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
  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. */
  54 static 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. */
  62 void 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
 120 int 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 */
 164 u32 __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
 196 void 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
 209 inline 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  */
 221 unsigned 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
 235 uint64_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
 245 phys_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 }