From: Sameer Goel <sameer.goel@linaro.org>
To: "Jan Beulich" <JBeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Cc: sstabellini@kernel.org, wei.liu2@citrix.com,
mjaggi@caviumnetworks.com, george.dunlap@eu.citrix.com,
Andrew.Cooper3@citrix.com, Julien Grall <julien.grall@arm.com>,
Ian.Jackson@citrix.com, xen-devel@lists.xenproject.org,
nd@arm.com, shankerd@codeaurora.org
Subject: Re: [PATCH 1/7] Port WARN_ON_ONCE() from Linux
Date: Fri, 18 May 2018 16:46:10 -0600 [thread overview]
Message-ID: <2afc35bc-3998-b10d-9b7c-e0306412b7f0@linaro.org> (raw)
In-Reply-To: <5A82C1F602000078001A73D2@prv-mh.provo.novell.com>
On 2/13/2018 2:46 AM, Jan Beulich wrote:
>>>> On 09.02.18 at 11:47, <roger.pau@citrix.com> wrote:
>> On Fri, Feb 09, 2018 at 10:45:25AM +0000, Julien Grall wrote:
>>> Hi,
>>>
>>> On 02/09/2018 10:29 AM, Roger Pau Monné wrote:
>>>> On Thu, Feb 08, 2018 at 08:10:49PM -0700, Sameer Goel wrote:
>>>>> diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
>>>>> index 1d9771340c..697212a061 100644
>>>>> --- a/xen/include/xen/lib.h
>>>>> +++ b/xen/include/xen/lib.h
>>>>> @@ -11,6 +11,19 @@
>>>>> #define BUG_ON(p) do { if (unlikely(p)) BUG(); } while (0)
>>>>> #define WARN_ON(p) do { if (unlikely(p)) WARN(); } while (0)
>>>>> +#define WARN_ON_ONCE(p) \
>>>>> +({ \
>>>>> + static bool __section(".data.unlikely") __warned; \
>>>>> + int __ret_warn_once = !!(p); \
>>>> ^ bool
>>>>
>>>>> + \
>>>>> + if ( unlikely(__ret_warn_once && !__warned) ) \
>>>>> + { \
>>>>> + __warned = true; \
>>>>> + WARN(); \
>>>>> + } \
>>>>> + unlikely(__ret_warn_once); \
>>>> Does this macro really need to return something? It seems weird to me
>>>> to allow usages like: if ( WARN_ON_ONCE...
>>> This construct is used in Linux (included in the driver ported):
>>>
>>> if (WARN_ON_ONCE(fwspec->iommu_priv)) {
>>> master = fwspec->iommu_priv;
>>> smmu = master->smmu;
>>> } else {
>>> ....
>>> }
>>>
>>> IHMO the makes the code nicer to read over:
>> OK, if that's intended I'm fine with it, just wanted to check.
> But WARN_ON() should then be given the same property, I think.
Not changing any already defined macros in Xen.
>
> Jan
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
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next prev parent reply other threads:[~2018-05-18 22:46 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-09 3:10 [PATCH 0/7] SMMUv3 driver Sameer Goel
2018-02-09 3:10 ` [PATCH 1/7] Port WARN_ON_ONCE() from Linux Sameer Goel
2018-02-09 10:29 ` Roger Pau Monné
2018-02-09 10:45 ` Julien Grall
2018-02-09 10:47 ` Roger Pau Monné
2018-02-13 9:46 ` Jan Beulich
2018-05-18 22:46 ` Sameer Goel [this message]
2018-02-12 14:49 ` Wei Liu
2018-02-13 9:48 ` Jan Beulich
2018-02-09 3:10 ` [PATCH 2/7] xen/bitops: Rename LOG_2 to ilog2 Sameer Goel
2018-02-12 14:46 ` Wei Liu
2018-02-09 3:10 ` [PATCH 3/7] passthrough/arm: Modify SMMU driver to use generic device definition Sameer Goel
2018-02-09 3:10 ` [PATCH 4/7] Add verbatim copy of arm-smmu-v3.c from Linux Sameer Goel
2018-02-09 3:10 ` [PATCH 5/7] xen/iommu: smmu-v3: Add Xen specific code to enable the ported driver Sameer Goel
2018-03-01 14:07 ` Julien Grall
2018-03-01 14:21 ` Jan Beulich
2018-03-01 14:33 ` Julien Grall
2018-03-01 15:38 ` Jan Beulich
2018-03-10 17:53 ` Manish Jaggi
2018-03-12 3:36 ` Manish Jaggi
2018-04-19 10:54 ` Manish Jaggi
2018-05-09 8:30 ` Manish Jaggi
2018-05-09 8:58 ` Julien Grall
2018-05-11 20:54 ` Sameer Goel
2018-05-18 22:38 ` Sameer Goel
2018-02-09 3:10 ` [PATCH 6/7] drivers/passthrough/arm: Refactor code for arm smmu drivers Sameer Goel
2018-02-09 10:43 ` Roger Pau Monné
2018-02-09 10:51 ` Julien Grall
2018-02-09 11:02 ` Roger Pau Monné
2018-02-09 11:12 ` Julien Grall
2018-05-18 23:00 ` Sameer Goel
2018-02-09 17:54 ` Sameer Goel
2018-03-01 14:24 ` Julien Grall
2018-02-09 3:10 ` [PATCH 7/7] xen/smmu: Add a new config define for legacy SMMU Sameer Goel
2018-03-01 14:35 ` [PATCH 0/7] SMMUv3 driver Julien Grall
2018-03-04 14:52 ` Manish Jaggi
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