Linux 4.2.1
[linux/fpc-iii.git] / drivers / gpu / drm / amd / amdkfd / kfd_doorbell.c
blobe621eba63126a09dc65f33ee59dd6bf47785e06d
1 /*
2 * Copyright 2014 Advanced Micro Devices, Inc.
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:
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
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.
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>
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
36 #define KERNEL_DOORBELL_PASID 1
37 #define KFD_SIZE_OF_DOORBELL_IN_BYTES 4
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.
53 /* # of doorbell bytes allocated for each process. */
54 static inline size_t doorbell_process_allocation(void)
56 return roundup(KFD_SIZE_OF_DOORBELL_IN_BYTES *
57 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
58 PAGE_SIZE);
61 /* Doorbell calculations for device init. */
62 void kfd_doorbell_init(struct kfd_dev *kfd)
64 size_t doorbell_start_offset;
65 size_t doorbell_aperture_size;
66 size_t doorbell_process_limit;
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.
74 doorbell_start_offset =
75 roundup(kfd->shared_resources.doorbell_start_offset,
76 doorbell_process_allocation());
78 doorbell_aperture_size =
79 rounddown(kfd->shared_resources.doorbell_aperture_size,
80 doorbell_process_allocation());
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;
89 kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
90 doorbell_start_offset;
92 kfd->doorbell_id_offset = doorbell_start_offset / sizeof(u32);
93 kfd->doorbell_process_limit = doorbell_process_limit - 1;
95 kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
96 doorbell_process_allocation());
98 BUG_ON(!kfd->doorbell_kernel_ptr);
100 pr_debug("kfd: doorbell initialization:\n");
101 pr_debug("kfd: doorbell base == 0x%08lX\n",
102 (uintptr_t)kfd->doorbell_base);
104 pr_debug("kfd: doorbell_id_offset == 0x%08lX\n",
105 kfd->doorbell_id_offset);
107 pr_debug("kfd: doorbell_process_limit == 0x%08lX\n",
108 doorbell_process_limit);
110 pr_debug("kfd: doorbell_kernel_offset == 0x%08lX\n",
111 (uintptr_t)kfd->doorbell_base);
113 pr_debug("kfd: doorbell aperture size == 0x%08lX\n",
114 kfd->shared_resources.doorbell_aperture_size);
116 pr_debug("kfd: doorbell kernel address == 0x%08lX\n",
117 (uintptr_t)kfd->doorbell_kernel_ptr);
120 int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma)
122 phys_addr_t address;
123 struct kfd_dev *dev;
126 * For simplicitly we only allow mapping of the entire doorbell
127 * allocation of a single device & process.
129 if (vma->vm_end - vma->vm_start != doorbell_process_allocation())
130 return -EINVAL;
132 /* Find kfd device according to gpu id */
133 dev = kfd_device_by_id(vma->vm_pgoff);
134 if (dev == NULL)
135 return -EINVAL;
137 /* Calculate physical address of doorbell */
138 address = kfd_get_process_doorbells(dev, process);
140 vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
141 VM_DONTDUMP | VM_PFNMAP;
143 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
145 pr_debug("mapping doorbell page:\n");
146 pr_debug(" target user address == 0x%08llX\n",
147 (unsigned long long) vma->vm_start);
148 pr_debug(" physical address == 0x%08llX\n", address);
149 pr_debug(" vm_flags == 0x%04lX\n", vma->vm_flags);
150 pr_debug(" size == 0x%04lX\n",
151 doorbell_process_allocation());
153 return io_remap_pfn_range(vma,
154 vma->vm_start,
155 address >> PAGE_SHIFT,
156 doorbell_process_allocation(),
157 vma->vm_page_prot);
161 /* get kernel iomem pointer for a doorbell */
162 u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
163 unsigned int *doorbell_off)
165 u32 inx;
167 BUG_ON(!kfd || !doorbell_off);
169 mutex_lock(&kfd->doorbell_mutex);
170 inx = find_first_zero_bit(kfd->doorbell_available_index,
171 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
173 __set_bit(inx, kfd->doorbell_available_index);
174 mutex_unlock(&kfd->doorbell_mutex);
176 if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
177 return NULL;
180 * Calculating the kernel doorbell offset using "faked" kernel
181 * pasid that allocated for kernel queues only
183 *doorbell_off = KERNEL_DOORBELL_PASID * (doorbell_process_allocation() /
184 sizeof(u32)) + inx;
186 pr_debug("kfd: get kernel queue doorbell\n"
187 " doorbell offset == 0x%08d\n"
188 " kernel address == 0x%08lX\n",
189 *doorbell_off, (uintptr_t)(kfd->doorbell_kernel_ptr + inx));
191 return kfd->doorbell_kernel_ptr + inx;
194 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
196 unsigned int inx;
198 BUG_ON(!kfd || !db_addr);
200 inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr);
202 mutex_lock(&kfd->doorbell_mutex);
203 __clear_bit(inx, kfd->doorbell_available_index);
204 mutex_unlock(&kfd->doorbell_mutex);
207 inline void write_kernel_doorbell(u32 __iomem *db, u32 value)
209 if (db) {
210 writel(value, db);
211 pr_debug("writing %d to doorbell address 0x%p\n", value, db);
216 * queue_ids are in the range [0,MAX_PROCESS_QUEUES) and are mapped 1:1
217 * to doorbells with the process's doorbell page
219 unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd,
220 struct kfd_process *process,
221 unsigned int queue_id)
224 * doorbell_id_offset accounts for doorbells taken by KGD.
225 * pasid * doorbell_process_allocation/sizeof(u32) adjusts
226 * to the process's doorbells
228 return kfd->doorbell_id_offset +
229 process->pasid * (doorbell_process_allocation()/sizeof(u32)) +
230 queue_id;
233 uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
235 uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size -
236 kfd->shared_resources.doorbell_start_offset) /
237 doorbell_process_allocation() + 1;
239 return num_of_elems;
243 phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
244 struct kfd_process *process)
246 return dev->doorbell_base +
247 process->pasid * doorbell_process_allocation();