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Diffstat (limited to 'include/hw/misc/android_pipe.h')
| -rw-r--r-- | include/hw/misc/android_pipe.h | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/include/hw/misc/android_pipe.h b/include/hw/misc/android_pipe.h new file mode 100644 index 0000000000..3fa7e18693 --- /dev/null +++ b/include/hw/misc/android_pipe.h @@ -0,0 +1,220 @@ +/* Copyright (C) 2011 The Android Open Source Project +** +** This software is licensed under the terms of the GNU General Public +** License version 2, as published by the Free Software Foundation, and +** may be copied, distributed, and modified under those terms. +** +** This program is distributed in the hope that it will be useful, +** but WITHOUT ANY WARRANTY; without even the implied warranty of +** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +** GNU General Public License for more details. +*/ +#ifndef _HW_ANDROID_PIPE_H +#define _HW_ANDROID_PIPE_H + +#include <stdbool.h> +#include <stdint.h> +#include "hw/hw.h" + +/* TECHNICAL NOTE: + * + * A android pipe is a very fast communication channel between the guest + * system and the emulator program. + * + * To open a new pipe to the emulator, a guest client will do the following: + * + * fd = open("/dev/qemu_pipe", O_RDWR); + * char invite[64]; + * snprintf(invite, sizeof invite, "%s", pipeName); + * ret = write(fd, invite, strlen(invite)); + * + * if (ret < 0) { + * // something bad happened, see errno + * } + * + * now read()/write() to communicate with <pipeName> service in the + * emulator. + * + * This header provides the interface used by pipe services in the emulator + * to receive new client connection and deal with them. + * + * + * 1/ Call android_pipe_add_type() to register a new pipe service by name. + * This must provide a pointer to a series of functions that will be called + * during normal pipe operations. + * + * 2/ When a client connects to the service, the 'init' callback will be called + * to create a new service-specific client identifier (which must returned + * by the function). + * + * 3/ Call android_pipe_close() to force the closure of a given pipe. + * + * 4/ Call android_pipe_signal() to signal a change of state to the pipe. + * + */ + +/* Buffer descriptor for sendBuffers() and recvBuffers() callbacks */ +typedef struct AndroidPipeBuffer { + uint8_t* data; + size_t size; +} AndroidPipeBuffer; + +/* Pipe handler funcs */ +typedef struct { + /* Create new client connection, 'hwpipe' must be passed to other + * android_pipe_xxx functions, while the returned value will be passed + * to other callbacks (e.g. close). 'pipeOpaque' is the value passed + * to android_pipe_add_type() when registering a given pipe service. + */ + void* (*init)( void* hwpipe, void* pipeOpaque, const char* args ); + + /* Called when the guest kernel has finally closed a pipe connection. + * This is the only place where you can release/free the client connection. + * You should never invoke this callback directly. Call android_pipe_close() + * instead. + */ + void (*close)( void* pipe ); + + /* Called when the guest is write()-ing to the pipe. Should return the + * number of bytes transfered, 0 for EOF status, or a negative error + * value otherwise, including PIPE_ERROR_AGAIN to indicate that the + * emulator is not ready to receive data yet. + */ + int (*sendBuffers)( void* pipe, const AndroidPipeBuffer* buffers, int numBuffers ); + + /* Same as sendBuffers when the guest is read()-ing from the pipe. */ + int (*recvBuffers)( void* pipe, AndroidPipeBuffer* buffers, int numBuffers ); + + /* Called when guest wants to poll the read/write status for the pipe. + * Should return a combination of PIPE_POLL_XXX flags. + */ + unsigned (*poll)( void* pipe ); + + /* Called to signal that the guest wants to be woken when the set of + * PIPE_WAKE_XXX bit-flags in 'flags' occur. When the condition occurs, + * then the pipe implementation shall call android_pipe_wake(). + */ + void (*wakeOn)( void* opaque, int flags ); + + /* Called to save the pipe's state to a QEMUFile, i.e. when saving + * snapshots. This can be NULL to indicate that no state can be saved. + * In this case, when the pipe is loaded, the emulator will automatically + * force-close so the next operation the guest performs on it will return + * a PIPE_ERROR_IO error code. + */ + void (*save)( void* pipe, QEMUFile* file ); + + /* Called to load the sate of a pipe from a QEMUFile. This will always + * correspond to the state of the pipe as saved by a previous call to + * the 'save' method. Can be NULL to indicate that the pipe state cannot + * be loaded. In this case, the emulator will automatically force-close + * it. + * + * In case of success, this returns 0, and the new pipe object is returned + * in '*ppipe'. In case of errno code is returned to indicate a failure. + * 'hwpipe' and 'pipeOpaque' are the same arguments than those passed + * to 'init'. + */ + void* (*load)( void* hwpipe, void* pipeOpaque, const char* args, QEMUFile* file); +} AndroidPipeFuncs; + +/* Register a new pipe handler type. 'pipeOpaque' is passed directly + * to 'init() when a new pipe is connected to. + */ +extern void android_pipe_add_type(const char* pipeName, + void* pipeOpaque, + const AndroidPipeFuncs* pipeFuncs ); + +/* This tells the guest system that we want to close the pipe and that + * further attempts to read or write to it will fail. This will not + * necessarily call the 'close' callback immediately though. + * + * This will also wake-up any blocked guest threads waiting for i/o. + */ +extern void android_pipe_close( void* hwpipe ); + +/* Signal that the pipe can be woken up. 'flags' must be a combination of + * PIPE_WAKE_READ and PIPE_WAKE_WRITE. + */ +extern void android_pipe_wake( void* hwpipe, unsigned flags ); + +/* The following definitions must match those in the kernel driver: + * + * For goldfish: + * android.googlesource.com/kernel/goldfish.git. + * $KERNEL/drivers/misc/qemupipe/qemu_pipe.c + * + * For ranchu: + * android.googlesource.com/kernel/common.git + * $KERNEL/drivers/staging/android/android_pipe.c + */ + +/* pipe device registers */ +#define PIPE_REG_COMMAND 0x00 /* write: value = command */ +#define PIPE_REG_STATUS 0x04 /* read */ +#define PIPE_REG_CHANNEL 0x08 /* read/write: channel id */ +#define PIPE_REG_SIZE 0x0c /* read/write: buffer size */ +#define PIPE_REG_ADDRESS 0x10 /* write: physical address */ +#define PIPE_REG_WAKES 0x14 /* read: wake flags */ +/* read/write: parameter buffer address */ +#define PIPE_REG_PARAMS_ADDR_LOW 0x18 +#define PIPE_REG_PARAMS_ADDR_HIGH 0x1c +/* write: access with paremeter buffer */ +#define PIPE_REG_ACCESS_PARAMS 0x20 +#define PIPE_REG_CHANNEL_HIGH 0x30 /* read/write: high 32 bit channel id */ +#define PIPE_REG_ADDRESS_HIGH 0x34 /* write: high 32 bit physical address */ + +/* list of commands for PIPE_REG_COMMAND */ +#define PIPE_CMD_OPEN 1 /* open new channel */ +#define PIPE_CMD_CLOSE 2 /* close channel (from guest) */ +#define PIPE_CMD_POLL 3 /* poll read/write status */ + +/* List of bitflags returned in status of CMD_POLL command */ +#define PIPE_POLL_IN (1 << 0) +#define PIPE_POLL_OUT (1 << 1) +#define PIPE_POLL_HUP (1 << 2) + +/* The following commands are related to write operations */ +#define PIPE_CMD_WRITE_BUFFER 4 /* send a user buffer to the emulator */ +#define PIPE_CMD_WAKE_ON_WRITE 5 /* tell the emulator to wake us when writing is possible */ + +/* The following commands are related to read operations, they must be + * listed in the same order than the corresponding write ones, since we + * will use (CMD_READ_BUFFER - CMD_WRITE_BUFFER) as a special offset + * in qemu_pipe_read_write() below. + */ +#define PIPE_CMD_READ_BUFFER 6 /* receive a page-contained buffer from the emulator */ +#define PIPE_CMD_WAKE_ON_READ 7 /* tell the emulator to wake us when reading is possible */ + +/* Possible status values used to signal errors - see qemu_pipe_error_convert */ +#define PIPE_ERROR_INVAL -1 +#define PIPE_ERROR_AGAIN -2 +#define PIPE_ERROR_NOMEM -3 +#define PIPE_ERROR_IO -4 + +/* Bit-flags used to signal events from the emulator */ +#define PIPE_WAKE_CLOSED (1 << 0) /* emulator closed pipe */ +#define PIPE_WAKE_READ (1 << 1) /* pipe can now be read from */ +#define PIPE_WAKE_WRITE (1 << 2) /* pipe can now be written to */ + +struct access_params{ + uint32_t channel; + uint32_t size; + uint32_t address; + uint32_t cmd; + uint32_t result; + /* reserved for future extension */ + uint32_t flags; +}; + +struct access_params_64 { + uint64_t channel; + uint32_t size; + uint64_t address; + uint32_t cmd; + uint32_t result; + /* reserved for future extension */ + uint32_t flags; +}; + +#endif /* _HW_ANDROID_PIPE_H */ |