From mboxrd@z Thu Jan 1 00:00:00 1970 From: david.vrabel@citrix.com (David Vrabel) Date: Mon, 27 Oct 2014 11:02:15 +0000 Subject: [Xen-devel] [PATCH v4 3/7] [RFC] arm/arm64: introduce is_dma_coherent In-Reply-To: References: <1412941908-5850-3-git-send-email-stefano.stabellini@eu.citrix.com> <20141010120702.GI7755@arm.com> <20141013125725.GA19156@arm.com> <20141024104746.GC1955@localhost> <20141024154353.GE20534@e104818-lin.cambridge.arm.com> <1414251629.3584.20.camel@citrix.com> Message-ID: <544E2637.8000902@citrix.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 25/10/14 17:15, Stefano Stabellini wrote: > On Sat, 25 Oct 2014, Ian Campbell wrote: >> On Sat, 2014-10-25 at 14:29 +0100, Stefano Stabellini wrote: >>> >>> Your suggestions and looking more at the code gave me another idea, that >>> I think is clean and at the same time suitable for 3.18. >>> What do you think of the following? It is simple, self-contained and >>> doesn't need a new flag in struct device. >> >> of_dma_is_coherent looks to be quite expensive though (walks up the >> Device Tree doing strcmps on each property of each node until it finds >> the one it is looking for. > > It takes spin_locks too! > Too bad, I think I'll have to ditch it. In that case I'l try the new > flag in struct device approach. If you're having to make changes to struct device, this is looking like a series for 3.19 (not 3.18). David