On 7/10/20 12:27 PM, Jason Gunthorpe wrote:
On Wed, Jul 01, 2020 at 03:53:47PM -0700, Ralph Campbell wrote:
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 series is based on 5.8.0-rc3 and is intended for Jason Gunthorpe's
hmm tree. These were originally part of a larger series:
https://lore.kernel.org/linux-mm/20200619215649.32297-1-rcampbell@xxxxxxxxxx/
Changes in v3:
Replaced the HMM_PFN_P[MU]D flags with hmm_pfn_to_map_order() to
indicate the size of the CPU mapping.
Changes in v2:
Make the hmm_range_fault() API changes into a separate series and add
two output flags for PMD/PUD instead of a single compund page flag as
suggested by Jason Gunthorpe.
Make the nouveau page table changes a separate patch as suggested by
Ben Skeggs.
Only add support for 2MB nouveau mappings initially since changing the
1:1 CPU/GPU page table size assumptions requires a bigger set of changes.
Rebase to 5.8.0-rc3.
Ralph Campbell (5):
nouveau/hmm: fault one page at a time
mm/hmm: add hmm_mapping order
nouveau: fix mapping 2MB sysmem pages
nouveau/hmm: support mapping large sysmem pages
hmm: add tests for HMM_PFN_PMD flag
Applied to hmm.git.
I edited the comment for hmm_pfn_to_map_order() and added a function
to compute the field.
Thanks,
Jason
Looks good, thanks.
