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        if (!idr_pre_get(&rproc->notifyids, GFP_KERNEL)) {
 203                dev_err(dev, "idr_pre_get failed\n");
 204                return -ENOMEM;
 205        }
 206
 207        /*
 208         * Allocate non-cacheable memory for the vring. In the future
 209         * this call will also configure the IOMMU for us
 210         * TODO: let the rproc know the da of this vring
 211         */
 212        va = dma_alloc_coherent(dev->parent, size, &dma, GFP_KERNEL);
 213        if (!va) {
 214                dev_err(dev->parent, "dma_alloc_coherent failed\n");
 215                return -EINVAL;
 216        }
 217
 218        /*
 219         * Assign an rproc-wide unique index for this vring
 220         * TODO: assign a notifyid for rvdev updates as well
 221         * TODO: let the rproc know the notifyid of this vring
 222         * TODO: support predefined notifyids (via resource table)
 223         */
 224        ret = idr_get_new(&rproc->notifyids, rvring, &notifyid);
 225        if (ret) {
 226                dev_err(dev, "idr_get_new failed: %d\n", ret);
 227                dma_free_coherent(dev->parent, size, va, dma);
 228                return ret;
 229        }
 230
 231        /* Store largest notifyid */
 232        rproc->max_notifyid = max(rproc->max_notifyid, notifyid);
 233
 234        dev_dbg(dev, "vring%d: va %p dma %llx size %x idr %d\n", i, va,
 235                                (unsigned long long)dma, size, notifyid);
 236
 237        rvring->va = va;
 238        rvring->dma = dma;
 239        rvring->notifyid = notifyid;
 240
 241        return 0;
 242}
 243
 244static int
 245rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
 246{
 247        struct rproc *rproc = rvdev->rproc;
 248        struct device *dev = &rproc->dev;
 249        struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
 250        struct rproc_vring *rvring = &rvdev->vring[i];
 251
 252        dev_dbg(dev, "vdev rsc: vring%d: da %x, qsz %d, align %d\n",
 253                                i, vring->da, vring->num, vring->align);
 254
 255        /* make sure reserved bytes are zeroes */
 256        if (vring->reserved) {
 257                dev_err(dev, "vring rsc has non zero reserved bytes\n");
 258                return -EINVAL;
 259        }
 260
 261        /* verify queue size and vring alignment are sane */
 262        if (!vring->num || !vring->align) {
 263                dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
 264                                                vring->num, vring->align);
 265                return -EINVAL;
 266        }
 267
 268        rvring->len = vring->num;
 269        rvring->align = vring->align;
 270        rvring->rvdev = rvdev;
 271
 272        return 0;
 273}
 274
 275static int rproc_max_notifyid(int id, void *p, void *data)
 276{
 277        int *maxid = data;
 278        *maxid = max(*maxid, id);
 279        return 0;
 280}
 281
 282void rproc_free_vring(struct rproc_vring *rvring)
 283{
 284        int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
 285        struct rproc *rproc = rvring->rvdev->rproc;
 286        int maxid = 0;
 287
 288        dma_free_coherent(rproc->dev.parent, size, rvring->va, rvring->dma);
 289        idr_remove(&rproc->notifyids, rvring->notifyid);
 290
 291        /* Find the largest remaining notifyid */
 292        idr_for_each(&rproc->notifyids, rproc_max_notifyid, &maxid);
 293        rproc->max_notifyid = maxid;
 294}
 295
 296/**
 297 * rproc_handle_vdev() - handle a vdev fw resource
 298 * @rproc: the remote processor
 299 * @rsc: the vring resource descriptor
 300 * @avail: size of available data (for sanity checking the image)
 301 *
 302 * This resource entry requests the host to statically register a virtio
 303 * device (vdev), and setup everything needed to support it. It contains
 304 * everything needed to make it possible: the virtio device id, virtio
 305 * device features, vrings information, virtio config space, etc...
 306 *
 307 * Before registering the vdev, the vrings are allocated from non-cacheable
 308 * physically contiguous memory. Currently we only support two vrings per
 309 * remote processor (temporary limitation). We might also want to consider
 310 * doing the vring allocation only later when ->find_vqs() is invoked, and
 311 * then release them upon ->del_vqs().
 312 *
 313 * Note: @da is currently not really handled correctly: we dynamically
 314 * allocate it using the DMA API, ignoring requested hard coded addresses,
 315 * and we don't take care of any required IOMMU programming. This is all
 316 * going to be taken care of when the generic iommu-based DMA API will be
 317 * merged. Meanwhile, statically-addressed iommu-based firmware images should
 318 * use RSC_DEVMEM resource entries to map their required @da to the physical
 319 * address of their base CMA region (ouch, hacky!).
 320 *
 321 * Returns 0 on success, or an appropriate error code otherwise
 322 */
 323static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
 324                                                                int avail)
 325{
 326        struct device *dev = &rproc->dev;
 327        struct rproc_vdev *rvdev;
 328        int i, ret;
 329
 330        /* make sure resource isn't truncated */
 331        if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
 332                        + rsc->config_len > avail) {
 333                dev_err(dev, "vdev rsc is truncated\n");
 334                return -EINVAL;
 335        }
 336
 337        /* make sure reserved bytes are zeroes */
 338        if (rsc->reserved[0] || rsc->reserved[1]) {
 339                dev_err(dev, "vdev rsc has non zero reserved bytes\n");
 340                return -EINVAL;
 341        }
 342
 343        dev_dbg(dev, "vdev rsc: id %d, dfeatures %x, cfg len %d, %d vrings\n",
 344                rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);
 345
 346        /* we currently support only two vrings per rvdev */
 347        if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
 348                dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
 349                return -EINVAL;
 350        }
 351
 352        rvdev = kzalloc(sizeof(struct rproc_vdev), GFP_KERNEL);
 353        if (!rvdev)
 354                return -ENOMEM;
 355
 356        rvdev->rproc = rproc;
 357
 358        /* parse the vrings */
 359        for (i = 0; i < rsc->num_of_vrings; i++) {
 360                ret = rproc_parse_vring(rvdev, rsc, i);
 361                if (ret)
 362                        goto free_rvdev;
 363        }
 364
 365        /* remember the device features */
 366        rvdev->dfeatures = rsc->dfeatures;
 367
 368        list_add_tail(&rvdev->node, &rproc->rvdevs);
 369
 370        /* it is now safe to add the virtio device */
 371        ret = rproc_add_virtio_dev(rvdev, rsc->id);
 372        if (ret)
 373                goto free_rvdev;
 374
 375        return 0;
 376
 377free_rvdev:
 378        kfree(rvdev);
 379        return ret;
 380}
 381
 382/**
 383 * rproc_handle_trace() - handle a shared trace buffer resource
 384 * @rproc: the remote processor
 385 * @rsc: the trace resource descriptor
 386 * @avail: size of available data (for sanity checking the image)
 387 *
 388 * In case the remote processor dumps trace logs into memory,
 389 * export it via debugfs.
 390 *
 391 * Currently, the 'da' member of @rsc should contain the device address
 392 * where the remote processor is dumping the traces. Later we could also
 393 * support dynamically allocating this address using the generic
 394 * DMA API (but currently there isn't a use case for that).
 395 *
 396 * Returns 0 on success, or an appropriate error code otherwise
 397 */
 398static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
 399                                                                int avail)
 400{
 401        struct rproc_mem_entry *trace;
 402        struct device *dev = &rproc->dev;
 403        void *ptr;
 404        char name[15];
 405
 406        if (sizeof(*rsc) > avail) {
 407                dev_err(dev, "trace rsc is truncated\n");
 408                return -EINVAL;
 409        }
 410
 411        /* make sure reserved bytes are zeroes */
 412        if (rsc->reserved) {
 413                dev_err(dev, "trace rsc has non zero reserved bytes\n");
 414                return -EINVAL;
 415        }
 416
 417        /* what's the kernel address of this resource ? */
 418        ptr = rproc_da_to_va(rproc, rsc->da, rsc->len);
 419        if (!ptr) {
 420                dev_err(dev, "erroneous trace resource entry\n");
 421                return -EINVAL;
 422        }
 423
 424        trace = kzalloc(sizeof(*trace), GFP_KERNEL);
 425        if (!trace) {
 426                dev_err(dev, "kzalloc trace failed\n");
 427                return -ENOMEM;
 428        }
 429
 430        /* set the trace buffer dma properties */
 431        trace->len = rsc->len;
 432        trace->va = ptr;
 433
 434        /* make sure snprintf always null terminates, even if truncating */
 435        snprintf(name, sizeof(name), "trace%d", rproc->num_traces);
 436
 437        /* create the debugfs entry */
 438        trace->priv = rproc_create_trace_file(name, rproc, trace);
 439        if (!trace->priv) {
 440                trace->va = NULL;
 441                kfree(trace);
 442                return -EINVAL;
 443        }
 444
 445        list_add_tail(&trace->node, &rproc->traces);
 446
 447        rproc->num_traces++;
 448
 449        dev_dbg(dev, "%s added: va %p, da 0x%x, len 0x%x\n", name, ptr,
 450                                                rsc->da, rsc->len);
 451
 452        return 0;
 453}
 454
 455/**
 456 * rproc_handle_devmem() - handle devmem resource entry
 457 * @rproc: remote processor handle
 458 * @rsc: the devmem resource entry
 459 * @avail: size of available data (for sanity checking the image)
 460 *
 461 * Remote processors commonly need to access certain on-chip peripherals.
 462 *
 463 * Some of these remote processors access memory via an iommu device,
 464 * and might require us to configure their iommu before they can access
 465 * the on-chip peripherals they need.
 466 *
 467 * This resource entry is a request to map such a peripheral device.
 468 *
 469 * These devmem entries will contain the physical address of the device in
 470 * the 'pa' member. If a specific device address is expected, then 'da' will
 471 * contain it (currently this is the only use case supported). 'len' will
 472 * contain the size of the physical region we need to map.
 473 *
 474 * Currently we just "trust" those devmem entries to contain valid physical
 475 * addresses, but this is going to change: we want the implementations to
 476 * tell us ranges of physical addresses the firmware is allowed to request,
 477 * and not allow firmwares to request access to physical addresses that
 478 * are outside those ranges.
 479 */
 480static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc,
 481                                                                int avail)
 482{
 483        struct rproc_mem_entry *mapping;
 484        struct device *dev = &rproc->dev;
 485        int ret;
 486
 487        /* no point in handling this resource without a valid iommu domain */
 488        if (!rproc->domain)
 489                return -EINVAL;
 490
 491        if (sizeof(*rsc) > avail) {
 492                dev_err(dev, "devmem rsc is truncated\n");
 493                return -EINVAL;
 494        }
 495
 496        /* make sure reserved bytes are zeroes */
 497        if (rsc->reserved) {
 498                dev_err(dev, "devmem rsc has non zero reserved bytes\n");
 499                return -EINVAL;
 500        }
 501
 502        mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
 503        if (!mapping) {
 504                dev_err(dev, "kzalloc mapping failed\n");
 505                return -ENOMEM;
 506        }
 507
 508        ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len, rsc->flags);
 509        if (ret) {
 510                dev_err(dev, "failed to map devmem: %d\n", ret);
 511                goto out;
 512        }
 513
 514        /*
 515         * We'll need this info later when we'll want to unmap everything
 516         * (e.g. on shutdown).
 517         *
 518         * We can't trust the remote processor not to change the resource
 519         * table, so we must maintain this info independently.
 520         */
 521        mapping->da = rsc->da;
 522        mapping->len = rsc->len;
 523        list_add_tail(&mapping->node, &rproc->mappings);
 524
 525        dev_dbg(dev, "mapped devmem pa 0x%x, da 0x%x, len 0x%x\n",
 526                                        rsc->pa, rsc->da, rsc->len);
 527
 528        return 0;
 529
 530out:
 531        kfree(mapping);
 532        return ret;
 533}
 534
 535/**
 536 * rproc_handle_carveout() - handle phys contig memory allocation requests
 537 * @rproc: rproc handle
 538 * @rsc: the resource entry
 539 * @avail: size of available data (for image validation)
 540 *
 541 * This function will handle firmware requests for allocation of physically
 542 * contiguous memory regions.
 543 *
 544 * These request entries should come first in the firmware's resource table,
 545 * as other firmware entries might request placing other data objects inside
 546 * these memory regions (e.g. data/code segments, trace resource entries, ...).
 547 *
 548 * Allocating memory this way helps utilizing the reserved physical memory
 549 * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
 550 * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
 551 * pressure is important; it may have a substantial impact on performance.
 552 */
 553static int rproc_handle_carveout(struct rproc *rproc,
 554                                struct fw_rsc_carveout *rsc, int avail)
 555{
 556        struct rproc_mem_entry *carveout, *mapping;
 557        struct device *dev = &rproc->dev;
 558        dma_addr_t dma;
 559        void *va;
 560        int ret;
 561
 562        if (sizeof(*rsc) > avail) {
 563                dev_err(dev, "carveout rsc is truncated\n");
 564                return -EINVAL;
 565        }
 566
 567        /* make sure reserved bytes are zeroes */
 568        if (rsc->reserved) {
 569                dev_err(dev, "carveout rsc has non zero reserved bytes\n");
 570                return -EINVAL;
 571        }
 572
 573        dev_dbg(dev, "carveout rsc: da %x, pa %x, len %x, flags %x\n",
 574                        rsc->da, rsc->pa, rsc->len, rsc->flags);
 575
 576        carveout = kzalloc(sizeof(*carveout), GFP_KERNEL);
 577        if (!carveout) {
 578                dev_err(dev, "kzalloc carveout failed\n");
 579                return -ENOMEM;
 580        }
 581
 582        va = dma_alloc_coherent(dev->parent, rsc->len, &dma, GFP_KERNEL);
 583        if (!va) {
 584                dev_err(dev->parent, "dma_alloc_coherent err: %d\n", rsc->len);
 585                ret = -ENOMEM;
 586                goto free_carv;
 587        }
 588
 589        dev_dbg(dev, "carveout va %p, dma %llx, len 0x%x\n", va,
 590                                        (unsigned long long)dma, rsc->len);
 591
 592        /*
 593         * Ok, this is non-standard.
 594         *
 595         * Sometimes we can't rely on the generic iommu-based DMA API
 596         * to dynamically allocate the device address and then set the IOMMU
 597         * tables accordingly, because some remote processors might
 598         * _require_ us to use hard coded device addresses that their
 599         * firmware was compiled with.
 600         *
 601         * In this case, we must use the IOMMU API directly and map
 602         * the memory to the device address as expected by the remote
 603         * processor.
 604         *
 605         * Obviously such remote processor devices should not be configured
 606         * to use the iommu-based DMA API: we expect 'dma' to contain the
 607         * physical address in this case.
 608         */
 609        if (rproc->domain) {
 610                mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
 611                if (!mapping) {
 612                        dev_err(dev, "kzalloc mapping failed\n");
 613                        ret = -ENOMEM;
 614                        goto dma_free;
 615                }
 616
 617                ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len,
 618                                                                rsc->flags);
 619                if (ret) {
 620                        dev_err(dev, "iommu_map failed: %d\n", ret);
 621                        goto free_mapping;
 622                }
 623
 624                /*
 625                 * We'll need this info later when we'll want to unmap
 626                 * everything (e.g. on shutdown).
 627                 *
 628                 * We can't trust the remote processor not to change the
 629                 * resource table, so we must maintain this info independently.
 630                 */
 631                mapping->da = rsc->da;
 632                mapping->len = rsc->len;
 633                list_add_tail(&mapping->node, &rproc->mappings);
 634
 635                dev_dbg(dev, "carveout mapped 0x%x to 0x%llx\n",
 636                                        rsc->da, (unsigned long long)dma);
 637        }
 638
 639        /*
 640         * Some remote processors might need to know the pa
 641         * even though they are behind an IOMMU. E.g., OMAP4's
 642         * remote M3 processor needs this so it can control
 643         * on-chip hardware accelerators that are not behind
 644         * the IOMMU, and therefor must know the pa.
 645         *
 646         * Generally we don't want to expose physical addresses
 647         * if we don't have to (remote processors are generally
 648         * _not_ trusted), so we might want to do this only for
 649         * remote processor that _must_ have this (e.g. OMAP4's
 650         * dual M3 subsystem).
 651         *
 652         * Non-IOMMU processors might also want to have this info.
 653         * In this case, the device address and the physical address
 654         * are the same.
 655         */
 656        rsc->pa = dma;
 657
 658        carveout->va = va;
 659        carveout->len = rsc->len;
 660        carveout->dma = dma;
 661        carveout->da = rsc->da;
 662
 663        list_add_tail(&carveout->node, &rproc->carveouts);
 664
 665        return 0;
 666
 667free_mapping:
 668        kfree(mapping);
 669dma_free:
 670        dma_free_coherent(dev->parent, rsc->len, va, dma);
 671free_carv:
 672        kfree(carveout);
 673        return ret;
 674}
 675
 676/*
 677 * A lookup table for resource handlers. The indices are defined in
 678 * enum fw_resource_type.
 679 */
 680static rproc_handle_resource_t rproc_handle_rsc[] = {
 681        [RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout,
 682        [RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem,
 683        [RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace,
 684        [RSC_VDEV] = NULL, /* VDEVs were handled upon registrarion */
 685};
 686
 687/* handle firmware resource entries before booting the remote processor */
 688static int
 689rproc_handle_boot_rsc(struct rproc *rproc, struct resource_table *table, int len)
 690{
 691        struct device *dev = &rproc->dev;
 692        rproc_handle_resource_t handler;
 693        int ret = 0, i;
 694
 695        for (i = 0; i < table->num; i++) {
 696                int offset = table->offset[i];
 697                struct fw_rsc_hdr *hdr = (void *)table + offset;
 698                int avail = len - offset - sizeof(*hdr);
 699                void *rsc = (void *)hdr + sizeof(*hdr);
 700
 701                /* make sure table isn't truncated */
 702                if (avail < 0) {
 703                        dev_err(dev, "rsc table is truncated\n");
 704                        return -EINVAL;
 705                }
 706
 707                dev_dbg(dev, "rsc: type %d\n", hdr->type);
 708
 709                if (hdr->type >= RSC_LAST) {
 710                        dev_warn(dev, "unsupported resource %d\n", hdr->type);
 711                        continue;
 712                }
 713
 714                handler = rproc_handle_rsc[hdr->type];
 715                if (!handler)
 716                        continue;
 717
 718                ret = handler(rproc, rsc, avail);
 719                if (ret)
 720                        break;
 721        }
 722
 723        return ret;
 724}
 725
 726/* handle firmware resource entries while registering the remote processor */
 727static int
 728rproc_handle_virtio_rsc(struct rproc *rproc, struct resource_table *table, int len)
 729{
 730        struct device *dev = &rproc->dev;
 731        int ret = 0, i;
 732
 733        for (i = 0; i < table->num; i++) {
 734                int offset = table->offset[i];
 735                struct fw_rsc_hdr *hdr = (void *)table + offset;
 736                int avail = len - offset - sizeof(*hdr);
 737                struct fw_rsc_vdev *vrsc;
 738
 739                /* make sure table isn't truncated */
 740                if (avail < 0) {
 741                        dev_err(dev, "rsc table is truncated\n");
 742                        return -EINVAL;
 743                }
 744
 745                dev_dbg(dev, "%s: rsc type %d\n", __func__, hdr->type);
 746
 747                if (hdr->type != RSC_VDEV)
 748                        continue;
 749
 750                vrsc = (struct fw_rsc_vdev *)hdr->data;
 751
 752                ret = rproc_handle_vdev(rproc, vrsc, avail);
 753                if (ret)
 754                        break;
 755        }
 756
 757        return ret;
 758}
 759
 760/**
 761 * rproc_resource_cleanup() - clean up and free all acquired resources
 762 * @rproc: rproc handle
 763 *
 764 * This function will free all resources acquired for @rproc, and it
 765 * is called whenever @rproc either shuts down or fails to boot.
 766 */
 767static void rproc_resource_cleanup(struct rproc *rproc)
 768{
 769        struct rproc_mem_entry *entry, *tmp;
 770        struct device *dev = &rproc->dev;
 771
 772        /* clean up debugfs trace entries */
 773        list_for_each_entry_safe(entry, tmp, &rproc->traces, node) {
 774                rproc_remove_trace_file(entry->priv);
 775                rproc->num_traces--;
 776                list_del(&entry->node);
 777                kfree(entry);
 778        }
 779
 780        /* clean up carveout allocations */
 781        list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) {
 782                dma_free_coherent(dev->parent, entry->len, entry->va, entry->dma);
 783                list_del(&entry->node);
 784                kfree(entry);
 785        }
 786
 787        /* clean up iommu mapping entries */
 788        list_for_each_entry_safe(entry, tmp, &rproc->mappings, node) {
 789                size_t unmapped;
 790
 791                unmapped = iommu_unmap(rproc->domain, entry->da, entry->len);
 792                if (unmapped != entry->len) {
 793                        /* nothing much to do besides complaining */
 794                        dev_err(dev, "failed to unmap %u/%zu\n", entry->len,
 795                                                                unmapped);
 796                }
 797
 798                list_del(&entry->node);
 799                kfree(entry);
 800        }
 801}
 802
 803/*
 804 * take a firmware and boot a remote processor with it.
 805 */
 806static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 807{
 808        struct device *dev = &rproc->dev;
 809        const char *name = rproc->firmware;
 810        struct resource_table *table;
 811        int ret, tablesz;
 812
 813        ret = rproc_fw_sanity_check(rproc, fw);
 814        if (ret)
 815                return ret;
 816
 817        dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
 818
 819        /*
 820         * if enabling an IOMMU isn't relevant for this rproc, this is
 821         * just a nop
 822         */
 823        ret = rproc_enable_iommu(rproc);
 824        if (ret) {
 825                dev_err(dev, "can't enable iommu: %d\n", ret);
 826                return ret;
 827        }
 828
 829        rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
 830
 831        /* look for the resource table */
 832        table = rproc_find_rsc_table(rproc, fw, &tablesz);
 833        if (!table) {
 834                ret = -EINVAL;
 835                goto clean_up;
 836        }
 837
 838        /* handle fw resources which are required to boot rproc */
 839        ret = rproc_handle_boot_rsc(rproc, table, tablesz);
 840        if (ret) {
 841                dev_err(dev, "Failed to process resources: %d\n", ret);
 842                goto clean_up;
 843        }
 844
 845        /* load the ELF segments to memory */
 846        ret = rproc_load_segments(rproc, fw);
 847        if (ret) {
 848                dev_err(dev, "Failed to load program segments: %d\n", ret);
 849                goto clean_up;
 850        }
 851
 852        /* power up the remote processor */
 853        ret = rproc->ops->start(rproc);
 854        if (ret) {
 855                dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
 856                goto clean_up;
 857        }
 858
 859        rproc->state = RPROC_RUNNING;
 860
 861        dev_info(dev, "remote processor %s is now up\n", rproc->name);
 862
 863        return 0;
 864
 865clean_up:
 866        rproc_resource_cleanup(rproc);
 867        rproc_disable_iommu(rproc);
 868        return ret;
 869}
 870
 871/*
 872 * take a firmware and look for virtio devices to register.
 873 *
 874 * Note: this function is called asynchronously upon registration of the
 875 * remote processor (so we must wait until it completes before we try
 876 * to unregister the device. one other option is just to use kref here,
 877 * that might be cleaner).
 878 */
 879static void rproc_fw_config_virtio(const struct firmware *fw, void *context)
 880{
 881        struct rproc *rproc = context;
 882        struct resource_table *table;
 883        int ret, tablesz;
 884
 885        if (rproc_fw_sanity_check(rproc, fw) < 0)
 886                goto out;
 887
 888        /* look for the resource table */
 889        table = rproc_find_rsc_table(rproc, fw,  &tablesz);
 890        if (!table)
 891                goto out;
 892
 893        /* look for virtio devices and register them */
 894        ret = rproc_handle_virtio_rsc(rproc, table, tablesz);
 895        if (ret)
 896                goto out;
 897
 898out:
 899        release_firmware(fw);
 900        /* allow rproc_del() contexts, if any, to proceed */
 901        complete_all(&rproc->firmware_loading_complete);
 902}
 903
 904static int rproc_add_virtio_devices(struct rproc *rproc)
 905{
 906        int ret;
 907
 908        /* rproc_del() calls must wait until async loader completes */
 909        init_completion(&rproc->firmware_loading_complete);
 910
 911        /*
 912         * We must retrieve early virtio configuration info from
 913         * the firmware (e.g. whether to register a virtio device,
 914         * what virtio features does it support, ...).
 915         *
 916         * We're initiating an asynchronous firmware loading, so we can
 917         * be built-in kernel code, without hanging the boot process.
 918         */
 919        ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG,
 920                                      rproc->firmware, &rproc->dev, GFP_KERNEL,
 921                                      rproc, rproc_fw_config_virtio);
 922        if (ret < 0) {
 923                dev_err(&rproc->dev, "request_firmware_nowait err: %d\n", ret);
 924                complete_all(&rproc->firmware_loading_complete);
 925        }
 926
 927        return ret;
 928}
 929
 930/**
 931 * rproc_trigger_recovery() - recover a remoteproc
 932 * @rproc: the remote processor
 933 *
 934 * The recovery is done by reseting all the virtio devices, that way all the
 935 * rpmsg drivers will be reseted along with the remote processor making the
 936 * remoteproc functional again.
 937 *
 938 * This function can sleep, so it cannot be called from atomic context.
 939 */
 940int rproc_trigger_recovery(struct rproc *rproc)
 941{
 942        struct rproc_vdev *rvdev, *rvtmp;
 943
 944        dev_err(&rproc->dev, "recovering %s\n", rproc->name);
 945
 946        init_completion(&rproc->crash_comp);
 947
 948        /* clean up remote vdev entries */
 949        list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
 950                rproc_remove_virtio_dev(rvdev);
 951
 952        /* wait until there is no more rproc users */
 953        wait_for_completion(&rproc->crash_comp);
 954
 955        return rproc_add_virtio_devices(rproc);
 956}
 957
 958/**
 959 * rproc_crash_handler_work() - handle a crash
 960 *
 961 * This function needs to handle everything related to a crash, like cpu
 962 * registers and stack dump, information to help to debug the fatal error, etc.
 963 */
 964static void rproc_crash_handler_work(struct work_struct *work)
 965{
 966        struct rproc *rproc = container_of(work, struct rproc, crash_handler);
 967        struct device *dev = &rproc->dev;
 968
 969        dev_dbg(dev, "enter %s\n", __func__);
 970
 971        mutex_lock(&rproc->lock);
 972
 973        if (rproc->state == RPROC_CRASHED || rproc->state == RPROC_OFFLINE) {
 974                /* handle only the first crash detected */
 975                mutex_unlock(&rproc->lock);
 976                return;
 977        }
 978
 979        rproc->state = RPROC_CRASHED;
 980        dev_err(dev, "handling crash #%u in %s\n", ++rproc->crash_cnt,
 981                rproc->name);
 982
 983        mutex_unlock(&rproc->lock);
 984
 985        if (!rproc->recovery_disabled)
 986                rproc_trigger_recovery(rproc);
 987}
 988
 989/**
 990 * rproc_boot() - boot a remote processor
 991 * @rproc: handle of a remote processor
 992 *
 993 * Boot a remote processor (i.e. load its firmware, power it on, ...).
 994 *
 995 * If the remote processor is already powered on, this function immediately
 996 * returns (successfully).
 997 *
 998 * Returns 0 on success, and an appropriate error value otherwise.
 999 */
1000int rproc_boot(struct rproc *rproc)
1001{
1002        const struct firmware *firmware_p;
1003        struct device *dev;
1004        int ret;
1005
1006        if (!rproc) {
1007                pr_err("invalid rproc handle\n");
1008                return -EINVAL;
1009        }
1010
1011        dev = &rproc->dev;
1012
1013        ret = mutex_lock_interruptible(&rproc->lock);
1014        if (ret) {
1015                dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
1016                return ret;
1017        }
1018
1019        /* loading a firmware is required */
1020        if (!rproc->firmware) {
1021                dev_err(dev, "%s: no firmware to load\n", __func__);
1022                ret = -EINVAL;
1023                goto unlock_mutex;
1024        }
1025
1026        /* prevent underlying implementation from being removed */
1027        if (!try_module_get(dev->parent->driver->owner)) {
1028                dev_err(dev, "%s: can't get owner\n", __func__);
1029                ret = -EINVAL;
1030                goto unlock_mutex;
1031        }
1032
1033        /* skip the boot process if rproc is already powered up */
1034        if (atomic_inc_return(&rproc->power) > 1) {
1035                ret = 0;
1036                goto unlock_mutex;
1037        }
1038
1039        dev_info(dev, "powering up %s\n", rproc->name);
1040
1041        /* load firmware */
1042        ret = request_firmware(&firmware_p, rproc->firmware, dev);
1043        if (ret < 0) {
1044                dev_err(dev, "request_firmware failed: %d\n", ret);
1045                goto downref_rproc;
1046        }
1047
1048        ret = rproc_fw_boot(rproc, firmware_p);
1049
1050        release_firmware(firmware_p);
1051
1052downref_rproc:
1053        if (ret) {
1054                module_put(dev->parent->driver->owner);
1055                atomic_dec(&rproc->power);
1056        }
1057unlock_mutex:
1058        mutex_unlock(&rproc->lock);
1059        return ret;
1060}
1061EXPORT_SYMBOL(rproc_boot);
1062
1063/**
1064 * rproc_shutdown() - power off the remote processor
1065 * @rproc: the remote processor
1066 *
1067 * Power off a remote processor (previously booted with rproc_boot()).
1068 *
1069 * In case @rproc is still being used by an additional user(s), then
1070 * this function will just decrement the power refcount and exit,
1071 * without really powering off the device.
1072 *
1073 * Every call to rproc_boot() must (eventually) be accompanied by a call
1074 * to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug.
1075 *
1076 * Notes:
1077 * - we're not decrementing the rproc's refcount, only the power refcount.
1078 *   which means that the @rproc handle stays valid even after rproc_shutdown()
1079 *   returns, and users can still use it with a subsequent rproc_boot(), if
1080 *   needed.
1081 */
1082void rproc_shutdown(struct rproc *rproc)
1083{
1084        struct device *dev = &rproc->dev;
1085        int ret;
1086
1087        ret = mutex_lock_interruptible(&rproc->lock);
1088        if (ret) {
1089                dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
1090                return;
1091        }
1092
1093        /* if the remote proc is still needed, bail out */
1094        if (!atomic_dec_and_test(&rproc->power))
1095                goto out;
1096
1097        /* power off the remote processor */
1098        ret = rproc->ops->stop(rproc);
1099        if (ret) {
1100                atomic_inc(&rproc->power);
1101                dev_err(dev, "can't stop rproc: %d\n", ret);
1102                goto out;
1103        }
1104
1105        /* clean up all acquired resources */
1106        rproc_resource_cleanup(rproc);
1107
1108        rproc_disable_iommu(rproc);
1109
1110        /* if in crash state, unlock crash handler */
1111        if (rproc->state == RPROC_CRASHED)
1112                complete_all(&rproc->crash_comp);
1113
1114        rproc->state = RPROC_OFFLINE;
1115
1116        dev_info(dev, "stopped remote processor %s\n", rproc->name);
1117
1118out:
1119        mutex_unlock(&rproc->lock);
1120        if (!ret)
1121                module_put(dev->parent->driver->owner);
1122}
1123EXPORT_SYMBOL(rproc_shutdown);
1124
1125/**
1126 * rproc_add() - register a remote processor
1127 * @rproc: the remote processor handle to register
1128 *
1129 * Registers @rproc with the remoteproc framework, after it has been
1130 * allocated with rproc_alloc().
1131 *
1132 * This is called by the platform-specific rproc implementation, whenever
1133 * a new remote processor device is probed.
1134 *
1135 * Returns 0 on success and an appropriate error code otherwise.
1136 *
1137 * Note: this function initiates an asynchronous firmware loading
1138 * context, which will look for virtio devices supported by the rproc's
1139 * firmware.
1140 *
1141 * If found, those virtio devices will be created and added, so as a result
1142 * of registering this remote processor, additional virtio drivers might be
1143 * probed.
1144 */
1145int rproc_add(struct rproc *rproc)
1146{
1147        struct device *dev = &rproc->dev;
1148        int ret;
1149
1150        ret = device_add(dev);
1151        if (ret < 0)
1152                return ret;
1153
1154        dev_info(dev, "%s is available\n", rproc->name);
1155
1156        dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n");
1157        dev_info(dev, "THE BINARY FORMAT IS NOT YET FINALIZED, and backward compatibility isn't yet guaranteed.\n");
1158
1159        /* create debugfs entries */
1160        rproc_create_debug_dir(rproc);
1161
1162        return rproc_add_virtio_devices(rproc);
1163}
1164EXPORT_SYMBOL(rproc_add);
1165
1166/**
1167 * rproc_type_release() - release a remote processor instance
1168 * @dev: the rproc's device
1169 *
1170 * This function should _never_ be called directly.
1171 *
1172 * It will be called by the driver core when no one holds a valid pointer
1173 * to @dev anymore.
1174 */
1175static void rproc_type_release(struct device *dev)
1176{
1177        struct rproc *rproc = container_of(dev, struct rproc, dev);
1178
1179        dev_info(&rproc->dev, "releasing %s\n", rproc->name);
1180
1181        rproc_delete_debug_dir(rproc);
1182
1183        idr_remove_all(&rproc->notifyids);
1184        idr_destroy(&rproc->notifyids);
1185
1186        if (rproc->index >= 0)
1187                ida_simple_remove(&rproc_dev_index, rproc->index);
1188
1189        kfree(rproc);
1190}
1191
1192static struct device_type rproc_type = {
1193        .name           = "remoteproc",
1194        .release        = rproc_type_release,
1195};
1196
1197/**
1198 * rproc_alloc() - allocate a remote processor handle
1199 * @dev: the underlying device
1200 * @name: name of this remote processor
1201 * @ops: platform-specific handlers (mainly start/stop)
1202 * @firmware: name of firmware file to load
1203 * @len: length of private data needed by the rproc driver (in bytes)
1204 *
1205 * Allocates a new remote processor handle, but does not register
1206 * it yet.
1207 *
1208 * This function should be used by rproc implementations during initialization
1209 * of the remote processor.
1210 *
1211 * After creating an rproc handle using this function, and when ready,
1212 * implementations should then call rproc_add() to complete
1213 * the registration of the remote processor.
1214 *
1215 * On success the new rproc is returned, and on failure, NULL.
1216 *
1217 * Note: _never_ directly deallocate @rproc, even if it was not registered
1218 * yet. Instead, when you need to unroll rproc_alloc(), use rproc_put().
1219 */
1220struct rproc *rproc_alloc(struct device *dev, const char *name,
1221                                const struct rproc_ops *ops,
1222                                const char *firmware, int len)
1223{
1224        struct rproc *rproc;
1225
1226        if (!dev || !name || !ops)
1227                return NULL;
1228
1229        rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL);
1230        if (!rproc) {
1231                dev_err(dev, "%s: kzalloc failed\n", __func__);
1232                return NULL;
1233        }
1234
1235        rproc->name = name;
1236        rproc->ops = ops;
1237        rproc->firmware = firmware;
1238        rproc->priv = &rproc[1];
1239
1240        device_initialize(&rproc->dev);
1241        rproc->dev.parent = dev;
1242        rproc->dev.type = &rproc_type;
1243
1244        /* Assign a unique device index and name */
1245        rproc->index = ida_simple_get(&rproc_dev_index, 0, 0, GFP_KERNEL);
1246        if (rproc->index < 0) {
1247                dev_err(dev, "ida_simple_get failed: %d\n", rproc->index);
1248                put_device(&rproc->dev);
1249                return NULL;
1250        }
1251
1252        dev_set_name(&rproc->dev, "remoteproc%d", rproc->index);
1253
1254        atomic_set(&rproc->power, 0);
1255
1256        /* Set ELF as the default fw_ops handler */
1257        rproc->fw_ops = &rproc_elf_fw_ops;
1258
1259        mutex_init(&rproc->lock);
1260
1261        idr_init(&rproc->notifyids);
1262
1263        INIT_LIST_HEAD(&rproc->carveouts);
1264        INIT_LIST_HEAD(&rproc->mappings);
1265        INIT_LIST_HEAD(&rproc->traces);
1266        INIT_LIST_HEAD(&rproc->rvdevs);
1267
1268        INIT_WORK(&rproc->crash_handler, rproc_crash_handler_work);
1269        init_completion(&rproc->crash_comp);
1270
1271        rproc->state = RPROC_OFFLINE;
1272
1273        return rproc;
1274}
1275EXPORT_SYMBOL(rproc_alloc);
1276
1277/**
1278 * rproc_put() - unroll rproc_alloc()
1279 * @rproc: the remote processor handle
1280 *
1281 * This function decrements the rproc dev refcount.
1282 *
1283 * If no one holds any reference to rproc anymore, then its refcount would
1284 * now drop to zero, and it would be freed.
1285 */
1286void rproc_put(struct rproc *rproc)
1287{
1288        put_device(&rproc->dev);
1289}
1290EXPORT_SYMBOL(rproc_put);
1291
1292/**
1293 * rproc_del() - unregister a remote processor
1294 * @rproc: rproc handle to unregister
1295 *
1296 * This function should be called when the platform specific rproc
1297 * implementation decides to remove the rproc device. it should
1298 * _only_ be called if a previous invocation of rproc_add()
1299 * has completed successfully.
1300 *
1301 * After rproc_del() returns, @rproc isn't freed yet, because
1302 * of the outstanding reference created by rproc_alloc. To decrement that
1303 * one last refcount, one still needs to call rproc_put().
1304 *
1305 * Returns 0 on success and -EINVAL if @rproc isn't valid.
1306 */
1307int rproc_del(struct rproc *rproc)
1308{
1309        struct rproc_vdev *rvdev, *tmp;
1310
1311        if (!rproc)
1312                return -EINVAL;
1313
1314        /* if rproc is just being registered, wait */
1315        wait_for_completion(&rproc->firmware_loading_complete);
1316
1317        /* clean up remote vdev entries */
1318        list_for_each_entry_safe(rvdev, tmp, &rproc->rvdevs, node)
1319                rproc_remove_virtio_dev(rvdev);
1320
1321        device_del(&rproc->dev);
1322
1323        return 0;
1324}
1325EXPORT_SYMBOL(rproc_del);
1326
1327/**
1328 * rproc_report_crash() - rproc crash reporter function
1329 * @rproc: remote processor
1330 * @type: crash type
1331 *
1332 * This function must be called every time a crash is detected by the low-level
1333 * drivers implementing a specific remoteproc. This should not be called from a
1334 * non-remoteproc driver.
1335 *
1336 * This function can be called from atomic/interrupt context.
1337 */
1338void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
1339{
1340        if (!rproc) {
1341                pr_err("NULL rproc pointer\n");
1342                return;
1343        }
1344
1345        dev_err(&rproc->dev, "crash detected in %s: type %s\n",
1346                rproc->name, rproc_crash_to_string(type));
1347
1348        /* create a new task to handle the error */
1349        schedule_work(&rproc->crash_handler);
1350}
1351EXPORT_SYMBOL(rproc_report_crash);
1352
1353static int __init remoteproc_init(void)
1354{
1355        rproc_init_debugfs();
1356
1357        return 0;
1358}
1359module_init(remoteproc_init);
1360
1361static void __exit remoteproc_exit(void)
1362{
1363        rproc_exit_debugfs();
1364}
1365module_exit(remoteproc_exit);
1366
1367MODULE_LICENSE("GPL v2");
1368MODULE_DESCRIPTION("Generic Remote Processor Framework");
1369
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