1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2023 Intel Corporation
4 */
5
6#include <linux/fault-inject.h>
7
8#include <drm/drm_managed.h>
9
10#include "xe_bo.h"
11#include "xe_device.h"
12#include "xe_ggtt.h"
13#include "xe_gt.h"
14#include "xe_memirq.h"
15#include "xe_migrate.h"
16#include "xe_pcode.h"
17#include "xe_sa.h"
18#include "xe_svm.h"
19#include "xe_tile.h"
20#include "xe_tile_sysfs.h"
21#include "xe_ttm_vram_mgr.h"
22#include "xe_vram.h"
23#include "xe_vram_types.h"
24#include "xe_wa.h"
25
26/**
27 * DOC: Multi-tile Design
28 *
29 * Different vendors use the term "tile" a bit differently, but in the Intel
30 * world, a 'tile' is pretty close to what most people would think of as being
31 * a complete GPU. When multiple GPUs are placed behind a single PCI device,
32 * that's what is referred to as a "multi-tile device." In such cases, pretty
33 * much all hardware is replicated per-tile, although certain responsibilities
34 * like PCI communication, reporting of interrupts to the OS, etc. are handled
35 * solely by the "root tile." A multi-tile platform takes care of tying the
36 * tiles together in a way such that interrupt notifications from remote tiles
37 * are forwarded to the root tile, the per-tile vram is combined into a single
38 * address space, etc.
39 *
40 * In contrast, a "GT" (which officially stands for "Graphics Technology") is
41 * the subset of a GPU/tile that is responsible for implementing graphics
42 * and/or media operations. The GT is where a lot of the driver implementation
43 * happens since it's where the hardware engines, the execution units, and the
44 * GuC all reside.
45 *
46 * Historically most Intel devices were single-tile devices that contained a
47 * single GT. PVC is an example of an Intel platform built on a multi-tile
48 * design (i.e., multiple GPUs behind a single PCI device); each PVC tile only
49 * has a single GT. In contrast, platforms like MTL that have separate chips
50 * for render and media IP are still only a single logical GPU, but the
51 * graphics and media IP blocks are each exposed as a separate GT within that
52 * single GPU. This is important from a software perspective because multi-GT
53 * platforms like MTL only replicate a subset of the GPU hardware and behave
54 * differently than multi-tile platforms like PVC where nearly everything is
55 * replicated.
56 *
57 * Per-tile functionality (shared by all GTs within the tile):
58 * - Complete 4MB MMIO space (containing SGunit/SoC registers, GT
59 * registers, display registers, etc.)
60 * - Global GTT
61 * - VRAM (if discrete)
62 * - Interrupt flows
63 * - Migration context
64 * - kernel batchbuffer pool
65 * - Primary GT
66 * - Media GT (if media version >= 13)
67 *
68 * Per-GT functionality:
69 * - GuC
70 * - Hardware engines
71 * - Programmable hardware units (subslices, EUs)
72 * - GSI subset of registers (multiple copies of these registers reside
73 * within the complete MMIO space provided by the tile, but at different
74 * offsets --- 0 for render, 0x380000 for media)
75 * - Multicast register steering
76 * - TLBs to cache page table translations
77 * - Reset capability
78 * - Low-level power management (e.g., C6)
79 * - Clock frequency
80 * - MOCS and PAT programming
81 */
82
83/**
84 * xe_tile_alloc - Perform per-tile memory allocation
85 * @tile: Tile to perform allocations for
86 *
87 * Allocates various per-tile data structures using DRM-managed allocations.
88 * Does not touch the hardware.
89 *
90 * Returns -ENOMEM if allocations fail, otherwise 0.
91 */
92static int xe_tile_alloc(struct xe_tile *tile)
93{
94 tile->mem.ggtt = xe_ggtt_alloc(tile);
95 if (!tile->mem.ggtt)
96 return -ENOMEM;
97
98 tile->migrate = xe_migrate_alloc(tile);
99 if (!tile->migrate)
100 return -ENOMEM;
101
102 return 0;
103}
104
105/**
106 * xe_tile_alloc_vram - Perform per-tile VRAM structs allocation
107 * @tile: Tile to perform allocations for
108 *
109 * Allocates VRAM per-tile data structures using DRM-managed allocations.
110 * Does not touch the hardware.
111 *
112 * Returns -ENOMEM if allocations fail, otherwise 0.
113 */
114int xe_tile_alloc_vram(struct xe_tile *tile)
115{
116 struct xe_device *xe = tile_to_xe(tile);
117 struct xe_vram_region *vram;
118
119 if (!IS_DGFX(xe))
120 return 0;
121
122 vram = xe_vram_region_alloc(xe, id: tile->id, XE_PL_VRAM0 + tile->id);
123 if (!vram)
124 return -ENOMEM;
125 tile->mem.vram = vram;
126
127 /*
128 * If the kernel_vram is not already allocated,
129 * it means that tile has common VRAM region for
130 * kernel and user space.
131 */
132 if (!tile->mem.kernel_vram)
133 tile->mem.kernel_vram = tile->mem.vram;
134
135 return 0;
136}
137
138/**
139 * xe_tile_init_early - Initialize the tile and primary GT
140 * @tile: Tile to initialize
141 * @xe: Parent Xe device
142 * @id: Tile ID
143 *
144 * Initializes per-tile resources that don't require any interactions with the
145 * hardware or any knowledge about the Graphics/Media IP version.
146 *
147 * Returns: 0 on success, negative error code on error.
148 */
149int xe_tile_init_early(struct xe_tile *tile, struct xe_device *xe, u8 id)
150{
151 int err;
152
153 tile->xe = xe;
154 tile->id = id;
155
156 err = xe_tile_alloc(tile);
157 if (err)
158 return err;
159
160 xe_pcode_init(tile);
161
162 return 0;
163}
164ALLOW_ERROR_INJECTION(xe_tile_init_early, ERRNO); /* See xe_pci_probe() */
165
166/**
167 * xe_tile_init_noalloc - Init tile up to the point where allocations can happen.
168 * @tile: The tile to initialize.
169 *
170 * This function prepares the tile to allow memory allocations to VRAM, but is
171 * not allowed to allocate memory itself. This state is useful for display
172 * readout, because the inherited display framebuffer will otherwise be
173 * overwritten as it is usually put at the start of VRAM.
174 *
175 * Note that since this is tile initialization, it should not perform any
176 * GT-specific operations, and thus does not need to hold GT forcewake.
177 *
178 * Returns: 0 on success, negative error code on error.
179 */
180int xe_tile_init_noalloc(struct xe_tile *tile)
181{
182 struct xe_device *xe = tile_to_xe(tile);
183
184 xe_wa_apply_tile_workarounds(tile);
185
186 if (xe->info.has_usm && IS_DGFX(xe))
187 xe_devm_add(tile, vr: tile->mem.vram);
188
189 if (IS_DGFX(xe) && !ttm_resource_manager_used(man: &tile->mem.vram->ttm.manager)) {
190 int err = xe_ttm_vram_mgr_init(xe, vram: tile->mem.vram);
191
192 if (err)
193 return err;
194 xe->info.mem_region_mask |= BIT(tile->mem.vram->id) << 1;
195 }
196
197 return xe_tile_sysfs_init(tile);
198}
199
200int xe_tile_init(struct xe_tile *tile)
201{
202 int err;
203
204 err = xe_memirq_init(memirq: &tile->memirq);
205 if (err)
206 return err;
207
208 tile->mem.kernel_bb_pool = xe_sa_bo_manager_init(tile, SZ_1M, align: 16);
209 if (IS_ERR(ptr: tile->mem.kernel_bb_pool))
210 return PTR_ERR(ptr: tile->mem.kernel_bb_pool);
211
212 return 0;
213}
214void xe_tile_migrate_wait(struct xe_tile *tile)
215{
216 xe_migrate_wait(m: tile->migrate);
217}
218

source code of linux/drivers/gpu/drm/xe/xe_tile.c