linux/drivers/remoteproc/remoteproc_core.c
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   1/*
   2 * Remote Processor Framework
   3 *
   4 * Copyright (C) 2011 Texas Instruments, Inc.
   5 * Copyright (C) 2011 Google, Inc.
   6 *
   7 * Ohad Ben-Cohen <ohad@wizery.com>
   8 * Brian Swetland <swetland@google.com>
   9 * Mark Grosen <mgrosen@ti.com>
  10 * Fernando Guzman Lugo <fernando.lugo@ti.com>
  11 * Suman Anna <s-anna@ti.com>
  12 * Robert Tivy <rtivy@ti.com>
  13 * Armando Uribe De Leon <x0095078@ti.com>
  14 *
  15 * This program is free software; you can redistribute it and/or
  16 * modify it under the terms of the GNU General Public License
  17 * version 2 as published by the Free Software Foundation.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 */
  24
  25#define pr_fmt(fmt)    "%s: " fmt, __func__
  26
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29#include <linux/device.h>
  30#include <linux/slab.h>
  31#include <linux/mutex.h>
  32#include <linux/dma-mapping.h>
  33#include <linux/firmware.h>
  34#include <linux/string.h>
  35#include <linux/debugfs.h>
  36#include <linux/remoteproc.h>
  37#include <linux/iommu.h>
  38#include <linux/idr.h>
  39#include <linux/elf.h>
  40#include <linux/virtio_ids.h>
  41#include <linux/virtio_ring.h>
  42#include <asm/byteorder.h>
  43
  44#include "remoteproc_internal.h"
  45
  46typedef int (*rproc_handle_resources_t)(struct rproc *rproc,
  47                                struct resource_table *table, int len);
  48typedef int (*rproc_handle_resource_t)(struct rproc *rproc, void *, int avail);
  49
  50/* Unique indices for remoteproc devices */
  51static DEFINE_IDA(rproc_dev_index);
  52
  53static const char * const rproc_crash_names[] = {
  54        [RPROC_MMUFAULT]        = "mmufault",
  55};
  56
  57/* translate rproc_crash_type to string */
  58static const char *rproc_crash_to_string(enum rproc_crash_type type)
  59{
  60        if (type < ARRAY_SIZE(rproc_crash_names))
  61                return rproc_crash_names[type];
  62        return "unkown";
  63}
  64
  65/*
  66 * This is the IOMMU fault handler we register with the IOMMU API
  67 * (when relevant; not all remote processors access memory through
  68 * an IOMMU).
  69 *
  70 * IOMMU core will invoke this handler whenever the remote processor
  71 * will try to access an unmapped device address.
  72 */
  73static int rproc_iommu_fault(struct iommu_domain *domain, struct device *dev,
  74                unsigned long iova, int flags, void *token)
  75{
  76        struct rproc *rproc = token;
  77
  78        dev_err(dev, "iommu fault: da 0x%lx flags 0x%x\n", iova, flags);
  79
  80        rproc_report_crash(rproc, RPROC_MMUFAULT);
  81
  82        /*
  83         * Let the iommu core know we're not really handling this fault;
  84         * we just used it as a recovery trigger.
  85         */
  86        return -ENOSYS;
  87}
  88
  89static int rproc_enable_iommu(struct rproc *rproc)
  90{
  91        struct iommu_domain *domain;
  92        struct device *dev = rproc->dev.parent;
  93        int ret;
  94
  95        /*
  96         * We currently use iommu_present() to decide if an IOMMU
  97         * setup is needed.
  98         *
  99         * This works for simple cases, but will easily fail with
 100         * platforms that do have an IOMMU, but not for this specific
 101         * rproc.
 102         *
 103         * This will be easily solved by introducing hw capabilities
 104         * that will be set by the remoteproc driver.
 105         */
 106        if (!iommu_present(dev->bus)) {
 107                dev_dbg(dev, "iommu not found\n");
 108                return 0;
 109        }
 110
 111        domain = iommu_domain_alloc(dev->bus);
 112        if (!domain) {
 113                dev_err(dev, "can't alloc iommu domain\n");
 114                return -ENOMEM;
 115        }
 116
 117        iommu_set_fault_handler(domain, rproc_iommu_fault, rproc);
 118
 119        ret = iommu_attach_device(domain, dev);
 120        if (ret) {
 121                dev_err(dev, "can't attach iommu device: %d\n", ret);
 122                goto free_domain;
 123        }
 124
 125        rproc->domain = domain;
 126
 127        return 0;
 128
 129free_domain:
 130        iommu_domain_free(domain);
 131        return ret;
 132}
 133
 134static void rproc_disable_iommu(struct rproc *rproc)
 135{
 136        struct iommu_domain *domain = rproc->domain;
 137        struct device *dev = rproc->dev.parent;
 138
 139        if (!domain)
 140                return;
 141
 142        iommu_detach_device(domain, dev);
 143        iommu_domain_free(domain);
 144
 145        return;
 146}
 147
 148/*
 149 * Some remote processors will ask us to allocate them physically contiguous
 150 * memory regions (which we call "carveouts"), and map them to specific
 151 * device addresses (which are hardcoded in the firmware).
 152 *
 153 * They may then ask us to copy objects into specific device addresses (e.g.
 154 * code/data sections) or expose us certain symbols in other device address
 155 * (e.g. their trace buffer).
 156 *
 157 * This function is an internal helper with which we can go over the allocated
 158 * carveouts and translate specific device address to kernel virtual addresses
 159 * so we can access the referenced memory.
 160 *
 161 * Note: phys_to_virt(iommu_iova_to_phys(rproc->domain, da)) will work too,
 162 * but only on kernel direct mapped RAM memory. Instead, we're just using
 163 * here the output of the DMA API, which should be more correct.
 164 */
 165void *rproc_da_to_va(struct rproc *rproc, u64 da, int len)
 166{
 167        struct rproc_mem_entry *carveout;
 168        void *ptr = NULL;
 169
 170        list_for_each_entry(carveout, &rproc->carveouts, node) {
 171                int offset = da - carveout->da;
 172
 173                /* try next carveout if da is too small */
 174                if (offset < 0)
 175                        continue;
 176
 177                /* try next carveout if da is too large */
 178                if (offset + len > carveout->len)
 179                        continue;
 180
 181                ptr = carveout->va + offset;
 182
 183                break;
 184        }
 185
 186        return ptr;
 187}
 188EXPORT_SYMBOL(rproc_da_to_va);
 189
 190int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
 191{
 192        struct rproc *rproc = rvdev->rproc;
 193        struct device *dev = &rproc->dev;
 194        struct rproc_vring *rvring = &rvdev->vring[i];
 195        dma_addr_t dma;
 196        void *va;
 197        int ret, size, notifyid;
 198
 199        /* actual size of vring (in bytes) */
 200        size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
 201
 202        /*
 203         * Allocate non-cacheable memory for the vring. In the future
 204         * this call will also configure the IOMMU for us
 205         * TODO: let the rproc know the da of this vring
 206         */
 207        va = dma_alloc_coherent(dev->parent, size, &dma, GFP_KERNEL);
 208        if (!va) {
 209                dev_err(dev->parent, "dma_alloc_coherent failed\n");
 210                return -EINVAL;
 211        }
 212
 213        /*
 214         * Assign an rproc-wide unique index for this vring
 215         * TODO: assign a notifyid for rvdev updates as well
 216         * TODO: let the rproc know the notifyid of this vring
 217         * TODO: support predefined notifyids (via resource table)
 218         */
 219        ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
 220        if (ret < 0) {
 221                dev_err(dev, "idr_alloc failed: %d\n", ret);
 222                dma_free_coherent(dev->parent, size, va, dma);
 223                return ret;
 224        }
 225        notifyid = ret;
 226
 227        /* Store largest notifyid */
 228        rproc->max_notifyid = max(rproc->max_notifyid, notifyid);
 229
 230        dev_dbg(dev, "vring%d: va %p dma %llx size %x idr %d\n", i, va,
 231                                (unsigned long long)dma, size, notifyid);
 232
 233        rvring->va = va;
 234        rvring->dma = dma;
 235        rvring->notifyid = notifyid;
 236
 237        return 0;
 238}
 239
 240static int
 241rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
 242{
 243        struct rproc *rproc = rvdev->rproc;
 244        struct device *dev = &rproc->dev;
 245        struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
 246        struct rproc_vring *rvring = &rvdev->vring[i];
 247
 248        dev_dbg(dev, "vdev rsc: vring%d: da %x, qsz %d, align %d\n",
 249                                i, vring->da, vring->num, vring->align);
 250
 251        /* make sure reserved bytes are zeroes */
 252        if (vring->reserved) {
 253                dev_err(dev, "vring rsc has non zero reserved bytes\n");
 254                return -EINVAL;
 255        }
 256
 257        /* verify queue size and vring alignment are sane */
 258        if (!vring->num || !vring->align) {
 259                dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
 260                                                vring->num, vring->align);
 261                return -EINVAL;
 262        }
 263
 264        rvring->len = vring->num;
 265        rvring->align = vring->align;
 266        rvring->rvdev = rvdev;
 267
 268        return 0;
 269}
 270
 271static int rproc_max_notifyid(int id, void *p, void *data)
 272{
 273        int *maxid = data;
 274        *maxid = max(*maxid, id);
 275        return 0;
 276}
 277
 278void rproc_free_vring(struct rproc_vring *rvring)
 279{
 280        int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
 281        struct rproc *rproc = rvring->rvdev->rproc;
 282        int maxid = 0;
 283
 284        dma_free_coherent(rproc->dev.parent, size, rvring->va, rvring->dma);
 285        idr_remove(&rproc->notifyids, rvring->notifyid);
 286
 287        /* Find the largest remaining notifyid */
 288        idr_for_each(&rproc->notifyids, rproc_max_notifyid, &maxid);
 289        rproc->max_notifyid = maxid;
 290}
 291
 292/**
 293 * rproc_handle_vdev() - handle a vdev fw resource
 294 * @rproc: the remote processor
 295 * @rsc: the vring resource descriptor
 296 * @avail: size of available data (for sanity checking the image)
 297 *
 298 * This resource entry requests the host to statically register a virtio
 299 * device (vdev), and setup everything needed to support it. It contains
 300 * everything needed to make it possible: the virtio device id, virtio
 301 * device features, vrings information, virtio config space, etc...
 302 *
 303 * Before registering the vdev, the vrings are allocated from non-cacheable
 304 * physically contiguous memory. Currently we only support two vrings per
 305 * remote processor (temporary limitation). We might also want to consider
 306 * doing the vring allocation only later when ->find_vqs() is invoked, and
 307 * then release them upon ->del_vqs().
 308 *
 309 * Note: @da is currently not really handled correctly: we dynamically
 310 * allocate it using the DMA API, ignoring requested hard coded addresses,
 311 * and we don't take care of any required IOMMU programming. This is all
 312 * going to be taken care of when the generic iommu-based DMA API will be
 313 * merged. Meanwhile, statically-addressed iommu-based firmware images should
 314 * use RSC_DEVMEM resource entries to map their required @da to the physical
 315 * address of their base CMA region (ouch, hacky!).
 316 *
 317 * Returns 0 on success, or an appropriate error code otherwise
 318 */
 319static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
 320                                                                int avail)
 321{
 322        struct device *dev = &rproc->dev;
 323        struct rproc_vdev *rvdev;
 324        int i, ret;
 325
 326        /* make sure resource isn't truncated */
 327        if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
 328                        + rsc->config_len > avail) {
 329                dev_err(dev, "vdev rsc is truncated\n");
 330                return -EINVAL;
 331        }
 332
 333        /* make sure reserved bytes are zeroes */
 334        if (rsc->reserved[0] || rsc->reserved[1]) {
 335                dev_err(dev, "vdev rsc has non zero reserved bytes\n");
 336                return -EINVAL;
 337        }
 338
 339        dev_dbg(dev, "vdev rsc: id %d, dfeatures %x, cfg len %d, %d vrings\n",
 340                rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);
 341
 342        /* we currently support only two vrings per rvdev */
 343        if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
 344                dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
 345                return -EINVAL;
 346        }
 347
 348        rvdev = kzalloc(sizeof(struct rproc_vdev), GFP_KERNEL);
 349        if (!rvdev)
 350                return -ENOMEM;
 351
 352        rvdev->rproc = rproc;
 353
 354        /* parse the vrings */
 355        for (i = 0; i < rsc->num_of_vrings; i++) {
 356                ret = rproc_parse_vring(rvdev, rsc, i);
 357                if (ret)
 358                        goto free_rvdev;
 359        }
 360
 361        /* remember the device features */
 362        rvdev->dfeatures = rsc->dfeatures;
 363
 364        list_add_tail(&rvdev->node, &rproc->rvdevs);
 365
 366        /* it is now safe to add the virtio device */
 367        ret = rproc_add_virtio_dev(rvdev, rsc->id);
 368        if (ret)
 369                goto remove_rvdev;
 370
 371        return 0;
 372
 373remove_rvdev:
 374        list_del(&rvdev->node);
 375free_rvdev:
 376        kfree(rvdev);
 377        return ret;
 378}
 379
 380/**
 381 * rproc_handle_trace() - handle a shared trace buffer resource
 382 * @rproc: the remote processor
 383 * @rsc: the trace resource descriptor
 384 * @avail: size of available data (for sanity checking the image)
 385 *
 386 * In case the remote processor dumps trace logs into memory,
 387 * export it via debugfs.
 388 *
 389 * Currently, the 'da' member of @rsc should contain the device address
 390 * where the remote processor is dumping the traces. Later we could also
 391 * support dynamically allocating this address using the generic
 392 * DMA API (but currently there isn't a use case for that).
 393 *
 394 * Returns 0 on success, or an appropriate error code otherwise
 395 */
 396static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
 397                                                                int avail)
 398{
 399        struct rproc_mem_entry *trace;
 400        struct device *dev = &rproc->dev;
 401        void *ptr;
 402        char name[15];
 403
 404        if (sizeof(*rsc) > avail) {
 405                dev_err(dev, "trace rsc is truncated\n");
 406                return -EINVAL;
 407        }
 408
 409        /* make sure reserved bytes are zeroes */
 410        if (rsc->reserved) {
 411                dev_err(dev, "trace rsc has non zero reserved bytes\n");
 412                return -EINVAL;
 413        }
 414
 415        /* what's the kernel address of this resource ? */
 416        ptr = rproc_da_to_va(rproc, rsc->da, rsc->len);
 417        if (!ptr) {
 418                dev_err(dev, "erroneous trace resource entry\n");
 419                return -EINVAL;
 420        }
 421
 422        trace = kzalloc(sizeof(*trace), GFP_KERNEL);
 423        if (!trace) {
 424                dev_err(dev, "kzalloc trace failed\n");
 425                return -ENOMEM;
 426        }
 427
 428        /* set the trace buffer dma properties */
 429        trace->len = rsc->len;
 430        trace->va = ptr;
 431
 432        /* make sure snprintf always null terminates, even if truncating */
 433        snprintf(name, sizeof(name), "trace%d", rproc->num_traces);
 434
 435        /* create the debugfs entry */
 436        trace->priv = rproc_create_trace_file(name, rproc, trace);
 437        if (!trace->priv) {
 438                trace->va = NULL;
 439                kfree(trace);
 440                return -EINVAL;
 441        }
 442
 443        list_add_tail(&trace->node, &rproc->traces);
 444
 445        rproc->num_traces++;
 446
 447        dev_dbg(dev, "%s added: va %p, da 0x%x, len 0x%x\n", name, ptr,
 448                                                rsc->da, rsc->len);
 449
 450        return 0;
 451}
 452
 453/**
 454 * rproc_handle_devmem() - handle devmem resource entry
 455 * @rproc: remote processor handle
 456 * @rsc: the devmem resource entry
 457 * @avail: size of available data (for sanity checking the image)
 458 *
 459 * Remote processors commonly need to access certain on-chip peripherals.
 460 *
 461 * Some of these remote processors access memory via an iommu device,
 462 * and might require us to configure their iommu before they can access
 463 * the on-chip peripherals they need.
 464 *
 465 * This resource entry is a request to map such a peripheral device.
 466 *
 467 * These devmem entries will contain the physical address of the device in
 468 * the 'pa' member. If a specific device address is expected, then 'da' will
 469 * contain it (currently this is the only use case supported). 'len' will
 470 * contain the size of the physical region we need to map.
 471 *
 472 * Currently we just "trust" those devmem entries to contain valid physical
 473 * addresses, but this is going to change: we want the implementations to
 474 * tell us ranges of physical addresses the firmware is allowed to request,
 475 * and not allow firmwares to request access to physical addresses that
 476 * are outside those ranges.
 477 */
 478static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc,
 479                                                                int avail)
 480{
 481        struct rproc_mem_entry *mapping;
 482        struct device *dev = &rproc->dev;
 483        int ret;
 484
 485        /* no point in handling this resource without a valid iommu domain */
 486        if (!rproc->domain)
 487                return -EINVAL;
 488
 489        if (sizeof(*rsc) > avail) {
 490                dev_err(dev, "devmem rsc is truncated\n");
 491                return -EINVAL;
 492        }
 493
 494        /* make sure reserved bytes are zeroes */
 495        if (rsc->reserved) {
 496                dev_err(dev, "devmem rsc has non zero reserved bytes\n");
 497                return -EINVAL;
 498        }
 499
 500        mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
 501        if (!mapping) {
 502                dev_err(dev, "kzalloc mapping failed\n");
 503                return -ENOMEM;
 504        }
 505
 506        ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len, rsc->flags);
 507        if (ret) {
 508                dev_err(dev, "failed to map devmem: %d\n", ret);
 509                goto out;
 510        }
 511
 512        /*
 513         * We'll need this info later when we'll want to unmap everything
 514         * (e.g. on shutdown).
 515         *
 516         * We can't trust the remote processor not to change the resource
 517         * table, so we must maintain this info independently.
 518         */
 519        mapping->da = rsc->da;
 520        mapping->len = rsc->len;
 521        list_add_tail(&mapping->node, &rproc->mappings);
 522
 523        dev_dbg(dev, "mapped devmem pa 0x%x, da 0x%x, len 0x%x\n",
 524                                        rsc->pa, rsc->da, rsc->len);
 525
 526        return 0;
 527
 528out:
 529        kfree(mapping);
 530        return ret;
 531}
 532
 533/**
 534 * rproc_handle_carveout() - handle phys contig memory allocation requests
 535 * @rproc: rproc handle
 536 * @rsc: the resource entry
 537 * @avail: size of available data (for image validation)
 538 *
 539 * This function will handle firmware requests for allocation of physically
 540 * contiguous memory regions.
 541 *
 542 * These request entries should come first in the firmware's resource table,
 543 * as other firmware entries might request placing other data objects inside
 544 * these memory regions (e.g. data/code segments, trace resource entries, ...).
 545 *
 546 * Allocating memory this way helps utilizing the reserved physical memory
 547 * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
 548 * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
 549 * pressure is important; it may have a substantial impact on performance.
 550 */
 551static int rproc_handle_carveout(struct rproc *rproc,
 552                                struct fw_rsc_carveout *rsc, int avail)
 553{
 554        struct rproc_mem_entry *carveout, *mapping;
 555        struct device *dev = &rproc->dev;
 556        dma_addr_t dma;
 557        void *va;
 558        int ret;
 559
 560        if (sizeof(*rsc) > avail) {
 561                dev_err(dev, "carveout rsc is truncated\n");
 562                return -EINVAL;
 563        }
 564
 565        /* make sure reserved bytes are zeroes */
 566        if (rsc->reserved) {
 567                dev_err(dev, "carveout rsc has non zero reserved bytes\n");
 568                return -EINVAL;
 569        }
 570
 571        dev_dbg(dev, "carveout rsc: da %x, pa %x, len %x, flags %x\n",
 572                        rsc->da, rsc->pa, rsc->len, rsc->flags);
 573
 574        carveout = kzalloc(sizeof(*carveout), GFP_KERNEL);
 575        if (!carveout) {
 576                dev_err(dev, "kzalloc carveout failed\n");
 577                return -ENOMEM;
 578        }
 579
 580        va = dma_alloc_coherent(dev->parent, rsc->len, &dma, GFP_KERNEL);
 581        if (!va) {
 582                dev_err(dev->parent, "dma_alloc_coherent err: %d\n", rsc->len);
 583                ret = -ENOMEM;
 584                goto free_carv;
 585        }
 586
 587        dev_dbg(dev, "carveout va %p, dma %llx, len 0x%x\n", va,
 588                                        (unsigned long long)dma, rsc->len);
 589
 590        /*
 591         * Ok, this is non-standard.
 592         *
 593         * Sometimes we can't rely on the generic iommu-based DMA API
 594         * to dynamically allocate the device address and then set the IOMMU
 595         * tables accordingly, because some remote processors might
 596         * _require_ us to use hard coded device addresses that their
 597         * firmware was compiled with.
 598         *
 599         * In this case, we must use the IOMMU API directly and map
 600         * the memory to the device address as expected by the remote
 601         * processor.
 602         *
 603         * Obviously such remote processor devices should not be configured
 604         * to use the iommu-based DMA API: we expect 'dma' to contain the
 605         * physical address in this case.
 606         */
 607        if (rproc->domain) {
 608                mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
 609                if (!mapping) {
 610                        dev_err(dev, "kzalloc mapping failed\n");
 611                        ret = -ENOMEM;
 612                        goto dma_free;
 613                }
 614
 615                ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len,
 616                                                                rsc->flags);
 617                if (ret) {
 618                        dev_err(dev, "iommu_map failed: %d\n", ret);
 619                        goto free_mapping;
 620                }
 621
 622                /*
 623                 * We'll need this info later when we'll want to unmap
 624                 * everything (e.g. on shutdown).
 625                 *
 626                 * We can't trust the remote processor not to change the
 627                 * resource table, so we must maintain this info independently.
 628                 */
 629                mapping->da = rsc->da;
 630                mapping->len = rsc->len;
 631                list_add_tail(&mapping->node, &rproc->mappings);
 632
 633                dev_dbg(dev, "carveout mapped 0x%x to 0x%llx\n",
 634                                        rsc->da, (unsigned long long)dma);
 635        }
 636
 637        /*
 638         * Some remote processors might need to know the pa
 639         * even though they are behind an IOMMU. E.g., OMAP4's
 640         * remote M3 processor needs this so it can control
 641         * on-chip hardware accelerators that are not behind
 642         * the IOMMU, and therefor must know the pa.
 643         *
 644         * Generally we don't want to expose physical addresses
 645         * if we don't have to (remote processors are generally
 646         * _not_ trusted), so we might want to do this only for
 647         * remote processor that _must_ have this (e.g. OMAP4's
 648         * dual M3 subsystem).
 649         *
 650         * Non-IOMMU processors might also want to have this info.
 651         * In this case, the device address and the physical address
 652         * are the same.
 653         */
 654        rsc->pa = dma;
 655
 656        carveout->va = va;
 657        carveout->len = rsc->len;
 658        carveout->dma = dma;
 659        carveout->da = rsc->da;
 660
 661        list_add_tail(&carveout->node, &rproc->carveouts);
 662
 663        return 0;
 664
 665free_mapping:
 666        kfree(mapping);
 667dma_free:
 668        dma_free_coherent(dev->parent, rsc->len, va, dma);
 669free_carv:
 670        kfree(carveout);
 671        return ret;
 672}
 673
 674/*
 675 * A lookup table for resource handlers. The indices are defined in
 676 * enum fw_resource_type.
 677 */
 678static rproc_handle_resource_t rproc_handle_rsc[] = {
 679        [RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout,
 680        [RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem,
 681        [RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace,
 682        [RSC_VDEV] = NULL, /* VDEVs were handled upon registrarion */
 683};
 684
 685/* handle firmware resource entries before booting the remote processor */
 686static int
 687rproc_handle_boot_rsc(struct rproc *rproc, struct resource_table *table, int len)
 688{
 689        struct device *dev = &rproc->dev;
 690        rproc_handle_resource_t handler;
 691        int ret = 0, i;
 692
 693        for (i = 0; i < table->num; i++) {
 694                int offset = table->offset[i];
 695                struct fw_rsc_hdr *hdr = (void *)table + offset;
 696                int avail = len - offset - sizeof(*hdr);
 697                void *rsc = (void *)hdr + sizeof(*hdr);
 698
 699                /* make sure table isn't truncated */
 700                if (avail < 0) {
 701                        dev_err(dev, "rsc table is truncated\n");
 702                        return -EINVAL;
 703                }
 704
 705                dev_dbg(dev, "rsc: type %d\n", hdr->type);
 706
 707                if (hdr->type >= RSC_LAST) {
 708                        dev_warn(dev, "unsupported resource %d\n", hdr->type);
 709                        continue;
 710                }
 711
 712                handler = rproc_handle_rsc[hdr->type];
 713                if (!handler)
 714                        continue;
 715
 716                ret = handler(rproc, rsc, avail);
 717                if (ret)
 718                        break;
 719        }
 720
 721        return ret;
 722}
 723
 724/* handle firmware resource entries while registering the remote processor */
 725static int
 726rproc_handle_virtio_rsc(struct rproc *rproc, struct resource_table *table, int len)
 727{
 728        struct device *dev = &rproc->dev;
 729        int ret = 0, i;
 730
 731        for (i = 0; i < table->num; i++) {
 732                int offset = table->offset[i];
 733                struct fw_rsc_hdr *hdr = (void *)table + offset;
 734                int avail = len - offset - sizeof(*hdr);
 735                struct fw_rsc_vdev *vrsc;
 736
 737                /* make sure table isn't truncated */
 738                if (avail < 0) {
 739                        dev_err(dev, "rsc table is truncated\n");
 740                        return -EINVAL;
 741                }
 742
 743                dev_dbg(dev, "%s: rsc type %d\n", __func__, hdr->type);
 744
 745                if (hdr->type != RSC_VDEV)
 746                        continue;
 747
 748                vrsc = (struct fw_rsc_vdev *)hdr->data;
 749
 750                ret = rproc_handle_vdev(rproc, vrsc, avail);
 751                if (ret)
 752                        break;
 753        }
 754
 755        return ret;
 756}
 757
 758/**
 759 * rproc_resource_cleanup() - clean up and free all acquired resources
 760 * @rproc: rproc handle
 761 *
 762 * This function will free all resources acquired for @rproc, and it
 763 * is called whenever @rproc either shuts down or fails to boot.
 764 */
 765static void rproc_resource_cleanup(struct rproc *rproc)
 766{
 767        struct rproc_mem_entry *entry, *tmp;
 768        struct device *dev = &rproc->dev;
 769
 770        /* clean up debugfs trace entries */
 771        list_for_each_entry_safe(entry, tmp, &rproc->traces, node) {
 772                rproc_remove_trace_file(entry->priv);
 773                rproc->num_traces--;
 774                list_del(&entry->node);
 775                kfree(entry);
 776        }
 777
 778        /* clean up carveout allocations */
 779        list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) {
 780                dma_free_coherent(dev->parent, entry->len, entry->va, entry->dma);
 781                list_del(&entry->node);
 782                kfree(entry);
 783        }
 784
 785        /* clean up iommu mapping entries */
 786        list_for_each_entry_safe(entry, tmp, &rproc->mappings, node) {
 787                size_t unmapped;
 788
 789                unmapped = iommu_unmap(rproc->domain, entry->da, entry->len);
 790                if (unmapped != entry->len) {
 791                        /* nothing much to do besides complaining */
 792                        dev_err(dev, "failed to unmap %u/%zu\n", entry->len,
 793                                                                unmapped);
 794                }
 795
 796                list_del(&entry->node);
 797                kfree(entry);
 798        }
 799}
 800
 801/*
 802 * take a firmware and boot a remote processor with it.
 803 */
 804static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 805{
 806        struct device *dev = &rproc->dev;
 807        const char *name = rproc->firmware;
 808        struct resource_table *table;
 809        int ret, tablesz;
 810
 811        ret = rproc_fw_sanity_check(rproc, fw);
 812        if (ret)
 813                return ret;
 814
 815        dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
 816
 817        /*
 818         * if enabling an IOMMU isn't relevant for this rproc, this is
 819         * just a nop
 820         */
 821        ret = rproc_enable_iommu(rproc);
 822        if (ret) {
 823                dev_err(dev, "can't enable iommu: %d\n", ret);
 824                return ret;
 825        }
 826
 827        rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
 828
 829        /* look for the resource table */
 830        table = rproc_find_rsc_table(rproc, fw, &tablesz);
 831        if (!table) {
 832                ret = -EINVAL;
 833                goto clean_up;
 834        }
 835
 836        /* handle fw resources which are required to boot rproc */
 837        ret = rproc_handle_boot_rsc(rproc, table, tablesz);
 838        if (ret) {
 839                dev_err(dev, "Failed to process resources: %d\n", ret);
 840                goto clean_up;
 841        }
 842
 843        /* load the ELF segments to memory */
 844        ret = rproc_load_segments(rproc, fw);
 845        if (ret) {
 846                dev_err(dev, "Failed to load program segments: %d\n", ret);
 847                goto clean_up;
 848        }
 849
 850        /* power up the remote processor */
 851        ret = rproc->ops->start(rproc);
 852        if (ret) {
 853                dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
 854                goto clean_up;
 855        }
 856
 857        rproc->state = RPROC_RUNNING;
 858
 859        dev_info(dev, "remote processor %s is now up\n", rproc->name);
 860
 861        return 0;
 862
 863clean_up:
 864        rproc_resource_cleanup(rproc);
 865        rproc_disable_iommu(rproc);
 866        return ret;
 867}
 868
 869/*
 870 * take a firmware and look for virtio devices to register.
 871 *
 872 * Note: this function is called asynchronously upon registration of the
 873 * remote processor (so we must wait until it completes before we try
 874 * to unregister the device. one other option is just to use kref here,
 875 * that might be cleaner).
 876 */
 877static void rproc_fw_config_virtio(const struct firmware *fw, void *context)
 878{
 879        struct rproc *rproc = context;
 880        struct resource_table *table;
 881        int ret, tablesz;
 882
 883        if (rproc_fw_sanity_check(rproc, fw) < 0)
 884                goto out;
 885
 886        /* look for the resource table */
 887        table = rproc_find_rsc_table(rproc, fw,  &tablesz);
 888        if (!table)
 889                goto out;
 890
 891        /* look for virtio devices and register them */
 892        ret = rproc_handle_virtio_rsc(rproc, table, tablesz);
 893        if (ret)
 894                goto out;
 895
 896out:
 897        release_firmware(fw);
 898        /* allow rproc_del() contexts, if any, to proceed */
 899        complete_all(&rproc->firmware_loading_complete);
 900}
 901
 902static int rproc_add_virtio_devices(struct rproc *rproc)
 903{
 904        int ret;
 905
 906        /* rproc_del() calls must wait until async loader completes */
 907        init_completion(&rproc->firmware_loading_complete);
 908
 909        /*
 910         * We must retrieve early virtio configuration info from
 911         * the firmware (e.g. whether to register a virtio device,
 912         * what virtio features does it support, ...).
 913         *
 914         * We're initiating an asynchronous firmware loading, so we can
 915         * be built-in kernel code, without hanging the boot process.
 916         */
 917        ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG,
 918                                      rproc->firmware, &rproc->dev, GFP_KERNEL,
 919                                      rproc, rproc_fw_config_virtio);
 920        if (ret < 0) {
 921                dev_err(&rproc->dev, "request_firmware_nowait err: %d\n", ret);
 922                complete_all(&rproc->firmware_loading_complete);
 923        }
 924
 925        return ret;
 926}
 927
 928/**
 929 * rproc_trigger_recovery() - recover a remoteproc
 930 * @rproc: the remote processor
 931 *
 932 * The recovery is done by reseting all the virtio devices, that way all the
 933 * rpmsg drivers will be reseted along with the remote processor making the
 934 * remoteproc functional again.
 935 *
 936 * This function can sleep, so it cannot be called from atomic context.
 937 */
 938int rproc_trigger_recovery(struct rproc *rproc)
 939{
 940        struct rproc_vdev *rvdev, *rvtmp;
 941
 942        dev_err(&rproc->dev, "recovering %s\n", rproc->name);
 943
 944        init_completion(&rproc->crash_comp);
 945
 946        /* clean up remote vdev entries */
 947        list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
 948                rproc_remove_virtio_dev(rvdev);
 949
 950        /* wait until there is no more rproc users */
 951        wait_for_completion(&rproc->crash_comp);
 952
 953        return rproc_add_virtio_devices(rproc);
 954}
 955
 956/**
 957 * rproc_crash_handler_work() - handle a crash
 958 *
 959 * This function needs to handle everything related to a crash, like cpu
 960 * registers and stack dump, information to help to debug the fatal error, etc.
 961 */
 962static void rproc_crash_handler_work(struct work_struct *work)
 963{
 964        struct rproc *rproc = container_of(work, struct rproc, crash_handler);
 965        struct device *dev = &rproc->dev;
 966
 967        dev_dbg(dev, "enter %s\n", __func__);
 968
 969        mutex_lock(&rproc->lock);
 970
 971        if (rproc->state == RPROC_CRASHED || rproc->state == RPROC_OFFLINE) {
 972                /* handle only the first crash detected */
 973                mutex_unlock(&rproc->lock);
 974                return;
 975        }
 976
 977        rproc->state = RPROC_CRASHED;
 978        dev_err(dev, "handling crash #%u in %s\n", ++rproc->crash_cnt,
 979                rproc->name);
 980
 981        mutex_unlock(&rproc->lock);
 982
 983        if (!rproc->recovery_disabled)
 984                rproc_trigger_recovery(rproc);
 985}
 986
 987/**
 988 * rproc_boot() - boot a remote processor
 989 * @rproc: handle of a remote processor
 990 *
 991 * Boot a remote processor (i.e. load its firmware, power it on, ...).
 992 *
 993 * If the remote processor is already powered on, this function immediately
 994 * returns (successfully).
 995 *
 996 * Returns 0 on success, and an appropriate error value otherwise.
 997 */
 998int rproc_boot(struct rproc *rproc)
 999{
1000        const struct firmware *firmware_p;
1001        struct device *dev;
1002        int ret;
1003
1004        if (!rproc) {
1005                pr_err("invalid rproc handle\n");
1006                return -EINVAL;
1007        }
1008
1009        dev = &rproc->dev;
1010
1011        ret = mutex_lock_interruptible(&rproc->lock);
1012        if (ret) {
1013                dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
1014                return ret;
1015        }
1016
1017        /* loading a firmware is required */
1018        if (!rproc->firmware) {
1019                dev_err(dev, "%s: no firmware to load\n", __func__);
1020                ret = -EINVAL;
1021                goto unlock_mutex;
1022        }
1023
1024        /* prevent underlying implementation from being removed */
1025        if (!try_module_get(dev->parent->driver->owner)) {
1026                dev_err(dev, "%s: can't get owner\n", __func__);
1027                ret = -EINVAL;
1028                goto unlock_mutex;
1029        }
1030
1031        /* skip the boot process if rproc is already powered up */
1032        if (atomic_inc_return(&rproc->power) > 1) {
1033                ret = 0;
1034                goto unlock_mutex;
1035        }
1036
1037        dev_info(dev, "powering up %s\n", rproc->name);
1038
1039        /* load firmware */
1040        ret = request_firmware(&firmware_p, rproc->firmware, dev);
1041        if (ret < 0) {
1042                dev_err(dev, "request_firmware failed: %d\n", ret);
1043                goto downref_rproc;
1044        }
1045
1046        ret = rproc_fw_boot(rproc, firmware_p);
1047
1048        release_firmware(firmware_p);
1049
1050downref_rproc:
1051        if (ret) {
1052                module_put(dev->parent->driver->owner);
1053                atomic_dec(&rproc->power);
1054        }
1055unlock_mutex:
1056        mutex_unlock(&rproc->lock);
1057        return ret;
1058}
1059EXPORT_SYMBOL(rproc_boot);
1060
1061/**
1062 * rproc_shutdown() - power off the remote processor
1063 * @rproc: the remote processor
1064 *
1065 * Power off a remote processor (previously booted with rproc_boot()).
1066 *
1067 * In case @rproc is still being used by an additional user(s), then
1068 * this function will just decrement the power refcount and exit,
1069 * without really powering off the device.
1070 *
1071 * Every call to rproc_boot() must (eventually) be accompanied by a call
1072 * to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug.
1073 *
1074 * Notes:
1075 * - we're not decrementing the rproc's refcount, only the power refcount.
1076 *   which means that the @rproc handle stays valid even after rproc_shutdown()
1077 *   returns, and users can still use it with a subsequent rproc_boot(), if
1078 *   needed.
1079 */
1080void rproc_shutdown(struct rproc *rproc)
1081{
1082        struct device *dev = &rproc->dev;
1083        int ret;
1084
1085        ret = mutex_lock_interruptible(&rproc->lock);
1086        if (ret) {
1087                dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
1088                return;
1089        }
1090
1091        /* if the remote proc is still needed, bail out */
1092        if (!atomic_dec_and_test(&rproc->power))
1093                goto out;
1094
1095        /* power off the remote processor */
1096        ret = rproc->ops->stop(rproc);
1097        if (ret) {
1098                atomic_inc(&rproc->power);
1099                dev_err(dev, "can't stop rproc: %d\n", ret);
1100                goto out;
1101        }
1102
1103        /* clean up all acquired resources */
1104        rproc_resource_cleanup(rproc);
1105
1106        rproc_disable_iommu(rproc);
1107
1108        /* if in crash state, unlock crash handler */
1109        if (rproc->state == RPROC_CRASHED)
1110                complete_all(&rproc->crash_comp);
1111
1112        rproc->state = RPROC_OFFLINE;
1113
1114        dev_info(dev, "stopped remote processor %s\n", rproc->name);
1115
1116out:
1117        mutex_unlock(&rproc->lock);
1118        if (!ret)
1119                module_put(dev->parent->driver->owner);
1120}
1121EXPORT_SYMBOL(rproc_shutdown);
1122
1123/**
1124 * rproc_add() - register a remote processor
1125 * @rproc: the remote processor handle to register
1126 *
1127 * Registers @rproc with the remoteproc framework, after it has been
1128 * allocated with rproc_alloc().
1129 *
1130 * This is called by the platform-specific rproc implementation, whenever
1131 * a new remote processor device is probed.
1132 *
1133 * Returns 0 on success and an appropriate error code otherwise.
1134 *
1135 * Note: this function initiates an asynchronous firmware loading
1136 * context, which will look for virtio devices supported by the rproc's
1137 * firmware.
1138 *
1139 * If found, those virtio devices will be created and added, so as a result
1140 * of registering this remote processor, additional virtio drivers might be
1141 * probed.
1142 */
1143int rproc_add(struct rproc *rproc)
1144{
1145        struct device *dev = &rproc->dev;
1146        int ret;
1147
1148        ret = device_add(dev);
1149        if (ret < 0)
1150                return ret;
1151
1152        dev_info(dev, "%s is available\n", rproc->name);
1153
1154        dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n");
1155        dev_info(dev, "THE BINARY FORMAT IS NOT YET FINALIZED, and backward compatibility isn't yet guaranteed.\n");
1156
1157        /* create debugfs entries */
1158        rproc_create_debug_dir(rproc);
1159
1160        return rproc_add_virtio_devices(rproc);
1161}
1162EXPORT_SYMBOL(rproc_add);
1163
1164/**
1165 * rproc_type_release() - release a remote processor instance
1166 * @dev: the rproc's device
1167 *
1168 * This function should _never_ be called directly.
1169 *
1170 * It will be called by the driver core when no one holds a valid pointer
1171 * to @dev anymore.
1172 */
1173static void rproc_type_release(struct device *dev)
1174{
1175        struct rproc *rproc = container_of(dev, struct rproc, dev);
1176
1177        dev_info(&rproc->dev, "releasing %s\n", rproc->name);
1178
1179        rproc_delete_debug_dir(rproc);
1180
1181        idr_destroy(&rproc->notifyids);
1182
1183        if (rproc->index >= 0)
1184                ida_simple_remove(&rproc_dev_index, rproc->index);
1185
1186        kfree(rproc);
1187}
1188
1189static struct device_type rproc_type = {
1190        .name           = "remoteproc",
1191        .release        = rproc_type_release,
1192};
1193
1194/**
1195 * rproc_alloc() - allocate a remote processor handle
1196 * @dev: the underlying device
1197 * @name: name of this remote processor
1198 * @ops: platform-specific handlers (mainly start/stop)
1199 * @firmware: name of firmware file to load
1200 * @len: length of private data needed by the rproc driver (in bytes)
1201 *
1202 * Allocates a new remote processor handle, but does not register
1203 * it yet.
1204 *
1205 * This function should be used by rproc implementations during initialization
1206 * of the remote processor.
1207 *
1208 * After creating an rproc handle using this function, and when ready,
1209 * implementations should then call rproc_add() to complete
1210 * the registration of the remote processor.
1211 *
1212 * On success the new rproc is returned, and on failure, NULL.
1213 *
1214 * Note: _never_ directly deallocate @rproc, even if it was not registered
1215 * yet. Instead, when you need to unroll rproc_alloc(), use rproc_put().
1216 */
1217struct rproc *rproc_alloc(struct device *dev, const char *name,
1218                                const struct rproc_ops *ops,
1219                                const char *firmware, int len)
1220{
1221        struct rproc *rproc;
1222
1223        if (!dev || !name || !ops)
1224                return NULL;
1225
1226        rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL);
1227        if (!rproc) {
1228                dev_err(dev, "%s: kzalloc failed\n", __func__);
1229                return NULL;
1230        }
1231
1232        rproc->name = name;
1233        rproc->ops = ops;
1234        rproc->firmware = firmware;
1235        rproc->priv = &rproc[1];
1236
1237        device_initialize(&rproc->dev);
1238        rproc->dev.parent = dev;
1239        rproc->dev.type = &rproc_type;
1240
1241        /* Assign a unique device index and name */
1242        rproc->index = ida_simple_get(&rproc_dev_index, 0, 0, GFP_KERNEL);
1243        if (rproc->index < 0) {
1244                dev_err(dev, "ida_simple_get failed: %d\n", rproc->index);
1245                put_device(&rproc->dev);
1246                return NULL;
1247        }
1248
1249        dev_set_name(&rproc->dev, "remoteproc%d", rproc->index);
1250
1251        atomic_set(&rproc->power, 0);
1252
1253        /* Set ELF as the default fw_ops handler */
1254        rproc->fw_ops = &rproc_elf_fw_ops;
1255
1256        mutex_init(&rproc->lock);
1257
1258        idr_init(&rproc->notifyids);
1259
1260        INIT_LIST_HEAD(&rproc->carveouts);
1261        INIT_LIST_HEAD(&rproc->mappings);
1262        INIT_LIST_HEAD(&rproc->traces);
1263        INIT_LIST_HEAD(&rproc->rvdevs);
1264
1265        INIT_WORK(&rproc->crash_handler, rproc_crash_handler_work);
1266        init_completion(&rproc->crash_comp);
1267
1268        rproc->state = RPROC_OFFLINE;
1269
1270        return rproc;
1271}
1272EXPORT_SYMBOL(rproc_alloc);
1273
1274/**
1275 * rproc_put() - unroll rproc_alloc()
1276 * @rproc: the remote processor handle
1277 *
1278 * This function decrements the rproc dev refcount.
1279 *
1280 * If no one holds any reference to rproc anymore, then its refcount would
1281 * now drop to zero, and it would be freed.
1282 */
1283void rproc_put(struct rproc *rproc)
1284{
1285        put_device(&rproc->dev);
1286}
1287EXPORT_SYMBOL(rproc_put);
1288
1289/**
1290 * rproc_del() - unregister a remote processor
1291 * @rproc: rproc handle to unregister
1292 *
1293 * This function should be called when the platform specific rproc
1294 * implementation decides to remove the rproc device. it should
1295 * _only_ be called if a previous invocation of rproc_add()
1296 * has completed successfully.
1297 *
1298 * After rproc_del() returns, @rproc isn't freed yet, because
1299 * of the outstanding reference created by rproc_alloc. To decrement that
1300 * one last refcount, one still needs to call rproc_put().
1301 *
1302 * Returns 0 on success and -EINVAL if @rproc isn't valid.
1303 */
1304int rproc_del(struct rproc *rproc)
1305{
1306        struct rproc_vdev *rvdev, *tmp;
1307
1308        if (!rproc)
1309                return -EINVAL;
1310
1311        /* if rproc is just being registered, wait */
1312        wait_for_completion(&rproc->firmware_loading_complete);
1313
1314        /* clean up remote vdev entries */
1315        list_for_each_entry_safe(rvdev, tmp, &rproc->rvdevs, node)
1316                rproc_remove_virtio_dev(rvdev);
1317
1318        device_del(&rproc->dev);
1319
1320        return 0;
1321}
1322EXPORT_SYMBOL(rproc_del);
1323
1324/**
1325 * rproc_report_crash() - rproc crash reporter function
1326 * @rproc: remote processor
1327 * @type: crash type
1328 *
1329 * This function must be called every time a crash is detected by the low-level
1330 * drivers implementing a specific remoteproc. This should not be called from a
1331 * non-remoteproc driver.
1332 *
1333 * This function can be called from atomic/interrupt context.
1334 */
1335void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
1336{
1337        if (!rproc) {
1338                pr_err("NULL rproc pointer\n");
1339                return;
1340        }
1341
1342        dev_err(&rproc->dev, "crash detected in %s: type %s\n",
1343                rproc->name, rproc_crash_to_string(type));
1344
1345        /* create a new task to handle the error */
1346        schedule_work(&rproc->crash_handler);
1347}
1348EXPORT_SYMBOL(rproc_report_crash);
1349
1350static int __init remoteproc_init(void)
1351{
1352        rproc_init_debugfs();
1353
1354        return 0;
1355}
1356module_init(remoteproc_init);
1357
1358static void __exit remoteproc_exit(void)
1359{
1360        rproc_exit_debugfs();
1361}
1362module_exit(remoteproc_exit);
1363
1364MODULE_LICENSE("GPL v2");
1365MODULE_DESCRIPTION("Generic Remote Processor Framework");
1366
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