From: Robin Murphy <robin.murphy@arm•com>
To: Christoph Hellwig <hch@lst•de>
Cc: iommu@lists•linux-foundation.org,
Marek Szyprowski <m.szyprowski@samsung•com>,
Benjamin Herrenschmidt <benh@kernel•crashing.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
linux-kernel@vger•kernel.org, linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH 4/5] dma-direct: implement complete bus_dma_mask handling
Date: Thu, 27 Sep 2018 17:41:36 +0100 [thread overview]
Message-ID: <b87ef7ac-81fc-c649-7ffb-73017ec99790@arm.com> (raw)
In-Reply-To: <20180927162737.GA11974@lst.de>
On 27/09/18 17:27, Christoph Hellwig wrote:
> On Thu, Sep 27, 2018 at 05:14:56PM +0100, Robin Murphy wrote:
>>> This just seemed more readable to me than min_not_zero, but if others
>>> prefer min_not_zero I can switch.
>>
>> Nah, just checking whether there were any intentionally different
>> assumptions compared to the couple of other places in the patch where
>> min_not_zero() *is* used. If it's purely a style thing then no worries
>> (personally I'd have written it yet another way anyway).
>
> I'm curious: how would you have written it?
Come to think of it, I actually already have, in iommu-dma:
if (dev->bus_dma_mask)
mask &= dev->bus_dma_mask;
but of course it's not so pretty for those cases where you don't already
have the local variable ready to go.
Robin.
WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm•com>
To: Christoph Hellwig <hch@lst•de>
Cc: linux-kernel@vger•kernel.org, iommu@lists•linux-foundation.org,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
linuxppc-dev@lists•ozlabs.org,
Marek Szyprowski <m.szyprowski@samsung•com>
Subject: Re: [PATCH 4/5] dma-direct: implement complete bus_dma_mask handling
Date: Thu, 27 Sep 2018 17:41:36 +0100 [thread overview]
Message-ID: <b87ef7ac-81fc-c649-7ffb-73017ec99790@arm.com> (raw)
Message-ID: <20180927164136.iPmiXebS8DfWSQkBHLZmZkMehNflY1dZ9xYLMc7T88w@z> (raw)
In-Reply-To: <20180927162737.GA11974@lst.de>
On 27/09/18 17:27, Christoph Hellwig wrote:
> On Thu, Sep 27, 2018 at 05:14:56PM +0100, Robin Murphy wrote:
>>> This just seemed more readable to me than min_not_zero, but if others
>>> prefer min_not_zero I can switch.
>>
>> Nah, just checking whether there were any intentionally different
>> assumptions compared to the couple of other places in the patch where
>> min_not_zero() *is* used. If it's purely a style thing then no worries
>> (personally I'd have written it yet another way anyway).
>
> I'm curious: how would you have written it?
Come to think of it, I actually already have, in iommu-dma:
if (dev->bus_dma_mask)
mask &= dev->bus_dma_mask;
but of course it's not so pretty for those cases where you don't already
have the local variable ready to go.
Robin.
next prev parent reply other threads:[~2018-09-27 16:41 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-20 18:52 dma mask related fixups (including full bus_dma_mask support) Christoph Hellwig
2018-09-20 18:52 ` [PATCH 1/5] dma-mapping: make the get_required_mask method available unconditionally Christoph Hellwig
2018-09-27 1:28 ` Benjamin Herrenschmidt
2018-09-20 18:52 ` [PATCH 2/5] dma-direct: add an explicit dma_direct_get_required_mask Christoph Hellwig
2018-09-27 1:31 ` Benjamin Herrenschmidt
2018-09-27 14:12 ` Robin Murphy
2018-09-27 15:28 ` Christoph Hellwig
2018-09-27 15:35 ` Robin Murphy
2018-09-20 18:52 ` [PATCH 3/5] dma-direct: refine dma_direct_alloc zone selection Christoph Hellwig
2018-09-27 1:45 ` Benjamin Herrenschmidt
2018-09-27 13:49 ` Christoph Hellwig
2018-09-28 0:06 ` Benjamin Herrenschmidt
2018-09-28 15:46 ` Christoph Hellwig
2018-09-27 14:30 ` Robin Murphy
2018-09-27 15:30 ` Christoph Hellwig
2018-09-27 15:38 ` Robin Murphy
2018-09-27 15:41 ` Christoph Hellwig
2018-09-20 18:52 ` [PATCH 4/5] dma-direct: implement complete bus_dma_mask handling Christoph Hellwig
2018-09-27 14:58 ` Robin Murphy
2018-09-27 15:32 ` Christoph Hellwig
2018-09-27 16:14 ` Robin Murphy
2018-09-27 16:14 ` Robin Murphy
2018-09-27 16:27 ` Christoph Hellwig
2018-09-27 16:27 ` Christoph Hellwig
2018-09-27 16:41 ` Robin Murphy [this message]
2018-09-27 16:41 ` Robin Murphy
2018-09-20 18:52 ` [PATCH 5/5] dma-direct: always allow dma mask <= physiscal memory size Christoph Hellwig
2018-09-27 1:50 ` Benjamin Herrenschmidt
2018-09-27 13:49 ` Christoph Hellwig
2018-09-27 15:07 ` Robin Murphy
-- strict thread matches above, loose matches on Subject: below --
2018-09-27 22:35 dma mask related fixups (including full bus_dma_mask support) v2 Christoph Hellwig
2018-09-27 22:35 ` [PATCH 4/5] dma-direct: implement complete bus_dma_mask handling Christoph Hellwig
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