From: Zhangshaokun <zhangshaokun@hisilicon.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>,
Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org,
Zhang Lei <zhang.lei@jp.fujitsu.com>,
Masayoshi Mizuma <msys.mizuma@gmail.com>,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] arm64/mm: Correct the cache line size warning with non coherent device
Date: Mon, 17 Jun 2019 19:00:34 +0800 [thread overview]
Message-ID: <7e567399-6f3d-b416-6636-c9f2f37ea407@hisilicon.com> (raw)
In-Reply-To: <20190617104555.GA1367@arrakis.emea.arm.com>
Hi Catalin,
On 2019/6/17 18:45, Catalin Marinas wrote:
> On Sat, Jun 15, 2019 at 10:44:33AM +0800, Zhangshaokun wrote:
>> On 2019/6/14 21:11, Masayoshi Mizuma wrote:
>>> diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
>>> index 6eaf1c07aa4e..7fa6828bb488 100644
>>> --- a/arch/arm64/kernel/cacheinfo.c
>>> +++ b/arch/arm64/kernel/cacheinfo.c
>>> @@ -19,12 +19,10 @@
>>>
>>> int cache_line_size(void)
>>> {
>>> - u32 cwg = cache_type_cwg();
>>> -
>>> if (coherency_max_size != 0)
>>> return coherency_max_size;
>>>
>>> - return cwg ? 4 << cwg : ARCH_DMA_MINALIGN;
>>> + return cache_line_size_of_cpu();
>>> }
>>
>> How about simplify it as this?
>>
>> int cache_line_size(void)
>> {
>> return coherency_max_size ? coherency_max_size :
>> cache_line_size_of_cpu();
>> }
>
> I don't see this as a simplification, easier to read with explicit 'if'.
>
Okay, I thought it can save some unnecessary lines :-).
>>> EXPORT_SYMBOL_GPL(cache_line_size);
>>>
>>> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
>>> index 1669618db08a..379589dc7113 100644
>>> --- a/arch/arm64/mm/dma-mapping.c
>>> +++ b/arch/arm64/mm/dma-mapping.c
>>> @@ -38,10 +38,6 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
>>>
>>> static int __init arm64_dma_init(void)
>>> {
>>> - WARN_TAINT(ARCH_DMA_MINALIGN < cache_line_size(),
>>> - TAINT_CPU_OUT_OF_SPEC,
>>> - "ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)",
>>> - ARCH_DMA_MINALIGN, cache_line_size());
>>> return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC));
>>> }
>>> arch_initcall(arm64_dma_init);
>>> @@ -56,7 +52,17 @@ void arch_teardown_dma_ops(struct device *dev)
>>> void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>>> const struct iommu_ops *iommu, bool coherent)
>>> {
>>> + int cls = cache_line_size_of_cpu();
>>
>> whether we need this local variable, how about use cache_line_size_of_cpu
>> directly in WARN_TAINT just like before.
>
> The reason being?
>
Since it is inline function, maybe it is unnecessary, it is trivial.
> Anyway, I'll queue v2 of this patch as is for 5.3. Thanks.
>
It's fine.
Thanks,
Shaokun
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-06-17 11:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-14 13:11 [PATCH v2] arm64/mm: Correct the cache line size warning with non coherent device Masayoshi Mizuma
2019-06-15 2:44 ` Zhangshaokun
2019-06-17 10:45 ` Catalin Marinas
2019-06-17 11:00 ` Zhangshaokun [this message]
2019-06-17 16:22 ` Catalin Marinas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7e567399-6f3d-b416-6636-c9f2f37ea407@hisilicon.com \
--to=zhangshaokun@hisilicon.com \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=m.mizuma@jp.fujitsu.com \
--cc=msys.mizuma@gmail.com \
--cc=robin.murphy@arm.com \
--cc=seto.hidetoshi@jp.fujitsu.com \
--cc=will.deacon@arm.com \
--cc=zhang.lei@jp.fujitsu.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).