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+/*
+ * 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 */