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         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
  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
 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 */
 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
 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
 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
 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
 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
 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
 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
 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 }