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 static DEFINE_IDA(doorbell_ida); 35 static unsigned int max_doorbell_slices; 36 #define KFD_SIZE_OF_DOORBELL_IN_BYTES 4 37 38 /* 39 * Each device exposes a doorbell aperture, a PCI MMIO aperture that 40 * receives 32-bit writes that are passed to queues as wptr values. 41 * The doorbells are intended to be written by applications as part 42 * of queueing work on user-mode queues. 43 * We assign doorbells to applications in PAGE_SIZE-sized and aligned chunks. 44 * We map the doorbell address space into user-mode when a process creates 45 * its first queue on each device. 46 * Although the mapping is done by KFD, it is equivalent to an mmap of 47 * the /dev/kfd with the particular device encoded in the mmap offset. 48 * There will be other uses for mmap of /dev/kfd, so only a range of 49 * offsets (KFD_MMAP_DOORBELL_START-END) is used for doorbells. 50 */ 51 52 /* # of doorbell bytes allocated for each process. */ 53 static inline size_t doorbell_process_allocation(void) 54 { 55 return roundup(KFD_SIZE_OF_DOORBELL_IN_BYTES * 56 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS, 57 PAGE_SIZE); 58 } 59 60 /* Doorbell calculations for device init. */ 61 int kfd_doorbell_init(struct kfd_dev *kfd) 62 { 63 size_t doorbell_start_offset; 64 size_t doorbell_aperture_size; 65 size_t doorbell_process_limit; 66 67 /* 68 * We start with calculations in bytes because the input data might 69 * only be byte-aligned. 70 * Only after we have done the rounding can we assume any alignment. 71 */ 72 73 doorbell_start_offset = 74 roundup(kfd->shared_resources.doorbell_start_offset, 75 doorbell_process_allocation()); 76 77 doorbell_aperture_size = 78 rounddown(kfd->shared_resources.doorbell_aperture_size, 79 doorbell_process_allocation()); 80 81 if (doorbell_aperture_size > doorbell_start_offset) 82 doorbell_process_limit = 83 (doorbell_aperture_size - doorbell_start_offset) / 84 doorbell_process_allocation(); 85 else 86 return -ENOSPC; 87 88 if (!max_doorbell_slices || 89 doorbell_process_limit < max_doorbell_slices) 90 max_doorbell_slices = doorbell_process_limit; 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 97 kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base, 98 doorbell_process_allocation()); 99 100 if (!kfd->doorbell_kernel_ptr) 101 return -ENOMEM; 102 103 pr_debug("Doorbell initialization:\n"); 104 pr_debug("doorbell base == 0x%08lX\n", 105 (uintptr_t)kfd->doorbell_base); 106 107 pr_debug("doorbell_id_offset == 0x%08lX\n", 108 kfd->doorbell_id_offset); 109 110 pr_debug("doorbell_process_limit == 0x%08lX\n", 111 doorbell_process_limit); 112 113 pr_debug("doorbell_kernel_offset == 0x%08lX\n", 114 (uintptr_t)kfd->doorbell_base); 115 116 pr_debug("doorbell aperture size == 0x%08lX\n", 117 kfd->shared_resources.doorbell_aperture_size); 118 119 pr_debug("doorbell kernel address == %p\n", kfd->doorbell_kernel_ptr); 120 121 return 0; 122 } 123 124 void kfd_doorbell_fini(struct kfd_dev *kfd) 125 { 126 if (kfd->doorbell_kernel_ptr) 127 iounmap(kfd->doorbell_kernel_ptr); 128 } 129 130 int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma) 131 { 132 phys_addr_t address; 133 struct kfd_dev *dev; 134 135 /* 136 * For simplicitly we only allow mapping of the entire doorbell 137 * allocation of a single device & process. 138 */ 139 if (vma->vm_end - vma->vm_start != doorbell_process_allocation()) 140 return -EINVAL; 141 142 /* Find kfd device according to gpu id */ 143 dev = kfd_device_by_id(vma->vm_pgoff); 144 if (!dev) 145 return -EINVAL; 146 147 /* Calculate physical address of doorbell */ 148 address = kfd_get_process_doorbells(dev, process); 149 150 vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE | 151 VM_DONTDUMP | VM_PFNMAP; 152 153 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 154 155 pr_debug("Mapping doorbell page\n" 156 " target user address == 0x%08llX\n" 157 " physical address == 0x%08llX\n" 158 " vm_flags == 0x%04lX\n" 159 " size == 0x%04lX\n", 160 (unsigned long long) vma->vm_start, address, vma->vm_flags, 161 doorbell_process_allocation()); 162 163 164 return io_remap_pfn_range(vma, 165 vma->vm_start, 166 address >> PAGE_SHIFT, 167 doorbell_process_allocation(), 168 vma->vm_page_prot); 169 } 170 171 172 /* get kernel iomem pointer for a doorbell */ 173 u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd, 174 unsigned int *doorbell_off) 175 { 176 u32 inx; 177 178 mutex_lock(&kfd->doorbell_mutex); 179 inx = find_first_zero_bit(kfd->doorbell_available_index, 180 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS); 181 182 __set_bit(inx, kfd->doorbell_available_index); 183 mutex_unlock(&kfd->doorbell_mutex); 184 185 if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS) 186 return NULL; 187 188 /* 189 * Calculating the kernel doorbell offset using the first 190 * doorbell page. 191 */ 192 *doorbell_off = kfd->doorbell_id_offset + inx; 193 194 pr_debug("Get kernel queue doorbell\n" 195 " doorbell offset == 0x%08X\n" 196 " kernel address == %p\n", 197 *doorbell_off, (kfd->doorbell_kernel_ptr + inx)); 198 199 return kfd->doorbell_kernel_ptr + inx; 200 } 201 202 void kfd_release_kernel_doorbell(struct kfd_dev *kfd, u32 __iomem *db_addr) 203 { 204 unsigned int inx; 205 206 inx = (unsigned int)(db_addr - kfd->doorbell_kernel_ptr); 207 208 mutex_lock(&kfd->doorbell_mutex); 209 __clear_bit(inx, kfd->doorbell_available_index); 210 mutex_unlock(&kfd->doorbell_mutex); 211 } 212 213 inline void write_kernel_doorbell(u32 __iomem *db, u32 value) 214 { 215 if (db) { 216 writel(value, db); 217 pr_debug("Writing %d to doorbell address %p\n", value, db); 218 } 219 } 220 221 /* 222 * queue_ids are in the range [0,MAX_PROCESS_QUEUES) and are mapped 1:1 223 * to doorbells with the process's doorbell page 224 */ 225 unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd, 226 struct kfd_process *process, 227 unsigned int queue_id) 228 { 229 /* 230 * doorbell_id_offset accounts for doorbells taken by KGD. 231 * index * doorbell_process_allocation/sizeof(u32) adjusts to 232 * the process's doorbells. 233 */ 234 return kfd->doorbell_id_offset + 235 process->doorbell_index 236 * 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->doorbell_index * doorbell_process_allocation(); 255 } 256 257 int kfd_alloc_process_doorbells(struct kfd_process *process) 258 { 259 int r = ida_simple_get(&doorbell_ida, 1, max_doorbell_slices, 260 GFP_KERNEL); 261 if (r > 0) 262 process->doorbell_index = r; 263 264 return r; 265 } 266 267 void kfd_free_process_doorbells(struct kfd_process *process) 268 { 269 if (process->doorbell_index) 270 ida_simple_remove(&doorbell_ida, process->doorbell_index); 271 } 272