On Sun, Mar 06, 2022 at 05:21:11AM +0200, Jarkko Sakkinen wrote: > On Sun, Mar 06, 2022 at 02:57:55AM +0000, Matthew Wilcox wrote: > > On Sun, Mar 06, 2022 at 04:15:33AM +0200, Jarkko Sakkinen wrote: > > > Sometimes you might want to use MAP_POPULATE to ask a device driver to > > > initialize the device memory in some specific manner. SGX driver can use > > > this to request more memory by issuing ENCLS[EAUG] x86 opcode for each > > > page in the address range. > > > > > > Add f_ops->populate() with the same parameters as f_ops->mmap() and make > > > it conditionally called inside call_mmap(). Update call sites > > > accodingly. > > > > Your device driver has a ->mmap operation. Why does it need another > > one? More explanation required here. > > f_ops->mmap() would require an additional parameter, which results > heavy refactoring. > > struct file_operations has 1125 references in the kernel tree, so I > decided to check this way around first. Are you saying that your device driver behaves differently if MAP_POPULATE is set versus if it isn't? That seems hideously broken.
