kernel.git/include/rdma/ib_umem_odp.h, branch linux-rolling-stable

RDMA/core: Convert UMEM ODP DMA mapping to caching IOVA and page linkage

2025-05-12T10:06:51Z

Reuse newly added DMA API to cache IOVA and only link/unlink pages in fast path for UMEM ODP flow. Tested-by: Jens Axboe Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky

RDMA/umem: Store ODP access mask information in PFN

2025-05-12T10:06:46Z

As a preparation to remove dma_list, store access mask in PFN pointer and not in dma_addr_t. Tested-by: Jens Axboe Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky

IB/core: Enable ODP sync without faulting

2020-10-01T19:44:05Z

Enable ODP sync without faulting, this improves performance by reducing the number of page faults in the system. The gain from this option is that the device page table can be aligned with the presented pages in the CPU page table without causing page faults. As of that, the overhead on data path from hardware point of view to trigger a fault which end-up by calling the driver to bring the pages will be dropped. Link: https://lore.kernel.org/r/20200930163828.1336747-3-leon@kernel.org Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

IB/core: Improve ODP to use hmm_range_fault()

2020-10-01T19:39:54Z

Move to use hmm_range_fault() instead of get_user_pags_remote() to improve performance in a few aspects: This includes: - Dropping the need to allocate and free memory to hold its output - No need any more to use put_page() to unpin the pages - The logic to detect contiguous pages is done based on the returned order, no need to run per page and evaluate. In addition, moving to use hmm_range_fault() enables to reduce page faults in the system with it's snapshot mode, this will be introduced in next patches from this series. As part of this, cleanup some flows and use the required data structures to work with hmm_range_fault(). Link: https://lore.kernel.org/r/20200930163828.1336747-2-leon@kernel.org Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

RDMA/include: Replace license text with SPDX tags

2020-07-29T17:48:36Z

The header files in RDMA subsystem are dual licensed and can be described by simple SPDX tag, so replace all of them at once together with making them use the same coding style for header guard defines. Link: https://lore.kernel.org/r/20200719072521.135260-1-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

IB: Allow calls to ib_umem_get from kernel ULPs

2020-01-16T14:14:28Z

So far the assumption was that ib_umem_get() and ib_umem_odp_get() are called from flows that start in UVERBS and therefore has a user context. This assumption restricts flows that are initiated by ULPs and need the service that ib_umem_get() provides. This patch changes ib_umem_get() and ib_umem_odp_get() to get IB device directly by relying on the fact that both UVERBS and ULPs sets that field correctly. Reviewed-by: Guy Levi Signed-off-by: Moni Shoua Signed-off-by: Leon Romanovsky

RDMA/odp: Use mmu_interval_notifier_insert()

2019-11-23T23:56:44Z

Replace the internal interval tree based mmu notifier with the new common mmu_interval_notifier_insert() API. This removes a lot of code and fixes a deadlock that can be triggered in ODP: zap_page_range() mmu_notifier_invalidate_range_start() [..] ib_umem_notifier_invalidate_range_start() down_read(&per_mm->umem_rwsem) unmap_single_vma() [..] __split_huge_page_pmd() mmu_notifier_invalidate_range_start() [..] ib_umem_notifier_invalidate_range_start() down_read(&per_mm->umem_rwsem) // DEADLOCK mmu_notifier_invalidate_range_end() up_read(&per_mm->umem_rwsem) mmu_notifier_invalidate_range_end() up_read(&per_mm->umem_rwsem) The umem_rwsem is held across the range_start/end as the ODP algorithm for invalidate_range_end cannot tolerate changes to the interval tree. However, due to the nested invalidation regions the second down_read() can deadlock if there are competing writers. The new core code provides an alternative scheme to solve this problem. Fixes: ca748c39ea3f ("RDMA/umem: Get rid of per_mm->notifier_count") Link: https://lore.kernel.org/r/20191112202231.3856-6-jgg@ziepe.ca Tested-by: Artemy Kovalyov Signed-off-by: Jason Gunthorpe

RDMA/mlx5: Rework implicit ODP destroy

2019-10-28T19:41:14Z

Use SRCU in a sensible way by removing all MRs in the implicit tree from the two xarrays (the update operation), then a synchronize, followed by a normal single threaded teardown. This is only a little unusual from the normal pattern as there can still be some work pending in the unbound wq that may also require a workqueue flush. This is tracked with a single atomic, consolidating the redundant existing atomics and wait queue. For understand-ability the entire ODP implicit create/destroy flow now largely exists in a single pair of functions within odp.c, with a few support functions for tearing down an unused child. Link: https://lore.kernel.org/r/20191009160934.3143-13-jgg@ziepe.ca Reviewed-by: Artemy Kovalyov Signed-off-by: Jason Gunthorpe

RDMA/mlx5: Use an xarray for the children of an implicit ODP

2019-10-28T19:41:14Z

Currently the child leaves are stored in the shared interval tree and every lookup for a child must be done under the interval tree rwsem. This is further complicated by dropping the rwsem during iteration (ie the odp_lookup(), odp_next() pattern), which requires a very tricky an difficult to understand locking scheme with SRCU. Instead reserve the interval tree for the exclusive use of the mmu notifier related code in umem_odp.c and give each implicit MR a xarray containing all the child MRs. Since the size of each child is 1GB of VA, a 1 level xarray will index 64G of VA, and a 2 level will index 2TB, making xarray a much better data structure choice than an interval tree. The locking properties of xarray will be used in the next patches to rework the implicit ODP locking scheme into something simpler. At this point, the xarray is locked by the implicit MR's umem_mutex, and read can also be locked by the odp_srcu. Link: https://lore.kernel.org/r/20191009160934.3143-10-jgg@ziepe.ca Reviewed-by: Artemy Kovalyov Signed-off-by: Jason Gunthorpe

RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'

2019-08-21T23:58:18Z

This is a significant simplification, no extra list is kept per FD, and the interval tree is now shared between all the ucontexts, reducing overhead if there are multiple ucontexts active. Link: https://lore.kernel.org/r/20190806231548.25242-7-jgg@ziepe.ca Signed-off-by: Jason Gunthorpe