| 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@csociety.purdue.edu | |
| II. IOP Access | |
| Access to the I2O subsystem is provided through the device file named | |
| /dev/i2o/ctl. This file is a character file with major number 10 and minor | |
| number 166. It can be created through the following command: | |
| mknod /dev/i2o/ctl 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. Setting 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 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 *(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 retrieved. 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 a software fragment 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). | |
| The fragments _must_ be sent in order and be 8K in size. The last | |
| fragment _may_ be shorter, however. The kernel will compute its | |
| size based on information in the sw->swlen field. | |
| Please note that SW transfers can take a long time. | |
| RETURNS | |
| This function returns 0 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 | |
| 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 a software fragment from the IOP identified | |
| by sw->iop, sw->sw_type, sw->sw_id and optionally sw->swlen fields. | |
| The UploadFlags, SwID, SwType and SwSize fields of the ExecSwUpload | |
| message are filled in with the values of sw->flags, sw->sw_id, | |
| sw->sw_type and *(sw->swlen). | |
| The fragments _must_ be requested in order and be 8K in size. The | |
| user is responsible for allocating memory pointed by sw->buf. The | |
| last fragment _may_ be shorter. | |
| Please note that SW transfers can take a long time. | |
| 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 | |
| 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 appropriately: | |
| 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 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 appropriately: | |
| 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 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 *(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/i2o/ctl 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 |