xref: /linux/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c (revision 22c55fb9eb92395d999b8404d73e58540d11bdd8)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright 2022 Advanced Micro Devices, Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  *
23  */
24 
25 #include "amdgpu.h"
26 
27 /**
28  * amdgpu_mm_rdoorbell - read a doorbell dword
29  *
30  * @adev: amdgpu_device pointer
31  * @index: doorbell index
32  *
33  * Returns the value in the doorbell aperture at the
34  * requested doorbell index (CIK).
35  */
36 u32 amdgpu_mm_rdoorbell(struct amdgpu_device *adev, u32 index)
37 {
38 	if (amdgpu_device_skip_hw_access(adev))
39 		return 0;
40 
41 	if (index < adev->doorbell.num_kernel_doorbells)
42 		return readl(adev->doorbell.cpu_addr + index);
43 
44 	dev_err(adev->dev, "reading beyond doorbell aperture: 0x%08x!\n",
45 		index);
46 	return 0;
47 }
48 
49 /**
50  * amdgpu_mm_wdoorbell - write a doorbell dword
51  *
52  * @adev: amdgpu_device pointer
53  * @index: doorbell index
54  * @v: value to write
55  *
56  * Writes @v to the doorbell aperture at the
57  * requested doorbell index (CIK).
58  */
59 void amdgpu_mm_wdoorbell(struct amdgpu_device *adev, u32 index, u32 v)
60 {
61 	if (amdgpu_device_skip_hw_access(adev))
62 		return;
63 
64 	if (index < adev->doorbell.num_kernel_doorbells)
65 		writel(v, adev->doorbell.cpu_addr + index);
66 	else
67 		dev_err(adev->dev,
68 			"writing beyond doorbell aperture: 0x%08x!\n", index);
69 }
70 
71 /**
72  * amdgpu_mm_rdoorbell64 - read a doorbell Qword
73  *
74  * @adev: amdgpu_device pointer
75  * @index: doorbell index
76  *
77  * Returns the value in the doorbell aperture at the
78  * requested doorbell index (VEGA10+).
79  */
80 u64 amdgpu_mm_rdoorbell64(struct amdgpu_device *adev, u32 index)
81 {
82 	if (amdgpu_device_skip_hw_access(adev))
83 		return 0;
84 
85 	if (index < adev->doorbell.num_kernel_doorbells)
86 		return atomic64_read((atomic64_t *)(adev->doorbell.cpu_addr + index));
87 
88 	dev_err(adev->dev, "reading beyond doorbell aperture: 0x%08x!\n",
89 		index);
90 	return 0;
91 }
92 
93 /**
94  * amdgpu_mm_wdoorbell64 - write a doorbell Qword
95  *
96  * @adev: amdgpu_device pointer
97  * @index: doorbell index
98  * @v: value to write
99  *
100  * Writes @v to the doorbell aperture at the
101  * requested doorbell index (VEGA10+).
102  */
103 void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v)
104 {
105 	if (amdgpu_device_skip_hw_access(adev))
106 		return;
107 
108 	if (index < adev->doorbell.num_kernel_doorbells)
109 		atomic64_set((atomic64_t *)(adev->doorbell.cpu_addr + index), v);
110 	else
111 		dev_err(adev->dev,
112 			"writing beyond doorbell aperture: 0x%08x!\n", index);
113 }
114 
115 /**
116  * amdgpu_doorbell_index_on_bar - Find doorbell's absolute offset in BAR
117  *
118  * @adev: amdgpu_device pointer
119  * @db_bo: doorbell object's bo
120  * @doorbell_index: doorbell relative index in this doorbell object
121  * @db_size: doorbell size is in byte
122  *
123  * returns doorbell's absolute index in BAR
124  */
125 uint32_t amdgpu_doorbell_index_on_bar(struct amdgpu_device *adev,
126 				      struct amdgpu_bo *db_bo,
127 				      uint32_t doorbell_index,
128 				      uint32_t db_size)
129 {
130 	int db_bo_offset;
131 
132 	db_bo_offset = amdgpu_bo_gpu_offset_no_check(db_bo);
133 
134 	/* doorbell index is 32 bit but doorbell's size can be 32 bit
135 	 * or 64 bit, so *db_size(in byte)/4 for alignment.
136 	 */
137 	return db_bo_offset / sizeof(u32) + doorbell_index *
138 	       DIV_ROUND_UP(db_size, 4);
139 }
140 
141 /**
142  * amdgpu_doorbell_create_kernel_doorbells - Create kernel doorbells for graphics
143  *
144  * @adev: amdgpu_device pointer
145  *
146  * Creates doorbells for graphics driver usages.
147  * returns 0 on success, error otherwise.
148  */
149 int amdgpu_doorbell_create_kernel_doorbells(struct amdgpu_device *adev)
150 {
151 	int r;
152 	int size;
153 
154 	/* SI HW does not have doorbells, skip allocation */
155 	if (adev->doorbell.num_kernel_doorbells == 0)
156 		return 0;
157 
158 	/* Reserve first num_kernel_doorbells (page-aligned) for kernel ops */
159 	size = ALIGN(adev->doorbell.num_kernel_doorbells * sizeof(u32), PAGE_SIZE);
160 
161 	/* Allocate an extra page for MES kernel usages (ring test) */
162 	adev->mes.db_start_dw_offset = size / sizeof(u32);
163 	size += PAGE_SIZE;
164 
165 	r = amdgpu_bo_create_kernel(adev,
166 				    size,
167 				    PAGE_SIZE,
168 				    AMDGPU_GEM_DOMAIN_DOORBELL,
169 				    &adev->doorbell.kernel_doorbells,
170 				    NULL,
171 				    (void **)&adev->doorbell.cpu_addr);
172 	if (r) {
173 		dev_err(adev->dev,
174 			"Failed to allocate kernel doorbells, err=%d\n", r);
175 		return r;
176 	}
177 
178 	adev->doorbell.num_kernel_doorbells = size / sizeof(u32);
179 	return 0;
180 }
181 
182 /*
183  * GPU doorbell aperture helpers function.
184  */
185 /**
186  * amdgpu_doorbell_init - Init doorbell driver information.
187  *
188  * @adev: amdgpu_device pointer
189  *
190  * Init doorbell driver information (CIK)
191  * Returns 0 on success, error on failure.
192  */
193 int amdgpu_doorbell_init(struct amdgpu_device *adev)
194 {
195 
196 	/* No doorbell on SI hardware generation */
197 	if (adev->asic_type < CHIP_BONAIRE) {
198 		adev->doorbell.base = 0;
199 		adev->doorbell.size = 0;
200 		adev->doorbell.num_kernel_doorbells = 0;
201 		return 0;
202 	}
203 
204 	if (pci_resource_flags(adev->pdev, 2) & IORESOURCE_UNSET)
205 		return -EINVAL;
206 
207 	amdgpu_asic_init_doorbell_index(adev);
208 
209 	/* doorbell bar mapping */
210 	adev->doorbell.base = pci_resource_start(adev->pdev, 2);
211 	adev->doorbell.size = pci_resource_len(adev->pdev, 2);
212 
213 	adev->doorbell.num_kernel_doorbells =
214 		min_t(u32, adev->doorbell.size / sizeof(u32),
215 		      adev->doorbell_index.max_assignment + 1);
216 	if (adev->doorbell.num_kernel_doorbells == 0)
217 		return -EINVAL;
218 
219 	/*
220 	 * For Vega, reserve and map two pages on doorbell BAR since SDMA
221 	 * paging queue doorbell use the second page. The
222 	 * AMDGPU_DOORBELL64_MAX_ASSIGNMENT definition assumes all the
223 	 * doorbells are in the first page. So with paging queue enabled,
224 	 * the max num_kernel_doorbells should + 1 page (0x400 in dword)
225 	 */
226 	if (adev->asic_type >= CHIP_VEGA10)
227 		adev->doorbell.num_kernel_doorbells += 0x400;
228 
229 	return 0;
230 }
231 
232 /**
233  * amdgpu_doorbell_fini - Tear down doorbell driver information.
234  *
235  * @adev: amdgpu_device pointer
236  *
237  * Tear down doorbell driver information (CIK)
238  */
239 void amdgpu_doorbell_fini(struct amdgpu_device *adev)
240 {
241 	amdgpu_bo_free_kernel(&adev->doorbell.kernel_doorbells,
242 			      NULL,
243 			      (void **)&adev->doorbell.cpu_addr);
244 }
245