xref: /linux/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c (revision 3c4fc7bf4c9e66fe71abcbf93f62f4ddb89b7f15)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Copyright 2014-2022 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 #include "kfd_priv.h"
24 #include <linux/mm.h>
25 #include <linux/mman.h>
26 #include <linux/slab.h>
27 #include <linux/io.h>
28 #include <linux/idr.h>
29 
30 /*
31  * This extension supports a kernel level doorbells management for the
32  * kernel queues using the first doorbell page reserved for the kernel.
33  */
34 
35 /*
36  * Each device exposes a doorbell aperture, a PCI MMIO aperture that
37  * receives 32-bit writes that are passed to queues as wptr values.
38  * The doorbells are intended to be written by applications as part
39  * of queueing work on user-mode queues.
40  * We assign doorbells to applications in PAGE_SIZE-sized and aligned chunks.
41  * We map the doorbell address space into user-mode when a process creates
42  * its first queue on each device.
43  * Although the mapping is done by KFD, it is equivalent to an mmap of
44  * the /dev/kfd with the particular device encoded in the mmap offset.
45  * There will be other uses for mmap of /dev/kfd, so only a range of
46  * offsets (KFD_MMAP_DOORBELL_START-END) is used for doorbells.
47  */
48 
49 /* # of doorbell bytes allocated for each process. */
50 size_t kfd_doorbell_process_slice(struct kfd_dev *kfd)
51 {
52 	if (!kfd->shared_resources.enable_mes)
53 		return roundup(kfd->device_info.doorbell_size *
54 				KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
55 				PAGE_SIZE);
56 	else
57 		return amdgpu_mes_doorbell_process_slice(
58 					(struct amdgpu_device *)kfd->adev);
59 }
60 
61 /* Doorbell calculations for device init. */
62 int kfd_doorbell_init(struct kfd_dev *kfd)
63 {
64 	size_t doorbell_start_offset;
65 	size_t doorbell_aperture_size;
66 	size_t doorbell_process_limit;
67 
68 	/*
69 	 * With MES enabled, just set the doorbell base as it is needed
70 	 * to calculate doorbell physical address.
71 	 */
72 	if (kfd->shared_resources.enable_mes) {
73 		kfd->doorbell_base =
74 			kfd->shared_resources.doorbell_physical_address;
75 		return 0;
76 	}
77 
78 	/*
79 	 * We start with calculations in bytes because the input data might
80 	 * only be byte-aligned.
81 	 * Only after we have done the rounding can we assume any alignment.
82 	 */
83 
84 	doorbell_start_offset =
85 			roundup(kfd->shared_resources.doorbell_start_offset,
86 					kfd_doorbell_process_slice(kfd));
87 
88 	doorbell_aperture_size =
89 			rounddown(kfd->shared_resources.doorbell_aperture_size,
90 					kfd_doorbell_process_slice(kfd));
91 
92 	if (doorbell_aperture_size > doorbell_start_offset)
93 		doorbell_process_limit =
94 			(doorbell_aperture_size - doorbell_start_offset) /
95 						kfd_doorbell_process_slice(kfd);
96 	else
97 		return -ENOSPC;
98 
99 	if (!kfd->max_doorbell_slices ||
100 	    doorbell_process_limit < kfd->max_doorbell_slices)
101 		kfd->max_doorbell_slices = doorbell_process_limit;
102 
103 	kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
104 				doorbell_start_offset;
105 
106 	kfd->doorbell_base_dw_offset = doorbell_start_offset / sizeof(u32);
107 
108 	kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
109 					   kfd_doorbell_process_slice(kfd));
110 
111 	if (!kfd->doorbell_kernel_ptr)
112 		return -ENOMEM;
113 
114 	pr_debug("Doorbell initialization:\n");
115 	pr_debug("doorbell base           == 0x%08lX\n",
116 			(uintptr_t)kfd->doorbell_base);
117 
118 	pr_debug("doorbell_base_dw_offset      == 0x%08lX\n",
119 			kfd->doorbell_base_dw_offset);
120 
121 	pr_debug("doorbell_process_limit  == 0x%08lX\n",
122 			doorbell_process_limit);
123 
124 	pr_debug("doorbell_kernel_offset  == 0x%08lX\n",
125 			(uintptr_t)kfd->doorbell_base);
126 
127 	pr_debug("doorbell aperture size  == 0x%08lX\n",
128 			kfd->shared_resources.doorbell_aperture_size);
129 
130 	pr_debug("doorbell kernel address == %p\n", kfd->doorbell_kernel_ptr);
131 
132 	return 0;
133 }
134 
135 void kfd_doorbell_fini(struct kfd_dev *kfd)
136 {
137 	if (kfd->doorbell_kernel_ptr)
138 		iounmap(kfd->doorbell_kernel_ptr);
139 }
140 
141 int kfd_doorbell_mmap(struct kfd_dev *dev, struct kfd_process *process,
142 		      struct vm_area_struct *vma)
143 {
144 	phys_addr_t address;
145 	struct kfd_process_device *pdd;
146 
147 	/*
148 	 * For simplicitly we only allow mapping of the entire doorbell
149 	 * allocation of a single device & process.
150 	 */
151 	if (vma->vm_end - vma->vm_start != kfd_doorbell_process_slice(dev))
152 		return -EINVAL;
153 
154 	pdd = kfd_get_process_device_data(dev, process);
155 	if (!pdd)
156 		return -EINVAL;
157 
158 	/* Calculate physical address of doorbell */
159 	address = kfd_get_process_doorbells(pdd);
160 	vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
161 				VM_DONTDUMP | VM_PFNMAP;
162 
163 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
164 
165 	pr_debug("Mapping doorbell page\n"
166 		 "     target user address == 0x%08llX\n"
167 		 "     physical address    == 0x%08llX\n"
168 		 "     vm_flags            == 0x%04lX\n"
169 		 "     size                == 0x%04lX\n",
170 		 (unsigned long long) vma->vm_start, address, vma->vm_flags,
171 		 kfd_doorbell_process_slice(dev));
172 
173 
174 	return io_remap_pfn_range(vma,
175 				vma->vm_start,
176 				address >> PAGE_SHIFT,
177 				kfd_doorbell_process_slice(dev),
178 				vma->vm_page_prot);
179 }
180 
181 
182 /* get kernel iomem pointer for a doorbell */
183 void __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
184 					unsigned int *doorbell_off)
185 {
186 	u32 inx;
187 
188 	mutex_lock(&kfd->doorbell_mutex);
189 	inx = find_first_zero_bit(kfd->doorbell_available_index,
190 					KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
191 
192 	__set_bit(inx, kfd->doorbell_available_index);
193 	mutex_unlock(&kfd->doorbell_mutex);
194 
195 	if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
196 		return NULL;
197 
198 	inx *= kfd->device_info.doorbell_size / sizeof(u32);
199 
200 	/*
201 	 * Calculating the kernel doorbell offset using the first
202 	 * doorbell page.
203 	 */
204 	*doorbell_off = kfd->doorbell_base_dw_offset + inx;
205 
206 	pr_debug("Get kernel queue doorbell\n"
207 			"     doorbell offset   == 0x%08X\n"
208 			"     doorbell index    == 0x%x\n",
209 		*doorbell_off, inx);
210 
211 	return kfd->doorbell_kernel_ptr + inx;
212 }
213 
214 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
215 {
216 	unsigned int inx;
217 
218 	inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr)
219 		* sizeof(u32) / kfd->device_info.doorbell_size;
220 
221 	mutex_lock(&kfd->doorbell_mutex);
222 	__clear_bit(inx, kfd->doorbell_available_index);
223 	mutex_unlock(&kfd->doorbell_mutex);
224 }
225 
226 void write_kernel_doorbell(void __iomem *db, u32 value)
227 {
228 	if (db) {
229 		writel(value, db);
230 		pr_debug("Writing %d to doorbell address %p\n", value, db);
231 	}
232 }
233 
234 void write_kernel_doorbell64(void __iomem *db, u64 value)
235 {
236 	if (db) {
237 		WARN(((unsigned long)db & 7) != 0,
238 		     "Unaligned 64-bit doorbell");
239 		writeq(value, (u64 __iomem *)db);
240 		pr_debug("writing %llu to doorbell address %p\n", value, db);
241 	}
242 }
243 
244 unsigned int kfd_get_doorbell_dw_offset_in_bar(struct kfd_dev *kfd,
245 					struct kfd_process_device *pdd,
246 					unsigned int doorbell_id)
247 {
248 	/*
249 	 * doorbell_base_dw_offset accounts for doorbells taken by KGD.
250 	 * index * kfd_doorbell_process_slice/sizeof(u32) adjusts to
251 	 * the process's doorbells. The offset returned is in dword
252 	 * units regardless of the ASIC-dependent doorbell size.
253 	 */
254 	if (!kfd->shared_resources.enable_mes)
255 		return kfd->doorbell_base_dw_offset +
256 			pdd->doorbell_index
257 			* kfd_doorbell_process_slice(kfd) / sizeof(u32) +
258 			doorbell_id *
259 			kfd->device_info.doorbell_size / sizeof(u32);
260 	else
261 		return amdgpu_mes_get_doorbell_dw_offset_in_bar(
262 				(struct amdgpu_device *)kfd->adev,
263 				pdd->doorbell_index, doorbell_id);
264 }
265 
266 uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
267 {
268 	uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size -
269 				kfd->shared_resources.doorbell_start_offset) /
270 					kfd_doorbell_process_slice(kfd) + 1;
271 
272 	return num_of_elems;
273 
274 }
275 
276 phys_addr_t kfd_get_process_doorbells(struct kfd_process_device *pdd)
277 {
278 	return pdd->dev->doorbell_base +
279 		pdd->doorbell_index * kfd_doorbell_process_slice(pdd->dev);
280 }
281 
282 int kfd_alloc_process_doorbells(struct kfd_dev *kfd, unsigned int *doorbell_index)
283 {
284 	int r = 0;
285 
286 	if (!kfd->shared_resources.enable_mes)
287 		r = ida_simple_get(&kfd->doorbell_ida, 1,
288 				   kfd->max_doorbell_slices, GFP_KERNEL);
289 	else
290 		r = amdgpu_mes_alloc_process_doorbells(
291 				(struct amdgpu_device *)kfd->adev,
292 				doorbell_index);
293 
294 	if (r > 0)
295 		*doorbell_index = r;
296 
297 	return r;
298 }
299 
300 void kfd_free_process_doorbells(struct kfd_dev *kfd, unsigned int doorbell_index)
301 {
302 	if (doorbell_index) {
303 		if (!kfd->shared_resources.enable_mes)
304 			ida_simple_remove(&kfd->doorbell_ida, doorbell_index);
305 		else
306 			amdgpu_mes_free_process_doorbells(
307 					(struct amdgpu_device *)kfd->adev,
308 					doorbell_index);
309 	}
310 }
311