diff options
Diffstat (limited to 'include/linux/remoteproc.h')
| -rw-r--r-- | include/linux/remoteproc.h | 289 |
1 files changed, 235 insertions, 54 deletions
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index ada4cb063dfe..6040f831f626 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -50,39 +50,51 @@ #define AMP_VRING_ALIGN (4096) /** - * struct fw_resource - describes an entry from the resource section - * @type: resource type - * @id: index number of the resource - * @da: device address of the resource - * @pa: physical address of the resource - * @len: size, in bytes, of the resource - * @flags: properties of the resource, e.g. iommu protection required - * @reserved: must be 0 atm - * @name: name of resource + * 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 * - * The remote processor firmware should contain a "resource table": - * array of 'struct fw_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. reserve a requested resource) and possibly also reply - * by overwriting a member inside 'struct fw_resource' with info about the - * allocated resource. - * - * Different resource entries use different members of this struct, - * with different meanings. This is pretty limiting and error-prone, - * so the plan is to move to variable-length TLV-based resource entries, - * where each resource type will have its own structure. + * 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_resource { +struct fw_rsc_hdr { u32 type; - u32 id; - u64 da; - u64 pa; - u32 len; - u32 flags; - u8 reserved[16]; - u8 name[48]; + u8 data[0]; } __packed; /** @@ -92,30 +104,13 @@ struct fw_resource { * 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. In this case, - * 'da' indicates the device address where logs are written to, - * and 'len' is the size of the trace buffer. - * @RSC_VRING: request for allocation of a virtio vring (address should - * be indicated in 'da', and 'len' should contain the number - * of buffers supported by the vring). - * @RSC_VIRTIO_DEV: this entry declares about support for a virtio device, - * and serves as the virtio header. 'da' holds the - * the virtio device features, 'pa' holds the virtio guest - * features, 'len' holds the virtio status, and 'flags' holds - * the virtio id (currently only VIRTIO_ID_RPMSG is supported). + * 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 * - * Most of the resource entries share the basic idea of address/length - * negotiation with the host: the firmware usually asks (on behalf of the - * remote processor that will soon be booted with it) for memory - * of size 'len' bytes, and the host needs to allocate it and provide - * the device/physical address (when relevant) in 'da'/'pa' respectively. - * - * If the firmware is compiled with hard coded device addresses, and - * can't handle dynamically allocated 'da' values, then the 'da' field - * will contain the expected device addresses (today we actually only support - * this scheme, as there aren't yet any use cases for dynamically allocated - * device addresses). + * 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 @@ -126,11 +121,197 @@ enum fw_resource_type { RSC_CARVEOUT = 0, RSC_DEVMEM = 1, RSC_TRACE = 2, - RSC_VRING = 3, - RSC_VIRTIO_DEV = 4, - RSC_LAST = 5, + 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 @@ -144,7 +325,7 @@ struct rproc_mem_entry { void *va; dma_addr_t dma; int len; - u64 da; + u32 da; void *priv; struct list_head node; }; @@ -226,7 +407,7 @@ struct rproc { struct list_head carveouts; struct list_head mappings; struct completion firmware_loading_complete; - u64 bootaddr; + u32 bootaddr; struct rproc_vdev *rvdev; }; |