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 struct device *cxl_get_phys_dev(struct pci_dev *dev)
  72 {
  73         struct cxl_afu *afu;
  74
  75         afu = cxl_pci_to_afu(dev);
  76
  77         return afu->adapter->dev.parent;
  78 }
  79
  80 int cxl_release_context(struct cxl_context *ctx)
  81 {
  82         if (ctx->status >= STARTED)
  83                 return -EBUSY;
  84
  85         cxl_context_free(ctx);
  86
  87         return 0;
  88 }
  89 EXPORT_SYMBOL_GPL(cxl_release_context);
  90
  91 static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
  92 {
  93         __u16 range;
  94         int r;
  95
  96         for (r = 0; r < CXL_IRQ_RANGES; r++) {
  97                 range = ctx->irqs.range[r];
  98                 if (num < range) {
  99                         return ctx->irqs.offset[r] + num;
 100                 }
 101                 num -= range;
 102         }
 103         return 0;
 104 }
 105
 106 int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
 107 {
 108         int res;
 109         irq_hw_number_t hwirq;
 110
 111         if (num == 0)
 112                 num = ctx->afu->pp_irqs;
 113         res = afu_allocate_irqs(ctx, num);
 114         if (!res && !cpu_has_feature(CPU_FTR_HVMODE)) {
 115                 /* In a guest, the PSL interrupt is not multiplexed. It was
 116                  * allocated above, and we need to set its handler
 117                  */
 118                 hwirq = cxl_find_afu_irq(ctx, 0);
 119                 if (hwirq)
 120                         cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl");
 121         }
 122         return res;
 123 }
 124 EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);
 125
 126 void cxl_free_afu_irqs(struct cxl_context *ctx)
 127 {
 128         irq_hw_number_t hwirq;
 129         unsigned int virq;
 130
 131         if (!cpu_has_feature(CPU_FTR_HVMODE)) {
 132                 hwirq = cxl_find_afu_irq(ctx, 0);
 133                 if (hwirq) {
 134                         virq = irq_find_mapping(NULL, hwirq);
 135                         if (virq)
 136                                 cxl_unmap_irq(virq, ctx);
 137                 }
 138         }
 139         afu_irq_name_free(ctx);
 140         cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
 141 }
 142 EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);
 143
 144 int cxl_map_afu_irq(struct cxl_context *ctx, int num,
 145                     irq_handler_t handler, void *cookie, char *name)
 146 {
 147         irq_hw_number_t hwirq;
 148
 149         /*
 150          * Find interrupt we are to register.
 151          */
 152         hwirq = cxl_find_afu_irq(ctx, num);
 153         if (!hwirq)
 154                 return -ENOENT;
 155
 156         return cxl_map_irq(ctx->afu->adapter, hwirq, handler, cookie, name);
 157 }
 158 EXPORT_SYMBOL_GPL(cxl_map_afu_irq);
 159
 160 void cxl_unmap_afu_irq(struct cxl_context *ctx, int num, void *cookie)
 161 {
 162         irq_hw_number_t hwirq;
 163         unsigned int virq;
 164
 165         hwirq = cxl_find_afu_irq(ctx, num);
 166         if (!hwirq)
 167                 return;
 168
 169         virq = irq_find_mapping(NULL, hwirq);
 170         if (virq)
 171                 cxl_unmap_irq(virq, cookie);
 172 }
 173 EXPORT_SYMBOL_GPL(cxl_unmap_afu_irq);
 174
 175 /*
 176  * Start a context
 177  * Code here similar to afu_ioctl_start_work().
 178  */
 179 int cxl_start_context(struct cxl_context *ctx, u64 wed,
 180                       struct task_struct *task)
 181 {
 182         int rc = 0;
 183         bool kernel = true;
 184
 185         pr_devel("%s: pe: %i\n", __func__, ctx->pe);
 186
 187         mutex_lock(&ctx->status_mutex);
 188         if (ctx->status == STARTED)
 189                 goto out; /* already started */
 190
 191         if (task) {
 192                 ctx->pid = get_task_pid(task, PIDTYPE_PID);
 193                 ctx->glpid = get_task_pid(task->group_leader, PIDTYPE_PID);
 194                 kernel = false;
 195         }
 196
 197         cxl_ctx_get();
 198
 199         if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
 200                 put_pid(ctx->pid);
 201                 cxl_ctx_put();
 202                 goto out;
 203         }
 204
 205         ctx->status = STARTED;
 206 out:
 207         mutex_unlock(&ctx->status_mutex);
 208         return rc;
 209 }
 210 EXPORT_SYMBOL_GPL(cxl_start_context);
 211
 212 int cxl_process_element(struct cxl_context *ctx)
 213 {
 214         return ctx->external_pe;
 215 }
 216 EXPORT_SYMBOL_GPL(cxl_process_element);
 217
 218 /* Stop a context.  Returns 0 on success, otherwise -Errno */
 219 int cxl_stop_context(struct cxl_context *ctx)
 220 {
 221         return __detach_context(ctx);
 222 }
 223 EXPORT_SYMBOL_GPL(cxl_stop_context);
 224
 225 void cxl_set_master(struct cxl_context *ctx)
 226 {
 227         ctx->master = true;
 228 }
 229 EXPORT_SYMBOL_GPL(cxl_set_master);
 230
 231 /* wrappers around afu_* file ops which are EXPORTED */
 232 int cxl_fd_open(struct inode *inode, struct file *file)
 233 {
 234         return afu_open(inode, file);
 235 }
 236 EXPORT_SYMBOL_GPL(cxl_fd_open);
 237 int cxl_fd_release(struct inode *inode, struct file *file)
 238 {
 239         return afu_release(inode, file);
 240 }
 241 EXPORT_SYMBOL_GPL(cxl_fd_release);
 242 long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 243 {
 244         return afu_ioctl(file, cmd, arg);
 245 }
 246 EXPORT_SYMBOL_GPL(cxl_fd_ioctl);
 247 int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm)
 248 {
 249         return afu_mmap(file, vm);
 250 }
 251 EXPORT_SYMBOL_GPL(cxl_fd_mmap);
 252 unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll)
 253 {
 254         return afu_poll(file, poll);
 255 }
 256 EXPORT_SYMBOL_GPL(cxl_fd_poll);
 257 ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
 258                         loff_t *off)
 259 {
 260         return afu_read(file, buf, count, off);
 261 }
 262 EXPORT_SYMBOL_GPL(cxl_fd_read);
 263
 264 #define PATCH_FOPS(NAME) if (!fops->NAME) fops->NAME = afu_fops.NAME
 265
 266 /* Get a struct file and fd for a context and attach the ops */
 267 struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
 268                         int *fd)
 269 {
 270         struct file *file;
 271         int rc, flags, fdtmp;
 272
 273         flags = O_RDWR | O_CLOEXEC;
 274
 275         /* This code is similar to anon_inode_getfd() */
 276         rc = get_unused_fd_flags(flags);
 277         if (rc < 0)
 278                 return ERR_PTR(rc);
 279         fdtmp = rc;
 280
 281         /*
 282          * Patch the file ops.  Needs to be careful that this is rentrant safe.
 283          */
 284         if (fops) {
 285                 PATCH_FOPS(open);
 286                 PATCH_FOPS(poll);
 287                 PATCH_FOPS(read);
 288                 PATCH_FOPS(release);
 289                 PATCH_FOPS(unlocked_ioctl);
 290                 PATCH_FOPS(compat_ioctl);
 291                 PATCH_FOPS(mmap);
 292         } else /* use default ops */
 293                 fops = (struct file_operations *)&afu_fops;
 294
 295         file = anon_inode_getfile("cxl", fops, ctx, flags);
 296         if (IS_ERR(file))
 297                 goto err_fd;
 298
 299         file->f_mapping = ctx->mapping;
 300
 301         *fd = fdtmp;
 302         return file;
 303
 304 err_fd:
 305         put_unused_fd(fdtmp);
 306         return NULL;
 307 }
 308 EXPORT_SYMBOL_GPL(cxl_get_fd);
 309
 310 struct cxl_context *cxl_fops_get_context(struct file *file)
 311 {
 312         return file->private_data;
 313 }
 314 EXPORT_SYMBOL_GPL(cxl_fops_get_context);
 315
 316 int cxl_start_work(struct cxl_context *ctx,
 317                    struct cxl_ioctl_start_work *work)
 318 {
 319         int rc;
 320
 321         /* code taken from afu_ioctl_start_work */
 322         if (!(work->flags & CXL_START_WORK_NUM_IRQS))
 323                 work->num_interrupts = ctx->afu->pp_irqs;
 324         else if ((work->num_interrupts < ctx->afu->pp_irqs) ||
 325                  (work->num_interrupts > ctx->afu->irqs_max)) {
 326                 return -EINVAL;
 327         }
 328
 329         rc = afu_register_irqs(ctx, work->num_interrupts);
 330         if (rc)
 331                 return rc;
 332
 333         rc = cxl_start_context(ctx, work->work_element_descriptor, current);
 334         if (rc < 0) {
 335                 afu_release_irqs(ctx, ctx);
 336                 return rc;
 337         }
 338
 339         return 0;
 340 }
 341 EXPORT_SYMBOL_GPL(cxl_start_work);
 342
 343 void __iomem *cxl_psa_map(struct cxl_context *ctx)
 344 {
 345         if (ctx->status != STARTED)
 346                 return NULL;
 347
 348         pr_devel("%s: psn_phys%llx size:%llx\n",
 349                 __func__, ctx->psn_phys, ctx->psn_size);
 350         return ioremap(ctx->psn_phys, ctx->psn_size);
 351 }
 352 EXPORT_SYMBOL_GPL(cxl_psa_map);
 353
 354 void cxl_psa_unmap(void __iomem *addr)
 355 {
 356         iounmap(addr);
 357 }
 358 EXPORT_SYMBOL_GPL(cxl_psa_unmap);
 359
 360 int cxl_afu_reset(struct cxl_context *ctx)
 361 {
 362         struct cxl_afu *afu = ctx->afu;
 363         int rc;
 364
 365         rc = cxl_ops->afu_reset(afu);
 366         if (rc)
 367                 return rc;
 368
 369         return cxl_ops->afu_check_and_enable(afu);
 370 }
 371 EXPORT_SYMBOL_GPL(cxl_afu_reset);
 372
 373 void cxl_perst_reloads_same_image(struct cxl_afu *afu,
 374                                   bool perst_reloads_same_image)
 375 {
 376         afu->adapter->perst_same_image = perst_reloads_same_image;
 377 }
 378 EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);
 379
 380 ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count)
 381 {
 382         struct cxl_afu *afu = cxl_pci_to_afu(dev);
 383
 384         return cxl_ops->read_adapter_vpd(afu->adapter, buf, count);
 385 }
 386 EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);