1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Passthrough DMA device driver 4 * -- Based on the CCP driver 5 * 6 * Copyright (C) 2016,2021 Advanced Micro Devices, Inc. 7 * 8 * Author: Sanjay R Mehta <sanju.mehta@amd.com> 9 * Author: Gary R Hook <gary.hook@amd.com> 10 */ 11 12 #include "ptdma.h" 13 #include "../dmaengine.h" 14 #include "../virt-dma.h" 15 16 static inline struct pt_dma_chan *to_pt_chan(struct dma_chan *dma_chan) 17 { 18 return container_of(dma_chan, struct pt_dma_chan, vc.chan); 19 } 20 21 static inline struct pt_dma_desc *to_pt_desc(struct virt_dma_desc *vd) 22 { 23 return container_of(vd, struct pt_dma_desc, vd); 24 } 25 26 static void pt_free_chan_resources(struct dma_chan *dma_chan) 27 { 28 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 29 30 vchan_free_chan_resources(&chan->vc); 31 } 32 33 static void pt_synchronize(struct dma_chan *dma_chan) 34 { 35 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 36 37 vchan_synchronize(&chan->vc); 38 } 39 40 static void pt_do_cleanup(struct virt_dma_desc *vd) 41 { 42 struct pt_dma_desc *desc = to_pt_desc(vd); 43 struct pt_device *pt = desc->pt; 44 45 kmem_cache_free(pt->dma_desc_cache, desc); 46 } 47 48 static int pt_dma_start_desc(struct pt_dma_desc *desc) 49 { 50 struct pt_passthru_engine *pt_engine; 51 struct pt_device *pt; 52 struct pt_cmd *pt_cmd; 53 struct pt_cmd_queue *cmd_q; 54 55 desc->issued_to_hw = 1; 56 57 pt_cmd = &desc->pt_cmd; 58 pt = pt_cmd->pt; 59 cmd_q = &pt->cmd_q; 60 pt_engine = &pt_cmd->passthru; 61 62 pt->tdata.cmd = pt_cmd; 63 64 /* Execute the command */ 65 pt_cmd->ret = pt_core_perform_passthru(cmd_q, pt_engine); 66 67 return 0; 68 } 69 70 static struct pt_dma_desc *pt_next_dma_desc(struct pt_dma_chan *chan) 71 { 72 /* Get the next DMA descriptor on the active list */ 73 struct virt_dma_desc *vd = vchan_next_desc(&chan->vc); 74 75 return vd ? to_pt_desc(vd) : NULL; 76 } 77 78 static struct pt_dma_desc *pt_handle_active_desc(struct pt_dma_chan *chan, 79 struct pt_dma_desc *desc) 80 { 81 struct dma_async_tx_descriptor *tx_desc; 82 struct virt_dma_desc *vd; 83 unsigned long flags; 84 85 /* Loop over descriptors until one is found with commands */ 86 do { 87 if (desc) { 88 if (!desc->issued_to_hw) { 89 /* No errors, keep going */ 90 if (desc->status != DMA_ERROR) 91 return desc; 92 } 93 94 tx_desc = &desc->vd.tx; 95 vd = &desc->vd; 96 } else { 97 tx_desc = NULL; 98 } 99 100 spin_lock_irqsave(&chan->vc.lock, flags); 101 102 if (desc) { 103 if (desc->status != DMA_COMPLETE) { 104 if (desc->status != DMA_ERROR) 105 desc->status = DMA_COMPLETE; 106 107 dma_cookie_complete(tx_desc); 108 dma_descriptor_unmap(tx_desc); 109 list_del(&desc->vd.node); 110 } else { 111 /* Don't handle it twice */ 112 tx_desc = NULL; 113 } 114 } 115 116 desc = pt_next_dma_desc(chan); 117 118 spin_unlock_irqrestore(&chan->vc.lock, flags); 119 120 if (tx_desc) { 121 dmaengine_desc_get_callback_invoke(tx_desc, NULL); 122 dma_run_dependencies(tx_desc); 123 vchan_vdesc_fini(vd); 124 } 125 } while (desc); 126 127 return NULL; 128 } 129 130 static void pt_cmd_callback(void *data, int err) 131 { 132 struct pt_dma_desc *desc = data; 133 struct dma_chan *dma_chan; 134 struct pt_dma_chan *chan; 135 int ret; 136 137 if (err == -EINPROGRESS) 138 return; 139 140 dma_chan = desc->vd.tx.chan; 141 chan = to_pt_chan(dma_chan); 142 143 if (err) 144 desc->status = DMA_ERROR; 145 146 while (true) { 147 /* Check for DMA descriptor completion */ 148 desc = pt_handle_active_desc(chan, desc); 149 150 /* Don't submit cmd if no descriptor or DMA is paused */ 151 if (!desc) 152 break; 153 154 ret = pt_dma_start_desc(desc); 155 if (!ret) 156 break; 157 158 desc->status = DMA_ERROR; 159 } 160 } 161 162 static struct pt_dma_desc *pt_alloc_dma_desc(struct pt_dma_chan *chan, 163 unsigned long flags) 164 { 165 struct pt_dma_desc *desc; 166 167 desc = kmem_cache_zalloc(chan->pt->dma_desc_cache, GFP_NOWAIT); 168 if (!desc) 169 return NULL; 170 171 vchan_tx_prep(&chan->vc, &desc->vd, flags); 172 173 desc->pt = chan->pt; 174 desc->pt->cmd_q.int_en = !!(flags & DMA_PREP_INTERRUPT); 175 desc->issued_to_hw = 0; 176 desc->status = DMA_IN_PROGRESS; 177 178 return desc; 179 } 180 181 static struct pt_dma_desc *pt_create_desc(struct dma_chan *dma_chan, 182 dma_addr_t dst, 183 dma_addr_t src, 184 unsigned int len, 185 unsigned long flags) 186 { 187 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 188 struct pt_passthru_engine *pt_engine; 189 struct pt_dma_desc *desc; 190 struct pt_cmd *pt_cmd; 191 192 desc = pt_alloc_dma_desc(chan, flags); 193 if (!desc) 194 return NULL; 195 196 pt_cmd = &desc->pt_cmd; 197 pt_cmd->pt = chan->pt; 198 pt_engine = &pt_cmd->passthru; 199 pt_cmd->engine = PT_ENGINE_PASSTHRU; 200 pt_engine->src_dma = src; 201 pt_engine->dst_dma = dst; 202 pt_engine->src_len = len; 203 pt_cmd->pt_cmd_callback = pt_cmd_callback; 204 pt_cmd->data = desc; 205 206 desc->len = len; 207 208 return desc; 209 } 210 211 static struct dma_async_tx_descriptor * 212 pt_prep_dma_memcpy(struct dma_chan *dma_chan, dma_addr_t dst, 213 dma_addr_t src, size_t len, unsigned long flags) 214 { 215 struct pt_dma_desc *desc; 216 217 desc = pt_create_desc(dma_chan, dst, src, len, flags); 218 if (!desc) 219 return NULL; 220 221 return &desc->vd.tx; 222 } 223 224 static struct dma_async_tx_descriptor * 225 pt_prep_dma_interrupt(struct dma_chan *dma_chan, unsigned long flags) 226 { 227 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 228 struct pt_dma_desc *desc; 229 230 desc = pt_alloc_dma_desc(chan, flags); 231 if (!desc) 232 return NULL; 233 234 return &desc->vd.tx; 235 } 236 237 static void pt_issue_pending(struct dma_chan *dma_chan) 238 { 239 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 240 struct pt_dma_desc *desc; 241 unsigned long flags; 242 bool engine_is_idle = true; 243 244 spin_lock_irqsave(&chan->vc.lock, flags); 245 246 desc = pt_next_dma_desc(chan); 247 if (desc) 248 engine_is_idle = false; 249 250 vchan_issue_pending(&chan->vc); 251 252 desc = pt_next_dma_desc(chan); 253 254 spin_unlock_irqrestore(&chan->vc.lock, flags); 255 256 /* If there was nothing active, start processing */ 257 if (engine_is_idle && desc) 258 pt_cmd_callback(desc, 0); 259 } 260 261 static enum dma_status 262 pt_tx_status(struct dma_chan *c, dma_cookie_t cookie, 263 struct dma_tx_state *txstate) 264 { 265 struct pt_device *pt = to_pt_chan(c)->pt; 266 struct pt_cmd_queue *cmd_q = &pt->cmd_q; 267 268 pt_check_status_trans(pt, cmd_q); 269 return dma_cookie_status(c, cookie, txstate); 270 } 271 272 static int pt_pause(struct dma_chan *dma_chan) 273 { 274 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 275 unsigned long flags; 276 277 spin_lock_irqsave(&chan->vc.lock, flags); 278 pt_stop_queue(&chan->pt->cmd_q); 279 spin_unlock_irqrestore(&chan->vc.lock, flags); 280 281 return 0; 282 } 283 284 static int pt_resume(struct dma_chan *dma_chan) 285 { 286 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 287 struct pt_dma_desc *desc = NULL; 288 unsigned long flags; 289 290 spin_lock_irqsave(&chan->vc.lock, flags); 291 pt_start_queue(&chan->pt->cmd_q); 292 desc = pt_next_dma_desc(chan); 293 spin_unlock_irqrestore(&chan->vc.lock, flags); 294 295 /* If there was something active, re-start */ 296 if (desc) 297 pt_cmd_callback(desc, 0); 298 299 return 0; 300 } 301 302 static int pt_terminate_all(struct dma_chan *dma_chan) 303 { 304 struct pt_dma_chan *chan = to_pt_chan(dma_chan); 305 unsigned long flags; 306 struct pt_cmd_queue *cmd_q = &chan->pt->cmd_q; 307 LIST_HEAD(head); 308 309 iowrite32(SUPPORTED_INTERRUPTS, cmd_q->reg_control + 0x0010); 310 spin_lock_irqsave(&chan->vc.lock, flags); 311 vchan_get_all_descriptors(&chan->vc, &head); 312 spin_unlock_irqrestore(&chan->vc.lock, flags); 313 314 vchan_dma_desc_free_list(&chan->vc, &head); 315 vchan_free_chan_resources(&chan->vc); 316 317 return 0; 318 } 319 320 int pt_dmaengine_register(struct pt_device *pt) 321 { 322 struct pt_dma_chan *chan; 323 struct dma_device *dma_dev = &pt->dma_dev; 324 char *cmd_cache_name; 325 char *desc_cache_name; 326 int ret; 327 328 pt->pt_dma_chan = devm_kzalloc(pt->dev, sizeof(*pt->pt_dma_chan), 329 GFP_KERNEL); 330 if (!pt->pt_dma_chan) 331 return -ENOMEM; 332 333 cmd_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL, 334 "%s-dmaengine-cmd-cache", 335 dev_name(pt->dev)); 336 if (!cmd_cache_name) 337 return -ENOMEM; 338 339 desc_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL, 340 "%s-dmaengine-desc-cache", 341 dev_name(pt->dev)); 342 if (!desc_cache_name) { 343 ret = -ENOMEM; 344 goto err_cache; 345 } 346 347 pt->dma_desc_cache = kmem_cache_create(desc_cache_name, 348 sizeof(struct pt_dma_desc), 0, 349 SLAB_HWCACHE_ALIGN, NULL); 350 if (!pt->dma_desc_cache) { 351 ret = -ENOMEM; 352 goto err_cache; 353 } 354 355 dma_dev->dev = pt->dev; 356 dma_dev->src_addr_widths = DMA_SLAVE_BUSWIDTH_64_BYTES; 357 dma_dev->dst_addr_widths = DMA_SLAVE_BUSWIDTH_64_BYTES; 358 dma_dev->directions = DMA_MEM_TO_MEM; 359 dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; 360 dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); 361 dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask); 362 363 /* 364 * PTDMA is intended to be used with the AMD NTB devices, hence 365 * marking it as DMA_PRIVATE. 366 */ 367 dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask); 368 369 INIT_LIST_HEAD(&dma_dev->channels); 370 371 chan = pt->pt_dma_chan; 372 chan->pt = pt; 373 374 /* Set base and prep routines */ 375 dma_dev->device_free_chan_resources = pt_free_chan_resources; 376 dma_dev->device_prep_dma_memcpy = pt_prep_dma_memcpy; 377 dma_dev->device_prep_dma_interrupt = pt_prep_dma_interrupt; 378 dma_dev->device_issue_pending = pt_issue_pending; 379 dma_dev->device_tx_status = pt_tx_status; 380 dma_dev->device_pause = pt_pause; 381 dma_dev->device_resume = pt_resume; 382 dma_dev->device_terminate_all = pt_terminate_all; 383 dma_dev->device_synchronize = pt_synchronize; 384 385 chan->vc.desc_free = pt_do_cleanup; 386 vchan_init(&chan->vc, dma_dev); 387 388 ret = dma_async_device_register(dma_dev); 389 if (ret) 390 goto err_reg; 391 392 return 0; 393 394 err_reg: 395 kmem_cache_destroy(pt->dma_desc_cache); 396 397 err_cache: 398 kmem_cache_destroy(pt->dma_cmd_cache); 399 400 return ret; 401 } 402 403 void pt_dmaengine_unregister(struct pt_device *pt) 404 { 405 struct dma_device *dma_dev = &pt->dma_dev; 406 407 dma_async_device_unregister(dma_dev); 408 409 kmem_cache_destroy(pt->dma_desc_cache); 410 kmem_cache_destroy(pt->dma_cmd_cache); 411 } 412