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  1. 21 Dec, 2007 2 commits
    • Masato Noguchi's avatar
      [POWERPC] cell: wrap master run control bit · c25620d7
      Masato Noguchi authored 
      Add platform specific SPU run control routines to the spufs.  The current
spufs implementation uses the SPU master run control bit (MFC_SR1[S]) to
control SPE execution, but the PS3 hypervisor does not support the use of
this feature.

This change adds the run control wrapper routies spu_enable_spu() and
spu_disable_spu().  The bare metal routines use the master run control
bit, and the PS3 specific routines use the priv2 run control register.

An outstanding enhancement for the PS3 would be to add a guard to check
for incorrect access to the spu problem state when the spu context is
disabled.  This check could be implemented with a flag added to the spu
context that would inhibit mapping problem state pages, and a routine
to unmap spu problem state pages.  When the spu is enabled with
ps3_enable_spu() the flag would be set allowing pages to be mapped,
and when the spu is disabled with ps3_disable_spu() the flag would be
cleared and mapped problem state pages would be unmapped.
Signed-off-by: default avatarMasato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: default avatarGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      c25620d7
    • Emil Medve's avatar
      [POWERPC] Optimize counting distinct entries in the relocation sections · eda09fbd
      Emil Medve authored 
      When a module has relocation sections with tens of thousands of
entries, counting the distinct/unique entries only (i.e. no
duplicates) at load time can take tens of seconds and up to minutes.
The sore point is the count_relocs() function which is called as part
of the architecture specific module loading processing path:

	-> load_module()			generic
	   -> module_frob_arch_sections()	arch specific
	      -> get_plt_size()		32-bit
	      -> get_stubs_size()	64-bit
		 -> count_relocs()

Here count_relocs is being called to find out how many distinct
targets of R_PPC_REL24 relocations there are, since each distinct
target needs a PLT entry or a stub created for it.

The previous counting algorithm has O(n^2) complexity.  Basically two
solutions were proposed on the e-mail list: a hash based approach and
a sort based approach.

The hash based approach is the fastest (O(n)) but the has it needs
additional memory and for certain corner cases it could take lots of
memory due to the degeneration of the hash.  One such proposal was
submitted here:

http://ozlabs.org/pipermail/linuxppc-dev/2007-June/037641.html

The sort based approach is slower (O(n * log n + n)) but if the
sorting is done "in place" it doesn't need additional memory.
This has O(n + n * log n) complexity with no additional memory
requirements.

This commit implements the in-place sort option.
Signed-off-by: default avatarEmil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      eda09fbd
  3. 20 Dec, 2007 38 commits