drivers/misc/cxl/api.c

   1 /*
   2  * Copyright 2014 IBM Corp.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9
  10 #include <linux/pci.h>
  11 #include <linux/slab.h>
  12 #include <linux/anon_inodes.h>
  13 #include <linux/file.h>
  14 #include <misc/cxl.h>
  15 #include <linux/fs.h>
  16
  17 #include "cxl.h"
  18
  19 struct cxl_context *cxl_dev_context_init(struct pci_dev *dev)
  20 {
  21         struct address_space *mapping;
  22         struct cxl_afu *afu;
  23         struct cxl_context  *ctx;
  24         int rc;
  25
  26         afu = cxl_pci_to_afu(dev);
  27
  28         ctx = cxl_context_alloc();
  29         if (IS_ERR(ctx)) {
  30                 rc = PTR_ERR(ctx);
  31                 goto err_dev;
  32         }
  33
  34         ctx->kernelapi = true;
  35
  36         /*
  37          * Make our own address space since we won't have one from the
  38          * filesystem like the user api has, and even if we do associate a file
  39          * with this context we don't want to use the global anonymous inode's
  40          * address space as that can invalidate unrelated users:
  41          */
  42         mapping = kmalloc(sizeof(struct address_space), GFP_KERNEL);
  43         if (!mapping) {
  44                 rc = -ENOMEM;
  45                 goto err_ctx;
  46         }
  47         address_space_init_once(mapping);
  48
  49         /* Make it a slave context.  We can promote it later? */
  50         rc = cxl_context_init(ctx, afu, false, mapping);
  51         if (rc)
  52                 goto err_mapping;
  53
  54         return ctx;
  55
  56 err_mapping:
  57         kfree(mapping);
  58 err_ctx:
  59         kfree(ctx);
  60 err_dev:
  61         return ERR_PTR(rc);
  62 }
  63 EXPORT_SYMBOL_GPL(cxl_dev_context_init);
  64
  65 struct cxl_context *cxl_get_context(struct pci_dev *dev)
  66 {
  67         return dev->dev.archdata.cxl_ctx;
  68 }
  69 EXPORT_SYMBOL_GPL(cxl_get_context);
  70
  71 int cxl_release_context(struct cxl_context *ctx)
  72 {
  73         if (ctx->status >= STARTED)
  74                 return -EBUSY;
  75
  76         cxl_context_free(ctx);
  77
  78         return 0;
  79 }
  80 EXPORT_SYMBOL_GPL(cxl_release_context);
  81
  82 static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
  83 {
  84         __u16 range;
  85         int r;
  86
  87         for (r = 0; r < CXL_IRQ_RANGES; r++) {
  88                 range = ctx->irqs.range[r];
  89                 if (num < range) {
  90                         return ctx->irqs.offset[r] + num;
  91                 }
  92                 num -= range;
  93         }
  94         return 0;
  95 }
  96
  97
  98 int cxl_set_priv(struct cxl_context *ctx, void *priv)
  99 {
 100         if (!ctx)
 101                 return -EINVAL;
 102
 103         ctx->priv = priv;
 104
 105         return 0;
 106 }
 107 EXPORT_SYMBOL_GPL(cxl_set_priv);
 108
 109 void *cxl_get_priv(struct cxl_context *ctx)
 110 {
 111         if (!ctx)
 112                 return ERR_PTR(-EINVAL);
 113
 114         return ctx->priv;
 115 }
 116 EXPORT_SYMBOL_GPL(cxl_get_priv);
 117
 118 int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
 119 {
 120         int res;
 121         irq_hw_number_t hwirq;
 122
 123         if (num == 0)
 124                 num = ctx->afu->pp_irqs;
 125         res = afu_allocate_irqs(ctx, num);
 126         if (res)
 127                 return res;
 128
 129         if (!cpu_has_feature(CPU_FTR_HVMODE)) {
 130                 /* In a guest, the PSL interrupt is not multiplexed. It was
 131                  * allocated above, and we need to set its handler
 132                  */
 133                 hwirq = cxl_find_afu_irq(ctx, 0);
 134                 if (hwirq)
 135                         cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl");
 136         }
 137
 138         if (ctx->status == STARTED) {
 139                 if (cxl_ops->update_ivtes)
 140                         cxl_ops->update_ivtes(ctx);
 141                 else WARN(1, "BUG: cxl_allocate_afu_irqs must be called prior to starting the context on this platform\n");
 142         }
 143
 144         return res;
 145 }
 146 EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);
 147
 148 void cxl_free_afu_irqs(struct cxl_context *ctx)
 149 {
 150         irq_hw_number_t hwirq;
 151         unsigned int virq;
 152
 153         if (!cpu_has_feature(CPU_FTR_HVMODE)) {
 154                 hwirq = cxl_find_afu_irq(ctx, 0);
 155                 if (hwirq) {
 156                         virq = irq_find_mapping(NULL, hwirq);
 157                         if (virq)
 158                                 cxl_unmap_irq(virq, ctx);
 159                 }
 160         }
 161         afu_irq_name_free(ctx);
 162         cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
 163 }
 164 EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);
 165
 166 int cxl_map_afu_irq(struct cxl_context *ctx, int num,
 167                     irq_handler_t handler, void *cookie, char *name)
 168 {
 169         irq_hw_number_t hwirq;
 170
 171         /*
 172          * Find interrupt we are to register.
 173          */
 174         hwirq = cxl_find_afu_irq(ctx, num);
 175         if (!hwirq)
 176                 return -ENOENT;
 177
 178         return cxl_map_irq(ctx->afu->adapter, hwirq, handler, cookie, name);
 179 }
 180 EXPORT_SYMBOL_GPL(cxl_map_afu_irq);
 181
 182 void cxl_unmap_afu_irq(struct cxl_context *ctx, int num, void *cookie)
 183 {
 184         irq_hw_number_t hwirq;
 185         unsigned int virq;
 186
 187         hwirq = cxl_find_afu_irq(ctx, num);
 188         if (!hwirq)
 189                 return;
 190
 191         virq = irq_find_mapping(NULL, hwirq);
 192         if (virq)
 193                 cxl_unmap_irq(virq, cookie);
 194 }
 195 EXPORT_SYMBOL_GPL(cxl_unmap_afu_irq);
 196
 197 /*
 198  * Start a context
 199  * Code here similar to afu_ioctl_start_work().
 200  */
 201 int cxl_start_context(struct cxl_context *ctx, u64 wed,
 202                       struct task_struct *task)
 203 {
 204         int rc = 0;
 205         bool kernel = true;
 206
 207         pr_devel("%s: pe: %i\n", __func__, ctx->pe);
 208
 209         mutex_lock(&ctx->status_mutex);
 210         if (ctx->status == STARTED)
 211                 goto out; /* already started */
 212
 213         if (task) {
 214                 ctx->pid = get_task_pid(task, PIDTYPE_PID);
 215                 ctx->glpid = get_task_pid(task->group_leader, PIDTYPE_PID);
 216                 kernel = false;
 217                 ctx->real_mode = false;
 218         }
 219
 220         cxl_ctx_get();
 221
 222         if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
 223                 put_pid(ctx->pid);
 224                 cxl_ctx_put();
 225                 goto out;
 226         }
 227
 228         ctx->status = STARTED;
 229 out:
 230         mutex_unlock(&ctx->status_mutex);
 231         return rc;
 232 }
 233 EXPORT_SYMBOL_GPL(cxl_start_context);
 234
 235 int cxl_process_element(struct cxl_context *ctx)
 236 {
 237         return ctx->external_pe;
 238 }
 239 EXPORT_SYMBOL_GPL(cxl_process_element);
 240
 241 /* Stop a context.  Returns 0 on success, otherwise -Errno */
 242 int cxl_stop_context(struct cxl_context *ctx)
 243 {
 244         return __detach_context(ctx);
 245 }
 246 EXPORT_SYMBOL_GPL(cxl_stop_context);
 247
 248 void cxl_set_master(struct cxl_context *ctx)
 249 {
 250         ctx->master = true;
 251 }
 252 EXPORT_SYMBOL_GPL(cxl_set_master);
 253
 254 int cxl_set_translation_mode(struct cxl_context *ctx, bool real_mode)
 255 {
 256         if (ctx->status == STARTED) {
 257                 /*
 258                  * We could potentially update the PE and issue an update LLCMD
 259                  * to support this, but it doesn't seem to have a good use case
 260                  * since it's trivial to just create a second kernel context
 261                  * with different translation modes, so until someone convinces
 262                  * me otherwise:
 263                  */
 264                 return -EBUSY;
 265         }
 266
 267         ctx->real_mode = real_mode;
 268         return 0;
 269 }
 270 EXPORT_SYMBOL_GPL(cxl_set_translation_mode);
 271
 272 /* wrappers around afu_* file ops which are EXPORTED */
 273 int cxl_fd_open(struct inode *inode, struct file *file)
 274 {
 275         return afu_open(inode, file);
 276 }
 277 EXPORT_SYMBOL_GPL(cxl_fd_open);
 278 int cxl_fd_release(struct inode *inode, struct file *file)
 279 {
 280         return afu_release(inode, file);
 281 }
 282 EXPORT_SYMBOL_GPL(cxl_fd_release);
 283 long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 284 {
 285         return afu_ioctl(file, cmd, arg);
 286 }
 287 EXPORT_SYMBOL_GPL(cxl_fd_ioctl);
 288 int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm)
 289 {
 290         return afu_mmap(file, vm);
 291 }
 292 EXPORT_SYMBOL_GPL(cxl_fd_mmap);
 293 unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll)
 294 {
 295         return afu_poll(file, poll);
 296 }
 297 EXPORT_SYMBOL_GPL(cxl_fd_poll);
 298 ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
 299                         loff_t *off)
 300 {
 301         return afu_read(file, buf, count, off);
 302 }
 303 EXPORT_SYMBOL_GPL(cxl_fd_read);
 304
 305 #define PATCH_FOPS(NAME) if (!fops->NAME) fops->NAME = afu_fops.NAME
 306
 307 /* Get a struct file and fd for a context and attach the ops */
 308 struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
 309                         int *fd)
 310 {
 311         struct file *file;
 312         int rc, flags, fdtmp;
 313
 314         flags = O_RDWR | O_CLOEXEC;
 315
 316         /* This code is similar to anon_inode_getfd() */
 317         rc = get_unused_fd_flags(flags);
 318         if (rc < 0)
 319                 return ERR_PTR(rc);
 320         fdtmp = rc;
 321
 322         /*
 323          * Patch the file ops.  Needs to be careful that this is rentrant safe.
 324          */
 325         if (fops) {
 326                 PATCH_FOPS(open);
 327                 PATCH_FOPS(poll);
 328                 PATCH_FOPS(read);
 329                 PATCH_FOPS(release);
 330                 PATCH_FOPS(unlocked_ioctl);
 331                 PATCH_FOPS(compat_ioctl);
 332                 PATCH_FOPS(mmap);
 333         } else /* use default ops */
 334                 fops = (struct file_operations *)&afu_fops;
 335
 336         file = anon_inode_getfile("cxl", fops, ctx, flags);
 337         if (IS_ERR(file))
 338                 goto err_fd;
 339
 340         file->f_mapping = ctx->mapping;
 341
 342         *fd = fdtmp;
 343         return file;
 344
 345 err_fd:
 346         put_unused_fd(fdtmp);
 347         return NULL;
 348 }
 349 EXPORT_SYMBOL_GPL(cxl_get_fd);
 350
 351 struct cxl_context *cxl_fops_get_context(struct file *file)
 352 {
 353         return file->private_data;
 354 }
 355 EXPORT_SYMBOL_GPL(cxl_fops_get_context);
 356
 357 void cxl_set_driver_ops(struct cxl_context *ctx,
 358                         struct cxl_afu_driver_ops *ops)
 359 {
 360         WARN_ON(!ops->fetch_event || !ops->event_delivered);
 361         atomic_set(&ctx->afu_driver_events, 0);
 362         ctx->afu_driver_ops = ops;
 363 }
 364 EXPORT_SYMBOL_GPL(cxl_set_driver_ops);
 365
 366 void cxl_context_events_pending(struct cxl_context *ctx,
 367                                 unsigned int new_events)
 368 {
 369         atomic_add(new_events, &ctx->afu_driver_events);
 370         wake_up_all(&ctx->wq);
 371 }
 372 EXPORT_SYMBOL_GPL(cxl_context_events_pending);
 373
 374 int cxl_start_work(struct cxl_context *ctx,
 375                    struct cxl_ioctl_start_work *work)
 376 {
 377         int rc;
 378
 379         /* code taken from afu_ioctl_start_work */
 380         if (!(work->flags & CXL_START_WORK_NUM_IRQS))
 381                 work->num_interrupts = ctx->afu->pp_irqs;
 382         else if ((work->num_interrupts < ctx->afu->pp_irqs) ||
 383                  (work->num_interrupts > ctx->afu->irqs_max)) {
 384                 return -EINVAL;
 385         }
 386
 387         rc = afu_register_irqs(ctx, work->num_interrupts);
 388         if (rc)
 389                 return rc;
 390
 391         rc = cxl_start_context(ctx, work->work_element_descriptor, current);
 392         if (rc < 0) {
 393                 afu_release_irqs(ctx, ctx);
 394                 return rc;
 395         }
 396
 397         return 0;
 398 }
 399 EXPORT_SYMBOL_GPL(cxl_start_work);
 400
 401 void __iomem *cxl_psa_map(struct cxl_context *ctx)
 402 {
 403         if (ctx->status != STARTED)
 404                 return NULL;
 405
 406         pr_devel("%s: psn_phys%llx size:%llx\n",
 407                 __func__, ctx->psn_phys, ctx->psn_size);
 408         return ioremap(ctx->psn_phys, ctx->psn_size);
 409 }
 410 EXPORT_SYMBOL_GPL(cxl_psa_map);
 411
 412 void cxl_psa_unmap(void __iomem *addr)
 413 {
 414         iounmap(addr);
 415 }
 416 EXPORT_SYMBOL_GPL(cxl_psa_unmap);
 417
 418 int cxl_afu_reset(struct cxl_context *ctx)
 419 {
 420         struct cxl_afu *afu = ctx->afu;
 421         int rc;
 422
 423         rc = cxl_ops->afu_reset(afu);
 424         if (rc)
 425                 return rc;
 426
 427         return cxl_ops->afu_check_and_enable(afu);
 428 }
 429 EXPORT_SYMBOL_GPL(cxl_afu_reset);
 430
 431 void cxl_perst_reloads_same_image(struct cxl_afu *afu,
 432                                   bool perst_reloads_same_image)
 433 {
 434         afu->adapter->perst_same_image = perst_reloads_same_image;
 435 }
 436 EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);
 437
 438 ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count)
 439 {
 440         struct cxl_afu *afu = cxl_pci_to_afu(dev);
 441
 442         return cxl_ops->read_adapter_vpd(afu->adapter, buf, count);
 443 }
 444 EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);