drivers/dma/idxd/dma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
   3 #include <linux/init.h>
   4 #include <linux/kernel.h>
   5 #include <linux/module.h>
   6 #include <linux/pci.h>
   7 #include <linux/device.h>
   8 #include <linux/io-64-nonatomic-lo-hi.h>
   9 #include <linux/dmaengine.h>
  10 #include <uapi/linux/idxd.h>
  11 #include "../dmaengine.h"
  12 #include "registers.h"
  13 #include "idxd.h"
  14
  15 static inline struct idxd_wq *to_idxd_wq(struct dma_chan *c)
  16 {
  17         struct idxd_dma_chan *idxd_chan;
  18
  19         idxd_chan = container_of(c, struct idxd_dma_chan, chan);
  20         return idxd_chan->wq;
  21 }
  22
  23 void idxd_dma_complete_txd(struct idxd_desc *desc,
  24                            enum idxd_complete_type comp_type,
  25                            bool free_desc)
  26 {
  27         struct idxd_device *idxd = desc->wq->idxd;
  28         struct dma_async_tx_descriptor *tx;
  29         struct dmaengine_result res;
  30         int complete = 1;
  31
  32         if (desc->completion->status == DSA_COMP_SUCCESS) {
  33                 res.result = DMA_TRANS_NOERROR;
  34         } else if (desc->completion->status) {
  35                 if (idxd->request_int_handles && comp_type != IDXD_COMPLETE_ABORT &&
  36                     desc->completion->status == DSA_COMP_INT_HANDLE_INVAL &&
  37                     idxd_queue_int_handle_resubmit(desc))
  38                         return;
  39                 res.result = DMA_TRANS_WRITE_FAILED;
  40         } else if (comp_type == IDXD_COMPLETE_ABORT) {
  41                 res.result = DMA_TRANS_ABORTED;
  42         } else {
  43                 complete = 0;
  44         }
  45
  46         tx = &desc->txd;
  47         if (complete && tx->cookie) {
  48                 dma_cookie_complete(tx);
  49                 dma_descriptor_unmap(tx);
  50                 dmaengine_desc_get_callback_invoke(tx, &res);
  51                 tx->callback = NULL;
  52                 tx->callback_result = NULL;
  53         }
  54
  55         if (free_desc)
  56                 idxd_free_desc(desc->wq, desc);
  57 }
  58
  59 static void op_flag_setup(unsigned long flags, u32 *desc_flags)
  60 {
  61         *desc_flags = IDXD_OP_FLAG_CRAV | IDXD_OP_FLAG_RCR;
  62         if (flags & DMA_PREP_INTERRUPT)
  63                 *desc_flags |= IDXD_OP_FLAG_RCI;
  64 }
  65
  66 static inline void idxd_prep_desc_common(struct idxd_wq *wq,
  67                                          struct dsa_hw_desc *hw, char opcode,
  68                                          u64 addr_f1, u64 addr_f2, u64 len,
  69                                          u64 compl, u32 flags)
  70 {
  71         hw->flags = flags;
  72         hw->opcode = opcode;
  73         hw->src_addr = addr_f1;
  74         hw->dst_addr = addr_f2;
  75         hw->xfer_size = len;
  76         /*
  77          * For dedicated WQ, this field is ignored and HW will use the WQCFG.priv
  78          * field instead. This field should be set to 0 for kernel descriptors
  79          * since kernel DMA on VT-d supports "user" privilege only.
  80          */
  81         hw->priv = 0;
  82         hw->completion_addr = compl;
  83 }
  84
  85 static struct dma_async_tx_descriptor *
  86 idxd_dma_prep_interrupt(struct dma_chan *c, unsigned long flags)
  87 {
  88         struct idxd_wq *wq = to_idxd_wq(c);
  89         u32 desc_flags;
  90         struct idxd_desc *desc;
  91
  92         if (wq->state != IDXD_WQ_ENABLED)
  93                 return NULL;
  94
  95         op_flag_setup(flags, &desc_flags);
  96         desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
  97         if (IS_ERR(desc))
  98                 return NULL;
  99
 100         idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_NOOP,
 101                               0, 0, 0, desc->compl_dma, desc_flags);
 102         desc->txd.flags = flags;
 103         return &desc->txd;
 104 }
 105
 106 static struct dma_async_tx_descriptor *
 107 idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
 108                        dma_addr_t dma_src, size_t len, unsigned long flags)
 109 {
 110         struct idxd_wq *wq = to_idxd_wq(c);
 111         u32 desc_flags;
 112         struct idxd_device *idxd = wq->idxd;
 113         struct idxd_desc *desc;
 114
 115         if (wq->state != IDXD_WQ_ENABLED)
 116                 return NULL;
 117
 118         if (len > idxd->max_xfer_bytes)
 119                 return NULL;
 120
 121         op_flag_setup(flags, &desc_flags);
 122         desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
 123         if (IS_ERR(desc))
 124                 return NULL;
 125
 126         idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
 127                               dma_src, dma_dest, len, desc->compl_dma,
 128                               desc_flags);
 129
 130         desc->txd.flags = flags;
 131
 132         return &desc->txd;
 133 }
 134
 135 static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
 136 {
 137         struct idxd_wq *wq = to_idxd_wq(chan);
 138         struct device *dev = &wq->idxd->pdev->dev;
 139
 140         idxd_wq_get(wq);
 141         dev_dbg(dev, "%s: client_count: %d\n", __func__,
 142                 idxd_wq_refcount(wq));
 143         return 0;
 144 }
 145
 146 static void idxd_dma_free_chan_resources(struct dma_chan *chan)
 147 {
 148         struct idxd_wq *wq = to_idxd_wq(chan);
 149         struct device *dev = &wq->idxd->pdev->dev;
 150
 151         idxd_wq_put(wq);
 152         dev_dbg(dev, "%s: client_count: %d\n", __func__,
 153                 idxd_wq_refcount(wq));
 154 }
 155
 156 static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
 157                                           dma_cookie_t cookie,
 158                                           struct dma_tx_state *txstate)
 159 {
 160         return DMA_OUT_OF_ORDER;
 161 }
 162
 163 /*
 164  * issue_pending() does not need to do anything since tx_submit() does the job
 165  * already.
 166  */
 167 static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
 168 {
 169 }
 170
 171 static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 172 {
 173         struct dma_chan *c = tx->chan;
 174         struct idxd_wq *wq = to_idxd_wq(c);
 175         dma_cookie_t cookie;
 176         int rc;
 177         struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
 178
 179         cookie = dma_cookie_assign(tx);
 180
 181         rc = idxd_submit_desc(wq, desc);
 182         if (rc < 0) {
 183                 idxd_free_desc(wq, desc);
 184                 return rc;
 185         }
 186
 187         return cookie;
 188 }
 189
 190 static void idxd_dma_release(struct dma_device *device)
 191 {
 192         struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
 193
 194         kfree(idxd_dma);
 195 }
 196
 197 int idxd_register_dma_device(struct idxd_device *idxd)
 198 {
 199         struct idxd_dma_dev *idxd_dma;
 200         struct dma_device *dma;
 201         struct device *dev = &idxd->pdev->dev;
 202         int rc;
 203
 204         idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
 205         if (!idxd_dma)
 206                 return -ENOMEM;
 207
 208         dma = &idxd_dma->dma;
 209         INIT_LIST_HEAD(&dma->channels);
 210         dma->dev = dev;
 211
 212         dma_cap_set(DMA_INTERRUPT, dma->cap_mask);
 213         dma_cap_set(DMA_PRIVATE, dma->cap_mask);
 214         dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
 215         dma->device_release = idxd_dma_release;
 216
 217         dma->device_prep_dma_interrupt = idxd_dma_prep_interrupt;
 218         if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
 219                 dma_cap_set(DMA_MEMCPY, dma->cap_mask);
 220                 dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
 221         }
 222
 223         dma->device_tx_status = idxd_dma_tx_status;
 224         dma->device_issue_pending = idxd_dma_issue_pending;
 225         dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
 226         dma->device_free_chan_resources = idxd_dma_free_chan_resources;
 227
 228         rc = dma_async_device_register(dma);
 229         if (rc < 0) {
 230                 kfree(idxd_dma);
 231                 return rc;
 232         }
 233
 234         idxd_dma->idxd = idxd;
 235         /*
 236          * This pointer is protected by the refs taken by the dma_chan. It will remain valid
 237          * as long as there are outstanding channels.
 238          */
 239         idxd->idxd_dma = idxd_dma;
 240         return 0;
 241 }
 242
 243 void idxd_unregister_dma_device(struct idxd_device *idxd)
 244 {
 245         dma_async_device_unregister(&idxd->idxd_dma->dma);
 246 }
 247
 248 static int idxd_register_dma_channel(struct idxd_wq *wq)
 249 {
 250         struct idxd_device *idxd = wq->idxd;
 251         struct dma_device *dma = &idxd->idxd_dma->dma;
 252         struct device *dev = &idxd->pdev->dev;
 253         struct idxd_dma_chan *idxd_chan;
 254         struct dma_chan *chan;
 255         int rc, i;
 256
 257         idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
 258         if (!idxd_chan)
 259                 return -ENOMEM;
 260
 261         chan = &idxd_chan->chan;
 262         chan->device = dma;
 263         list_add_tail(&chan->device_node, &dma->channels);
 264
 265         for (i = 0; i < wq->num_descs; i++) {
 266                 struct idxd_desc *desc = wq->descs[i];
 267
 268                 dma_async_tx_descriptor_init(&desc->txd, chan);
 269                 desc->txd.tx_submit = idxd_dma_tx_submit;
 270         }
 271
 272         rc = dma_async_device_channel_register(dma, chan);
 273         if (rc < 0) {
 274                 kfree(idxd_chan);
 275                 return rc;
 276         }
 277
 278         wq->idxd_chan = idxd_chan;
 279         idxd_chan->wq = wq;
 280         get_device(wq_confdev(wq));
 281
 282         return 0;
 283 }
 284
 285 static void idxd_unregister_dma_channel(struct idxd_wq *wq)
 286 {
 287         struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
 288         struct dma_chan *chan = &idxd_chan->chan;
 289         struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
 290
 291         dma_async_device_channel_unregister(&idxd_dma->dma, chan);
 292         list_del(&chan->device_node);
 293         kfree(wq->idxd_chan);
 294         wq->idxd_chan = NULL;
 295         put_device(wq_confdev(wq));
 296 }
 297
 298 static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
 299 {
 300         struct device *dev = &idxd_dev->conf_dev;
 301         struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
 302         struct idxd_device *idxd = wq->idxd;
 303         int rc;
 304
 305         if (idxd->state != IDXD_DEV_ENABLED)
 306                 return -ENXIO;
 307
 308         mutex_lock(&wq->wq_lock);
 309         wq->type = IDXD_WQT_KERNEL;
 310
 311         rc = drv_enable_wq(wq);
 312         if (rc < 0) {
 313                 dev_dbg(dev, "Enable wq %d failed: %d\n", wq->id, rc);
 314                 rc = -ENXIO;
 315                 goto err;
 316         }
 317
 318         rc = idxd_register_dma_channel(wq);
 319         if (rc < 0) {
 320                 idxd->cmd_status = IDXD_SCMD_DMA_CHAN_ERR;
 321                 dev_dbg(dev, "Failed to register dma channel\n");
 322                 goto err_dma;
 323         }
 324
 325         idxd->cmd_status = 0;
 326         mutex_unlock(&wq->wq_lock);
 327         return 0;
 328
 329 err_dma:
 330         drv_disable_wq(wq);
 331 err:
 332         wq->type = IDXD_WQT_NONE;
 333         mutex_unlock(&wq->wq_lock);
 334         return rc;
 335 }
 336
 337 static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
 338 {
 339         struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
 340
 341         mutex_lock(&wq->wq_lock);
 342         __idxd_wq_quiesce(wq);
 343         idxd_unregister_dma_channel(wq);
 344         drv_disable_wq(wq);
 345         mutex_unlock(&wq->wq_lock);
 346 }
 347
 348 static enum idxd_dev_type dev_types[] = {
 349         IDXD_DEV_WQ,
 350         IDXD_DEV_NONE,
 351 };
 352
 353 struct idxd_device_driver idxd_dmaengine_drv = {
 354         .probe = idxd_dmaengine_drv_probe,
 355         .remove = idxd_dmaengine_drv_remove,
 356         .name = "dmaengine",
 357         .type = dev_types,
 358 };
 359 EXPORT_SYMBOL_GPL(idxd_dmaengine_drv);