SPU_RUN(2)                 Linux Programmer's Manual                SPU_RUN(2)

       spu_run - execute an SPU context

       #include <sys/spu.h>

       int spu_run(int fd, unsigned int *npc, unsigned int *event);

       Note: There is no glibc wrapper for this system call; see NOTES.

       The  spu_run()  system  call is used on PowerPC machines that implement
       the Cell Broadband Engine Architecture in order to  access  Synergistic
       Processor  Units (SPUs).  The fd argument is a file descriptor returned
       by spu_create(2) that refers to a specific SPU context.  When the  con-
       text  gets  scheduled to a physical SPU, it starts execution at the in-
       struction pointer passed in npc.

       Execution of SPU code happens  synchronously,  meaning  that  spu_run()
       blocks  while  the SPU is still running.  If there is a need to execute
       SPU code in parallel with other code on either the main  CPU  or  other
       SPUs,  a  new  thread  of  execution must be created first (e.g., using

       When spu_run() returns, the current value of the SPU program counter is
       written  to  npc, so successive calls to spu_run() can use the same npc

       The event argument provides a buffer for an extended status  code.   If
       the  SPU  context  was created with the SPU_CREATE_EVENTS_ENABLED flag,
       then this buffer is populated by the Linux kernel before spu_run()  re-

       The status code may be one (or more) of the following constants:

              A DMA alignment error occurred.

              An invalid MFC DMA command was attempted.

              A DMA storage error occurred.

              An illegal instruction was executed.

       NULL is a valid value for the event argument.  In this case, the events
       will not be reported to the calling process.

       On success, spu_run() returns the value of the spu_status register.  On
       error,  it  returns  -1 and sets errno to one of the error codes listed

       The spu_status register value is a bit mask of status codes and option-
       ally 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 a stop-and-signal instruction.

       0x04   SPU was stopped by a halt instruction.

       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.

              The bits masked with this value contain the code returned from a
              stop-and-signal  instruction.   These bits are valid only if the
              0x02 bit is set.

       If spu_run() has not returned an error, one  or  more  bits  among  the
       lower eight ones are always set.

       EBADF  fd is not a valid file descriptor.

       EFAULT npc  is not a valid pointer, or event is non-NULL and an invalid

       EINTR  A signal occurred while spu_run()  was  in  progress;  see  sig-
              nal(7).   The  npc  value  has  been  updated to the new program
              counter value if necessary.

       EINVAL fd is not a valid file descriptor returned from spu_create(2).

       ENOMEM There was not enough memory available to handle a page fault re-
              sulting  from  a  Memory Flow Controller (MFC) direct memory ac-

       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.

       The spu_run() system call was added to Linux in kernel 2.6.16.

       This call is Linux-specific and implemented only by the PowerPC  archi-
       tecture.  Programs using this system call are not portable.

       Glibc  does  not  provide a wrapper for this system call; call it using
       syscall(2).  Note however, that spu_run() is meant to be used from  li-
       braries  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 recommended libraries.

       The  following  is  an example of running a simple, one-instruction SPU
       program with the spu_run() system call.

       #include <stdlib.h>
       #include <stdint.h>
       #include <unistd.h>
       #include <stdio.h>
       #include <sys/types.h>
       #include <fcntl.h>

       #define handle_error(msg) \
           do { perror(msg); exit(EXIT_FAILURE); } while (0)

       int main(void)
           int context, fd, spu_status;
           uint32_t instruction, npc;

           context = spu_create("/spu/example-context", 0, 0755);
           if (context == -1)

           /* write a 'stop 0x1234' instruction to the SPU's
            * local store memory
           instruction = 0x00001234;

           fd = open("/spu/example-context/mem", O_RDWR);
           if (fd == -1)
           write(fd, &instruction, sizeof(instruction));

           /* set npc to the starting instruction address of the
            * SPU program. Since we wrote the instruction at the
            * start of the mem file, the entry point will be 0x0
           npc = 0;

           spu_status = spu_run(context, &npc, NULL);
           if (spu_status == -1)

           /* we should see a status code of 0x1234002:
            *   0x00000002 (spu was stopped due to stop-and-signal)
            * | 0x12340000 (the stop-and-signal code)
           printf("SPU Status: 0x%08x\n", spu_status);


       close(2), spu_create(2), capabilities(7), spufs(7)

       This page is part of release 5.05 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at

Linux                             2019-03-06                        SPU_RUN(2)
Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2024 Hurricane Electric. All Rights Reserved.