On 12/02/2025 10:01, Maxime Ripard wrote: > On Wed, Feb 12, 2025 at 09:49:56AM +0000, Florent Tomasin wrote: >> Note that the CMA patches were initially shared to help reproduce my >> environment of development, I can isolate them in a separate patch >> series and include a reference or "base-commit:" tag to it in the >> Panthor protected mode RFC, to help progress this review in another >> thread. It will avoid overlapping these two topics: >> >> - Multiple standalone CMA heaps support >> - Panthor protected mode handling > > You keep insisting on using CMA here, but it's really not clear to me > why you would need CMA in the first place. > > By CMA, do you mean the CMA allocator, and thus would provide buffers > through the usual dma_alloc_* API, or would any allocator providing > physically contiguous memory work? You are correct only the CMA allocator is relevant. I needed a way to sub-allocate from a carved-out memory. > In the latter case, would something like this work: > https://lore.kernel.org/all/20240515-dma-buf-ecc-heap-v1-1-54cbbd049511@xxxxxxxxxx/ Thanks for sharing this link, I was not aware previous work was done on this aspect. The new carveout heap introduced in the series could probably be a good alternative. I will play-around with it and share some updates. Appreciated, Florent
