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1 | SPUFS(2) Linux Programmer's Manual SPUFS(2) | ||
2 | |||
3 | |||
4 | |||
5 | NAME | ||
6 | spufs - the SPU file system | ||
7 | |||
8 | |||
9 | DESCRIPTION | ||
10 | The SPU file system is used on PowerPC machines that implement the Cell | ||
11 | Broadband Engine Architecture in order to access Synergistic Processor | ||
12 | Units (SPUs). | ||
13 | |||
14 | The file system provides a name space similar to posix shared memory or | ||
15 | message queues. Users that have write permissions on the file system | ||
16 | can use spu_create(2) to establish SPU contexts in the spufs root. | ||
17 | |||
18 | Every SPU context is represented by a directory containing a predefined | ||
19 | set of files. These files can be used for manipulating the state of the | ||
20 | logical SPU. Users can change permissions on those files, but not actu- | ||
21 | ally add or remove files. | ||
22 | |||
23 | |||
24 | MOUNT OPTIONS | ||
25 | uid=<uid> | ||
26 | set the user owning the mount point, the default is 0 (root). | ||
27 | |||
28 | gid=<gid> | ||
29 | set the group owning the mount point, the default is 0 (root). | ||
30 | |||
31 | |||
32 | FILES | ||
33 | The files in spufs mostly follow the standard behavior for regular sys- | ||
34 | tem calls like read(2) or write(2), but often support only a subset of | ||
35 | the operations supported on regular file systems. This list details the | ||
36 | supported operations and the deviations from the behaviour in the | ||
37 | respective man pages. | ||
38 | |||
39 | All files that support the read(2) operation also support readv(2) and | ||
40 | all files that support the write(2) operation also support writev(2). | ||
41 | All files support the access(2) and stat(2) family of operations, but | ||
42 | only the st_mode, st_nlink, st_uid and st_gid fields of struct stat | ||
43 | contain reliable information. | ||
44 | |||
45 | All files support the chmod(2)/fchmod(2) and chown(2)/fchown(2) opera- | ||
46 | tions, but will not be able to grant permissions that contradict the | ||
47 | possible operations, e.g. read access on the wbox file. | ||
48 | |||
49 | The current set of files is: | ||
50 | |||
51 | |||
52 | /mem | ||
53 | the contents of the local storage memory of the SPU. This can be | ||
54 | accessed like a regular shared memory file and contains both code and | ||
55 | data in the address space of the SPU. The possible operations on an | ||
56 | open mem file are: | ||
57 | |||
58 | read(2), pread(2), write(2), pwrite(2), lseek(2) | ||
59 | These operate as documented, with the exception that seek(2), | ||
60 | write(2) and pwrite(2) are not supported beyond the end of the | ||
61 | file. The file size is the size of the local storage of the SPU, | ||
62 | which normally is 256 kilobytes. | ||
63 | |||
64 | mmap(2) | ||
65 | Mapping mem into the process address space gives access to the | ||
66 | SPU local storage within the process address space. Only | ||
67 | MAP_SHARED mappings are allowed. | ||
68 | |||
69 | |||
70 | /mbox | ||
71 | The first SPU to CPU communication mailbox. This file is read-only and | ||
72 | can be read in units of 32 bits. The file can only be used in non- | ||
73 | blocking mode and it even poll() will not block on it. The possible | ||
74 | operations on an open mbox file are: | ||
75 | |||
76 | read(2) | ||
77 | If a count smaller than four is requested, read returns -1 and | ||
78 | sets errno to EINVAL. If there is no data available in the mail | ||
79 | box, the return value is set to -1 and errno becomes EAGAIN. | ||
80 | When data has been read successfully, four bytes are placed in | ||
81 | the data buffer and the value four is returned. | ||
82 | |||
83 | |||
84 | /ibox | ||
85 | The second SPU to CPU communication mailbox. This file is similar to | ||
86 | the first mailbox file, but can be read in blocking I/O mode, and the | ||
87 | poll familiy of system calls can be used to wait for it. The possible | ||
88 | operations on an open ibox file are: | ||
89 | |||
90 | read(2) | ||
91 | If a count smaller than four is requested, read returns -1 and | ||
92 | sets errno to EINVAL. If there is no data available in the mail | ||
93 | box and the file descriptor has been opened with O_NONBLOCK, the | ||
94 | return value is set to -1 and errno becomes EAGAIN. | ||
95 | |||
96 | If there is no data available in the mail box and the file | ||
97 | descriptor has been opened without O_NONBLOCK, the call will | ||
98 | block until the SPU writes to its interrupt mailbox channel. | ||
99 | When data has been read successfully, four bytes are placed in | ||
100 | the data buffer and the value four is returned. | ||
101 | |||
102 | poll(2) | ||
103 | Poll on the ibox file returns (POLLIN | POLLRDNORM) whenever | ||
104 | data is available for reading. | ||
105 | |||
106 | |||
107 | /wbox | ||
108 | The CPU to SPU communation mailbox. It is write-only can can be written | ||
109 | in units of 32 bits. If the mailbox is full, write() will block and | ||
110 | poll can be used to wait for it becoming empty again. The possible | ||
111 | operations on an open wbox file are: write(2) If a count smaller than | ||
112 | four is requested, write returns -1 and sets errno to EINVAL. If there | ||
113 | is no space available in the mail box and the file descriptor has been | ||
114 | opened with O_NONBLOCK, the return value is set to -1 and errno becomes | ||
115 | EAGAIN. | ||
116 | |||
117 | If there is no space available in the mail box and the file descriptor | ||
118 | has been opened without O_NONBLOCK, the call will block until the SPU | ||
119 | reads from its PPE mailbox channel. When data has been read success- | ||
120 | fully, four bytes are placed in the data buffer and the value four is | ||
121 | returned. | ||
122 | |||
123 | poll(2) | ||
124 | Poll on the ibox file returns (POLLOUT | POLLWRNORM) whenever | ||
125 | space is available for writing. | ||
126 | |||
127 | |||
128 | /mbox_stat | ||
129 | /ibox_stat | ||
130 | /wbox_stat | ||
131 | Read-only files that contain the length of the current queue, i.e. how | ||
132 | many words can be read from mbox or ibox or how many words can be | ||
133 | written to wbox without blocking. The files can be read only in 4-byte | ||
134 | units and return a big-endian binary integer number. The possible | ||
135 | operations on an open *box_stat file are: | ||
136 | |||
137 | read(2) | ||
138 | If a count smaller than four is requested, read returns -1 and | ||
139 | sets errno to EINVAL. Otherwise, a four byte value is placed in | ||
140 | the data buffer, containing the number of elements that can be | ||
141 | read from (for mbox_stat and ibox_stat) or written to (for | ||
142 | wbox_stat) the respective mail box without blocking or resulting | ||
143 | in EAGAIN. | ||
144 | |||
145 | |||
146 | /npc | ||
147 | /decr | ||
148 | /decr_status | ||
149 | /spu_tag_mask | ||
150 | /event_mask | ||
151 | /srr0 | ||
152 | Internal registers of the SPU. The representation is an ASCII string | ||
153 | with the numeric value of the next instruction to be executed. These | ||
154 | can be used in read/write mode for debugging, but normal operation of | ||
155 | programs should not rely on them because access to any of them except | ||
156 | npc requires an SPU context save and is therefore very inefficient. | ||
157 | |||
158 | The contents of these files are: | ||
159 | |||
160 | npc Next Program Counter | ||
161 | |||
162 | decr SPU Decrementer | ||
163 | |||
164 | decr_status Decrementer Status | ||
165 | |||
166 | spu_tag_mask MFC tag mask for SPU DMA | ||
167 | |||
168 | event_mask Event mask for SPU interrupts | ||
169 | |||
170 | srr0 Interrupt Return address register | ||
171 | |||
172 | |||
173 | The possible operations on an open npc, decr, decr_status, | ||
174 | spu_tag_mask, event_mask or srr0 file are: | ||
175 | |||
176 | read(2) | ||
177 | When the count supplied to the read call is shorter than the | ||
178 | required length for the pointer value plus a newline character, | ||
179 | subsequent reads from the same file descriptor will result in | ||
180 | completing the string, regardless of changes to the register by | ||
181 | a running SPU task. When a complete string has been read, all | ||
182 | subsequent read operations will return zero bytes and a new file | ||
183 | descriptor needs to be opened to read the value again. | ||
184 | |||
185 | write(2) | ||
186 | A write operation on the file results in setting the register to | ||
187 | the value given in the string. The string is parsed from the | ||
188 | beginning to the first non-numeric character or the end of the | ||
189 | buffer. Subsequent writes to the same file descriptor overwrite | ||
190 | the previous setting. | ||
191 | |||
192 | |||
193 | /fpcr | ||
194 | This file gives access to the Floating Point Status and Control Regis- | ||
195 | ter as a four byte long file. The operations on the fpcr file are: | ||
196 | |||
197 | read(2) | ||
198 | If a count smaller than four is requested, read returns -1 and | ||
199 | sets errno to EINVAL. Otherwise, a four byte value is placed in | ||
200 | the data buffer, containing the current value of the fpcr regis- | ||
201 | ter. | ||
202 | |||
203 | write(2) | ||
204 | If a count smaller than four is requested, write returns -1 and | ||
205 | sets errno to EINVAL. Otherwise, a four byte value is copied | ||
206 | from the data buffer, updating the value of the fpcr register. | ||
207 | |||
208 | |||
209 | /signal1 | ||
210 | /signal2 | ||
211 | The two signal notification channels of an SPU. These are read-write | ||
212 | files that operate on a 32 bit word. Writing to one of these files | ||
213 | triggers an interrupt on the SPU. The value writting to the signal | ||
214 | files can be read from the SPU through a channel read or from host user | ||
215 | space through the file. After the value has been read by the SPU, it | ||
216 | is reset to zero. The possible operations on an open signal1 or sig- | ||
217 | nal2 file are: | ||
218 | |||
219 | read(2) | ||
220 | If a count smaller than four is requested, read returns -1 and | ||
221 | sets errno to EINVAL. Otherwise, a four byte value is placed in | ||
222 | the data buffer, containing the current value of the specified | ||
223 | signal notification register. | ||
224 | |||
225 | write(2) | ||
226 | If a count smaller than four is requested, write returns -1 and | ||
227 | sets errno to EINVAL. Otherwise, a four byte value is copied | ||
228 | from the data buffer, updating the value of the specified signal | ||
229 | notification register. The signal notification register will | ||
230 | either be replaced with the input data or will be updated to the | ||
231 | bitwise OR or the old value and the input data, depending on the | ||
232 | contents of the signal1_type, or signal2_type respectively, | ||
233 | file. | ||
234 | |||
235 | |||
236 | /signal1_type | ||
237 | /signal2_type | ||
238 | These two files change the behavior of the signal1 and signal2 notifi- | ||
239 | cation files. The contain a numerical ASCII string which is read as | ||
240 | either "1" or "0". In mode 0 (overwrite), the hardware replaces the | ||
241 | contents of the signal channel with the data that is written to it. in | ||
242 | mode 1 (logical OR), the hardware accumulates the bits that are subse- | ||
243 | quently written to it. The possible operations on an open signal1_type | ||
244 | or signal2_type file are: | ||
245 | |||
246 | read(2) | ||
247 | When the count supplied to the read call is shorter than the | ||
248 | required length for the digit plus a newline character, subse- | ||
249 | quent reads from the same file descriptor will result in com- | ||
250 | pleting the string. When a complete string has been read, all | ||
251 | subsequent read operations will return zero bytes and a new file | ||
252 | descriptor needs to be opened to read the value again. | ||
253 | |||
254 | write(2) | ||
255 | A write operation on the file results in setting the register to | ||
256 | the value given in the string. The string is parsed from the | ||
257 | beginning to the first non-numeric character or the end of the | ||
258 | buffer. Subsequent writes to the same file descriptor overwrite | ||
259 | the previous setting. | ||
260 | |||
261 | |||
262 | EXAMPLES | ||
263 | /etc/fstab entry | ||
264 | none /spu spufs gid=spu 0 0 | ||
265 | |||
266 | |||
267 | AUTHORS | ||
268 | Arnd Bergmann <arndb@de.ibm.com>, Mark Nutter <mnutter@us.ibm.com>, | ||
269 | Ulrich Weigand <Ulrich.Weigand@de.ibm.com> | ||
270 | |||
271 | SEE ALSO | ||
272 | capabilities(7), close(2), spu_create(2), spu_run(2), spufs(7) | ||
273 | |||
274 | |||
275 | |||
276 | Linux 2005-09-28 SPUFS(2) | ||
277 | |||
278 | ------------------------------------------------------------------------------ | ||
279 | |||
280 | SPU_RUN(2) Linux Programmer's Manual SPU_RUN(2) | ||
281 | |||
282 | |||
283 | |||
284 | NAME | ||
285 | spu_run - execute an spu context | ||
286 | |||
287 | |||
288 | SYNOPSIS | ||
289 | #include <sys/spu.h> | ||
290 | |||
291 | int spu_run(int fd, unsigned int *npc, unsigned int *event); | ||
292 | |||
293 | DESCRIPTION | ||
294 | The spu_run system call is used on PowerPC machines that implement the | ||
295 | Cell Broadband Engine Architecture in order to access Synergistic Pro- | ||
296 | cessor Units (SPUs). It uses the fd that was returned from spu_cre- | ||
297 | ate(2) to address a specific SPU context. When the context gets sched- | ||
298 | uled to a physical SPU, it starts execution at the instruction pointer | ||
299 | passed in npc. | ||
300 | |||
301 | Execution of SPU code happens synchronously, meaning that spu_run does | ||
302 | not return while the SPU is still running. If there is a need to exe- | ||
303 | cute SPU code in parallel with other code on either the main CPU or | ||
304 | other SPUs, you need to create a new thread of execution first, e.g. | ||
305 | using the pthread_create(3) call. | ||
306 | |||
307 | When spu_run returns, the current value of the SPU instruction pointer | ||
308 | is written back to npc, so you can call spu_run again without updating | ||
309 | the pointers. | ||
310 | |||
311 | event can be a NULL pointer or point to an extended status code that | ||
312 | gets filled when spu_run returns. It can be one of the following con- | ||
313 | stants: | ||
314 | |||
315 | SPE_EVENT_DMA_ALIGNMENT | ||
316 | A DMA alignment error | ||
317 | |||
318 | SPE_EVENT_SPE_DATA_SEGMENT | ||
319 | A DMA segmentation error | ||
320 | |||
321 | SPE_EVENT_SPE_DATA_STORAGE | ||
322 | A DMA storage error | ||
323 | |||
324 | If NULL is passed as the event argument, these errors will result in a | ||
325 | signal delivered to the calling process. | ||
326 | |||
327 | RETURN VALUE | ||
328 | spu_run returns the value of the spu_status register or -1 to indicate | ||
329 | an error and set errno to one of the error codes listed below. The | ||
330 | spu_status register value contains a bit mask of status codes and | ||
331 | optionally a 14 bit code returned from the stop-and-signal instruction | ||
332 | on the SPU. The bit masks for the status codes are: | ||
333 | |||
334 | 0x02 SPU was stopped by stop-and-signal. | ||
335 | |||
336 | 0x04 SPU was stopped by halt. | ||
337 | |||
338 | 0x08 SPU is waiting for a channel. | ||
339 | |||
340 | 0x10 SPU is in single-step mode. | ||
341 | |||
342 | 0x20 SPU has tried to execute an invalid instruction. | ||
343 | |||
344 | 0x40 SPU has tried to access an invalid channel. | ||
345 | |||
346 | 0x3fff0000 | ||
347 | The bits masked with this value contain the code returned from | ||
348 | stop-and-signal. | ||
349 | |||
350 | There are always one or more of the lower eight bits set or an error | ||
351 | code is returned from spu_run. | ||
352 | |||
353 | ERRORS | ||
354 | EAGAIN or EWOULDBLOCK | ||
355 | fd is in non-blocking mode and spu_run would block. | ||
356 | |||
357 | EBADF fd is not a valid file descriptor. | ||
358 | |||
359 | EFAULT npc is not a valid pointer or status is neither NULL nor a valid | ||
360 | pointer. | ||
361 | |||
362 | EINTR A signal occured while spu_run was in progress. The npc value | ||
363 | has been updated to the new program counter value if necessary. | ||
364 | |||
365 | EINVAL fd is not a file descriptor returned from spu_create(2). | ||
366 | |||
367 | ENOMEM Insufficient memory was available to handle a page fault result- | ||
368 | ing from an MFC direct memory access. | ||
369 | |||
370 | ENOSYS the functionality is not provided by the current system, because | ||
371 | either the hardware does not provide SPUs or the spufs module is | ||
372 | not loaded. | ||
373 | |||
374 | |||
375 | NOTES | ||
376 | spu_run is meant to be used from libraries that implement a more | ||
377 | abstract interface to SPUs, not to be used from regular applications. | ||
378 | See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec- | ||
379 | ommended libraries. | ||
380 | |||
381 | |||
382 | CONFORMING TO | ||
383 | This call is Linux specific and only implemented by the ppc64 architec- | ||
384 | ture. Programs using this system call are not portable. | ||
385 | |||
386 | |||
387 | BUGS | ||
388 | The code does not yet fully implement all features lined out here. | ||
389 | |||
390 | |||
391 | AUTHOR | ||
392 | Arnd Bergmann <arndb@de.ibm.com> | ||
393 | |||
394 | SEE ALSO | ||
395 | capabilities(7), close(2), spu_create(2), spufs(7) | ||
396 | |||
397 | |||
398 | |||
399 | Linux 2005-09-28 SPU_RUN(2) | ||
400 | |||
401 | ------------------------------------------------------------------------------ | ||
402 | |||
403 | SPU_CREATE(2) Linux Programmer's Manual SPU_CREATE(2) | ||
404 | |||
405 | |||
406 | |||
407 | NAME | ||
408 | spu_create - create a new spu context | ||
409 | |||
410 | |||
411 | SYNOPSIS | ||
412 | #include <sys/types.h> | ||
413 | #include <sys/spu.h> | ||
414 | |||
415 | int spu_create(const char *pathname, int flags, mode_t mode); | ||
416 | |||
417 | DESCRIPTION | ||
418 | The spu_create system call is used on PowerPC machines that implement | ||
419 | the Cell Broadband Engine Architecture in order to access Synergistic | ||
420 | Processor Units (SPUs). It creates a new logical context for an SPU in | ||
421 | pathname and returns a handle to associated with it. pathname must | ||
422 | point to a non-existing directory in the mount point of the SPU file | ||
423 | system (spufs). When spu_create is successful, a directory gets cre- | ||
424 | ated on pathname and it is populated with files. | ||
425 | |||
426 | The returned file handle can only be passed to spu_run(2) or closed, | ||
427 | other operations are not defined on it. When it is closed, all associ- | ||
428 | ated directory entries in spufs are removed. When the last file handle | ||
429 | pointing either inside of the context directory or to this file | ||
430 | descriptor is closed, the logical SPU context is destroyed. | ||
431 | |||
432 | The parameter flags can be zero or any bitwise or'd combination of the | ||
433 | following constants: | ||
434 | |||
435 | SPU_RAWIO | ||
436 | Allow mapping of some of the hardware registers of the SPU into | ||
437 | user space. This flag requires the CAP_SYS_RAWIO capability, see | ||
438 | capabilities(7). | ||
439 | |||
440 | The mode parameter specifies the permissions used for creating the new | ||
441 | directory in spufs. mode is modified with the user's umask(2) value | ||
442 | and then used for both the directory and the files contained in it. The | ||
443 | file permissions mask out some more bits of mode because they typically | ||
444 | support only read or write access. See stat(2) for a full list of the | ||
445 | possible mode values. | ||
446 | |||
447 | |||
448 | RETURN VALUE | ||
449 | spu_create returns a new file descriptor. It may return -1 to indicate | ||
450 | an error condition and set errno to one of the error codes listed | ||
451 | below. | ||
452 | |||
453 | |||
454 | ERRORS | ||
455 | EACCESS | ||
456 | The current user does not have write access on the spufs mount | ||
457 | point. | ||
458 | |||
459 | EEXIST An SPU context already exists at the given path name. | ||
460 | |||
461 | EFAULT pathname is not a valid string pointer in the current address | ||
462 | space. | ||
463 | |||
464 | EINVAL pathname is not a directory in the spufs mount point. | ||
465 | |||
466 | ELOOP Too many symlinks were found while resolving pathname. | ||
467 | |||
468 | EMFILE The process has reached its maximum open file limit. | ||
469 | |||
470 | ENAMETOOLONG | ||
471 | pathname was too long. | ||
472 | |||
473 | ENFILE The system has reached the global open file limit. | ||
474 | |||
475 | ENOENT Part of pathname could not be resolved. | ||
476 | |||
477 | ENOMEM The kernel could not allocate all resources required. | ||
478 | |||
479 | ENOSPC There are not enough SPU resources available to create a new | ||
480 | context or the user specific limit for the number of SPU con- | ||
481 | texts has been reached. | ||
482 | |||
483 | ENOSYS the functionality is not provided by the current system, because | ||
484 | either the hardware does not provide SPUs or the spufs module is | ||
485 | not loaded. | ||
486 | |||
487 | ENOTDIR | ||
488 | A part of pathname is not a directory. | ||
489 | |||
490 | |||
491 | |||
492 | NOTES | ||
493 | spu_create is meant to be used from libraries that implement a more | ||
494 | abstract interface to SPUs, not to be used from regular applications. | ||
495 | See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec- | ||
496 | ommended libraries. | ||
497 | |||
498 | |||
499 | FILES | ||
500 | pathname must point to a location beneath the mount point of spufs. By | ||
501 | convention, it gets mounted in /spu. | ||
502 | |||
503 | |||
504 | CONFORMING TO | ||
505 | This call is Linux specific and only implemented by the ppc64 architec- | ||
506 | ture. Programs using this system call are not portable. | ||
507 | |||
508 | |||
509 | BUGS | ||
510 | The code does not yet fully implement all features lined out here. | ||
511 | |||
512 | |||
513 | AUTHOR | ||
514 | Arnd Bergmann <arndb@de.ibm.com> | ||
515 | |||
516 | SEE ALSO | ||
517 | capabilities(7), close(2), spu_run(2), spufs(7) | ||
518 | |||
519 | |||
520 | |||
521 | Linux 2005-09-28 SPU_CREATE(2) | ||
diff --git a/Documentation/powerpc/00-INDEX b/Documentation/powerpc/00-INDEX index e7bea0a407b4..d6d65b9bcfe3 100644 --- a/Documentation/powerpc/00-INDEX +++ b/Documentation/powerpc/00-INDEX | |||
@@ -8,12 +8,18 @@ please mail me. | |||
8 | cpu_features.txt | 8 | cpu_features.txt |
9 | - info on how we support a variety of CPUs with minimal compile-time | 9 | - info on how we support a variety of CPUs with minimal compile-time |
10 | options. | 10 | options. |
11 | eeh-pci-error-recovery.txt | ||
12 | - info on PCI Bus EEH Error Recovery | ||
13 | hvcs.txt | ||
14 | - IBM "Hypervisor Virtual Console Server" Installation Guide | ||
15 | mpc52xx.txt | ||
16 | - Linux 2.6.x on MPC52xx family | ||
11 | ppc_htab.txt | 17 | ppc_htab.txt |
12 | - info about the Linux/PPC /proc/ppc_htab entry | 18 | - info about the Linux/PPC /proc/ppc_htab entry |
13 | smp.txt | ||
14 | - use and state info about Linux/PPC on MP machines | ||
15 | SBC8260_memory_mapping.txt | 19 | SBC8260_memory_mapping.txt |
16 | - EST SBC8260 board info | 20 | - EST SBC8260 board info |
21 | smp.txt | ||
22 | - use and state info about Linux/PPC on MP machines | ||
17 | sound.txt | 23 | sound.txt |
18 | - info on sound support under Linux/PPC | 24 | - info on sound support under Linux/PPC |
19 | zImage_layout.txt | 25 | zImage_layout.txt |