Re: [PATCH 06/11] iommu: Add iommu_device_set_fwnode() interface

From: Joerg Roedel <jroedel@suse.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will.deacon@arm.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	David Woodhouse <dwmw2@infradead.org>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 06/11] iommu: Add iommu_device_set_fwnode() interface
Date: Fri, 10 Feb 2017 17:11:22 +0100	[thread overview]
Message-ID: <20170210161122.GB18474@suse.de> (raw)
In-Reply-To: <f770249b-ad98-10d8-ea79-dc10cef7f4df@arm.com>

On Fri, Feb 10, 2017 at 04:03:07PM +0000, Robin Murphy wrote:
> Yeah, on reflection explicit initialisation is certainly easier to read
> than a bunch of arguments handled implicitly by register(), but then
> from that angle, even more clear would be to simply have the drivers
> write the relevant struct members directly - I'd be quite happy with
> that, and we then don't have to add another setter to iommu.h for every
> new struct member (and risk it looking like Java code...)

Yeah, that was my first approach. But there is the Intel VT-d anomaly,
where a part of the driver can be built-in (dmar.c) with
CONFIG_IOMMU_API=N. In this case 'struct iommu_device' is empty, and
trying to access the members directly doesn't compile anymore.

I have to look if this anomaly could be removed, then it is probably the
best to set the struct members directly without wrapper functions.

	Joerg