/* * \brief Block-driver interface * \author Christian Helmuth * \author Sebastian Sumpf * \author Stefan kalkowski * \date 2011-05-23 */ /* * Copyright (C) 2011-2013 Genode Labs GmbH * * This file is part of the Genode OS framework, which is distributed * under the terms of the GNU General Public License version 2. */ #ifndef _INCLUDE__BLOCK__DRIVER_H_ #define _INCLUDE__BLOCK__DRIVER_H_ #include #include #include #include #include namespace Block { class Driver_session; class Driver; struct Driver_factory; }; class Block::Driver_session : public Block::Session_rpc_object { public: /** * Constructor * * \param tx_ds dataspace used as communication buffer * for the tx packet stream * \param ep entry point used for packet-stream channel */ Driver_session(Genode::Dataspace_capability tx_ds, Genode::Rpc_entrypoint &ep) : Session_rpc_object(tx_ds, ep) { } /** * Acknowledges a packet processed by the driver to the client * * \param packet the packet to acknowledge * \param success indicated whether the processing was successful * * \throw Ack_congestion */ virtual void ack_packet(Packet_descriptor &packet, bool success) = 0; }; /** * Interface to be implemented by the device-specific driver code */ class Block::Driver { private: Driver_session *_session = nullptr; public: /** * Exceptions */ class Io_error : public ::Genode::Exception { }; class Request_congestion : public ::Genode::Exception { }; /** * Request block size for driver and medium */ virtual Genode::size_t block_size() = 0; /** * Request capacity of medium in blocks */ virtual Block::sector_t block_count() = 0; /** * Request operations supported by the device */ virtual Session::Operations ops() = 0; /** * Read from medium * * \param block_number number of first block to read * \param block_count number of blocks to read * \param buffer output buffer for read request * \param packet packet descriptor from the client * * \throw Request_congestion * * Note: should be overridden by DMA non-capable devices */ virtual void read(sector_t block_number, Genode::size_t block_count, char * buffer, Packet_descriptor &packet) { throw Io_error(); } /** * Write to medium * * \param block_number number of first block to write * \param block_count number of blocks to write * \param buffer buffer for write request * \param packet packet descriptor from the client * * \throw Request_congestion * * Note: should be overridden by DMA non-capable, non-ROM devices */ virtual void write(sector_t block_number, Genode::size_t block_count, const char * buffer, Packet_descriptor &packet) { throw Io_error(); } /** * Read from medium using DMA * * \param block_number number of first block to read * \param block_count number of blocks to read * \param phys phyiscal address of read buffer * \param packet packet descriptor from the client * * \throw Request_congestion * * Note: should be overridden by DMA capable devices */ virtual void read_dma(sector_t block_number, Genode::size_t block_count, Genode::addr_t phys, Packet_descriptor &packet) { throw Io_error(); } /** * Write to medium using DMA * * \param block_number number of first block to write * \param block_count number of blocks to write * \param phys physical address of write buffer * \param packet packet descriptor from the client * * \throw Request_congestion * * Note: should be overridden by DMA capable, non-ROM devices */ virtual void write_dma(sector_t block_number, Genode::size_t block_count, Genode::addr_t phys, Packet_descriptor &packet) { throw Io_error(); } /** * Check if DMA is enabled for driver * * \return true if DMA is enabled, false otherwise * * Note: has to be overriden by DMA-capable devices */ virtual bool dma_enabled() { return false; } /** * Allocate buffer which is suitable for DMA. * * Note: has to be overriden by DMA-capable devices */ virtual Genode::Ram_dataspace_capability alloc_dma_buffer(Genode::size_t size) { return Genode::env()->ram_session()->alloc(size); } /** * Free buffer which is suitable for DMA. * * Note: has to be overriden by DMA-capable devices */ virtual void free_dma_buffer(Genode::Ram_dataspace_capability c) { return Genode::env()->ram_session()->free(c); } /** * Synchronize with device. * * Note: should be overriden by (e.g. intermediate) components, * which cache data */ virtual void sync() {} /** * Informs the driver that the client session was closed * * Note: drivers with state (e.g. asynchronously working) * should override this function, and reset their internal state */ virtual void session_invalidated() { } /** * Set single session component of the driver * * Session might get used to acknowledge requests. */ void session(Driver_session *session) { if (!(_session = session)) session_invalidated(); } /** * Acknowledge a packet after processing finished to the client * * \param p packet to acknowledge */ void ack_packet(Packet_descriptor &p, bool success = true) { if (_session) _session->ack_packet(p, success); } }; /** * Interface for constructing the driver object */ struct Block::Driver_factory { /** * Construct new driver */ virtual Driver *create() = 0; /** * Destroy driver */ virtual void destroy(Driver *driver) = 0; }; #endif /* _BLOCK__DRIVER_H_ */