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1/*
2 * Copyright 2014 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 */
22#include "kfd_priv.h"
23#include <linux/mm.h>
24#include <linux/mman.h>
25#include <linux/slab.h>
26#include <linux/io.h>
27
28/*
29 * This extension supports a kernel level doorbells management for
30 * the kernel queues.
31 * Basically the last doorbells page is devoted to kernel queues
32 * and that's assures that any user process won't get access to the
33 * kernel doorbells page
34 */
35
36#define KERNEL_DOORBELL_PASID 1
37#define KFD_SIZE_OF_DOORBELL_IN_BYTES 4
38
39/*
40 * Each device exposes a doorbell aperture, a PCI MMIO aperture that
41 * receives 32-bit writes that are passed to queues as wptr values.
42 * The doorbells are intended to be written by applications as part
43 * of queueing work on user-mode queues.
44 * We assign doorbells to applications in PAGE_SIZE-sized and aligned chunks.
45 * We map the doorbell address space into user-mode when a process creates
46 * its first queue on each device.
47 * Although the mapping is done by KFD, it is equivalent to an mmap of
48 * the /dev/kfd with the particular device encoded in the mmap offset.
49 * There will be other uses for mmap of /dev/kfd, so only a range of
50 * offsets (KFD_MMAP_DOORBELL_START-END) is used for doorbells.
51 */
52
53/* # of doorbell bytes allocated for each process. */
54static inline size_t doorbell_process_allocation(void)
55{
56 return roundup(KFD_SIZE_OF_DOORBELL_IN_BYTES *
57 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
58 PAGE_SIZE);
59}
60
61/* Doorbell calculations for device init. */
62void 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 * We start with calculations in bytes because the input data might
70 * only be byte-aligned.
71 * Only after we have done the rounding can we assume any alignment.
72 */
73
74 doorbell_start_offset =
75 roundup(kfd->shared_resources.doorbell_start_offset,
76 doorbell_process_allocation());
77
78 doorbell_aperture_size =
79 rounddown(kfd->shared_resources.doorbell_aperture_size,
80 doorbell_process_allocation());
81
82 if (doorbell_aperture_size > doorbell_start_offset)
83 doorbell_process_limit =
84 (doorbell_aperture_size - doorbell_start_offset) /
85 doorbell_process_allocation();
86 else
87 doorbell_process_limit = 0;
88
89 kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
90 doorbell_start_offset;
91
92 kfd->doorbell_id_offset = doorbell_start_offset / sizeof(u32);
93 kfd->doorbell_process_limit = doorbell_process_limit - 1;
94
95 kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
96 doorbell_process_allocation());
97
98 BUG_ON(!kfd->doorbell_kernel_ptr);
99
100 pr_debug("kfd: doorbell initialization:\n");
101 pr_debug("kfd: doorbell base == 0x%08lX\n",
102 (uintptr_t)kfd->doorbell_base);
103
104 pr_debug("kfd: doorbell_id_offset == 0x%08lX\n",
105 kfd->doorbell_id_offset);
106
107 pr_debug("kfd: doorbell_process_limit == 0x%08lX\n",
108 doorbell_process_limit);
109
110 pr_debug("kfd: doorbell_kernel_offset == 0x%08lX\n",
111 (uintptr_t)kfd->doorbell_base);
112
113 pr_debug("kfd: doorbell aperture size == 0x%08lX\n",
114 kfd->shared_resources.doorbell_aperture_size);
115
116 pr_debug("kfd: doorbell kernel address == 0x%08lX\n",
117 (uintptr_t)kfd->doorbell_kernel_ptr);
118}
119
120int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma)
121{
122 phys_addr_t address;
123 struct kfd_dev *dev;
124
125 /*
126 * For simplicitly we only allow mapping of the entire doorbell
127 * allocation of a single device & process.
128 */
129 if (vma->vm_end - vma->vm_start != doorbell_process_allocation())
130 return -EINVAL;
131
132 /* Find kfd device according to gpu id */
133 dev = kfd_device_by_id(vma->vm_pgoff);
134 if (dev == NULL)
135 return -EINVAL;
136
137 /* Calculate physical address of doorbell */
138 address = kfd_get_process_doorbells(dev, process);
139
140 vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
141 VM_DONTDUMP | VM_PFNMAP;
142
143 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
144
145 pr_debug("kfd: mapping doorbell page in %s\n"
146 " target user address == 0x%08llX\n"
147 " physical address == 0x%08llX\n"
148 " vm_flags == 0x%04lX\n"
149 " size == 0x%04lX\n",
150 __func__,
151 (unsigned long long) vma->vm_start, address, vma->vm_flags,
152 doorbell_process_allocation());
153
154
155 return io_remap_pfn_range(vma,
156 vma->vm_start,
157 address >> PAGE_SHIFT,
158 doorbell_process_allocation(),
159 vma->vm_page_prot);
160}
161
162
163/* get kernel iomem pointer for a doorbell */
164u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
165 unsigned int *doorbell_off)
166{
167 u32 inx;
168
169 BUG_ON(!kfd || !doorbell_off);
170
171 mutex_lock(&kfd->doorbell_mutex);
172 inx = find_first_zero_bit(kfd->doorbell_available_index,
173 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
174
175 __set_bit(inx, kfd->doorbell_available_index);
176 mutex_unlock(&kfd->doorbell_mutex);
177
178 if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
179 return NULL;
180
181 /*
182 * Calculating the kernel doorbell offset using "faked" kernel
183 * pasid that allocated for kernel queues only
184 */
185 *doorbell_off = KERNEL_DOORBELL_PASID * (doorbell_process_allocation() /
186 sizeof(u32)) + inx;
187
188 pr_debug("kfd: get kernel queue doorbell\n"
189 " doorbell offset == 0x%08X\n"
190 " kernel address == 0x%08lX\n",
191 *doorbell_off, (uintptr_t)(kfd->doorbell_kernel_ptr + inx));
192
193 return kfd->doorbell_kernel_ptr + inx;
194}
195
196void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
197{
198 unsigned int inx;
199
200 BUG_ON(!kfd || !db_addr);
201
202 inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr);
203
204 mutex_lock(&kfd->doorbell_mutex);
205 __clear_bit(inx, kfd->doorbell_available_index);
206 mutex_unlock(&kfd->doorbell_mutex);
207}
208
209inline void write_kernel_doorbell(u32 __iomem *db, u32 value)
210{
211 if (db) {
212 writel(value, db);
213 pr_debug("writing %d to doorbell address 0x%p\n", value, db);
214 }
215}
216
217/*
218 * queue_ids are in the range [0,MAX_PROCESS_QUEUES) and are mapped 1:1
219 * to doorbells with the process's doorbell page
220 */
221unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd,
222 struct kfd_process *process,
223 unsigned int queue_id)
224{
225 /*
226 * doorbell_id_offset accounts for doorbells taken by KGD.
227 * pasid * doorbell_process_allocation/sizeof(u32) adjusts
228 * to the process's doorbells
229 */
230 return kfd->doorbell_id_offset +
231 process->pasid * (doorbell_process_allocation()/sizeof(u32)) +
232 queue_id;
233}
234
235uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
236{
237 uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size -
238 kfd->shared_resources.doorbell_start_offset) /
239 doorbell_process_allocation() + 1;
240
241 return num_of_elems;
242
243}
244
245phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
246 struct kfd_process *process)
247{
248 return dev->doorbell_base +
249 process->pasid * doorbell_process_allocation();
250}