From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Joerg Roedel <joro@8bytes.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 02/19] dma-iommu: cleanup dma-iommu.h
Date: Wed, 6 Feb 2019 15:08:26 +0000 [thread overview]
Message-ID: <5bf081c2-2b8c-d3d1-c93e-468c8f3cef67@arm.com> (raw)
In-Reply-To: <20190201161305.GI6532@lst.de>
On 01/02/2019 16:13, Christoph Hellwig wrote:
> On Fri, Feb 01, 2019 at 02:47:17PM +0000, Robin Murphy wrote:
>> On 14/01/2019 09:41, Christoph Hellwig wrote:
>>> No need for a __KERNEL__ guard outside uapi, make sure we pull in the
>>> includes unconditionally so users can rely on it, and add a missing
>>> comment describing the #else cpp statement. Last but not least include
>>> <linux/errno.h> instead of the asm version, which is frowned upon.
>>
>> I think the __KERNEL__ and asm/errno.h slip-ups are things I cargo-culted
>> from the arch code as a fresh-faced noob yet to learn the finer details, so
>> ack for those parts. The forward-declarations, though, were a deliberate
>> effort to minimise header dependencies and compilation bloat for includers
>> who absolutely wouldn't care, and specifically to try to avoid setting
>> transitive include expectations since they always seem to end up breaking
>> someone's config somewhere down the line. Admittedly this little backwater
>> is hardly comparable to the likes of the sched.h business, but I'm still
>> somewhat on the fence about that change :/
>
> As far as I can tell almost all users of linux/dma-iommu.h require
> CONFIG_DMA_IOMMU to be enabled anyway..
Other than dma-iommu.c itself, none of them *require* it - only
arch/arm64 selects it (the one from MTK_IOMMU is just bogus), and a lot
of the drivers also build for at least one other architecture (and/or
arm64 with !IOMMU_API).
Either way, I have no vehement objection to the change, I just don't see
any positive value in it.
Robin.
WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 02/19] dma-iommu: cleanup dma-iommu.h
Date: Wed, 6 Feb 2019 15:08:26 +0000 [thread overview]
Message-ID: <5bf081c2-2b8c-d3d1-c93e-468c8f3cef67@arm.com> (raw)
In-Reply-To: <20190201161305.GI6532@lst.de>
On 01/02/2019 16:13, Christoph Hellwig wrote:
> On Fri, Feb 01, 2019 at 02:47:17PM +0000, Robin Murphy wrote:
>> On 14/01/2019 09:41, Christoph Hellwig wrote:
>>> No need for a __KERNEL__ guard outside uapi, make sure we pull in the
>>> includes unconditionally so users can rely on it, and add a missing
>>> comment describing the #else cpp statement. Last but not least include
>>> <linux/errno.h> instead of the asm version, which is frowned upon.
>>
>> I think the __KERNEL__ and asm/errno.h slip-ups are things I cargo-culted
>> from the arch code as a fresh-faced noob yet to learn the finer details, so
>> ack for those parts. The forward-declarations, though, were a deliberate
>> effort to minimise header dependencies and compilation bloat for includers
>> who absolutely wouldn't care, and specifically to try to avoid setting
>> transitive include expectations since they always seem to end up breaking
>> someone's config somewhere down the line. Admittedly this little backwater
>> is hardly comparable to the likes of the sched.h business, but I'm still
>> somewhat on the fence about that change :/
>
> As far as I can tell almost all users of linux/dma-iommu.h require
> CONFIG_DMA_IOMMU to be enabled anyway..
Other than dma-iommu.c itself, none of them *require* it - only
arch/arm64 selects it (the one from MTK_IOMMU is just bogus), and a lot
of the drivers also build for at least one other architecture (and/or
arm64 with !IOMMU_API).
Either way, I have no vehement objection to the change, I just don't see
any positive value in it.
Robin.
WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 02/19] dma-iommu: cleanup dma-iommu.h
Date: Wed, 6 Feb 2019 15:08:26 +0000 [thread overview]
Message-ID: <5bf081c2-2b8c-d3d1-c93e-468c8f3cef67@arm.com> (raw)
In-Reply-To: <20190201161305.GI6532@lst.de>
On 01/02/2019 16:13, Christoph Hellwig wrote:
> On Fri, Feb 01, 2019 at 02:47:17PM +0000, Robin Murphy wrote:
>> On 14/01/2019 09:41, Christoph Hellwig wrote:
>>> No need for a __KERNEL__ guard outside uapi, make sure we pull in the
>>> includes unconditionally so users can rely on it, and add a missing
>>> comment describing the #else cpp statement. Last but not least include
>>> <linux/errno.h> instead of the asm version, which is frowned upon.
>>
>> I think the __KERNEL__ and asm/errno.h slip-ups are things I cargo-culted
>> from the arch code as a fresh-faced noob yet to learn the finer details, so
>> ack for those parts. The forward-declarations, though, were a deliberate
>> effort to minimise header dependencies and compilation bloat for includers
>> who absolutely wouldn't care, and specifically to try to avoid setting
>> transitive include expectations since they always seem to end up breaking
>> someone's config somewhere down the line. Admittedly this little backwater
>> is hardly comparable to the likes of the sched.h business, but I'm still
>> somewhat on the fence about that change :/
>
> As far as I can tell almost all users of linux/dma-iommu.h require
> CONFIG_DMA_IOMMU to be enabled anyway..
Other than dma-iommu.c itself, none of them *require* it - only
arch/arm64 selects it (the one from MTK_IOMMU is just bogus), and a lot
of the drivers also build for at least one other architecture (and/or
arm64 with !IOMMU_API).
Either way, I have no vehement objection to the change, I just don't see
any positive value in it.
Robin.
_______________________________________________
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:[~2019-02-06 15:08 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-14 9:41 implement generic dma_map_ops for IOMMUs Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 01/19] dma-mapping: add a Kconfig symbol to indicated arch_dma_prep_coherent presence Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-01 14:22 ` Robin Murphy
2019-02-01 14:22 ` Robin Murphy
2019-02-01 16:12 ` Christoph Hellwig
2019-02-01 16:12 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 02/19] dma-iommu: cleanup dma-iommu.h Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-01 14:47 ` Robin Murphy
2019-02-01 14:47 ` Robin Murphy
2019-02-01 16:13 ` Christoph Hellwig
2019-02-01 16:13 ` Christoph Hellwig
2019-02-06 15:08 ` Robin Murphy [this message]
2019-02-06 15:08 ` Robin Murphy
2019-02-06 15:08 ` Robin Murphy
2019-02-11 15:59 ` Christoph Hellwig
2019-02-11 15:59 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 03/19] dma-iommu: don't use a scatterlist in iommu_dma_alloc Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-01 15:24 ` Robin Murphy
2019-02-01 15:24 ` Robin Murphy
2019-02-01 16:16 ` Christoph Hellwig
2019-02-01 16:16 ` Christoph Hellwig
2019-02-06 15:28 ` Robin Murphy
2019-02-06 15:28 ` Robin Murphy
2019-02-11 16:00 ` Christoph Hellwig
2019-02-11 16:00 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 04/19] dma-iommu: remove the flush_page callback Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-01 15:28 ` Robin Murphy
2019-02-01 15:28 ` Robin Murphy
2019-01-14 9:41 ` [PATCH 05/19] dma-iommu: move the arm64 wrappers to common code Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 06/19] dma-iommu: fix and refactor iommu_dma_mmap Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-05 15:02 ` Robin Murphy
2019-02-05 15:02 ` Robin Murphy
2019-02-11 16:03 ` Christoph Hellwig
2019-02-11 16:03 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 07/19] dma-iommu: fix and refactor iommu_dma_get_sgtable Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 08/19] dma-iommu: move __iommu_dma_map Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 09/19] dma-iommu: refactor page array remap helpers Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 10/19] dma-iommu: factor atomic pool allocations into helpers Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 11/19] dma-iommu: factor contiguous " Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 12/19] dma-iommu: refactor iommu_dma_free Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 13/19] dma-iommu: don't remap contiguous allocations for coherent devices Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 14/19] dma-iommu: factor contiguous remapped allocations into helpers Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 15/19] dma-iommu: refactor iommu_dma_alloc Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 16/19] dma-iommu: don't depend on CONFIG_DMA_DIRECT_REMAP Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-06 11:55 ` Robin Murphy
2019-02-06 11:55 ` Robin Murphy
2019-02-11 16:39 ` Christoph Hellwig
2019-02-11 16:39 ` Christoph Hellwig
2019-01-14 9:41 ` [PATCH 17/19] dma-iommu: switch copyright boilerplace to SPDX Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-06 11:57 ` Robin Murphy
2019-02-06 11:57 ` Robin Murphy
2019-01-14 9:41 ` [PATCH 18/19] arm64: switch copyright boilerplace to SPDX in dma-mapping.c Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-02-06 12:19 ` Robin Murphy
2019-02-06 12:19 ` Robin Murphy
2019-01-14 9:41 ` [PATCH 19/19] arm64: trim includes " Christoph Hellwig
2019-01-14 9:41 ` Christoph Hellwig
2019-01-28 7:53 ` implement generic dma_map_ops for IOMMUs Christoph Hellwig
2019-01-28 7:53 ` Christoph Hellwig
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