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
  27 /*
  28  * This extension supports a kernel level doorbells management for
  29  * the kernel queues.
  30  * Basically the last doorbells page is devoted to kernel queues
  31  * and that's assures that any user process won't get access to the
  32  * kernel doorbells page
  33  */
  34 static DEFINE_MUTEX(doorbell_mutex);
  35 static unsigned long doorbell_available_index[
  36         DIV_ROUND_UP(KFD_MAX_NUM_OF_QUEUES_PER_PROCESS, BITS_PER_LONG)] = { 0 };
  37
  38 #define KERNEL_DOORBELL_PASID 1
  39 #define KFD_SIZE_OF_DOORBELL_IN_BYTES 4
  40
  41 /*
  42  * Each device exposes a doorbell aperture, a PCI MMIO aperture that
  43  * receives 32-bit writes that are passed to queues as wptr values.
  44  * The doorbells are intended to be written by applications as part
  45  * of queueing work on user-mode queues.
  46  * We assign doorbells to applications in PAGE_SIZE-sized and aligned chunks.
  47  * We map the doorbell address space into user-mode when a process creates
  48  * its first queue on each device.
  49  * Although the mapping is done by KFD, it is equivalent to an mmap of
  50  * the /dev/kfd with the particular device encoded in the mmap offset.
  51  * There will be other uses for mmap of /dev/kfd, so only a range of
  52  * offsets (KFD_MMAP_DOORBELL_START-END) is used for doorbells.
  53  */
  54
  55 /* # of doorbell bytes allocated for each process. */
  56 static inline size_t doorbell_process_allocation(void)
  57 {
  58         return roundup(KFD_SIZE_OF_DOORBELL_IN_BYTES *
  59                         KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
  60                         PAGE_SIZE);
  61 }
  62
  63 /* Doorbell calculations for device init. */
  64 void kfd_doorbell_init(struct kfd_dev *kfd)
  65 {
  66         size_t doorbell_start_offset;
  67         size_t doorbell_aperture_size;
  68         size_t doorbell_process_limit;
  69
  70         /*
  71          * We start with calculations in bytes because the input data might
  72          * only be byte-aligned.
  73          * Only after we have done the rounding can we assume any alignment.
  74          */
  75
  76         doorbell_start_offset =
  77                         roundup(kfd->shared_resources.doorbell_start_offset,
  78                                         doorbell_process_allocation());
  79
  80         doorbell_aperture_size =
  81                         rounddown(kfd->shared_resources.doorbell_aperture_size,
  82                                         doorbell_process_allocation());
  83
  84         if (doorbell_aperture_size > doorbell_start_offset)
  85                 doorbell_process_limit =
  86                         (doorbell_aperture_size - doorbell_start_offset) /
  87                                                 doorbell_process_allocation();
  88         else
  89                 doorbell_process_limit = 0;
  90
  91         kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
  92                                 doorbell_start_offset;
  93
  94         kfd->doorbell_id_offset = doorbell_start_offset / sizeof(u32);
  95         kfd->doorbell_process_limit = doorbell_process_limit - 1;
  96
  97         kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
  98                                                 doorbell_process_allocation());
  99
 100         BUG_ON(!kfd->doorbell_kernel_ptr);
 101
 102         pr_debug("kfd: doorbell initialization:\n");
 103         pr_debug("kfd: doorbell base           == 0x%08lX\n",
 104                         (uintptr_t)kfd->doorbell_base);
 105
 106         pr_debug("kfd: doorbell_id_offset      == 0x%08lX\n",
 107                         kfd->doorbell_id_offset);
 108
 109         pr_debug("kfd: doorbell_process_limit  == 0x%08lX\n",
 110                         doorbell_process_limit);
 111
 112         pr_debug("kfd: doorbell_kernel_offset  == 0x%08lX\n",
 113                         (uintptr_t)kfd->doorbell_base);
 114
 115         pr_debug("kfd: doorbell aperture size  == 0x%08lX\n",
 116                         kfd->shared_resources.doorbell_aperture_size);
 117
 118         pr_debug("kfd: doorbell kernel address == 0x%08lX\n",
 119                         (uintptr_t)kfd->doorbell_kernel_ptr);
 120 }
 121
 122 int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma)
 123 {
 124         phys_addr_t address;
 125         struct kfd_dev *dev;
 126
 127         /*
 128          * For simplicitly we only allow mapping of the entire doorbell
 129          * allocation of a single device & process.
 130          */
 131         if (vma->vm_end - vma->vm_start != doorbell_process_allocation())
 132                 return -EINVAL;
 133
 134         /* Find kfd device according to gpu id */
 135         dev = kfd_device_by_id(vma->vm_pgoff);
 136         if (dev == NULL)
 137                 return -EINVAL;
 138
 139         /* Find if pdd exists for combination of process and gpu id */
 140         if (!kfd_get_process_device_data(dev, process, 0))
 141                 return -EINVAL;
 142
 143         /* Calculate physical address of doorbell */
 144         address = kfd_get_process_doorbells(dev, process);
 145
 146         vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
 147                                 VM_DONTDUMP | VM_PFNMAP;
 148
 149         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 150
 151         pr_debug("kfd: mapping doorbell page in kfd_doorbell_mmap\n"
 152                  "     target user address == 0x%08llX\n"
 153                  "     physical address    == 0x%08llX\n"
 154                  "     vm_flags            == 0x%04lX\n"
 155                  "     size                == 0x%04lX\n",
 156                  (unsigned long long) vma->vm_start, address, vma->vm_flags,
 157                  doorbell_process_allocation());
 158
 159
 160         return io_remap_pfn_range(vma,
 161                                 vma->vm_start,
 162                                 address >> PAGE_SHIFT,
 163                                 doorbell_process_allocation(),
 164                                 vma->vm_page_prot);
 165 }
 166
 167
 168 /* get kernel iomem pointer for a doorbell */
 169 u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
 170                                         unsigned int *doorbell_off)
 171 {
 172         u32 inx;
 173
 174         BUG_ON(!kfd || !doorbell_off);
 175
 176         mutex_lock(&doorbell_mutex);
 177         inx = find_first_zero_bit(doorbell_available_index,
 178                                         KFD_MAX_NUM_OF_QUEUES_PER_PROCESS);
 179
 180         __set_bit(inx, doorbell_available_index);
 181         mutex_unlock(&doorbell_mutex);
 182
 183         if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS)
 184                 return NULL;
 185
 186         /*
 187          * Calculating the kernel doorbell offset using "faked" kernel
 188          * pasid that allocated for kernel queues only
 189          */
 190         *doorbell_off = KERNEL_DOORBELL_PASID * (doorbell_process_allocation() /
 191                                                         sizeof(u32)) + inx;
 192
 193         pr_debug("kfd: get kernel queue doorbell\n"
 194                          "     doorbell offset   == 0x%08d\n"
 195                          "     kernel address    == 0x%08lX\n",
 196                 *doorbell_off, (uintptr_t)(kfd->doorbell_kernel_ptr + inx));
 197
 198         return kfd->doorbell_kernel_ptr + inx;
 199 }
 200
 201 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr)
 202 {
 203         unsigned int inx;
 204
 205         BUG_ON(!kfd || !db_addr);
 206
 207         inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr);
 208
 209         mutex_lock(&doorbell_mutex);
 210         __clear_bit(inx, doorbell_available_index);
 211         mutex_unlock(&doorbell_mutex);
 212 }
 213
 214 inline void write_kernel_doorbell(u32 __iomem *db, u32 value)
 215 {
 216         if (db) {
 217                 writel(value, db);
 218                 pr_debug("writing %d to doorbell address 0x%p\n", value, db);
 219         }
 220 }
 221
 222 /*
 223  * queue_ids are in the range [0,MAX_PROCESS_QUEUES) and are mapped 1:1
 224  * to doorbells with the process's doorbell page
 225  */
 226 unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd,
 227                                         struct kfd_process *process,
 228                                         unsigned int queue_id)
 229 {
 230         /*
 231          * doorbell_id_offset accounts for doorbells taken by KGD.
 232          * pasid * doorbell_process_allocation/sizeof(u32) adjusts
 233          * to the process's doorbells
 234          */
 235         return kfd->doorbell_id_offset +
 236                 process->pasid * (doorbell_process_allocation()/sizeof(u32)) +
 237                 queue_id;
 238 }
 239
 240 uint64_t kfd_get_number_elems(struct kfd_dev *kfd)
 241 {
 242         uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size -
 243                                 kfd->shared_resources.doorbell_start_offset) /
 244                                         doorbell_process_allocation() + 1;
 245
 246         return num_of_elems;
 247
 248 }
 249
 250 phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
 251                                         struct kfd_process *process)
 252 {
 253         return dev->doorbell_base +
 254                 process->pasid * doorbell_process_allocation();
 255 }