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

   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 #include <linux/idr.h>
  28
  29 /*
  30  * This extension supports a kernel level doorbells management for the
  31  * kernel queues using the first doorbell page reserved for the kernel.
  32  */
  33
  34 /*
  35  * Each device exposes a doorbell aperture, a PCI MMIO aperture that
  36  * receives 32-bit writes that are passed to queues as wptr values.
  37  * The doorbells are intended to be written by applications as part
  38  * of queueing work on user-mode queues.
  39  * We assign doorbells to applications in PAGE_SIZE-sized and aligned chunks.
  40  * We map the doorbell address space into user-mode when a process creates
  41  * its first queue on each device.
  42  * Although the mapping is done by KFD, it is equivalent to an mmap of
  43  * the /dev/kfd with the particular device encoded in the mmap offset.
  44  * There will be other uses for mmap of /dev/kfd, so only a range of
  45  * offsets (KFD_MMAP_DOORBELL_START-END) is used for doorbells.
  46  */
  47
  48 /* # of doorbell bytes allocated for each process. */
  49 size_t kfd_doorbell_process_slice(struct kfd_dev *kfd)
  50 {
  51         return roundup(kfd->device_info->doorbell_size *
  52                         KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
  53                         PAGE_SIZE);
  54 }
  55
  56 /* Doorbell calculations for device init. */
  57 int kfd_doorbell_init(struct kfd_dev *kfd)
  58 {
  59         size_t doorbell_start_offset;
  60         size_t doorbell_aperture_size;
  61         size_t doorbell_process_limit;
  62
  63         /*
  64          * We start with calculations in bytes because the input data might
  65          * only be byte-aligned.
  66          * Only after we have done the rounding can we assume any alignment.
  67          */
  68
  69         doorbell_start_offset =
  70                         roundup(kfd->shared_resources.doorbell_start_offset,
  71                                         kfd_doorbell_process_slice(kfd));
  72
  73         doorbell_aperture_size =
  74                         rounddown(kfd->shared_resources.doorbell_aperture_size,
  75                                         kfd_doorbell_process_slice(kfd));
  76
  77         if (doorbell_aperture_size > doorbell_start_offset)
  78                 doorbell_process_limit =
  79                         (doorbell_aperture_size - doorbell_start_offset) /
  80                                                 kfd_doorbell_process_slice(kfd);
  81         else
  82                 return -ENOSPC;
  83
  84         if (!kfd->max_doorbell_slices ||
  85             doorbell_process_limit < kfd->max_doorbell_slices)
  86                 kfd->max_doorbell_slices = doorbell_process_limit;
  87
  88         kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
  89                                 doorbell_start_offset;
  90
  91         kfd->doorbell_base_dw_offset = doorbell_start_offset / sizeof(u32);
  92
  93         kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
  94                                            kfd_doorbell_process_slice(kfd));
  95
  96         if (!kfd->doorbell_kernel_ptr)
  97                 return -ENOMEM;
  98
  99         pr_debug("Doorbell initialization:\n");
 100         pr_debug("doorbell base           == 0x%08lX\n",
 101                         (uintptr_t)kfd->doorbell_base);
 102
 103         pr_debug("doorbell_base_dw_offset      == 0x%08lX\n",
 104                         kfd->doorbell_base_dw_offset);
 105
 106         pr_debug("doorbell_process_limit  == 0x%08lX\n",
 107                         doorbell_process_limit);
 108
 109         pr_debug("doorbell_kernel_offset  == 0x%08lX\n",
 110                         (uintptr_t)kfd->doorbell_base);
 111
 112         pr_debug("doorbell aperture size  == 0x%08lX\n",
 113                         kfd->shared_resources.doorbell_aperture_size);
 114
 115         pr_debug("doorbell kernel address == %p\n", kfd->doorbell_kernel_ptr);
 116
 117         return 0;
 118 }
 119
 120 void kfd_doorbell_fini(struct kfd_dev *kfd)
 121 {
 122         if (kfd->doorbell_kernel_ptr)
 123                 iounmap(kfd->doorbell_kernel_ptr);
 124 }
 125
 126 int kfd_doorbell_mmap(struct kfd_dev *dev, struct kfd_process *process,
 127                       struct vm_area_struct *vma)
 128 {
 129         phys_addr_t address;
 130         struct kfd_process_device *pdd;
 131
 132         /*
 133          * For simplicitly we only allow mapping of the entire doorbell
 134          * allocation of a single device & process.
 135          */
 136         if (vma->vm_end - vma->vm_start != kfd_doorbell_process_slice(dev))
 137                 return -EINVAL;
 138
 139         pdd = kfd_get_process_device_data(dev, process);
 140         if (!pdd)
 141                 return -EINVAL;
 142
 143         /* Calculate physical address of doorbell */
 144         address = kfd_get_process_doorbells(pdd);
 145         vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
 146                                 VM_DONTDUMP | VM_PFNMAP;
 147
 148         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 149
 150         pr_debug("Mapping doorbell page\n"
 151                  "     target user address == 0x%08llX\n"
 152                  "     physical address    == 0x%08llX\n"
 153                  "     vm_flags            == 0x%04lX\n"
 154                  "     size                == 0x%04lX\n",
 155                  (unsigned long long) vma->vm_start, address, vma->vm_flags,
 156                  kfd_doorbell_process_slice(dev));
 157
 158
 159         return io_remap_pfn_range(vma,
 160                                 vma->vm_start,
 161                                 address >> PAGE_SHIFT,
 162                                 kfd_doorbell_process_slice(dev),
 163                                 vma->vm_page_prot);
 164 }
 165
 166
 167 /* get kernel iomem pointer for a doorbell */
 168 void __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
 169                                         unsigned int *doorbell_off)
 170 {
 171         u32 inx;
 172
 173         mutex_lock(&kfd->doorbell_mutex);
 174         inx = find_first_zero_bit(kfd->doorbell_available_index,
 175                                         KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
 176
 177         __set_bit(inx, kfd->doorbell_available_index);
 178         mutex_unlock(&kfd->doorbell_mutex);
 179
 180         if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
 181                 return NULL;
 182
 183         inx *= kfd->device_info->doorbell_size / sizeof(u32);
 184
 185         /*
 186          * Calculating the kernel doorbell offset using the first
 187          * doorbell page.
 188          */
 189         *doorbell_off = kfd->doorbell_base_dw_offset + inx;
 190
 191         pr_debug("Get kernel queue doorbell\n"
 192                         "     doorbell offset   == 0x%08X\n"
 193                         "     doorbell index    == 0x%x\n",
 194                 *doorbell_off, inx);
 195
 196         return kfd->doorbell_kernel_ptr + inx;
 197 }
 198
 199 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
 200 {
 201         unsigned int inx;
 202
 203         inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr)
 204                 * sizeof(u32) / kfd->device_info->doorbell_size;
 205
 206         mutex_lock(&kfd->doorbell_mutex);
 207         __clear_bit(inx, kfd->doorbell_available_index);
 208         mutex_unlock(&kfd->doorbell_mutex);
 209 }
 210
 211 void write_kernel_doorbell(void __iomem *db, u32 value)
 212 {
 213         if (db) {
 214                 writel(value, db);
 215                 pr_debug("Writing %d to doorbell address %p\n", value, db);
 216         }
 217 }
 218
 219 void write_kernel_doorbell64(void __iomem *db, u64 value)
 220 {
 221         if (db) {
 222                 WARN(((unsigned long)db & 7) != 0,
 223                      "Unaligned 64-bit doorbell");
 224                 writeq(value, (u64 __iomem *)db);
 225                 pr_debug("writing %llu to doorbell address %p\n", value, db);
 226         }
 227 }
 228
 229 unsigned int kfd_get_doorbell_dw_offset_in_bar(struct kfd_dev *kfd,
 230                                         struct kfd_process_device *pdd,
 231                                         unsigned int doorbell_id)
 232 {
 233         /*
 234          * doorbell_base_dw_offset accounts for doorbells taken by KGD.
 235          * index * kfd_doorbell_process_slice/sizeof(u32) adjusts to
 236          * the process's doorbells. The offset returned is in dword
 237          * units regardless of the ASIC-dependent doorbell size.
 238          */
 239         return kfd->doorbell_base_dw_offset +
 240                 pdd->doorbell_index
 241                 * kfd_doorbell_process_slice(kfd) / sizeof(u32) +
 242                 doorbell_id * kfd->device_info->doorbell_size / sizeof(u32);
 243 }
 244
 245 uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
 246 {
 247         uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size -
 248                                 kfd->shared_resources.doorbell_start_offset) /
 249                                         kfd_doorbell_process_slice(kfd) + 1;
 250
 251         return num_of_elems;
 252
 253 }
 254
 255 phys_addr_t kfd_get_process_doorbells(struct kfd_process_device *pdd)
 256 {
 257         return pdd->dev->doorbell_base +
 258                 pdd->doorbell_index * kfd_doorbell_process_slice(pdd->dev);
 259 }
 260
 261 int kfd_alloc_process_doorbells(struct kfd_dev *kfd, unsigned int *doorbell_index)
 262 {
 263         int r = ida_simple_get(&kfd->doorbell_ida, 1, kfd->max_doorbell_slices,
 264                                 GFP_KERNEL);
 265         if (r > 0)
 266                 *doorbell_index = r;
 267
 268         return r;
 269 }
 270
 271 void kfd_free_process_doorbells(struct kfd_dev *kfd, unsigned int doorbell_index)
 272 {
 273         if (doorbell_index)
 274                 ida_simple_remove(&kfd->doorbell_ida, doorbell_index);
 275 }