linux-kernel - Re: [PATCH v1 02/10] x86, intel-mid: Remove "weak" from function declarations

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Date:	Mon, 20 Oct 2014 10:15:17 -0600
From:	Bjorn Helgaas <bhelgaas@...gle.com>
To:	David Cohen <david.a.cohen@...ux.intel.com>
Cc:	sathyanarayanan kuppuswamy 
	<sathyanarayanan.kuppuswamy@...ux.intel.com>,
	Jason Wessel <jason.wessel@...driver.com>,
	Ralf Baechle <ralf@...ux-mips.org>,
	Ingo Molnar <mingo@...hat.com>,
	John Stultz <john.stultz@...aro.org>,
	Eric Paris <eparis@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>
Subject: Re: [PATCH v1 02/10] x86, intel-mid: Remove "weak" from function declarations

On Thu, Oct 16, 2014 at 7:41 PM, David Cohen
<david.a.cohen@...ux.intel.com> wrote:
> Hi Bjorn and Sathya,
>
> On Thu, Oct 16, 2014 at 05:42:11PM -0700, sathyanarayanan kuppuswamy wrote:
>> Hi Bjorn,
>>
>> On 10/15/2014 04:26 PM, Bjorn Helgaas wrote:
>> >[+cc David, Kuppuswamy, x86; sorry, I botched my "stg mail" so you
>> >weren't included the first time]
>> >
>> >On Wed, Oct 15, 2014 at 11:05 AM, Bjorn Helgaas <bhelgaas@...gle.com> wrote:
>> >>For the following interfaces:
>> >>
>> >>   get_penwell_ops()
>> >>   get_cloverview_ops()
>> >>   get_tangier_ops()
>> >>
>> >>there is only one implementation, so they do not need to be marked "weak".
>> >>
>> >>Remove the "weak" attribute from their declarations.
>> >>
>> >>Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
>> >>CC: David Cohen <david.a.cohen@...ux.intel.com>
>> >>CC: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
>> >>CC: x86@...nel.org
>> >>---
>> >>  arch/x86/platform/intel-mid/intel_mid_weak_decls.h |    7 +++----
>> >>  1 file changed, 3 insertions(+), 4 deletions(-)
>> >>
>> >>diff --git a/arch/x86/platform/intel-mid/intel_mid_weak_decls.h b/arch/x86/platform/intel-mid/intel_mid_weak_decls.h
>> >>index 46aa25c8ce06..3c1c3866d82b 100644
>> >>--- a/arch/x86/platform/intel-mid/intel_mid_weak_decls.h
>> Please remove this file and move the contents to asm/intel-mid.h.

I don't know or care enough about intel-mid to do this myself.  Right
now, I'm just trying to remove unnecessary and incorrect usage of
"weak" in header files.

> I partially agree :)
>
> Historically, this file was created because we could not build all intel
> mid variants at once. So we have to select only one during compilation
> time, which was fixed already.
>
> But we don't need to expose those functions outside intel-mid's
> directory, which means asm/intel-mid.h isn't the best option IMHO.
>
> If you want, I can send a small re-work instead: we get rid of this
> header file completely and simplify a bit what is exposed by
> asm/intel-mid.h. Or you can keep this patch and then I send the re-work
> on top of it. Anyway I'm fine.

It's fine with me if you want to rework this to remove the header
completely.  When I pointed this out in January [1], you mentioned
plans for that.  But I think we should merge this patch in the interim
to remove the use of "weak" in a header file.  If we leave bad
examples in the tree, they just proliferate.

[1] http://lkml.kernel.org/r/20140128013013.GA31626@psi-dev26.jf.intel.com


>> >>+++ b/arch/x86/platform/intel-mid/intel_mid_weak_decls.h
>> >>@@ -10,10 +10,9 @@
>> >>   */
>> >>
>> >>
>> >>-/* __attribute__((weak)) makes these declarations overridable */
>> >>  /* For every CPU addition a new get_<cpuname>_ops interface needs
>> >>   * to be added.
>> >>   */
>> >>-extern void *get_penwell_ops(void) __attribute__((weak));
>> >>-extern void *get_cloverview_ops(void) __attribute__((weak));
>> >>-extern void *get_tangier_ops(void) __attribute__((weak));
>> >>+extern void *get_penwell_ops(void);
>> >>+extern void *get_cloverview_ops(void);
>> >>+extern void *get_tangier_ops(void);
>> >>
>>
>> --
>> Sathyanarayanan Kuppuswamy
>> Android kernel developer
>>
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