On Tue, 8 Jan 2019, Michael Ellerman wrote:
The reason why that doesn't work boils down to introspection. (This was mentioned elsewhere in this email thread.) For example, we presently have code like this, ssize_t nvram_get_size(void) { if (ppc_md.nvram_size) return ppc_md.nvram_size(); return -1; } EXPORT_SYMBOL(nvram_get_size); This construction means we get to decide at run-time which of the NVRAM functions should be used. (Whereas your example makes a build-time decision.)Right, but we only need to make a runtime decision on powerpc (right?).
It's needed in many places outside of powerpc. Otherwise the caller can't determine at run-time which ops are implemented. Hence you have to duplicate the caller for each supported configuration that you build. Already, this precludes a shared misc device implementation and belies the "generic" in drivers/char/generic_nvram.c. --
