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 int 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 if (!kfd->doorbell_kernel_ptr) 99 return -ENOMEM; 100 101 pr_debug("Doorbell initialization:\n"); 102 pr_debug("doorbell base == 0x%08lX\n", 103 (uintptr_t)kfd->doorbell_base); 104 105 pr_debug("doorbell_id_offset == 0x%08lX\n", 106 kfd->doorbell_id_offset); 107 108 pr_debug("doorbell_process_limit == 0x%08lX\n", 109 doorbell_process_limit); 110 111 pr_debug("doorbell_kernel_offset == 0x%08lX\n", 112 (uintptr_t)kfd->doorbell_base); 113 114 pr_debug("doorbell aperture size == 0x%08lX\n", 115 kfd->shared_resources.doorbell_aperture_size); 116 117 pr_debug("doorbell kernel address == 0x%08lX\n", 118 (uintptr_t)kfd->doorbell_kernel_ptr); 119 120 return 0; 121 } 122 123 void kfd_doorbell_fini(struct kfd_dev *kfd) 124 { 125 if (kfd->doorbell_kernel_ptr) 126 iounmap(kfd->doorbell_kernel_ptr); 127 } 128 129 int kfd_doorbell_mmap(struct kfd_process *process, struct vm_area_struct *vma) 130 { 131 phys_addr_t address; 132 struct kfd_dev *dev; 133 134 /* 135 * For simplicitly we only allow mapping of the entire doorbell 136 * allocation of a single device & process. 137 */ 138 if (vma->vm_end - vma->vm_start != doorbell_process_allocation()) 139 return -EINVAL; 140 141 /* Find kfd device according to gpu id */ 142 dev = kfd_device_by_id(vma->vm_pgoff); 143 if (!dev) 144 return -EINVAL; 145 146 /* Calculate physical address of doorbell */ 147 address = kfd_get_process_doorbells(dev, process); 148 149 vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE | 150 VM_DONTDUMP | VM_PFNMAP; 151 152 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 153 154 pr_debug("Mapping doorbell page\n" 155 " target user address == 0x%08llX\n" 156 " physical address == 0x%08llX\n" 157 " vm_flags == 0x%04lX\n" 158 " size == 0x%04lX\n", 159 (unsigned long long) vma->vm_start, address, vma->vm_flags, 160 doorbell_process_allocation()); 161 162 163 return io_remap_pfn_range(vma, 164 vma->vm_start, 165 address >> PAGE_SHIFT, 166 doorbell_process_allocation(), 167 vma->vm_page_prot); 168 } 169 170 171 /* get kernel iomem pointer for a doorbell */ 172 u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd, 173 unsigned int *doorbell_off) 174 { 175 u32 inx; 176 177 mutex_lock(&kfd->doorbell_mutex); 178 inx = find_first_zero_bit(kfd->doorbell_available_index, 179 KFD_MAX_NUM_OF_QUEUES_PER_PROCESS); 180 181 __set_bit(inx, kfd->doorbell_available_index); 182 mutex_unlock(&kfd->doorbell_mutex); 183 184 if (inx >= KFD_MAX_NUM_OF_QUEUES_PER_PROCESS) 185 return NULL; 186 187 /* 188 * Calculating the kernel doorbell offset using "faked" kernel 189 * pasid that allocated for kernel queues only 190 */ 191 *doorbell_off = KERNEL_DOORBELL_PASID * (doorbell_process_allocation() / 192 sizeof(u32)) + inx; 193 194 pr_debug("Get kernel queue doorbell\n" 195 " doorbell offset == 0x%08X\n" 196 " kernel address == 0x%08lX\n", 197 *doorbell_off, (uintptr_t)(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 0x%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 * pasid * doorbell_process_allocation/sizeof(u32) adjusts 232 * to the process's doorbells 233 */ 234 return kfd->doorbell_id_offset + 235 process->pasid * (doorbell_process_allocation()/sizeof(u32)) + 236 queue_id; 237 } 238 239 uint64_t kfd_get_number_elems(struct kfd_dev *kfd) 240 { 241 uint64_t num_of_elems = (kfd->shared_resources.doorbell_aperture_size - 242 kfd->shared_resources.doorbell_start_offset) / 243 doorbell_process_allocation() + 1; 244 245 return num_of_elems; 246 247 } 248 249 phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev, 250 struct kfd_process *process) 251 { 252 return dev->doorbell_base + 253 process->pasid * doorbell_process_allocation(); 254 } 255