xref: /openbsd/sys/dev/pci/drm/amd/amdkfd/kfd_doorbell.c (revision f005ef32)
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. */
kfd_doorbell_process_slice(struct kfd_dev * kfd)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. */
kfd_doorbell_init(struct kfd_dev * kfd)62 int kfd_doorbell_init(struct kfd_dev *kfd)
63 {
64 	int size = PAGE_SIZE;
65 	int r;
66 
67 	/*
68 	 * Todo: KFD kernel level operations need only one doorbell for
69 	 * ring test/HWS. So instead of reserving a whole page here for
70 	 * kernel, reserve and consume a doorbell from existing KGD kernel
71 	 * doorbell page.
72 	 */
73 
74 	/* Bitmap to dynamically allocate doorbells from kernel page */
75 	kfd->doorbell_bitmap = bitmap_zalloc(size / sizeof(u32), GFP_KERNEL);
76 	if (!kfd->doorbell_bitmap) {
77 		DRM_ERROR("Failed to allocate kernel doorbell bitmap\n");
78 		return -ENOMEM;
79 	}
80 
81 	/* Alloc a doorbell page for KFD kernel usages */
82 	r = amdgpu_bo_create_kernel(kfd->adev,
83 				    size,
84 				    PAGE_SIZE,
85 				    AMDGPU_GEM_DOMAIN_DOORBELL,
86 				    &kfd->doorbells,
87 				    NULL,
88 				    (void **)&kfd->doorbell_kernel_ptr);
89 	if (r) {
90 		pr_err("failed to allocate kernel doorbells\n");
91 		bitmap_free(kfd->doorbell_bitmap);
92 		return r;
93 	}
94 
95 	pr_debug("Doorbell kernel address == %p\n", kfd->doorbell_kernel_ptr);
96 	return 0;
97 }
98 
kfd_doorbell_fini(struct kfd_dev * kfd)99 void kfd_doorbell_fini(struct kfd_dev *kfd)
100 {
101 	bitmap_free(kfd->doorbell_bitmap);
102 	amdgpu_bo_free_kernel(&kfd->doorbells, NULL,
103 			     (void **)&kfd->doorbell_kernel_ptr);
104 }
105 
kfd_doorbell_mmap(struct kfd_node * dev,struct kfd_process * process,struct vm_area_struct * vma)106 int kfd_doorbell_mmap(struct kfd_node *dev, struct kfd_process *process,
107 		      struct vm_area_struct *vma)
108 {
109 	phys_addr_t address;
110 	struct kfd_process_device *pdd;
111 
112 	/*
113 	 * For simplicitly we only allow mapping of the entire doorbell
114 	 * allocation of a single device & process.
115 	 */
116 	if (vma->vm_end - vma->vm_start != kfd_doorbell_process_slice(dev->kfd))
117 		return -EINVAL;
118 
119 	pdd = kfd_get_process_device_data(dev, process);
120 	if (!pdd)
121 		return -EINVAL;
122 
123 	/* Calculate physical address of doorbell */
124 	address = kfd_get_process_doorbells(pdd);
125 	if (!address)
126 		return -ENOMEM;
127 	vm_flags_set(vma, VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
128 				VM_DONTDUMP | VM_PFNMAP);
129 
130 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
131 
132 	pr_debug("Mapping doorbell page\n"
133 		 "     target user address == 0x%08llX\n"
134 		 "     physical address    == 0x%08llX\n"
135 		 "     vm_flags            == 0x%04lX\n"
136 		 "     size                == 0x%04lX\n",
137 		 (unsigned long long) vma->vm_start, address, vma->vm_flags,
138 		 kfd_doorbell_process_slice(dev->kfd));
139 
140 
141 	return io_remap_pfn_range(vma,
142 				vma->vm_start,
143 				address >> PAGE_SHIFT,
144 				kfd_doorbell_process_slice(dev->kfd),
145 				vma->vm_page_prot);
146 }
147 
148 
149 /* get kernel iomem pointer for a doorbell */
kfd_get_kernel_doorbell(struct kfd_dev * kfd,unsigned int * doorbell_off)150 void __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
151 					unsigned int *doorbell_off)
152 {
153 	u32 inx;
154 
155 	mutex_lock(&kfd->doorbell_mutex);
156 	inx = find_first_zero_bit(kfd->doorbell_bitmap, PAGE_SIZE / sizeof(u32));
157 
158 	__set_bit(inx, kfd->doorbell_bitmap);
159 	mutex_unlock(&kfd->doorbell_mutex);
160 
161 	if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
162 		return NULL;
163 
164 	*doorbell_off = amdgpu_doorbell_index_on_bar(kfd->adev,
165 						     kfd->doorbells,
166 						     inx,
167 						     kfd->device_info.doorbell_size);
168 	inx *= 2;
169 
170 	pr_debug("Get kernel queue doorbell\n"
171 			"     doorbell offset   == 0x%08X\n"
172 			"     doorbell index    == 0x%x\n",
173 		*doorbell_off, inx);
174 
175 	return kfd->doorbell_kernel_ptr + inx;
176 }
177 
kfd_release_kernel_doorbell(struct kfd_dev * kfd,u32 __iomem * db_addr)178 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
179 {
180 	unsigned int inx;
181 
182 	inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr);
183 	inx /= 2;
184 
185 	mutex_lock(&kfd->doorbell_mutex);
186 	__clear_bit(inx, kfd->doorbell_bitmap);
187 	mutex_unlock(&kfd->doorbell_mutex);
188 }
189 
write_kernel_doorbell(void __iomem * db,u32 value)190 void write_kernel_doorbell(void __iomem *db, u32 value)
191 {
192 	if (db) {
193 		writel(value, db);
194 		pr_debug("Writing %d to doorbell address %p\n", value, db);
195 	}
196 }
197 
write_kernel_doorbell64(void __iomem * db,u64 value)198 void write_kernel_doorbell64(void __iomem *db, u64 value)
199 {
200 	if (db) {
201 		WARN(((unsigned long)db & 7) != 0,
202 		     "Unaligned 64-bit doorbell");
203 		writeq(value, (u64 __iomem *)db);
204 		pr_debug("writing %llu to doorbell address %p\n", value, db);
205 	}
206 }
207 
init_doorbell_bitmap(struct qcm_process_device * qpd,struct kfd_dev * dev)208 static int init_doorbell_bitmap(struct qcm_process_device *qpd,
209 				struct kfd_dev *dev)
210 {
211 	unsigned int i;
212 	int range_start = dev->shared_resources.non_cp_doorbells_start;
213 	int range_end = dev->shared_resources.non_cp_doorbells_end;
214 
215 	if (!KFD_IS_SOC15(dev))
216 		return 0;
217 
218 	/* Mask out doorbells reserved for SDMA, IH, and VCN on SOC15. */
219 	pr_debug("reserved doorbell 0x%03x - 0x%03x\n", range_start, range_end);
220 	pr_debug("reserved doorbell 0x%03x - 0x%03x\n",
221 			range_start + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
222 			range_end + KFD_QUEUE_DOORBELL_MIRROR_OFFSET);
223 
224 	for (i = 0; i < KFD_MAX_NUM_OF_QUEUES_PER_PROCESS / 2; i++) {
225 		if (i >= range_start && i <= range_end) {
226 			__set_bit(i, qpd->doorbell_bitmap);
227 			__set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
228 				  qpd->doorbell_bitmap);
229 		}
230 	}
231 
232 	return 0;
233 }
234 
kfd_get_process_doorbells(struct kfd_process_device * pdd)235 phys_addr_t kfd_get_process_doorbells(struct kfd_process_device *pdd)
236 {
237 	struct amdgpu_device *adev = pdd->dev->adev;
238 	uint32_t first_db_index;
239 
240 	if (!pdd->qpd.proc_doorbells) {
241 		if (kfd_alloc_process_doorbells(pdd->dev->kfd, pdd))
242 			/* phys_addr_t 0 is error */
243 			return 0;
244 	}
245 
246 	first_db_index = amdgpu_doorbell_index_on_bar(adev,
247 						      pdd->qpd.proc_doorbells,
248 						      0,
249 						      pdd->dev->kfd->device_info.doorbell_size);
250 	return adev->doorbell.base + first_db_index * sizeof(uint32_t);
251 }
252 
kfd_alloc_process_doorbells(struct kfd_dev * kfd,struct kfd_process_device * pdd)253 int kfd_alloc_process_doorbells(struct kfd_dev *kfd, struct kfd_process_device *pdd)
254 {
255 	int r;
256 	struct qcm_process_device *qpd = &pdd->qpd;
257 
258 	/* Allocate bitmap for dynamic doorbell allocation */
259 	qpd->doorbell_bitmap = bitmap_zalloc(KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
260 					     GFP_KERNEL);
261 	if (!qpd->doorbell_bitmap) {
262 		DRM_ERROR("Failed to allocate process doorbell bitmap\n");
263 		return -ENOMEM;
264 	}
265 
266 	r = init_doorbell_bitmap(&pdd->qpd, kfd);
267 	if (r) {
268 		DRM_ERROR("Failed to initialize process doorbells\n");
269 		r = -ENOMEM;
270 		goto err;
271 	}
272 
273 	/* Allocate doorbells for this process */
274 	r = amdgpu_bo_create_kernel(kfd->adev,
275 				    kfd_doorbell_process_slice(kfd),
276 				    PAGE_SIZE,
277 				    AMDGPU_GEM_DOMAIN_DOORBELL,
278 				    &qpd->proc_doorbells,
279 				    NULL,
280 				    NULL);
281 	if (r) {
282 		DRM_ERROR("Failed to allocate process doorbells\n");
283 		goto err;
284 	}
285 	return 0;
286 
287 err:
288 	bitmap_free(qpd->doorbell_bitmap);
289 	qpd->doorbell_bitmap = NULL;
290 	return r;
291 }
292 
kfd_free_process_doorbells(struct kfd_dev * kfd,struct kfd_process_device * pdd)293 void kfd_free_process_doorbells(struct kfd_dev *kfd, struct kfd_process_device *pdd)
294 {
295 	struct qcm_process_device *qpd = &pdd->qpd;
296 
297 	if (qpd->doorbell_bitmap) {
298 		bitmap_free(qpd->doorbell_bitmap);
299 		qpd->doorbell_bitmap = NULL;
300 	}
301 
302 	amdgpu_bo_free_kernel(&qpd->proc_doorbells, NULL, NULL);
303 }
304