drm/xe: Introduce a new DRM driver for Intel GPUs

Xe, is a new driver for Intel GPUs that supports both integrated and
discrete platforms starting with Tiger Lake (first Intel Xe Architecture).

The code is at a stage where it is already functional and has experimental
support for multiple platforms starting from Tiger Lake, with initial
support implemented in Mesa (for Iris and Anv, our OpenGL and Vulkan
drivers), as well as in NEO (for OpenCL and Level0).

The new Xe driver leverages a lot from i915.

As for display, the intent is to share the display code with the i915
driver so that there is maximum reuse there. But it is not added
in this patch.

This initial work is a collaboration of many people and unfortunately
the big squashed patch won't fully honor the proper credits. But let's
get some git quick stats so we can at least try to preserve some of the
credits:

Co-developed-by: Matthew Brost <matthew.brost@intel.com>
Co-developed-by: Matthew Auld <matthew.auld@intel.com>
Co-developed-by: Matt Roper <matthew.d.roper@intel.com>
Co-developed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Co-developed-by: Francois Dugast <francois.dugast@intel.com>
Co-developed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Co-developed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Co-developed-by: Philippe Lecluse <philippe.lecluse@intel.com>
Co-developed-by: Nirmoy Das <nirmoy.das@intel.com>
Co-developed-by: Jani Nikula <jani.nikula@intel.com>
Co-developed-by: José Roberto de Souza <jose.souza@intel.com>
Co-developed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Co-developed-by: Dave Airlie <airlied@redhat.com>
Co-developed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Co-developed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Co-developed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>

1 files changed, 189 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/abi/guc_communication_ctb_abi.h b/drivers/gpu/drm/xe/abi/guc_communication_ctb_abi.h
new file mode 100644
index 000000000000..41244055cc0c
--- /dev/null
+++ b/drivers/gpu/drm/xe/abi/guc_communication_ctb_abi.h
@@ -0,0 +1,189 @@
+/* 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			256u
+#define GUC_CTB_MSG_0_FENCE			(0xffff << 16)
+#define GUC_CTB_MSG_0_FORMAT			(0xf << 12)
+#define   GUC_CTB_FORMAT_HXG			0u
+#define GUC_CTB_MSG_0_RESERVED			(0xf << 8)
+#define GUC_CTB_MSG_0_NUM_DWORDS		(0xff << 0)
+
+/**
+ * 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 stored in the buffer descriptor.
+ * Buffer descriptor holds tail and head fields that represents active data
+ * stream. The tail field is updated by the data producer (sender), and head
+ * field is updated by the data consumer (receiver)::
+ *
+ *      +------------+
+ *      | DESCRIPTOR |          +=================+============+========+
+ *      +============+          |                 | MESSAGE(s) |        |
+ *      | address    |--------->+=================+============+========+
+ *      +------------+
+ *      | head       |          ^-----head--------^
+ *      +------------+
+ *      | tail       |          ^---------tail-----------------^
+ *      +------------+
+ *      | size       |          ^---------------size--------------------^
+ *      +------------+
+ *
+ * Each message in data stream starts with the single u32 treated as a header,
+ * followed by optional set of u32 data that makes message specific payload::
+ *
+ *      +------------+---------+---------+---------+
+ *      |         MESSAGE                          |
+ *      +------------+---------+---------+---------+
+ *      |   msg[0]   |   [1]   |   ...   |  [n-1]  |
+ *      +------------+---------+---------+---------+
+ *      |   MESSAGE  |       MESSAGE PAYLOAD       |
+ *      +   HEADER   +---------+---------+---------+
+ *      |            |    0    |   ...   |    n    |
+ *      +======+=====+=========+=========+=========+
+ *      | 31:16| code|         |         |         |
+ *      +------+-----+         |         |         |
+ *      |  15:5|flags|         |         |         |
+ *      +------+-----+         |         |         |
+ *      |   4:0|  len|         |         |         |
+ *      +------+-----+---------+---------+---------+
+ *
+ *                   ^-------------len-------------^
+ *
+ * The message header consists of:
+ *
+ * - **len**, indicates length of the message payload (in u32)
+ * - **code**, indicates message code
+ * - **flags**, holds various bits to control message handling
+ */
+
+/*
+ * Definition of the command transport message header (DW0)
+ *
+ * bit[4..0]	message len (in dwords)
+ * bit[7..5]	reserved
+ * bit[8]	response (G2H only)
+ * bit[8]	write fence to desc (H2G only)
+ * bit[9]	write status to H2G buff (H2G only)
+ * bit[10]	send status back via G2H (H2G only)
+ * bit[15..11]	reserved
+ * bit[31..16]	action code
+ */
+#define GUC_CT_MSG_LEN_SHIFT			0
+#define GUC_CT_MSG_LEN_MASK			0x1F
+#define GUC_CT_MSG_IS_RESPONSE			(1 << 8)
+#define GUC_CT_MSG_WRITE_FENCE_TO_DESC		(1 << 8)
+#define GUC_CT_MSG_WRITE_STATUS_TO_BUFF		(1 << 9)
+#define GUC_CT_MSG_SEND_STATUS			(1 << 10)
+#define GUC_CT_MSG_ACTION_SHIFT			16
+#define GUC_CT_MSG_ACTION_MASK			0xFFFF
+
+#endif