8bfafde086
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 <yishaih@nvidia.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
116 lines
3.4 KiB
C
116 lines
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
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/*
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* Copyright (c) 2014 Mellanox Technologies. All rights reserved.
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*/
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#ifndef IB_UMEM_ODP_H
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#define IB_UMEM_ODP_H
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#include <rdma/ib_umem.h>
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#include <rdma/ib_verbs.h>
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struct ib_umem_odp {
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struct ib_umem umem;
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struct mmu_interval_notifier notifier;
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struct pid *tgid;
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/* An array of the pfns included in the on-demand paging umem. */
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unsigned long *pfn_list;
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/*
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* An array with DMA addresses mapped for pfns in pfn_list.
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* The lower two bits designate access permissions.
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* See ODP_READ_ALLOWED_BIT and ODP_WRITE_ALLOWED_BIT.
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*/
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dma_addr_t *dma_list;
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/*
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* The umem_mutex protects the page_list and dma_list fields of an ODP
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* umem, allowing only a single thread to map/unmap pages. The mutex
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* also protects access to the mmu notifier counters.
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*/
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struct mutex umem_mutex;
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void *private; /* for the HW driver to use. */
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int npages;
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/*
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* An implicit odp umem cannot be DMA mapped, has 0 length, and serves
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* only as an anchor for the driver to hold onto the per_mm. FIXME:
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* This should be removed and drivers should work with the per_mm
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* directly.
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*/
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bool is_implicit_odp;
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unsigned int page_shift;
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};
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static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
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{
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return container_of(umem, struct ib_umem_odp, umem);
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}
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/* Returns the first page of an ODP umem. */
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static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
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{
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return umem_odp->notifier.interval_tree.start;
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}
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/* Returns the address of the page after the last one of an ODP umem. */
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static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
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{
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return umem_odp->notifier.interval_tree.last + 1;
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}
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static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
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{
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return (ib_umem_end(umem_odp) - ib_umem_start(umem_odp)) >>
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umem_odp->page_shift;
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}
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/*
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* The lower 2 bits of the DMA address signal the R/W permissions for
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* the entry. To upgrade the permissions, provide the appropriate
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* bitmask to the map_dma_pages function.
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*
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* Be aware that upgrading a mapped address might result in change of
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* the DMA address for the page.
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*/
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#define ODP_READ_ALLOWED_BIT (1<<0ULL)
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#define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
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#define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
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#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
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struct ib_umem_odp *
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ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
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int access, const struct mmu_interval_notifier_ops *ops);
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struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
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int access);
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struct ib_umem_odp *
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ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
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size_t size,
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const struct mmu_interval_notifier_ops *ops);
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void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
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int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 start_offset,
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u64 bcnt, u64 access_mask, bool fault);
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void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
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u64 bound);
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#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
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static inline struct ib_umem_odp *
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ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
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int access, const struct mmu_interval_notifier_ops *ops)
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{
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return ERR_PTR(-EINVAL);
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}
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static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
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#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
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#endif /* IB_UMEM_ODP_H */
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