candidate.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.