drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c

   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 }