spufs.txt

linux 内核源代码

EXAMPLES
       /etc/fstab entry
              none      /spu      spufs     gid=spu   0    0


AUTHORS
       Arnd  Bergmann  <[e-mail]>,  Mark  Nutter <[e-mail]>,
       Ulrich Weigand <[e-mail]>

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 <[e-mail]>

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
       EACCESS
              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 <[e-mail]>

SEE ALSO
       capabilities(7), close(2), spu_run(2), spufs(7)



Linux                             2005-09-28                     SPU_CREATE(2)