/*
* 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/kref.h>
#include <linux/klist.h>
#include <linux/mutex.h>
#include <linux/virtio.h>
#include <linux/completion.h>
#include <linux/idr.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 {
u32 ver;
u32 num;
u32 reserved[2];
u32 offset[0];
} __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 {
u32 type;
u8 data[0];
} __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
*
* 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 {
RSC_CARVEOUT = 0,
RSC_DEVMEM = 1,
RSC_TRACE = 2,
RSC_VDEV = 3,
RSC_LAST = 4,
};
#define FW_RSC_ADDR_ANY (0xFFFFFFFFFFFFFFFF)
/**
* 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 {
u32 da;
u32 pa;
u32 len;
u32 flags;
u32 reserved;
u8 name[32];
} __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 {
u32 da;
u32 pa;
u32 len;
u32 flags;
u32 reserved;
u8 name[32];
} __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 {
u32 da;
u32 len;
u32 reserved;
u8 name[32];
} __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 is 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.
* @reserved: reserved (must be zero)
*
* 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 {
u32 da;
u32 align;
u32 num;
u32 notifyid;
u32 reserved;
} __packed;
/**
* struct fw_rsc_vdev - virtio device header
* @id: virtio device id (as in virtio_ids.h)
* @notifyid is 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 is a place holder used by the host to write back the
* negotiated features that are supported by both sides.
* @config_len is the size of the virtio config space of this vdev. The config
* space lies in the resource table immediate after this vdev header.
* @status is 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 is 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: 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.
*
* Note: 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 {
u32 id;
u32 notifyid;
u32 dfeatures;
u32 gfeatures;
u32 config_len;
u8 status;
u8 num_of_vrings;
u8 reserved[2];
struct fw_rsc_vdev_vring vring[0];
} __packed;
/**
* struct rproc_mem_entry - memory entry descriptor
* @va: virtual address
* @dma: dma address
* @len: length, in bytes
* @da: device address
* @priv: associated data
* @node: list node
*/
struct rproc_mem_entry {
void *va;
dma_addr_t dma;
int len;
u32 da;
void *priv;
struct list_head node;
};
struct rproc;
/**
* struct rproc_ops - platform-specific device handlers
* @start: power on the device and boot it
* @stop: power off the device
* @kick: kick a virtqueue (virtqueue id given as a parameter)
*/
struct rproc_ops {
int (*start)(struct rproc *rproc);
int (*stop)(struct rproc *rproc);
void (*kick)(struct rproc *rproc, int vqid);
};
/**
* 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_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 {
RPROC_OFFLINE = 0,
RPROC_SUSPENDED = 1,
RPROC_RUNNING = 2,
RPROC_CRASHED = 3,
RPROC_LAST = 4,
};
/**
* struct rproc - represents a physical remote processor device
* @node: klist 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: underlying device
* @refcount: refcount of users that have a valid pointer to this rproc
* @power: refcount of users who need this rproc powered up
* @state: state of the device
* @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
* @firmware_loading_complete: marks e/o asynchronous firmware loading
* @bootaddr: address of first instruction to boot rproc with (optional)
* @rvdevs: list of remote virtio devices
* @notifyids: idr for dynamically assigning rproc-wide unique notify ids
*/
struct rproc {
struct klist_node node;
struct iommu_domain *domain;
const char *name;
const char *firmware;
void *priv;
const struct rproc_ops *ops;
struct device *dev;
struct kref refcount;
atomic_t power;
unsigned int state;
struct mutex lock;
struct dentry *dbg_dir;
struct list_head traces;
int num_traces;
struct list_head carveouts;
struct list_head mappings;
struct completion firmware_loading_complete;
u32 bootaddr;
struct list_head rvdevs;
struct idr notifyids;
};
/* we currently support only two vrings per rvdev */
#define RVDEV_NUM_VRINGS 2
/**
* struct rproc_vring - remoteproc vring state
* @va: virtual address
* @dma: dma address
* @len: length, in bytes
* @da: device address
* @align: vring alignment
* @notifyid: rproc-specific unique vring index
* @rvdev: remote vdev
* @vq: the virtqueue of this vring
*/
struct rproc_vring {
void *va;
dma_addr_t dma;
int len;
u32 da;
u32 align;
int notifyid;
struct rproc_vdev *rvdev;
struct virtqueue *vq;
};
/**
* struct rproc_vdev - remoteproc state for a supported virtio device
* @node: list node
* @rproc: the rproc handle
* @vdev: the virio device
* @vring: the vrings for this vdev
* @dfeatures: virtio device features
* @gfeatures: virtio guest features
*/
struct rproc_vdev {
struct list_head node;
struct rproc *rproc;
struct virtio_device vdev;
struct rproc_vring vring[RVDEV_NUM_VRINGS];
unsigned long dfeatures;
unsigned long gfeatures;
};
struct rproc *rproc_get_by_name(const char *name);
void rproc_put(struct rproc *rproc);
struct rproc *rproc_alloc(struct device *dev, const char *name,
const struct rproc_ops *ops,
const char *firmware, int len);
void rproc_free(struct rproc *rproc);
int rproc_register(struct rproc *rproc);
int rproc_unregister(struct rproc *rproc);
int rproc_boot(struct rproc *rproc);
void rproc_shutdown(struct rproc *rproc);
static inline struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
{
return container_of(vdev, struct rproc_vdev, vdev);
}
static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
{
struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
return rvdev->rproc;
}
#endif /* REMOTEPROC_H */
