1
2Linux I2O User Space Interface
3rev 0.3 - 04/20/99
4
5=============================================================================
6Originally written by Deepak Saxena(deepak@plexity.net)
7Currently maintained by Deepak Saxena(deepak@plexity.net)
8=============================================================================
9
10I. Introduction
11
12The Linux I2O subsystem provides a set of ioctl() commands that can be
13utilized by user space applications to communicate with IOPs and devices
14on individual IOPs. This document defines the specific ioctl() commands
15that are available to the user and provides examples of their uses.
16
17This document assumes the reader is familiar with or has access to the
18I2O specification as no I2O message parameters are outlined.  For information
19on the specification, see http://www.i2osig.org
20
21This document and the I2O user space interface are currently maintained
22by Deepak Saxena.  Please send all comments, errata, and bug fixes to
23deepak@csociety.purdue.edu
24
25II. IOP Access
26
27Access to the I2O subsystem is provided through the device file named
28/dev/i2o/ctl.  This file is a character file with major number 10 and minor
29number 166.  It can be created through the following command:
30
31   mknod /dev/i2o/ctl c 10 166
32
33III. Determining the IOP Count
34
35   SYNOPSIS
36
37   ioctl(fd, I2OGETIOPS,  int *count);
38
39   u8 count[MAX_I2O_CONTROLLERS];
40
41   DESCRIPTION
42
43   This function returns the system's active IOP table.  count should
44   point to a buffer containing MAX_I2O_CONTROLLERS entries.  Upon
45   returning, each entry will contain a non-zero value if the given
46   IOP unit is active, and NULL if it is inactive or non-existent.
47
48   RETURN VALUE.
49
50   Returns 0 if no errors occur, and -1 otherwise.  If an error occurs,
51   errno is set appropriately:
52
53     EFAULT   Invalid user space pointer was passed
54
55IV. Getting Hardware Resource Table
56
57   SYNOPSIS
58
59   ioctl(fd, I2OHRTGET, struct i2o_cmd_hrt *hrt);
60
61      struct i2o_cmd_hrtlct
62      {
63         u32   iop;      /* IOP unit number */
64         void  *resbuf;  /* Buffer for result */
65         u32   *reslen;  /* Buffer length in bytes */
66      };
67
68   DESCRIPTION
69
70   This function returns the Hardware Resource Table of the IOP specified
71   by hrt->iop in the buffer pointed to by hrt->resbuf. The actual size of
72   the data is written into *(hrt->reslen).
73
74   RETURNS
75
76   This function returns 0 if no errors occur. If an error occurs, -1
77   is returned and errno is set appropriately:
78
79      EFAULT      Invalid user space pointer was passed
80      ENXIO       Invalid IOP number
81      ENOBUFS     Buffer not large enough.  If this occurs, the required
82                  buffer length is written into *(hrt->reslen)
83
84V. Getting Logical Configuration Table
85
86   SYNOPSIS
87
88   ioctl(fd, I2OLCTGET, struct i2o_cmd_lct *lct);
89
90      struct i2o_cmd_hrtlct
91      {
92         u32   iop;      /* IOP unit number */
93         void  *resbuf;  /* Buffer for result */
94         u32   *reslen;  /* Buffer length in bytes */
95      };
96
97   DESCRIPTION
98
99   This function returns the Logical Configuration Table of the IOP specified
100   by lct->iop in the buffer pointed to by lct->resbuf. The actual size of
101   the data is written into *(lct->reslen).
102
103   RETURNS
104
105   This function returns 0 if no errors occur. If an error occurs, -1
106   is returned and errno is set appropriately:
107
108      EFAULT      Invalid user space pointer was passed
109      ENXIO       Invalid IOP number
110      ENOBUFS     Buffer not large enough.  If this occurs, the required
111                  buffer length is written into *(lct->reslen)
112
113VI. Settting Parameters
114
115   SYNOPSIS
116
117   ioctl(fd, I2OPARMSET, struct i2o_parm_setget *ops);
118
119      struct i2o_cmd_psetget
120      {
121         u32   iop;      /* IOP unit number */
122         u32   tid;      /* Target device TID */
123         void  *opbuf;   /* Operation List buffer */
124         u32   oplen;    /* Operation List buffer length in bytes */
125         void  *resbuf;  /* Result List buffer */
126         u32   *reslen;  /* Result List buffer length in bytes */
127      };
128
129   DESCRIPTION
130
131   This function posts a UtilParamsSet message to the device identified
132   by ops->iop and ops->tid.  The operation list for the message is
133   sent through the ops->opbuf buffer, and the result list is written
134   into the buffer pointed to by ops->resbuf.  The number of bytes
135   written is placed into *(ops->reslen).
136
137   RETURNS
138
139   The return value is the size in bytes of the data written into
140   ops->resbuf if no errors occur.  If an error occurs, -1 is returned
141   and errno is set appropriatly:
142
143      EFAULT      Invalid user space pointer was passed
144      ENXIO       Invalid IOP number
145      ENOBUFS     Buffer not large enough.  If this occurs, the required
146                  buffer length is written into *(ops->reslen)
147      ETIMEDOUT   Timeout waiting for reply message
148      ENOMEM      Kernel memory allocation error
149
150   A return value of 0 does not mean that the value was actually
151   changed properly on the IOP.  The user should check the result
152   list to determine the specific status of the transaction.
153
154VII. Getting Parameters
155
156   SYNOPSIS
157
158   ioctl(fd, I2OPARMGET, struct i2o_parm_setget *ops);
159
160      struct i2o_parm_setget
161      {
162         u32   iop;      /* IOP unit number */
163         u32   tid;      /* Target device TID */
164         void  *opbuf;   /* Operation List buffer */
165         u32   oplen;    /* Operation List buffer length in bytes */
166         void  *resbuf;  /* Result List buffer */
167         u32   *reslen;  /* Result List buffer length in bytes */
168      };
169
170   DESCRIPTION
171
172   This function posts a UtilParamsGet message to the device identified
173   by ops->iop and ops->tid.  The operation list for the message is
174   sent through the ops->opbuf buffer, and the result list is written
175   into the buffer pointed to by ops->resbuf.  The actual size of data
176   written is placed into *(ops->reslen).
177
178   RETURNS
179
180      EFAULT      Invalid user space pointer was passed
181      ENXIO       Invalid IOP number
182      ENOBUFS     Buffer not large enough.  If this occurs, the required
183                  buffer length is written into *(ops->reslen)
184      ETIMEDOUT   Timeout waiting for reply message
185      ENOMEM      Kernel memory allocation error
186
187   A return value of 0 does not mean that the value was actually
188   properly retrieved.  The user should check the result list
189   to determine the specific status of the transaction.
190
191VIII. Downloading Software
192
193   SYNOPSIS
194
195   ioctl(fd, I2OSWDL, struct i2o_sw_xfer *sw);
196
197      struct i2o_sw_xfer
198      {
199         u32   iop;       /* IOP unit number */
200         u8    flags;     /* DownloadFlags field */
201         u8    sw_type;   /* Software type */
202         u32   sw_id;     /* Software ID */
203         void  *buf;      /* Pointer to software buffer */
204         u32   *swlen;    /* Length of software buffer */
205         u32   *maxfrag;  /* Number of fragments */
206         u32   *curfrag;  /* Current fragment number */
207      };
208
209   DESCRIPTION
210
211   This function downloads a software fragment pointed by sw->buf
212   to the iop identified by sw->iop. The DownloadFlags, SwID, SwType
213   and SwSize fields of the ExecSwDownload message are filled in with
214   the values of sw->flags, sw->sw_id, sw->sw_type and *(sw->swlen).
215
216   The fragments _must_ be sent in order and be 8K in size. The last
217   fragment _may_ be shorter, however. The kernel will compute its
218   size based on information in the sw->swlen field.
219
220   Please note that SW transfers can take a long time.
221
222   RETURNS
223
224   This function returns 0 no errors occur. If an error occurs, -1
225   is returned and errno is set appropriatly:
226
227      EFAULT      Invalid user space pointer was passed
228      ENXIO       Invalid IOP number
229      ETIMEDOUT   Timeout waiting for reply message
230      ENOMEM      Kernel memory allocation error
231
232IX. Uploading Software
233
234   SYNOPSIS
235
236   ioctl(fd, I2OSWUL, struct i2o_sw_xfer *sw);
237
238      struct i2o_sw_xfer
239      {
240         u32   iop;      /* IOP unit number */
241         u8    flags; 	 /* UploadFlags */
242         u8    sw_type;  /* Software type */
243         u32   sw_id;    /* Software ID */
244         void  *buf;     /* Pointer to software buffer */
245         u32   *swlen;   /* Length of software buffer */
246         u32   *maxfrag; /* Number of fragments */
247         u32   *curfrag; /* Current fragment number */
248      };
249
250   DESCRIPTION
251
252   This function uploads a software fragment from the IOP identified
253   by sw->iop, sw->sw_type, sw->sw_id and optionally sw->swlen fields.
254   The UploadFlags, SwID, SwType and SwSize fields of the ExecSwUpload
255   message are filled in with the values of sw->flags, sw->sw_id,
256   sw->sw_type and *(sw->swlen).
257
258   The fragments _must_ be requested in order and be 8K in size. The
259   user is responsible for allocating memory pointed by sw->buf. The
260   last fragment _may_ be shorter.
261
262   Please note that SW transfers can take a long time.
263
264   RETURNS
265
266   This function returns 0 if no errors occur.  If an error occurs, -1
267   is returned and errno is set appropriatly:
268
269      EFAULT      Invalid user space pointer was passed
270      ENXIO       Invalid IOP number
271      ETIMEDOUT   Timeout waiting for reply message
272      ENOMEM      Kernel memory allocation error
273
274X. Removing Software
275
276   SYNOPSIS
277
278   ioctl(fd, I2OSWDEL, struct i2o_sw_xfer *sw);
279
280      struct i2o_sw_xfer
281      {
282         u32   iop;      /* IOP unit number */
283         u8    flags; 	 /* RemoveFlags */
284         u8    sw_type;  /* Software type */
285         u32   sw_id;    /* Software ID */
286         void  *buf;     /* Unused */
287         u32   *swlen;   /* Length of the software data */
288         u32   *maxfrag; /* Unused */
289         u32   *curfrag; /* Unused */
290      };
291
292   DESCRIPTION
293
294   This function removes software from the IOP identified by sw->iop.
295   The RemoveFlags, SwID, SwType and SwSize fields of the ExecSwRemove message
296   are filled in with the values of sw->flags, sw->sw_id, sw->sw_type and
297   *(sw->swlen). Give zero in *(sw->len) if the value is unknown. IOP uses
298   *(sw->swlen) value to verify correct identication of the module to remove.
299   The actual size of the module is written into *(sw->swlen).
300
301   RETURNS
302
303   This function returns 0 if no errors occur.  If an error occurs, -1
304   is returned and errno is set appropriatly:
305
306      EFAULT      Invalid user space pointer was passed
307      ENXIO       Invalid IOP number
308      ETIMEDOUT   Timeout waiting for reply message
309      ENOMEM      Kernel memory allocation error
310
311X. Validating Configuration
312
313   SYNOPSIS
314
315   ioctl(fd, I2OVALIDATE, int *iop);
316	u32 iop;
317
318   DESCRIPTION
319
320   This function posts an ExecConfigValidate message to the controller
321   identified by iop. This message indicates that the current
322   configuration is accepted. The iop changes the status of suspect drivers
323   to valid and may delete old drivers from its store.
324
325   RETURNS
326
327   This function returns 0 if no erro occur.  If an error occurs, -1 is
328   returned and errno is set appropriatly:
329
330      ETIMEDOUT   Timeout waiting for reply message
331      ENXIO       Invalid IOP number
332
333XI. Configuration Dialog
334
335   SYNOPSIS
336
337   ioctl(fd, I2OHTML, struct i2o_html *htquery);
338      struct i2o_html
339      {
340         u32   iop;      /* IOP unit number */
341         u32   tid;      /* Target device ID */
342         u32   page;     /* HTML page */
343         void  *resbuf;  /* Buffer for reply HTML page */
344         u32   *reslen;  /* Length in bytes of reply buffer */
345         void  *qbuf;    /* Pointer to HTTP query string */
346         u32   qlen;     /* Length in bytes of query string buffer */
347      };
348
349   DESCRIPTION
350
351   This function posts an UtilConfigDialog message to the device identified
352   by htquery->iop and htquery->tid.  The requested HTML page number is
353   provided by the htquery->page field, and the resultant data is stored
354   in the buffer pointed to by htquery->resbuf.  If there is an HTTP query
355   string that is to be sent to the device, it should be sent in the buffer
356   pointed to by htquery->qbuf.  If there is no query string, this field
357   should be set to NULL. The actual size of the reply received is written
358   into *(htquery->reslen).
359
360   RETURNS
361
362   This function returns 0 if no error occur. If an error occurs, -1
363   is returned and errno is set appropriatly:
364
365      EFAULT      Invalid user space pointer was passed
366      ENXIO       Invalid IOP number
367      ENOBUFS     Buffer not large enough.  If this occurs, the required
368                  buffer length is written into *(ops->reslen)
369      ETIMEDOUT   Timeout waiting for reply message
370      ENOMEM      Kernel memory allocation error
371
372XII. Events
373
374    In the process of determining this.  Current idea is to have use
375    the select() interface to allow user apps to periodically poll
376    the /dev/i2o/ctl device for events.  When select() notifies the user
377    that an event is available, the user would call read() to retrieve
378    a list of all the events that are pending for the specific device.
379
380=============================================================================
381Revision History
382=============================================================================
383
384Rev 0.1 - 04/01/99
385- Initial revision
386
387Rev 0.2 - 04/06/99
388- Changed return values to match UNIX ioctl() standard.  Only return values
389  are 0 and -1.  All errors are reported through errno.
390- Added summary of proposed possible event interfaces
391
392Rev 0.3 - 04/20/99
393- Changed all ioctls() to use pointers to user data instead of actual data
394- Updated error values to match the code
395