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 } 276