Messages in this thread | | | Date | Tue, 11 Feb 2014 21:27:36 +0100 | From | Tomasz Figa <> | Subject | Re: [PATCH v2 1/5] drivers: of: add initialization code for reserved memory |
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On 11.02.2014 21:19, Josh Cartwright wrote: > On Tue, Feb 11, 2014 at 09:04:21PM +0100, Tomasz Figa wrote: >> >> >> On 11.02.2014 21:02, Benjamin Herrenschmidt wrote: >>> On Tue, 2014-02-11 at 19:01 +0000, Grant Likely wrote: >>> >>>>> except that the former IMHO better suits the definition of memory >>>>> region, which I see as a single contiguous range of memory and can be >>>>> simplified to have a single reg entry per region. >>>> >>>> My point is rather if multiple reg tuples are found in a reserved memory >>>> node, the kernel must respect them and reserve the memory. I'm not >>>> arguing about whether or not that makes for a good binding. >>> >>> agreed. >> >> My point is why, if the binding defines that just a single tuple should be >> provided. > > FWIW, the usecase I had mentioned in reply to Grant in the patch 5/5 > thread [1] could make use of this. The shared memory region is split > into a main chunk and several "auxiliary" chunk, but collectively these > regions all share the same heap state. > > Josh > > 1: http://lkml.kernel.org/r/20140205192502.GO20228@joshc.qualcomm.com >
The use case seems fine, but I believe it could be properly represented in device tree using multiple single-reg regions as well, unless the consumer can request a block of memory that crosses boundary of two sub-regions specified by reg entries of single region.
Best regards, Tomasz
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