Messages in this thread Patch in this message | | | Date | Thu, 14 May 2009 16:19:03 +0900 | From | Hitoshi Mitake <> | Subject | Re: [PATCH] x86: Remove readq()/writeq() on 32-bit |
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On Wed, 13 May 2009 20:49:26 -0400 Jeff Garzik <jeff@garzik.org> wrote:
> H. Peter Anvin wrote: > > Jeff Garzik wrote: > >> Judging from this thread and past, I think people will continue to > >> complain and get confused, even with the above. > >> > > > > Do you really think so? Seems unfortunate, since an API rename would be > > way more invasive. This is the entirety of the header patch > > (compile-tested using 32-bit allyesconfig). > > The header patch does not lessen the confusion, because you cannot look > at the code and immediately tell what is going on... > > Having a single function's behavior change based on #include selection > is /not/ intuitive at all, particularly for driver writers. That is > unlike almost every other Linux API, where functions' behavior stays > constant across platforms, regardless of magic "under the hood." > > That sort of trick is reserved for arch maintainers who know what they > are doing :) > > Jeff > > >
I found another way: Making architecture with atomic readq/writeq provide HAVE_READQ_ATOMIC/HAVE_WRITEQ_ATOMIC and making architecture with non-atomic readq/writeq provide HAVE_READQ/HAVE_WRITEQ. (HAVE_READQ_ATOMIC/HAVE_WRITEQ_ATOMIC should double as HAVE_READQ/HAVE_WRITEQ.)
So driver programmers who need atomic readq/writeq can judge existence of API they really need. If platform doesn't provide atomic readq/writeq, drivers need these can be disabled by Kconfig. And bugs Roland and David talking about will be banished. How about this? > Roland and David I wrote a test patch. Request for comments.
Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
--- arch/x86/Kconfig | 16 ++++++++++++++-- 1 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index df9e885..c94fc48 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -19,8 +19,6 @@ config X86_64 config X86 def_bool y select HAVE_AOUT if X86_32 - select HAVE_READQ - select HAVE_WRITEQ select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_IDE select HAVE_OPROFILE @@ -2022,6 +2020,20 @@ config HAVE_ATOMIC_IOMAP def_bool y depends on X86_32 +config HAVE_READQ + def_bool y + +config HAVE_WRITEQ + def_bool y + +config HAVE_READQ_ATOMIC + def_bool y + depends on X86_64 + +config HAVE_WRITEQ_ATOMIC + def_bool y + depends on X86_64 + source "net/Kconfig" source "drivers/Kconfig" -- 1.5.6.5
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