This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] Provide a stub ioperm implementation for ARMv5 and later
- From: Aurelien Jarno <aurelien at aurel32 dot net>
- To: Phil Blundell <pb at pbcl dot net>
- Cc: libc-alpha at sourceware dot org
- Date: Sat, 12 Dec 2015 21:45:38 +0100
- Subject: Re: [PATCH] Provide a stub ioperm implementation for ARMv5 and later
- Authentication-results: sourceware.org; auth=none
- References: <1449946774-18072-1-git-send-email-aurelien at aurel32 dot net> <1449951987 dot 2002 dot 52 dot camel at pbcl dot net>
On 2015-12-12 20:26, Phil Blundell wrote:
> On Sat, 2015-12-12 at 19:59 +0100, Aurelien Jarno wrote:
> > The ioperm, iopl, in{b,w,l} and out{b,w,l} functions only make sense
> > on ARMv4.
>
> This statement isn't strictly true. There is no inherent relationship
> between the architecture level and the availability or not of the
> port-mapped I/O functions. And, in fact, a quick survey suggests that
> there is at least one counterexample in the kernel: CONFIG_ARCH_VIPER is
> a PXA25x board (hence ARMv5TE) and seems to include ISA. So, I am not
> all that keen on this patch.
This patch was actually in answer to the remark from Arnd Bergmann on
the other ioperm patch. I admit I should have checked more in details
about that.
> If you wanted to clean up the ioperm code a bit then it would probably
> make sense to remove all the legacy stuff that grubs around
> in /proc/cpuinfo and /etc/arm_systype to figure out what sort of machine
> it's on, since this is only needed for kernels that are so old as to
> lack the CTL_BUS_ISA sysctls.
OK, I'll have a look at that someday.
Aurelien
--
Aurelien Jarno GPG: 4096R/1DDD8C9B
aurelien@aurel32.net http://www.aurel32.net