diff options
| author | Steve French <sfrench@us.ibm.com> | 2006-03-20 16:58:09 +0000 |
|---|---|---|
| committer | Steve French <sfrench@us.ibm.com> | 2006-03-20 16:58:09 +0000 |
| commit | fd4a0b92db6a57cba8d03efbe1cebf91f9124ce0 (patch) | |
| tree | 5886a08bfa1132058b06074f4666a36dc5ddd2a1 /include/asm-mips/io.h | |
| parent | 88274815f7477dc7550439413ab87c5ce4c5a623 (diff) | |
| parent | 7705a8792b0fc82fd7d4dd923724606bbfd9fb20 (diff) | |
Merge with /pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'include/asm-mips/io.h')
| -rw-r--r-- | include/asm-mips/io.h | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/include/asm-mips/io.h b/include/asm-mips/io.h index 8c011aa61af..ba1d7bbc15d 100644 --- a/include/asm-mips/io.h +++ b/include/asm-mips/io.h @@ -4,7 +4,7 @@ * for more details. * * Copyright (C) 1994, 1995 Waldorf GmbH - * Copyright (C) 1994 - 2000 Ralf Baechle + * Copyright (C) 1994 - 2000, 06 Ralf Baechle * Copyright (C) 1999, 2000 Silicon Graphics, Inc. * Copyright (C) 2004, 2005 MIPS Technologies, Inc. All rights reserved. * Author: Maciej W. Rozycki <macro@mips.com> @@ -103,8 +103,20 @@ */ extern const unsigned long mips_io_port_base; -#define set_io_port_base(base) \ - do { * (unsigned long *) &mips_io_port_base = (base); } while (0) +/* + * Gcc will generate code to load the value of mips_io_port_base after each + * function call which may be fairly wasteful in some cases. So we don't + * play quite by the book. We tell gcc mips_io_port_base is a long variable + * which solves the code generation issue. Now we need to violate the + * aliasing rules a little to make initialization possible and finally we + * will need the barrier() to fight side effects of the aliasing chat. + * This trickery will eventually collapse under gcc's optimizer. Oh well. + */ +static inline void set_io_port_base(unsigned long base) +{ + * (unsigned long *) &mips_io_port_base = base; + barrier(); +} /* * Thanks to James van Artsdalen for a better timing-fix than |