Nouveau currently only supports mapping PAGE_SIZE sized pages of system
memory when shared virtual memory (SVM) is enabled. Use the new
hmm_pfn_to_map_order() function to support mapping system memory pages
that are PMD_SIZE.
Signed-off-by: Ralph Campbell
---
The goal for this series is to introduce the hmm_pfn_to_map_order()
function. This allows a device driver to know that a given 4K PFN is
actually mapped by the CPU using a larger sized CPU page table entry and
therefore the device driver can safely map system memory using larger
device MMU PTEs.
The nvif_object_ioctl() method NVIF_VMM_V0_PFNMAP wasn't correctly
setting the hardware specific GPU page table entries for 2MB sized
pages. Fix this by adding functions to set and clear PD0 GPU page
table entries.
Signed-off-by: Ralph Campbell
---
drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c
hmm_range_fault() returns an array of page frame numbers and flags for
how the pages are mapped in the requested process' page tables. The PFN
can be used to get the struct page with hmm_pfn_to_page() and the page
size order can be determined with compound_order(page) but if the page
is larger
The SVM page fault handler groups faults into a range of contiguous
virtual addresses and requests hmm_range_fault() to populate and
return the page frame number of system memory mapped by the CPU.
In preparation for supporting large pages to be mapped by the GPU,
process faults one page at a
Add a sanity test for hmm_range_fault() returning the page mapping size
order.
Signed-off-by: Ralph Campbell
---
lib/test_hmm.c | 4 ++
lib/test_hmm_uapi.h| 4 ++
tools/testing/selftests/vm/hmm-tests.c | 76 ++
3 files
