Linux I2O User Space Interface rev 0.3 - 04/20/99 ============================================================================= Originally written by Deepak Saxena(deepak@plexity.net) Currently maintained by Deepak Saxena(deepak@plexity.net) ============================================================================= I. Introduction The Linux I2O subsystem provides a set of ioctl() commands that can be utilized by user space applications to communicate with IOPs and devices on individual IOPs. This document defines the specific ioctl() commands that are available to the user and provides examples of their uses. This document assumes the reader is familiar with or has access to the I2O specification as no I2O message parameters are outlined. For information on the specification, see http://www.i2osig.org This document and the I2O user space interface are currently maintained by Deepak Saxena. Please send all comments, errata, and bug fixes to deepak@plexity.net II. IOP Access Access to the I2O subsystem is provided through the device file named /dev/i2octl. This file is a character file with major number 10 and minor number 166. It can be created through the following command: mknod /dev/i2octl c 10 166 III. Determining the IOP Count SYNOPSIS ioctl(fd, I2OGETIOPS, int *count); u8 count[MAX_I2O_CONTROLLERS]; DESCRIPTION This function returns the system's active IOP table. count should point to a buffer containing MAX_I2O_CONTROLLERS entries. Upon returning, each entry will contain a non-zero value if the given IOP unit is active, and NULL if it is inactive or non-existent. RETURN VALUE. Returns 0 if no errors occur, and -1 otherwise. If an error occurs, errno is set appropriately: EFAULT Invalid user space pointer was passed IV. Getting Hardware Resource Table SYNOPSIS ioctl(fd, I2OHRTGET, struct i2o_cmd_hrt *hrt); struct i2o_cmd_hrtlct { u32 iop; /* IOP unit number */ void *resbuf; /* Buffer for result */ u32 *reslen; /* Buffer length in bytes */ }; DESCRIPTION This function returns the Hardware Resource Table of the IOP specified by hrt->iop in the buffer pointed to by hrt->resbuf. The actual size of the data is written into *(hrt->reslen). RETURNS This function returns 0 if no errors occur. If an error occurs, -1 is returned and errno is set appropriately: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ENOBUFS Buffer not large enough. If this occurs, the required buffer length is written into *(hrt->reslen) V. Getting Logical Configuration Table SYNOPSIS ioctl(fd, I2OLCTGET, struct i2o_cmd_lct *lct); struct i2o_cmd_hrtlct { u32 iop; /* IOP unit number */ void *resbuf; /* Buffer for result */ u32 *reslen; /* Buffer length in bytes */ }; DESCRIPTION This function returns the Logical Configuration Table of the IOP specified by lct->iop in the buffer pointed to by lct->resbuf. The actual size of the data is written into *(lct->reslen). RETURNS This function returns 0 if no errors occur. If an error occurs, -1 is returned and errno is set appropriately: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ENOBUFS Buffer not large enough. If this occurs, the required buffer length is written into *(lct->reslen) VI. Settting Parameters SYNOPSIS ioctl(fd, I2OPARMSET, struct i2o_parm_setget *ops); struct i2o_cmd_psetget { u32 iop; /* IOP unit number */ u32 tid; /* Target device TID */ void *opbuf; /* Operation List buffer */ u32 oplen; /* Operation List buffer length in bytes */ void *resbuf; /* Result List buffer */ u32 *reslen; /* Result List buffer length in bytes */ }; DESCRIPTION This function posts a UtilParamsSet message to the device identified by ops->iop and ops->tid. The operation list for the message is sent through the ops->opbuf buffer, and the result list is written into the buffer pointed to by ops->resbuf. The number of bytes written is placed into *(ops->reslen). RETURNS The return value is the size in bytes of the data written into ops->resbuf if no errors occur. If an error occurs, -1 is returned and errno is set appropriatly: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ENOBUFS Buffer not large enough. If this occurs, the required buffer length is written into *(ops->reslen) ETIMEDOUT Timeout waiting for reply message ENOMEM Kernel memory allocation error A return value of 0 does not mean that the value was actually changed properly on the IOP. The user should check the result list to determine the specific status of the transaction. VII. Getting Parameters SYNOPSIS ioctl(fd, I2OPARMGET, struct i2o_parm_setget *ops); struct i2o_parm_setget { u32 iop; /* IOP unit number */ u32 tid; /* Target device TID */ void *opbuf; /* Operation List buffer */ u32 oplen; /* Operation List buffer length in bytes */ void *resbuf; /* Result List buffer */ u32 *reslen; /* Result List buffer length in bytes */ }; DESCRIPTION This function posts a UtilParamsGet message to the device identified by ops->iop and ops->tid. The operation list for the message is sent through the ops->opbuf buffer, and the result list is written into the buffer pointed to by ops->resbuf. The actual size of data written is placed into *(ops->reslen). RETURNS EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ENOBUFS Buffer not large enough. If this occurs, the required buffer length is written into *(ops->reslen) ETIMEDOUT Timeout waiting for reply message ENOMEM Kernel memory allocation error A return value of 0 does not mean that the value was actually properly retreived. The user should check the result list to determine the specific status of the transaction. VIII. Downloading Software SYNOPSIS ioctl(fd, I2OSWDL, struct i2o_sw_xfer *sw); struct i2o_sw_xfer { u32 iop; /* IOP unit number */ u8 flags; /* DownloadFlags field */ u8 sw_type; /* Software type */ u32 sw_id; /* Software ID */ void *buf; /* Pointer to software buffer */ u32 *swlen; /* Length of software buffer */ u32 *maxfrag; /* Number of fragments */ u32 *curfrag; /* Current fragment number */ }; DESCRIPTION This function downloads the software pointed by sw->buf to the iop identified by sw->iop. The DownloadFlags, SwID, SwType and SwSize fields of the ExecSwDownload message are filled in with the values of sw->flags, sw->sw_id, sw->sw_type and *(sw->swlen). Once the ioctl() is called and software transfer begins, the user can read the value *(sw->maxfrag) and *(sw->curfrag) to determine the status of the software transfer. As the IOP is very slow when it comes to SW transfers, this can be used by a separate thread to report status to the user. The user _should not_ write to this memory location until the ioctl() has returned. RETURNS This function returns 0 no errors occur. If an error occurs, -1 is returned and errno is set appropriatly: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ETIMEDOUT Timeout waiting for reply message ENOMEM Kernel memory allocation error IX. Uploading Software SYNOPSIS ioctl(fd, I2OSWUL, struct i2o_sw_xfer *sw); struct i2o_sw_xfer { u32 iop; /* IOP unit number */ u8 flags; /* UploadFlags */ u8 sw_type; /* Software type */ u32 sw_id; /* Software ID */ void *buf; /* Pointer to software buffer */ u32 *swlen; /* Length of software buffer */ u32 *maxfrag; /* Number of fragments */ u32 *curfrag; /* Current fragment number */ }; DESCRIPTION This function uploads software from the IOP identified by sw->iop and places it in the buffer pointed to by sw->buf. The length of the buffer is given in *(sw->swlen). The UploadFlags, SwID and SwType fields of the ExecSwUpload message are filled in with the values of sw->flags, sw->sw_id and sw->sw_type. Once the ioctl() is called and software transfer begins, the user can read the value *(sw->maxfrag) and *(sw->curfrag) to determine the status of the software transfer. As the IOP is very slow when it comes to SW transfers, this can be used by a separate thread to report status to the user. The user _should not_ write to this memory location until the ioctl() has returned. RETURNS This function returns 0 if no errors occur. If an error occurs, -1 is returned and errno is set appropriatly: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ETIMEDOUT Timeout waiting for reply message ENOMEM Kernel memory allocation error X. Removing Software SYNOPSIS ioctl(fd, I2OSWDEL, struct i2o_sw_xfer *sw); struct i2o_sw_xfer { u32 iop; /* IOP unit number */ u8 flags; /* RemoveFlags */ u8 sw_type; /* Software type */ u32 sw_id; /* Software ID */ void *buf; /* Unused */ u32 *swlen; /* Length of the software data */ u32 *maxfrag; /* Unused */ u32 *curfrag; /* Unused */ }; DESCRIPTION This function removes software from the IOP identified by sw->iop. The RemoveFlags, SwID, SwType and SwSize fields of the ExecSwRemove message are filled in with the values of sw->flags, sw->sw_id, sw->sw_type and *(sw->swlen). Give zero in *(sw->len) if the value is unknown. IOP uses *(sw->swlen) value to verify correct identication of the module to remove. The actual size of the module is written into *(sw->swlen). RETURNS This function returns 0 if no errors occur. If an error occurs, -1 is returned and errno is set appropriatly: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ETIMEDOUT Timeout waiting for reply message ENOMEM Kernel memory allocation error X. Validating Configuration SYNOPSIS ioctl(fd, I2OVALIDATE, int *iop); u32 iop; DESCRIPTION This function posts an ExecConfigValidate message to the controller identified by iop. This message indicates that the the current configuration is accepted. The iop changes the status of suspect drivers to valid and may delete old drivers from its store. RETURNS This function returns 0 if no erro occur. If an error occurs, -1 is returned and errno is set appropriatly: ETIMEDOUT Timeout waiting for reply message ENXIO Invalid IOP number XI. Configuration Dialog SYNOPSIS ioctl(fd, I2OHTML, struct i2o_html *htquery); struct i2o_html { u32 iop; /* IOP unit number */ u32 tid; /* Target device ID */ u32 page; /* HTML page */ void *resbuf; /* Buffer for reply HTML page */ u32 *reslen; /* Length in bytes of reply buffer */ void *qbuf; /* Pointer to HTTP query string */ u32 qlen; /* Length in bytes of query string buffer */ }; DESCRIPTION This function posts an UtilConfigDialog message to the device identified by htquery->iop and htquery->tid. The requested HTML page number is provided by the htquery->page field, and the resultant data is stored in the buffer pointed to by htquery->resbuf. If there is an HTTP query string that is to be sent to the device, it should be sent in the buffer pointed to by htquery->qbuf. If there is no query string, this field should be set to NULL. The actual size of the reply received is written into *(htquery->reslen). RETURNS This function returns 0 if no error occur. If an error occurs, -1 is returned and errno is set appropriatly: EFAULT Invalid user space pointer was passed ENXIO Invalid IOP number ENOBUFS Buffer not large enough. If this occurs, the required buffer length is written into *(ops->reslen) ETIMEDOUT Timeout waiting for reply message ENOMEM Kernel memory allocation error XII. Events In the process of determining this. Current idea is to have use the select() interface to allow user apps to periodically poll the /dev/i2octl device for events. When select() notifies the user that an event is available, the user would call read() to retrieve a list of all the events that are pending for the specific device. ============================================================================= Revision History ============================================================================= Rev 0.1 - 04/01/99 - Initial revision Rev 0.2 - 04/06/99 - Changed return values to match UNIX ioctl() standard. Only return values are 0 and -1. All errors are reported through errno. - Added summary of proposed possible event interfaces Rev 0.3 - 04/20/99 - Changed all ioctls() to use pointers to user data instead of actual data - Updated error values to match the code