linux/include/linux/remoteproc.h

/*
 * Remote Processor Framework
 *
 * Copyright(c) 2011 Texas Instruments, Inc.
 * Copyright(c) 2011 Google, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.
 * * Neither the name Texas Instruments nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef REMOTEPROC_H
#define REMOTEPROC_H

#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/virtio.h>
#include <linux/cdev.h>
#include <linux/completion.h>
#include <linux/idr.h>
#include <linux/of.h>

/**
 * struct resource_table - firmware resource table header
 * @ver: version number
 * @num: number of resource entries
 * @reserved: reserved (must be zero)
 * @offset: array of offsets pointing at the various resource entries
 *
 * A resource table is essentially a list of system resources required
 * by the remote processor. It may also include configuration entries.
 * If needed, the remote processor firmware should contain this table
 * as a dedicated ".resource_table" ELF section.
 *
 * Some resources entries are mere announcements, where the host is informed
 * of specific remoteproc configuration. Other entries require the host to
 * do something (e.g. allocate a system resource). Sometimes a negotiation
 * is expected, where the firmware requests a resource, and once allocated,
 * the host should provide back its details (e.g. address of an allocated
 * memory region).
 *
 * The header of the resource table, as expressed by this structure,
 * contains a version number (should we need to change this format in the
 * future), the number of available resource entries, and their offsets
 * in the table.
 *
 * Immediately following this header are the resource entries themselves,
 * each of which begins with a resource entry header (as described below).
 */
struct resource_table {} __packed;

/**
 * struct fw_rsc_hdr - firmware resource entry header
 * @type: resource type
 * @data: resource data
 *
 * Every resource entry begins with a 'struct fw_rsc_hdr' header providing
 * its @type. The content of the entry itself will immediately follow
 * this header, and it should be parsed according to the resource type.
 */
struct fw_rsc_hdr {} __packed;

/**
 * enum fw_resource_type - types of resource entries
 *
 * @RSC_CARVEOUT:   request for allocation of a physically contiguous
 *		    memory region.
 * @RSC_DEVMEM:     request to iommu_map a memory-based peripheral.
 * @RSC_TRACE:	    announces the availability of a trace buffer into which
 *		    the remote processor will be writing logs.
 * @RSC_VDEV:       declare support for a virtio device, and serve as its
 *		    virtio header.
 * @RSC_LAST:       just keep this one at the end of standard resources
 * @RSC_VENDOR_START:	start of the vendor specific resource types range
 * @RSC_VENDOR_END:	end of the vendor specific resource types range
 *
 * For more details regarding a specific resource type, please see its
 * dedicated structure below.
 *
 * Please note that these values are used as indices to the rproc_handle_rsc
 * lookup table, so please keep them sane. Moreover, @RSC_LAST is used to
 * check the validity of an index before the lookup table is accessed, so
 * please update it as needed.
 */
enum fw_resource_type {};

#define FW_RSC_ADDR_ANY

/**
 * struct fw_rsc_carveout - physically contiguous memory request
 * @da: device address
 * @pa: physical address
 * @len: length (in bytes)
 * @flags: iommu protection flags
 * @reserved: reserved (must be zero)
 * @name: human-readable name of the requested memory region
 *
 * This resource entry requests the host to allocate a physically contiguous
 * memory region.
 *
 * These request entries should precede other firmware resource entries,
 * as other entries might request placing other data objects inside
 * these memory regions (e.g. data/code segments, trace resource entries, ...).
 *
 * Allocating memory this way helps utilizing the reserved physical memory
 * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
 * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
 * pressure is important; it may have a substantial impact on performance.
 *
 * If the firmware is compiled with static addresses, then @da should specify
 * the expected device address of this memory region. If @da is set to
 * FW_RSC_ADDR_ANY, then the host will dynamically allocate it, and then
 * overwrite @da with the dynamically allocated address.
 *
 * We will always use @da to negotiate the device addresses, even if it
 * isn't using an iommu. In that case, though, it will obviously contain
 * physical addresses.
 *
 * Some remote processors needs to know the allocated physical address
 * even if they do use an iommu. This is needed, e.g., if they control
 * hardware accelerators which access the physical memory directly (this
 * is the case with OMAP4 for instance). In that case, the host will
 * overwrite @pa with the dynamically allocated physical address.
 * Generally we don't want to expose physical addresses if we don't have to
 * (remote processors are generally _not_ trusted), so we might want to
 * change this to happen _only_ when explicitly required by the hardware.
 *
 * @flags is used to provide IOMMU protection flags, and @name should
 * (optionally) contain a human readable name of this carveout region
 * (mainly for debugging purposes).
 */
struct fw_rsc_carveout {} __packed;

/**
 * struct fw_rsc_devmem - iommu mapping request
 * @da: device address
 * @pa: physical address
 * @len: length (in bytes)
 * @flags: iommu protection flags
 * @reserved: reserved (must be zero)
 * @name: human-readable name of the requested region to be mapped
 *
 * This resource entry requests the host to iommu map a physically contiguous
 * memory region. This is needed in case the remote processor requires
 * access to certain memory-based peripherals; _never_ use it to access
 * regular memory.
 *
 * This is obviously only needed if the remote processor is accessing memory
 * via an iommu.
 *
 * @da should specify the required device address, @pa should specify
 * the physical address we want to map, @len should specify the size of
 * the mapping and @flags is the IOMMU protection flags. As always, @name may
 * (optionally) contain a human readable name of this mapping (mainly for
 * debugging purposes).
 *
 * Note: at this point we just "trust" those devmem entries to contain valid
 * physical addresses, but this isn't safe and will be changed: eventually we
 * want remoteproc implementations to provide us ranges of physical addresses
 * the firmware is allowed to request, and not allow firmwares to request
 * access to physical addresses that are outside those ranges.
 */
struct fw_rsc_devmem {} __packed;

/**
 * struct fw_rsc_trace - trace buffer declaration
 * @da: device address
 * @len: length (in bytes)
 * @reserved: reserved (must be zero)
 * @name: human-readable name of the trace buffer
 *
 * This resource entry provides the host information about a trace buffer
 * into which the remote processor will write log messages.
 *
 * @da specifies the device address of the buffer, @len specifies
 * its size, and @name may contain a human readable name of the trace buffer.
 *
 * After booting the remote processor, the trace buffers are exposed to the
 * user via debugfs entries (called trace0, trace1, etc..).
 */
struct fw_rsc_trace {} __packed;

/**
 * struct fw_rsc_vdev_vring - vring descriptor entry
 * @da: device address
 * @align: the alignment between the consumer and producer parts of the vring
 * @num: num of buffers supported by this vring (must be power of two)
 * @notifyid: a unique rproc-wide notify index for this vring. This notify
 * index is used when kicking a remote processor, to let it know that this
 * vring is triggered.
 * @pa: physical address
 *
 * This descriptor is not a resource entry by itself; it is part of the
 * vdev resource type (see below).
 *
 * Note that @da should either contain the device address where
 * the remote processor is expecting the vring, or indicate that
 * dynamically allocation of the vring's device address is supported.
 */
struct fw_rsc_vdev_vring {} __packed;

/**
 * struct fw_rsc_vdev - virtio device header
 * @id: virtio device id (as in virtio_ids.h)
 * @notifyid: a unique rproc-wide notify index for this vdev. This notify
 * index is used when kicking a remote processor, to let it know that the
 * status/features of this vdev have changes.
 * @dfeatures: specifies the virtio device features supported by the firmware
 * @gfeatures: a place holder used by the host to write back the
 * negotiated features that are supported by both sides.
 * @config_len: the size of the virtio config space of this vdev. The config
 * space lies in the resource table immediate after this vdev header.
 * @status: a place holder where the host will indicate its virtio progress.
 * @num_of_vrings: indicates how many vrings are described in this vdev header
 * @reserved: reserved (must be zero)
 * @vring: an array of @num_of_vrings entries of 'struct fw_rsc_vdev_vring'.
 *
 * This resource is a virtio device header: it provides information about
 * the vdev, and is then used by the host and its peer remote processors
 * to negotiate and share certain virtio properties.
 *
 * By providing this resource entry, the firmware essentially asks remoteproc
 * to statically allocate a vdev upon registration of the rproc (dynamic vdev
 * allocation is not yet supported).
 *
 * Note:
 * 1. unlike virtualization systems, the term 'host' here means
 *    the Linux side which is running remoteproc to control the remote
 *    processors. We use the name 'gfeatures' to comply with virtio's terms,
 *    though there isn't really any virtualized guest OS here: it's the host
 *    which is responsible for negotiating the final features.
 *    Yeah, it's a bit confusing.
 *
 * 2. immediately following this structure is the virtio config space for
 *    this vdev (which is specific to the vdev; for more info, read the virtio
 *    spec). The size of the config space is specified by @config_len.
 */
struct fw_rsc_vdev {} __packed;

struct rproc;

/**
 * struct rproc_mem_entry - memory entry descriptor
 * @va:	virtual address
 * @is_iomem: io memory
 * @dma: dma address
 * @len: length, in bytes
 * @da: device address
 * @release: release associated memory
 * @priv: associated data
 * @name: associated memory region name (optional)
 * @node: list node
 * @rsc_offset: offset in resource table
 * @flags: iommu protection flags
 * @of_resm_idx: reserved memory phandle index
 * @alloc: specific memory allocator function
 */
struct rproc_mem_entry {};

struct firmware;

/**
 * enum rsc_handling_status - return status of rproc_ops handle_rsc hook
 * @RSC_HANDLED:	resource was handled
 * @RSC_IGNORED:	resource was ignored
 */
enum rsc_handling_status {};

/**
 * struct rproc_ops - platform-specific device handlers
 * @prepare:	prepare device for code loading
 * @unprepare:	unprepare device after stop
 * @start:	power on the device and boot it
 * @stop:	power off the device
 * @attach:	attach to a device that his already powered up
 * @detach:	detach from a device, leaving it powered up
 * @kick:	kick a virtqueue (virtqueue id given as a parameter)
 * @da_to_va:	optional platform hook to perform address translations
 * @parse_fw:	parse firmware to extract information (e.g. resource table)
 * @handle_rsc:	optional platform hook to handle vendor resources. Should return
 *		RSC_HANDLED if resource was handled, RSC_IGNORED if not handled
 *		and a negative value on error
 * @find_loaded_rsc_table: find the loaded resource table from firmware image
 * @get_loaded_rsc_table: get resource table installed in memory
 *			  by external entity
 * @load:		load firmware to memory, where the remote processor
 *			expects to find it
 * @sanity_check:	sanity check the fw image
 * @get_boot_addr:	get boot address to entry point specified in firmware
 * @panic:	optional callback to react to system panic, core will delay
 *		panic at least the returned number of milliseconds
 * @coredump:	  collect firmware dump after the subsystem is shutdown
 */
struct rproc_ops {};

/**
 * enum rproc_state - remote processor states
 * @RPROC_OFFLINE:	device is powered off
 * @RPROC_SUSPENDED:	device is suspended; needs to be woken up to receive
 *			a message.
 * @RPROC_RUNNING:	device is up and running
 * @RPROC_CRASHED:	device has crashed; need to start recovery
 * @RPROC_DELETED:	device is deleted
 * @RPROC_ATTACHED:	device has been booted by another entity and the core
 *			has attached to it
 * @RPROC_DETACHED:	device has been booted by another entity and waiting
 *			for the core to attach to it
 * @RPROC_LAST:		just keep this one at the end
 *
 * Please note that the values of these states are used as indices
 * to rproc_state_string, a state-to-name lookup table,
 * so please keep the two synchronized. @RPROC_LAST is used to check
 * the validity of an index before the lookup table is accessed, so
 * please update it as needed too.
 */
enum rproc_state {};

/**
 * enum rproc_crash_type - remote processor crash types
 * @RPROC_MMUFAULT:	iommu fault
 * @RPROC_WATCHDOG:	watchdog bite
 * @RPROC_FATAL_ERROR:	fatal error
 *
 * Each element of the enum is used as an array index. So that, the value of
 * the elements should be always something sane.
 *
 * Feel free to add more types when needed.
 */
enum rproc_crash_type {};

/**
 * enum rproc_dump_mechanism - Coredump options for core
 * @RPROC_COREDUMP_DISABLED:	Don't perform any dump
 * @RPROC_COREDUMP_ENABLED:	Copy dump to separate buffer and carry on with
 *				recovery
 * @RPROC_COREDUMP_INLINE:	Read segments directly from device memory. Stall
 *				recovery until all segments are read
 */
enum rproc_dump_mechanism {};

/**
 * struct rproc_dump_segment - segment info from ELF header
 * @node:	list node related to the rproc segment list
 * @da:		device address of the segment
 * @size:	size of the segment
 * @priv:	private data associated with the dump_segment
 * @dump:	custom dump function to fill device memory segment associated
 *		with coredump
 * @offset:	offset of the segment
 */
struct rproc_dump_segment {};

/**
 * enum rproc_features - features supported
 *
 * @RPROC_FEAT_ATTACH_ON_RECOVERY: The remote processor does not need help
 *				   from Linux to recover, such as firmware
 *				   loading. Linux just needs to attach after
 *				   recovery.
 */

enum rproc_features {};

/**
 * struct rproc - represents a physical remote processor device
 * @node: list node of this rproc object
 * @domain: iommu domain
 * @name: human readable name of the rproc
 * @firmware: name of firmware file to be loaded
 * @priv: private data which belongs to the platform-specific rproc module
 * @ops: platform-specific start/stop rproc handlers
 * @dev: virtual device for refcounting and common remoteproc behavior
 * @power: refcount of users who need this rproc powered up
 * @state: state of the device
 * @dump_conf: Currently selected coredump configuration
 * @lock: lock which protects concurrent manipulations of the rproc
 * @dbg_dir: debugfs directory of this rproc device
 * @traces: list of trace buffers
 * @num_traces: number of trace buffers
 * @carveouts: list of physically contiguous memory allocations
 * @mappings: list of iommu mappings we initiated, needed on shutdown
 * @bootaddr: address of first instruction to boot rproc with (optional)
 * @rvdevs: list of remote virtio devices
 * @subdevs: list of subdevices, to following the running state
 * @notifyids: idr for dynamically assigning rproc-wide unique notify ids
 * @index: index of this rproc device
 * @crash_handler: workqueue for handling a crash
 * @crash_cnt: crash counter
 * @recovery_disabled: flag that state if recovery was disabled
 * @max_notifyid: largest allocated notify id.
 * @table_ptr: pointer to the resource table in effect
 * @clean_table: copy of the resource table without modifications.  Used
 *		 when a remote processor is attached or detached from the core
 * @cached_table: copy of the resource table
 * @table_sz: size of @cached_table
 * @has_iommu: flag to indicate if remote processor is behind an MMU
 * @auto_boot: flag to indicate if remote processor should be auto-started
 * @sysfs_read_only: flag to make remoteproc sysfs files read only
 * @dump_segments: list of segments in the firmware
 * @nb_vdev: number of vdev currently handled by rproc
 * @elf_class: firmware ELF class
 * @elf_machine: firmware ELF machine
 * @cdev: character device of the rproc
 * @cdev_put_on_release: flag to indicate if remoteproc should be shutdown on @char_dev release
 * @features: indicate remoteproc features
 */
struct rproc {};

/**
 * struct rproc_subdev - subdevice tied to a remoteproc
 * @node: list node related to the rproc subdevs list
 * @prepare: prepare function, called before the rproc is started
 * @start: start function, called after the rproc has been started
 * @stop: stop function, called before the rproc is stopped; the @crashed
 *	    parameter indicates if this originates from a recovery
 * @unprepare: unprepare function, called after the rproc has been stopped
 */
struct rproc_subdev {};

/* we currently support only two vrings per rvdev */

#define RVDEV_NUM_VRINGS

/**
 * struct rproc_vring - remoteproc vring state
 * @va:	virtual address
 * @num: vring size
 * @da: device address
 * @align: vring alignment
 * @notifyid: rproc-specific unique vring index
 * @rvdev: remote vdev
 * @vq: the virtqueue of this vring
 */
struct rproc_vring {};

/**
 * struct rproc_vdev - remoteproc state for a supported virtio device
 * @subdev: handle for registering the vdev as a rproc subdevice
 * @pdev: remoteproc virtio platform device
 * @id: virtio device id (as in virtio_ids.h)
 * @node: list node
 * @rproc: the rproc handle
 * @vring: the vrings for this vdev
 * @rsc_offset: offset of the vdev's resource entry
 * @index: vdev position versus other vdev declared in resource table
 */
struct rproc_vdev {};

struct rproc *rproc_get_by_phandle(phandle phandle);
struct rproc *rproc_get_by_child(struct device *dev);

struct rproc *rproc_alloc(struct device *dev, const char *name,
			  const struct rproc_ops *ops,
			  const char *firmware, int len);
void rproc_put(struct rproc *rproc);
int rproc_add(struct rproc *rproc);
int rproc_del(struct rproc *rproc);
void rproc_free(struct rproc *rproc);
void rproc_resource_cleanup(struct rproc *rproc);

struct rproc *devm_rproc_alloc(struct device *dev, const char *name,
			       const struct rproc_ops *ops,
			       const char *firmware, int len);
int devm_rproc_add(struct device *dev, struct rproc *rproc);

void rproc_add_carveout(struct rproc *rproc, struct rproc_mem_entry *mem);

struct rproc_mem_entry *
rproc_mem_entry_init(struct device *dev,
		     void *va, dma_addr_t dma, size_t len, u32 da,
		     int (*alloc)(struct rproc *, struct rproc_mem_entry *),
		     int (*release)(struct rproc *, struct rproc_mem_entry *),
		     const char *name, ...);

struct rproc_mem_entry *
rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len,
			     u32 da, const char *name, ...);

int rproc_boot(struct rproc *rproc);
int rproc_shutdown(struct rproc *rproc);
int rproc_detach(struct rproc *rproc);
int rproc_set_firmware(struct rproc *rproc, const char *fw_name);
void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
void *rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem);

/* from remoteproc_coredump.c */
void rproc_coredump_cleanup(struct rproc *rproc);
void rproc_coredump(struct rproc *rproc);
void rproc_coredump_using_sections(struct rproc *rproc);
int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size);
int rproc_coredump_add_custom_segment(struct rproc *rproc,
				      dma_addr_t da, size_t size,
				      void (*dumpfn)(struct rproc *rproc,
						     struct rproc_dump_segment *segment,
						     void *dest, size_t offset,
						     size_t size),
				      void *priv);
int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine);

void rproc_add_subdev(struct rproc *rproc, struct rproc_subdev *subdev);

void rproc_remove_subdev(struct rproc *rproc, struct rproc_subdev *subdev);

#endif /* REMOTEPROC_H */