On Tue, Aug 1, 2023 at 10:18 AM Christoph Hellwig hch@lst.de wrote:
On Tue, Aug 01, 2023 at 10:42:42PM +0530, Pintu Agarwal wrote:
I agree that reserved is not a very useful name. Unfortuately the name of the region leaks to userspace through cma_heap.
So I think we need prep patches to hardcode "reserved" in add_default_cma_heap first, and then remove the cma_get_name first.
Sorry, but I could not fully understand your comments. Can you please elaborate a little more what changes are required in cma_heap if we change "reserved" to "global-cma-region" ?
Step 1:
Instead of setting exp_info.name to cma_get_name(cma); in __add_cma_heap just set it to "reserved", probably by passing a name argument. You can also remove the unused data argument to __add_cma_heap and/or just fold that function into the only caller while you're at it.
So, forgive me, I've not had a chance to look into this, but my recollection was "reserved" is the name we see on x86, but other names are possibly provided via the dts node?
I believe on the hikey board its "linux,cma" is the name, so forcing it to reserved would break that.
Maybe instead add a compat config option to force the cma name (so x86 can set it to "default" if needed)?
thanks -john