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The basic structure of this patch is to make the small page allocator and the large page allocator into pointers (where they used to be just structs). Then assign each of those pointers to the same actual allocator since the buddy allocator has supported mixed page sizes since its inception. For the rest of the driver some changes had to be made in order to actually support mixed pages in a single address space. 1. Unifying the allocation page size determination Since the allocation and map operations happen at distinct times both mapping and allocation of GVA space must agree on page size. This is because the allocation has to separate allocations into separate PDEs to avoid the necessity of supporting mixed PDEs. To this end a function __get_pte_size() was introduced which is used both by the balloc code and the core GPU MM code. It determines page size based only on the length of the mapping/ allocation. 2. Fixed address allocation + page size Similar to regular mappings/GVA allocations fixed address mapping page size determination had to be modified. In the past the address of the mapping determined page size since the address space split was by address (low addresses were small pages, high addresses large pages). Since that is no longer the case the page size field in the reserve memory ioctl is now honored by the mapping code. When, for instance, CUDA makes a memory reservation it specifies small or large pages. When CUDA requests mappings to be made within that address range the page size is then looked up in the reserved memory struct. Fixed address reservations were also modified to now always allocate at a PDE granularity (64M or 128M depending on large page size. This prevents non-fixed allocations from ending up in the same PDE and causing kernel panics or GMMU faults. 3. The rest... The rest of the changes are just by products of the above. Lots of places required minor updates to use a pointer to the GVA allocator struct instead of the struct itself. Lastly, this change is not truly complete. More work remains to be done in order to fully remove the notion that there was such a thing as separate address spaces for different page sizes. Basically after this patch what remains is cleanup and proper documentation. Bug 1396644 Bug 1729947 Change-Id: If51ab396a37ba16c69e434adb47edeef083dce57 Signed-off-by: Alex Waterman <alexw@nvidia.com> Reviewed-on: http://git-master/r/1265300 GVS: Gerrit_Virtual_Submit Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>