On 10/20/2023 3:20 PM, Yong Wu (吴勇) wrote: > On Thu, 2023-10-19 at 10:16 +0530, Vijayanand Jitta wrote: >> >> Instead of having a vendor specific binding for cma area, How about >> retrieving >> > https://lore.kernel.org/lkml/1594948208-4739-1-git-send-email-hayashi.kunihiko@xxxxxxxxxxxxx/ >> ? >> dma_heap_add_cma can just associate cma region and create a heap. So, >> we can reuse cma heap >> code for allocation instead of replicating that code here. >> > > Thanks for the reference. I guess we can't use it. There are two > reasons: > > a) The secure heap driver is a pure software driver and we have no > device for it, therefore we cannot call dma_heap_add_cma. > Hi Yong, We're considering using struct cma as the function argument to dma_heap_add_cma() rather than struct device. Would this help resolve the problem of usage with dma_heap_add_cma()? > b) The CMA area here is dynamic for SVP. Normally this CMA can be used > in the kernel. In the SVP case we use cma_alloc to get it and pass the > entire CMA physical start address and size into TEE to protect the CMA > region. The original CMA heap cannot help with the TEE part. > Referring the conversation at https://lore.kernel.org/lkml/7a2995de23c24ef22c071c6976c02b97e9b50126.camel@xxxxxxxxxxxx/; since we're considering abstracting secure mem ops, would it make sense to use the default CMA heap ops (cma_heap_ops), allocate buffers from it and secure each allocated buffer? Thanks, Jaskaran. > Thanks. > >> Thanks, >> Vijay >> >> >>
