1. 17 Feb, 2015 28 commits
  2. 16 Feb, 2015 11 commits
  3. 12 Feb, 2015 1 commit
    • Paul Burton's avatar
      MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS · 9791554b
      Paul Burton authored
      Userland code may be built using an ABI which permits linking to objects
      that have more restrictive floating point requirements. For example,
      userland code may be built to target the O32 FPXX ABI. Such code may be
      linked with other FPXX code, or code built for either one of the more
      restrictive FP32 or FP64. When linking with more restrictive code, the
      overall requirement of the process becomes that of the more restrictive
      code. The kernel has no way to know in advance which mode the process
      will need to be executed in, and indeed it may need to change during
      execution. The dynamic loader is the only code which will know the
      overall required mode, and so it needs to have a means to instruct the
      kernel to switch the FP mode of the process.
      
      This patch introduces 2 new options to the prctl syscall which provide
      such a capability. The FP mode of the process is represented as a
      simple bitmask combining a number of mode bits mirroring those present
      in the hardware. Userland can either retrieve the current FP mode of
      the process:
      
        mode = prctl(PR_GET_FP_MODE);
      
      or modify the current FP mode of the process:
      
        err = prctl(PR_SET_FP_MODE, new_mode);
      Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
      Cc: Matthew Fortune <matthew.fortune@imgtec.com>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/8899/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      9791554b