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 static DEFINE_MUTEX(doorbell_mutex);
  36 static unsigned long doorbell_available_index[
  37         DIV_ROUND_UP(KFD_MAX_NUM_OF_QUEUES_PER_PROCESS, BITS_PER_LONG)] = { 0 };
  38
  39 #define KERNEL_DOORBELL_PASID 1
  40 #define KFD_SIZE_OF_DOORBELL_IN_BYTES 4
  41
  42 /*
  43  * Each device exposes a doorbell aperture, a PCI MMIO aperture that
  44  * receives 32-bit writes that are passed to queues as wptr values.
  45  * The doorbells are intended to be written by applications as part
  46  * of queueing work on user-mode queues.
  47  * We assign doorbells to applications in PAGE_SIZE-sized and aligned chunks.
  48  * We map the doorbell address space into user-mode when a process creates
  49  * its first queue on each device.
  50  * Although the mapping is done by KFD, it is equivalent to an mmap of
  51  * the /dev/kfd with the particular device encoded in the mmap offset.
  52  * There will be other uses for mmap of /dev/kfd, so only a range of
  53  * offsets (KFD_MMAP_DOORBELL_START-END) is used for doorbells.
  54  */
  55
  56 /* # of doorbell bytes allocated for each process. */
  57 static inline size_t doorbell_process_allocation(void)
  58 {
  59         return roundup(KFD_SIZE_OF_DOORBELL_IN_BYTES *
  60                         KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
  61                         PAGE_SIZE);
  62 }
  63
  64 /* Doorbell calculations for device init. */
  65 void kfd_doorbell_init(struct kfd_dev *kfd)
  66 {
  67         size_t doorbell_start_offset;
  68         size_t doorbell_aperture_size;
  69         size_t doorbell_process_limit;
  70
  71         /*
  72          * We start with calculations in bytes because the input data might
  73          * only be byte-aligned.
  74          * Only after we have done the rounding can we assume any alignment.
  75          */
  76
  77         doorbell_start_offset =
  78                         roundup(kfd->shared_resources.doorbell_start_offset,
  79                                         doorbell_process_allocation());
  80
  81         doorbell_aperture_size =
  82                         rounddown(kfd->shared_resources.doorbell_aperture_size,
  83                                         doorbell_process_allocation());
  84
  85         if (doorbell_aperture_size > doorbell_start_offset)
  86                 doorbell_process_limit =
  87                         (doorbell_aperture_size - doorbell_start_offset) /
  88                                                 doorbell_process_allocation();
  89         else
  90                 doorbell_process_limit = 0;
  91
  92         kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
  93                                 doorbell_start_offset;
  94
  95         kfd->doorbell_id_offset = doorbell_start_offset / sizeof(u32);
  96         kfd->doorbell_process_limit = doorbell_process_limit - 1;
  97
  98         kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
  99                                                 doorbell_process_allocation());
 100
 101         BUG_ON(!kfd->doorbell_kernel_ptr);
 102
 103         pr_debug("kfd: doorbell initialization:\n");
 104         pr_debug("kfd: doorbell base           == 0x%08lX\n",
 105                         (uintptr_t)kfd->doorbell_base);
 106
 107         pr_debug("kfd: doorbell_id_offset      == 0x%08lX\n",
 108                         kfd->doorbell_id_offset);
 109
 110         pr_debug("kfd: doorbell_process_limit  == 0x%08lX\n",
 111                         doorbell_process_limit);
 112
 113         pr_debug("kfd: doorbell_kernel_offset  == 0x%08lX\n",
 114                         (uintptr_t)kfd->doorbell_base);
 115
 116         pr_debug("kfd: doorbell aperture size  == 0x%08lX\n",
 117                         kfd->shared_resources.doorbell_aperture_size);
 118
 119         pr_debug("kfd: doorbell kernel address == 0x%08lX\n",
 120                         (uintptr_t)kfd->doorbell_kernel_ptr);
 121 }
 122
 123 int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma)
 124 {
 125         phys_addr_t address;
 126         struct kfd_dev *dev;
 127
 128         /*
 129          * For simplicitly we only allow mapping of the entire doorbell
 130          * allocation of a single device & process.
 131          */
 132         if (vma->vm_end - vma->vm_start != doorbell_process_allocation())
 133                 return -EINVAL;
 134
 135         /* Find kfd device according to gpu id */
 136         dev = kfd_device_by_id(vma->vm_pgoff);
 137         if (dev == NULL)
 138                 return -EINVAL;
 139
 140         /* Calculate physical address of doorbell */
 141         address = kfd_get_process_doorbells(dev, process);
 142
 143         vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
 144                                 VM_DONTDUMP | VM_PFNMAP;
 145
 146         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 147
 148         pr_debug("kfd: mapping doorbell page in kfd_doorbell_mmap\n"
 149                  "     target user address == 0x%08llX\n"
 150                  "     physical address    == 0x%08llX\n"
 151                  "     vm_flags            == 0x%04lX\n"
 152                  "     size                == 0x%04lX\n",
 153                  (unsigned long long) vma->vm_start, address, vma->vm_flags,
 154                  doorbell_process_allocation());
 155
 156
 157         return io_remap_pfn_range(vma,
 158                                 vma->vm_start,
 159                                 address >> PAGE_SHIFT,
 160                                 doorbell_process_allocation(),
 161                                 vma->vm_page_prot);
 162 }
 163
 164
 165 /* get kernel iomem pointer for a doorbell */
 166 u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
 167                                         unsigned int *doorbell_off)
 168 {
 169         u32 inx;
 170
 171         BUG_ON(!kfd || !doorbell_off);
 172
 173         mutex_lock(&doorbell_mutex);
 174         inx = find_first_zero_bit(doorbell_available_index,
 175                                         KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
 176
 177         __set_bit(inx, doorbell_available_index);
 178         mutex_unlock(&doorbell_mutex);
 179
 180         if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
 181                 return NULL;
 182
 183         /*
 184          * Calculating the kernel doorbell offset using "faked" kernel
 185          * pasid that allocated for kernel queues only
 186          */
 187         *doorbell_off = KERNEL_DOORBELL_PASID * (doorbell_process_allocation() /
 188                                                         sizeof(u32)) + inx;
 189
 190         pr_debug("kfd: get kernel queue doorbell\n"
 191                          "     doorbell offset   == 0x%08d\n"
 192                          "     kernel address    == 0x%08lX\n",
 193                 *doorbell_off, (uintptr_t)(kfd->doorbell_kernel_ptr + inx));
 194
 195         return kfd->doorbell_kernel_ptr + inx;
 196 }
 197
 198 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
 199 {
 200         unsigned int inx;
 201
 202         BUG_ON(!kfd || !db_addr);
 203
 204         inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr);
 205
 206         mutex_lock(&doorbell_mutex);
 207         __clear_bit(inx, doorbell_available_index);
 208         mutex_unlock(&doorbell_mutex);
 209 }
 210
 211 inline void write_kernel_doorbell(u32 __iomem *db, u32 value)
 212 {
 213         if (db) {
 214                 writel(value, db);
 215                 pr_debug("writing %d to doorbell address 0x%p\n", value, db);
 216         }
 217 }
 218
 219 /*
 220  * queue_ids are in the range [0,MAX_PROCESS_QUEUES) and are mapped 1:1
 221  * to doorbells with the process's doorbell page
 222  */
 223 unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd,
 224                                         struct kfd_process *process,
 225                                         unsigned int queue_id)
 226 {
 227         /*
 228          * doorbell_id_offset accounts for doorbells taken by KGD.
 229          * pasid * doorbell_process_allocation/sizeof(u32) adjusts
 230          * to the process's doorbells
 231          */
 232         return kfd->doorbell_id_offset +
 233                 process->pasid * (doorbell_process_allocation()/sizeof(u32)) +
 234                 queue_id;
 235 }
 236
 237 uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
 238 {
 239         uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size -
 240                                 kfd->shared_resources.doorbell_start_offset) /
 241                                         doorbell_process_allocation() + 1;
 242
 243         return num_of_elems;
 244
 245 }
 246
 247 phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
 248                                         struct kfd_process *process)
 249 {
 250         return dev->doorbell_base +
 251                 process->pasid * doorbell_process_allocation();
 252 }