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diff --git a/Documentation/filesystems/spufs.txt b/Documentation/filesystems/spufs.txt deleted file mode 100644 index eb9e3aa63026..000000000000 --- a/Documentation/filesystems/spufs.txt +++ /dev/null @@ -1,521 +0,0 @@ -SPUFS(2) Linux Programmer's Manual SPUFS(2) - - - -NAME - spufs - the SPU file system - - -DESCRIPTION - The SPU file system is used on PowerPC machines that implement the Cell - Broadband Engine Architecture in order to access Synergistic Processor - Units (SPUs). - - The file system provides a name space similar to posix shared memory or - message queues. Users that have write permissions on the file system - can use spu_create(2) to establish SPU contexts in the spufs root. - - Every SPU context is represented by a directory containing a predefined - set of files. These files can be used for manipulating the state of the - logical SPU. Users can change permissions on those files, but not actu- - ally add or remove files. - - -MOUNT OPTIONS - uid=<uid> - set the user owning the mount point, the default is 0 (root). - - gid=<gid> - set the group owning the mount point, the default is 0 (root). - - -FILES - The files in spufs mostly follow the standard behavior for regular sys- - tem calls like read(2) or write(2), but often support only a subset of - the operations supported on regular file systems. This list details the - supported operations and the deviations from the behaviour in the - respective man pages. - - All files that support the read(2) operation also support readv(2) and - all files that support the write(2) operation also support writev(2). - All files support the access(2) and stat(2) family of operations, but - only the st_mode, st_nlink, st_uid and st_gid fields of struct stat - contain reliable information. - - All files support the chmod(2)/fchmod(2) and chown(2)/fchown(2) opera- - tions, but will not be able to grant permissions that contradict the - possible operations, e.g. read access on the wbox file. - - The current set of files is: - - - /mem - the contents of the local storage memory of the SPU. This can be - accessed like a regular shared memory file and contains both code and - data in the address space of the SPU. The possible operations on an - open mem file are: - - read(2), pread(2), write(2), pwrite(2), lseek(2) - These operate as documented, with the exception that seek(2), - write(2) and pwrite(2) are not supported beyond the end of the - file. The file size is the size of the local storage of the SPU, - which normally is 256 kilobytes. - - mmap(2) - Mapping mem into the process address space gives access to the - SPU local storage within the process address space. Only - MAP_SHARED mappings are allowed. - - - /mbox - The first SPU to CPU communication mailbox. This file is read-only and - can be read in units of 32 bits. The file can only be used in non- - blocking mode and it even poll() will not block on it. The possible - operations on an open mbox file are: - - read(2) - If a count smaller than four is requested, read returns -1 and - sets errno to EINVAL. If there is no data available in the mail - box, the return value is set to -1 and errno becomes EAGAIN. - When data has been read successfully, four bytes are placed in - the data buffer and the value four is returned. - - - /ibox - The second SPU to CPU communication mailbox. This file is similar to - the first mailbox file, but can be read in blocking I/O mode, and the - poll family of system calls can be used to wait for it. The possible - operations on an open ibox file are: - - read(2) - If a count smaller than four is requested, read returns -1 and - sets errno to EINVAL. If there is no data available in the mail - box and the file descriptor has been opened with O_NONBLOCK, the - return value is set to -1 and errno becomes EAGAIN. - - If there is no data available in the mail box and the file - descriptor has been opened without O_NONBLOCK, the call will - block until the SPU writes to its interrupt mailbox channel. - When data has been read successfully, four bytes are placed in - the data buffer and the value four is returned. - - poll(2) - Poll on the ibox file returns (POLLIN | POLLRDNORM) whenever - data is available for reading. - - - /wbox - The CPU to SPU communation mailbox. It is write-only and can be written - in units of 32 bits. If the mailbox is full, write() will block and - poll can be used to wait for it becoming empty again. The possible - operations on an open wbox file are: write(2) If a count smaller than - four is requested, write returns -1 and sets errno to EINVAL. If there - is no space available in the mail box and the file descriptor has been - opened with O_NONBLOCK, the return value is set to -1 and errno becomes - EAGAIN. - - If there is no space available in the mail box and the file descriptor - has been opened without O_NONBLOCK, the call will block until the SPU - reads from its PPE mailbox channel. When data has been read success- - fully, four bytes are placed in the data buffer and the value four is - returned. - - poll(2) - Poll on the ibox file returns (POLLOUT | POLLWRNORM) whenever - space is available for writing. - - - /mbox_stat - /ibox_stat - /wbox_stat - Read-only files that contain the length of the current queue, i.e. how - many words can be read from mbox or ibox or how many words can be - written to wbox without blocking. The files can be read only in 4-byte - units and return a big-endian binary integer number. The possible - operations on an open *box_stat file are: - - read(2) - If a count smaller than four is requested, read returns -1 and - sets errno to EINVAL. Otherwise, a four byte value is placed in - the data buffer, containing the number of elements that can be - read from (for mbox_stat and ibox_stat) or written to (for - wbox_stat) the respective mail box without blocking or resulting - in EAGAIN. - - - /npc - /decr - /decr_status - /spu_tag_mask - /event_mask - /srr0 - Internal registers of the SPU. The representation is an ASCII string - with the numeric value of the next instruction to be executed. These - can be used in read/write mode for debugging, but normal operation of - programs should not rely on them because access to any of them except - npc requires an SPU context save and is therefore very inefficient. - - The contents of these files are: - - npc Next Program Counter - - decr SPU Decrementer - - decr_status Decrementer Status - - spu_tag_mask MFC tag mask for SPU DMA - - event_mask Event mask for SPU interrupts - - srr0 Interrupt Return address register - - - The possible operations on an open npc, decr, decr_status, - spu_tag_mask, event_mask or srr0 file are: - - read(2) - When the count supplied to the read call is shorter than the - required length for the pointer value plus a newline character, - subsequent reads from the same file descriptor will result in - completing the string, regardless of changes to the register by - a running SPU task. When a complete string has been read, all - subsequent read operations will return zero bytes and a new file - descriptor needs to be opened to read the value again. - - write(2) - A write operation on the file results in setting the register to - the value given in the string. The string is parsed from the - beginning to the first non-numeric character or the end of the - buffer. Subsequent writes to the same file descriptor overwrite - the previous setting. - - - /fpcr - This file gives access to the Floating Point Status and Control Regis- - ter as a four byte long file. The operations on the fpcr file are: - - read(2) - If a count smaller than four is requested, read returns -1 and - sets errno to EINVAL. Otherwise, a four byte value is placed in - the data buffer, containing the current value of the fpcr regis- - ter. - - write(2) - If a count smaller than four is requested, write returns -1 and - sets errno to EINVAL. Otherwise, a four byte value is copied - from the data buffer, updating the value of the fpcr register. - - - /signal1 - /signal2 - The two signal notification channels of an SPU. These are read-write - files that operate on a 32 bit word. Writing to one of these files - triggers an interrupt on the SPU. The value written to the signal - files can be read from the SPU through a channel read or from host user - space through the file. After the value has been read by the SPU, it - is reset to zero. The possible operations on an open signal1 or sig- - nal2 file are: - - read(2) - If a count smaller than four is requested, read returns -1 and - sets errno to EINVAL. Otherwise, a four byte value is placed in - the data buffer, containing the current value of the specified - signal notification register. - - write(2) - If a count smaller than four is requested, write returns -1 and - sets errno to EINVAL. Otherwise, a four byte value is copied - from the data buffer, updating the value of the specified signal - notification register. The signal notification register will - either be replaced with the input data or will be updated to the - bitwise OR or the old value and the input data, depending on the - contents of the signal1_type, or signal2_type respectively, - file. - - - /signal1_type - /signal2_type - These two files change the behavior of the signal1 and signal2 notifi- - cation files. The contain a numerical ASCII string which is read as - either "1" or "0". In mode 0 (overwrite), the hardware replaces the - contents of the signal channel with the data that is written to it. in - mode 1 (logical OR), the hardware accumulates the bits that are subse- - quently written to it. The possible operations on an open signal1_type - or signal2_type file are: - - read(2) - When the count supplied to the read call is shorter than the - required length for the digit plus a newline character, subse- - quent reads from the same file descriptor will result in com- - pleting the string. When a complete string has been read, all - subsequent read operations will return zero bytes and a new file - descriptor needs to be opened to read the value again. - - write(2) - A write operation on the file results in setting the register to - the value given in the string. The string is parsed from the - beginning to the first non-numeric character or the end of the - buffer. Subsequent writes to the same file descriptor overwrite - the previous setting. - - -EXAMPLES - /etc/fstab entry - none /spu spufs gid=spu 0 0 - - -AUTHORS - Arnd Bergmann <arndb@de.ibm.com>, Mark Nutter <mnutter@us.ibm.com>, - Ulrich Weigand <Ulrich.Weigand@de.ibm.com> - -SEE ALSO - capabilities(7), close(2), spu_create(2), spu_run(2), spufs(7) - - - -Linux 2005-09-28 SPUFS(2) - ------------------------------------------------------------------------------- - -SPU_RUN(2) Linux Programmer's Manual SPU_RUN(2) - - - -NAME - spu_run - execute an spu context - - -SYNOPSIS - #include <sys/spu.h> - - int spu_run(int fd, unsigned int *npc, unsigned int *event); - -DESCRIPTION - The spu_run system call is used on PowerPC machines that implement the - Cell Broadband Engine Architecture in order to access Synergistic Pro- - cessor Units (SPUs). It uses the fd that was returned from spu_cre- - ate(2) to address a specific SPU context. When the context gets sched- - uled to a physical SPU, it starts execution at the instruction pointer - passed in npc. - - Execution of SPU code happens synchronously, meaning that spu_run does - not return while the SPU is still running. If there is a need to exe- - cute SPU code in parallel with other code on either the main CPU or - other SPUs, you need to create a new thread of execution first, e.g. - using the pthread_create(3) call. - - When spu_run returns, the current value of the SPU instruction pointer - is written back to npc, so you can call spu_run again without updating - the pointers. - - event can be a NULL pointer or point to an extended status code that - gets filled when spu_run returns. It can be one of the following con- - stants: - - SPE_EVENT_DMA_ALIGNMENT - A DMA alignment error - - SPE_EVENT_SPE_DATA_SEGMENT - A DMA segmentation error - - SPE_EVENT_SPE_DATA_STORAGE - A DMA storage error - - If NULL is passed as the event argument, these errors will result in a - signal delivered to the calling process. - -RETURN VALUE - spu_run returns the value of the spu_status register or -1 to indicate - an error and set errno to one of the error codes listed below. The - spu_status register value contains a bit mask of status codes and - optionally a 14 bit code returned from the stop-and-signal instruction - on the SPU. The bit masks for the status codes are: - - 0x02 SPU was stopped by stop-and-signal. - - 0x04 SPU was stopped by halt. - - 0x08 SPU is waiting for a channel. - - 0x10 SPU is in single-step mode. - - 0x20 SPU has tried to execute an invalid instruction. - - 0x40 SPU has tried to access an invalid channel. - - 0x3fff0000 - The bits masked with this value contain the code returned from - stop-and-signal. - - There are always one or more of the lower eight bits set or an error - code is returned from spu_run. - -ERRORS - EAGAIN or EWOULDBLOCK - fd is in non-blocking mode and spu_run would block. - - EBADF fd is not a valid file descriptor. - - EFAULT npc is not a valid pointer or status is neither NULL nor a valid - pointer. - - EINTR A signal occurred while spu_run was in progress. The npc value - has been updated to the new program counter value if necessary. - - EINVAL fd is not a file descriptor returned from spu_create(2). - - ENOMEM Insufficient memory was available to handle a page fault result- - ing from an MFC direct memory access. - - ENOSYS the functionality is not provided by the current system, because - either the hardware does not provide SPUs or the spufs module is - not loaded. - - -NOTES - spu_run is meant to be used from libraries that implement a more - abstract interface to SPUs, not to be used from regular applications. - See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec- - ommended libraries. - - -CONFORMING TO - This call is Linux specific and only implemented by the ppc64 architec- - ture. Programs using this system call are not portable. - - -BUGS - The code does not yet fully implement all features lined out here. - - -AUTHOR - Arnd Bergmann <arndb@de.ibm.com> - -SEE ALSO - capabilities(7), close(2), spu_create(2), spufs(7) - - - -Linux 2005-09-28 SPU_RUN(2) - ------------------------------------------------------------------------------- - -SPU_CREATE(2) Linux Programmer's Manual SPU_CREATE(2) - - - -NAME - spu_create - create a new spu context - - -SYNOPSIS - #include <sys/types.h> - #include <sys/spu.h> - - int spu_create(const char *pathname, int flags, mode_t mode); - -DESCRIPTION - The spu_create system call is used on PowerPC machines that implement - the Cell Broadband Engine Architecture in order to access Synergistic - Processor Units (SPUs). It creates a new logical context for an SPU in - pathname and returns a handle to associated with it. pathname must - point to a non-existing directory in the mount point of the SPU file - system (spufs). When spu_create is successful, a directory gets cre- - ated on pathname and it is populated with files. - - The returned file handle can only be passed to spu_run(2) or closed, - other operations are not defined on it. When it is closed, all associ- - ated directory entries in spufs are removed. When the last file handle - pointing either inside of the context directory or to this file - descriptor is closed, the logical SPU context is destroyed. - - The parameter flags can be zero or any bitwise or'd combination of the - following constants: - - SPU_RAWIO - Allow mapping of some of the hardware registers of the SPU into - user space. This flag requires the CAP_SYS_RAWIO capability, see - capabilities(7). - - The mode parameter specifies the permissions used for creating the new - directory in spufs. mode is modified with the user's umask(2) value - and then used for both the directory and the files contained in it. The - file permissions mask out some more bits of mode because they typically - support only read or write access. See stat(2) for a full list of the - possible mode values. - - -RETURN VALUE - spu_create returns a new file descriptor. It may return -1 to indicate - an error condition and set errno to one of the error codes listed - below. - - -ERRORS - EACCES - The current user does not have write access on the spufs mount - point. - - EEXIST An SPU context already exists at the given path name. - - EFAULT pathname is not a valid string pointer in the current address - space. - - EINVAL pathname is not a directory in the spufs mount point. - - ELOOP Too many symlinks were found while resolving pathname. - - EMFILE The process has reached its maximum open file limit. - - ENAMETOOLONG - pathname was too long. - - ENFILE The system has reached the global open file limit. - - ENOENT Part of pathname could not be resolved. - - ENOMEM The kernel could not allocate all resources required. - - ENOSPC There are not enough SPU resources available to create a new - context or the user specific limit for the number of SPU con- - texts has been reached. - - ENOSYS the functionality is not provided by the current system, because - either the hardware does not provide SPUs or the spufs module is - not loaded. - - ENOTDIR - A part of pathname is not a directory. - - - -NOTES - spu_create is meant to be used from libraries that implement a more - abstract interface to SPUs, not to be used from regular applications. - See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec- - ommended libraries. - - -FILES - pathname must point to a location beneath the mount point of spufs. By - convention, it gets mounted in /spu. - - -CONFORMING TO - This call is Linux specific and only implemented by the ppc64 architec- - ture. Programs using this system call are not portable. - - -BUGS - The code does not yet fully implement all features lined out here. - - -AUTHOR - Arnd Bergmann <arndb@de.ibm.com> - -SEE ALSO - capabilities(7), close(2), spu_run(2), spufs(7) - - - -Linux 2005-09-28 SPU_CREATE(2) |