patch-2.4.9 linux/Documentation/parisc/mm

• Lines: 32
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.4.8/linux/Documentation/parisc/mm
• Orig date: Tue Dec 5 12:29:38 2000

diff -u --recursive --new-file v2.4.8/linux/Documentation/parisc/mm linux/Documentation/parisc/mm
@@ -1,31 +0,0 @@
-
-The current state of Linux/PA-RISC mm is BROKEN.
-
-Someone needs to sit down and thoroughly rewrite all the cache flushing
-macro definitions.  Here are some of the problems, followed by what I
-think needs to be done about them.
-
-(1) We're using fdce / fice everywhere.  This has to stop (except in
-the routines which flush the entire cache).  The right instructions to
-be using are fdc/fic.
-
-(2) fdc/fic will throw exceptions if the address they reference isn't
-mapped.  Therefore we need to check the page is mapped before flushing
-(we're guaranteed not to have the page dirty if we don't have a software
-mapping for it any longer, right?)
-
-(3) the flush macros are right now tunnelled down to one routine to flush
-the data cache and one routine to flush the insn cache.  this is wrong.
-we should take hints from how we're called and optimise our routines
-accordingly.
-
-(4) fdc/fic actually take space register arguments.  fic takes an 3-bit sr
-argument and fdc takes a 2-bit sr argument.  right now, there's a lot of
-pissing about with %sr1 and all the macros use %sr1.  This is crazy.  We
-normally _know_ what's being referred to, and it's the current task.  So
-if we want to flush that, just use %sr3.  If it happens to be kernel,
-use %sr0 for fdc and %sr4 for fic.
-
-(5) we need to write flush_kernel_dcache_range and use it on kernel
-addresses.  all the macros are defined to work on the _current task's_
-virtual address space.