Hi, On Thu, Jan 30, 2025 at 01:08:58PM +0000, Florent Tomasin wrote: > This patch introduces a cma-heap probe function, allowing > users to register custom cma heaps in the device tree. > > A "memory-region" is bound to the cma heap at probe time > allowing allocation of DMA buffers from that heap. > > Use cases: > - registration of carved out secure heaps. Some devices > are implementing secure memory by reserving a specific > memory regions for that purpose. For example, this is the > case of platforms making use of early version of > ARM TrustZone. In such a case, the CMA heap would de-facto become un-mappable for userspace, right? > - registration of multiple memory regions at different > locations for efficiency or HW integration reasons. > For example, a peripheral may expect to share data at a > specific location in RAM. This information could have been > programmed by a FW prior to the kernel boot. How would you differentiate between them? Maxime
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