include/linux/remoteproc.h

   1 /*
   2  * Remote Processor Framework
   3  *
   4  * Copyright(c) 2011 Texas Instruments, Inc.
   5  * Copyright(c) 2011 Google, Inc.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * * Redistributions of source code must retain the above copyright
  13  *   notice, this list of conditions and the following disclaimer.
  14  * * Redistributions in binary form must reproduce the above copyright
  15  *   notice, this list of conditions and the following disclaimer in
  16  *   the documentation and/or other materials provided with the
  17  *   distribution.
  18  * * Neither the name Texas Instruments nor the names of its
  19  *   contributors may be used to endorse or promote products derived
  20  *   from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #ifndef REMOTEPROC_H
  36 #define REMOTEPROC_H
  37
  38 #include <linux/types.h>
  39 #include <linux/klist.h>
  40 #include <linux/mutex.h>
  41 #include <linux/virtio.h>
  42 #include <linux/completion.h>
  43 #include <linux/idr.h>
  44
  45 /**
  46  * struct resource_table - firmware resource table header
  47  * @ver: version number
  48  * @num: number of resource entries
  49  * @reserved: reserved (must be zero)
  50  * @offset: array of offsets pointing at the various resource entries
  51  *
  52  * A resource table is essentially a list of system resources required
  53  * by the remote processor. It may also include configuration entries.
  54  * If needed, the remote processor firmware should contain this table
  55  * as a dedicated ".resource_table" ELF section.
  56  *
  57  * Some resources entries are mere announcements, where the host is informed
  58  * of specific remoteproc configuration. Other entries require the host to
  59  * do something (e.g. allocate a system resource). Sometimes a negotiation
  60  * is expected, where the firmware requests a resource, and once allocated,
  61  * the host should provide back its details (e.g. address of an allocated
  62  * memory region).
  63  *
  64  * The header of the resource table, as expressed by this structure,
  65  * contains a version number (should we need to change this format in the
  66  * future), the number of available resource entries, and their offsets
  67  * in the table.
  68  *
  69  * Immediately following this header are the resource entries themselves,
  70  * each of which begins with a resource entry header (as described below).
  71  */
  72 struct resource_table {
  73         u32 ver;
  74         u32 num;
  75         u32 reserved[2];
  76         u32 offset[0];
  77 } __packed;
  78
  79 /**
  80  * struct fw_rsc_hdr - firmware resource entry header
  81  * @type: resource type
  82  * @data: resource data
  83  *
  84  * Every resource entry begins with a 'struct fw_rsc_hdr' header providing
  85  * its @type. The content of the entry itself will immediately follow
  86  * this header, and it should be parsed according to the resource type.
  87  */
  88 struct fw_rsc_hdr {
  89         u32 type;
  90         u8 data[0];
  91 } __packed;
  92
  93 /**
  94  * enum fw_resource_type - types of resource entries
  95  *
  96  * @RSC_CARVEOUT:   request for allocation of a physically contiguous
  97  *                  memory region.
  98  * @RSC_DEVMEM:     request to iommu_map a memory-based peripheral.
  99  * @RSC_TRACE:      announces the availability of a trace buffer into which
 100  *                  the remote processor will be writing logs.
 101  * @RSC_VDEV:       declare support for a virtio device, and serve as its
 102  *                  virtio header.
 103  * @RSC_LAST:       just keep this one at the end
 104  *
 105  * For more details regarding a specific resource type, please see its
 106  * dedicated structure below.
 107  *
 108  * Please note that these values are used as indices to the rproc_handle_rsc
 109  * lookup table, so please keep them sane. Moreover, @RSC_LAST is used to
 110  * check the validity of an index before the lookup table is accessed, so
 111  * please update it as needed.
 112  */
 113 enum fw_resource_type {
 114         RSC_CARVEOUT    = 0,
 115         RSC_DEVMEM      = 1,
 116         RSC_TRACE       = 2,
 117         RSC_VDEV        = 3,
 118         RSC_LAST        = 4,
 119 };
 120
 121 #define FW_RSC_ADDR_ANY (0xFFFFFFFFFFFFFFFF)
 122
 123 /**
 124  * struct fw_rsc_carveout - physically contiguous memory request
 125  * @da: device address
 126  * @pa: physical address
 127  * @len: length (in bytes)
 128  * @flags: iommu protection flags
 129  * @reserved: reserved (must be zero)
 130  * @name: human-readable name of the requested memory region
 131  *
 132  * This resource entry requests the host to allocate a physically contiguous
 133  * memory region.
 134  *
 135  * These request entries should precede other firmware resource entries,
 136  * as other entries might request placing other data objects inside
 137  * these memory regions (e.g. data/code segments, trace resource entries, ...).
 138  *
 139  * Allocating memory this way helps utilizing the reserved physical memory
 140  * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
 141  * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
 142  * pressure is important; it may have a substantial impact on performance.
 143  *
 144  * If the firmware is compiled with static addresses, then @da should specify
 145  * the expected device address of this memory region. If @da is set to
 146  * FW_RSC_ADDR_ANY, then the host will dynamically allocate it, and then
 147  * overwrite @da with the dynamically allocated address.
 148  *
 149  * We will always use @da to negotiate the device addresses, even if it
 150  * isn't using an iommu. In that case, though, it will obviously contain
 151  * physical addresses.
 152  *
 153  * Some remote processors needs to know the allocated physical address
 154  * even if they do use an iommu. This is needed, e.g., if they control
 155  * hardware accelerators which access the physical memory directly (this
 156  * is the case with OMAP4 for instance). In that case, the host will
 157  * overwrite @pa with the dynamically allocated physical address.
 158  * Generally we don't want to expose physical addresses if we don't have to
 159  * (remote processors are generally _not_ trusted), so we might want to
 160  * change this to happen _only_ when explicitly required by the hardware.
 161  *
 162  * @flags is used to provide IOMMU protection flags, and @name should
 163  * (optionally) contain a human readable name of this carveout region
 164  * (mainly for debugging purposes).
 165  */
 166 struct fw_rsc_carveout {
 167         u32 da;
 168         u32 pa;
 169         u32 len;
 170         u32 flags;
 171         u32 reserved;
 172         u8 name[32];
 173 } __packed;
 174
 175 /**
 176  * struct fw_rsc_devmem - iommu mapping request
 177  * @da: device address
 178  * @pa: physical address
 179  * @len: length (in bytes)
 180  * @flags: iommu protection flags
 181  * @reserved: reserved (must be zero)
 182  * @name: human-readable name of the requested region to be mapped
 183  *
 184  * This resource entry requests the host to iommu map a physically contiguous
 185  * memory region. This is needed in case the remote processor requires
 186  * access to certain memory-based peripherals; _never_ use it to access
 187  * regular memory.
 188  *
 189  * This is obviously only needed if the remote processor is accessing memory
 190  * via an iommu.
 191  *
 192  * @da should specify the required device address, @pa should specify
 193  * the physical address we want to map, @len should specify the size of
 194  * the mapping and @flags is the IOMMU protection flags. As always, @name may
 195  * (optionally) contain a human readable name of this mapping (mainly for
 196  * debugging purposes).
 197  *
 198  * Note: at this point we just "trust" those devmem entries to contain valid
 199  * physical addresses, but this isn't safe and will be changed: eventually we
 200  * want remoteproc implementations to provide us ranges of physical addresses
 201  * the firmware is allowed to request, and not allow firmwares to request
 202  * access to physical addresses that are outside those ranges.
 203  */
 204 struct fw_rsc_devmem {
 205         u32 da;
 206         u32 pa;
 207         u32 len;
 208         u32 flags;
 209         u32 reserved;
 210         u8 name[32];
 211 } __packed;
 212
 213 /**
 214  * struct fw_rsc_trace - trace buffer declaration
 215  * @da: device address
 216  * @len: length (in bytes)
 217  * @reserved: reserved (must be zero)
 218  * @name: human-readable name of the trace buffer
 219  *
 220  * This resource entry provides the host information about a trace buffer
 221  * into which the remote processor will write log messages.
 222  *
 223  * @da specifies the device address of the buffer, @len specifies
 224  * its size, and @name may contain a human readable name of the trace buffer.
 225  *
 226  * After booting the remote processor, the trace buffers are exposed to the
 227  * user via debugfs entries (called trace0, trace1, etc..).
 228  */
 229 struct fw_rsc_trace {
 230         u32 da;
 231         u32 len;
 232         u32 reserved;
 233         u8 name[32];
 234 } __packed;
 235
 236 /**
 237  * struct fw_rsc_vdev_vring - vring descriptor entry
 238  * @da: device address
 239  * @align: the alignment between the consumer and producer parts of the vring
 240  * @num: num of buffers supported by this vring (must be power of two)
 241  * @notifyid is a unique rproc-wide notify index for this vring. This notify
 242  * index is used when kicking a remote processor, to let it know that this
 243  * vring is triggered.
 244  * @reserved: reserved (must be zero)
 245  *
 246  * This descriptor is not a resource entry by itself; it is part of the
 247  * vdev resource type (see below).
 248  *
 249  * Note that @da should either contain the device address where
 250  * the remote processor is expecting the vring, or indicate that
 251  * dynamically allocation of the vring's device address is supported.
 252  */
 253 struct fw_rsc_vdev_vring {
 254         u32 da;
 255         u32 align;
 256         u32 num;
 257         u32 notifyid;
 258         u32 reserved;
 259 } __packed;
 260
 261 /**
 262  * struct fw_rsc_vdev - virtio device header
 263  * @id: virtio device id (as in virtio_ids.h)
 264  * @notifyid is a unique rproc-wide notify index for this vdev. This notify
 265  * index is used when kicking a remote processor, to let it know that the
 266  * status/features of this vdev have changes.
 267  * @dfeatures specifies the virtio device features supported by the firmware
 268  * @gfeatures is a place holder used by the host to write back the
 269  * negotiated features that are supported by both sides.
 270  * @config_len is the size of the virtio config space of this vdev. The config
 271  * space lies in the resource table immediate after this vdev header.
 272  * @status is a place holder where the host will indicate its virtio progress.
 273  * @num_of_vrings indicates how many vrings are described in this vdev header
 274  * @reserved: reserved (must be zero)
 275  * @vring is an array of @num_of_vrings entries of 'struct fw_rsc_vdev_vring'.
 276  *
 277  * This resource is a virtio device header: it provides information about
 278  * the vdev, and is then used by the host and its peer remote processors
 279  * to negotiate and share certain virtio properties.
 280  *
 281  * By providing this resource entry, the firmware essentially asks remoteproc
 282  * to statically allocate a vdev upon registration of the rproc (dynamic vdev
 283  * allocation is not yet supported).
 284  *
 285  * Note: unlike virtualization systems, the term 'host' here means
 286  * the Linux side which is running remoteproc to control the remote
 287  * processors. We use the name 'gfeatures' to comply with virtio's terms,
 288  * though there isn't really any virtualized guest OS here: it's the host
 289  * which is responsible for negotiating the final features.
 290  * Yeah, it's a bit confusing.
 291  *
 292  * Note: immediately following this structure is the virtio config space for
 293  * this vdev (which is specific to the vdev; for more info, read the virtio
 294  * spec). the size of the config space is specified by @config_len.
 295  */
 296 struct fw_rsc_vdev {
 297         u32 id;
 298         u32 notifyid;
 299         u32 dfeatures;
 300         u32 gfeatures;
 301         u32 config_len;
 302         u8 status;
 303         u8 num_of_vrings;
 304         u8 reserved[2];
 305         struct fw_rsc_vdev_vring vring[0];
 306 } __packed;
 307
 308 /**
 309  * struct rproc_mem_entry - memory entry descriptor
 310  * @va: virtual address
 311  * @dma: dma address
 312  * @len: length, in bytes
 313  * @da: device address
 314  * @priv: associated data
 315  * @node: list node
 316  */
 317 struct rproc_mem_entry {
 318         void *va;
 319         dma_addr_t dma;
 320         int len;
 321         u32 da;
 322         void *priv;
 323         struct list_head node;
 324 };
 325
 326 struct rproc;
 327
 328 /**
 329  * struct rproc_ops - platform-specific device handlers
 330  * @start:      power on the device and boot it
 331  * @stop:       power off the device
 332  * @kick:       kick a virtqueue (virtqueue id given as a parameter)
 333  */
 334 struct rproc_ops {
 335         int (*start)(struct rproc *rproc);
 336         int (*stop)(struct rproc *rproc);
 337         void (*kick)(struct rproc *rproc, int vqid);
 338 };
 339
 340 /**
 341  * enum rproc_state - remote processor states
 342  * @RPROC_OFFLINE:      device is powered off
 343  * @RPROC_SUSPENDED:    device is suspended; needs to be woken up to receive
 344  *                      a message.
 345  * @RPROC_RUNNING:      device is up and running
 346  * @RPROC_CRASHED:      device has crashed; need to start recovery
 347  * @RPROC_LAST:         just keep this one at the end
 348  *
 349  * Please note that the values of these states are used as indices
 350  * to rproc_state_string, a state-to-name lookup table,
 351  * so please keep the two synchronized. @RPROC_LAST is used to check
 352  * the validity of an index before the lookup table is accessed, so
 353  * please update it as needed too.
 354  */
 355 enum rproc_state {
 356         RPROC_OFFLINE   = 0,
 357         RPROC_SUSPENDED = 1,
 358         RPROC_RUNNING   = 2,
 359         RPROC_CRASHED   = 3,
 360         RPROC_LAST      = 4,
 361 };
 362
 363 /**
 364  * enum rproc_crash_type - remote processor crash types
 365  * @RPROC_MMUFAULT:     iommu fault
 366  *
 367  * Each element of the enum is used as an array index. So that, the value of
 368  * the elements should be always something sane.
 369  *
 370  * Feel free to add more types when needed.
 371  */
 372 enum rproc_crash_type {
 373         RPROC_MMUFAULT,
 374 };
 375
 376 /**
 377  * struct rproc - represents a physical remote processor device
 378  * @node: klist node of this rproc object
 379  * @domain: iommu domain
 380  * @name: human readable name of the rproc
 381  * @firmware: name of firmware file to be loaded
 382  * @priv: private data which belongs to the platform-specific rproc module
 383  * @ops: platform-specific start/stop rproc handlers
 384  * @dev: virtual device for refcounting and common remoteproc behavior
 385  * @fw_ops: firmware-specific handlers
 386  * @power: refcount of users who need this rproc powered up
 387  * @state: state of the device
 388  * @lock: lock which protects concurrent manipulations of the rproc
 389  * @dbg_dir: debugfs directory of this rproc device
 390  * @traces: list of trace buffers
 391  * @num_traces: number of trace buffers
 392  * @carveouts: list of physically contiguous memory allocations
 393  * @mappings: list of iommu mappings we initiated, needed on shutdown
 394  * @firmware_loading_complete: marks e/o asynchronous firmware loading
 395  * @bootaddr: address of first instruction to boot rproc with (optional)
 396  * @rvdevs: list of remote virtio devices
 397  * @notifyids: idr for dynamically assigning rproc-wide unique notify ids
 398  * @index: index of this rproc device
 399  * @crash_handler: workqueue for handling a crash
 400  * @crash_cnt: crash counter
 401  * @crash_comp: completion used to sync crash handler and the rproc reload
 402  * @recovery_disabled: flag that state if recovery was disabled
 403  * @max_notifyid: largest allocated notify id.
 404  * @table_ptr: pointer to the resource table in effect
 405  * @cached_table: copy of the resource table
 406  * @table_csum: checksum of the resource table
 407  */
 408 struct rproc {
 409         struct klist_node node;
 410         struct iommu_domain *domain;
 411         const char *name;
 412         const char *firmware;
 413         void *priv;
 414         const struct rproc_ops *ops;
 415         struct device dev;
 416         const struct rproc_fw_ops *fw_ops;
 417         atomic_t power;
 418         unsigned int state;
 419         struct mutex lock;
 420         struct dentry *dbg_dir;
 421         struct list_head traces;
 422         int num_traces;
 423         struct list_head carveouts;
 424         struct list_head mappings;
 425         struct completion firmware_loading_complete;
 426         u32 bootaddr;
 427         struct list_head rvdevs;
 428         struct idr notifyids;
 429         int index;
 430         struct work_struct crash_handler;
 431         unsigned crash_cnt;
 432         struct completion crash_comp;
 433         bool recovery_disabled;
 434         int max_notifyid;
 435         struct resource_table *table_ptr;
 436         struct resource_table *cached_table;
 437         u32 table_csum;
 438 };
 439
 440 /* we currently support only two vrings per rvdev */
 441
 442 #define RVDEV_NUM_VRINGS 2
 443
 444 /**
 445  * struct rproc_vring - remoteproc vring state
 446  * @va: virtual address
 447  * @dma: dma address
 448  * @len: length, in bytes
 449  * @da: device address
 450  * @align: vring alignment
 451  * @notifyid: rproc-specific unique vring index
 452  * @rvdev: remote vdev
 453  * @vq: the virtqueue of this vring
 454  */
 455 struct rproc_vring {
 456         void *va;
 457         dma_addr_t dma;
 458         int len;
 459         u32 da;
 460         u32 align;
 461         int notifyid;
 462         struct rproc_vdev *rvdev;
 463         struct virtqueue *vq;
 464 };
 465
 466 /**
 467  * struct rproc_vdev - remoteproc state for a supported virtio device
 468  * @node: list node
 469  * @rproc: the rproc handle
 470  * @vdev: the virio device
 471  * @vring: the vrings for this vdev
 472  * @rsc_offset: offset of the vdev's resource entry
 473  */
 474 struct rproc_vdev {
 475         struct list_head node;
 476         struct rproc *rproc;
 477         struct virtio_device vdev;
 478         struct rproc_vring vring[RVDEV_NUM_VRINGS];
 479         u32 rsc_offset;
 480 };
 481
 482 struct rproc *rproc_alloc(struct device *dev, const char *name,
 483                                 const struct rproc_ops *ops,
 484                                 const char *firmware, int len);
 485 void rproc_put(struct rproc *rproc);
 486 int rproc_add(struct rproc *rproc);
 487 int rproc_del(struct rproc *rproc);
 488
 489 int rproc_boot(struct rproc *rproc);
 490 void rproc_shutdown(struct rproc *rproc);
 491 void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
 492
 493 static inline struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
 494 {
 495         return container_of(vdev, struct rproc_vdev, vdev);
 496 }
 497
 498 static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
 499 {
 500         struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
 501
 502         return rvdev->rproc;
 503 }
 504
 505 #endif /* REMOTEPROC_H */