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. */
50size_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. */
62int 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
99void 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
106int 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 */
150void __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
178void 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
190void 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
198void 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
208static 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
235phys_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
253int 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
287err:
288	bitmap_free(qpd->doorbell_bitmap);
289	qpd->doorbell_bitmap = NULL;
290	return r;
291}
292
293void 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