1/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
  2/*
  3 * Copyright (c) 2014 Mellanox Technologies. All rights reserved.
  4 */
  5
  6#ifndef IB_UMEM_ODP_H
  7#define IB_UMEM_ODP_H
  8
  9#include <rdma/ib_umem.h>
 10#include <rdma/ib_verbs.h>
 11
 12struct ib_umem_odp {
 13	struct ib_umem umem;
 14	struct mmu_interval_notifier notifier;
 15	struct pid *tgid;
 16
 17	/*
 18	 * An array of the pages included in the on-demand paging umem.
 19	 * Indices of pages that are currently not mapped into the device will
 20	 * contain NULL.
 21	 */
 22	struct page		**page_list;
 23	/*
 24	 * An array of the same size as page_list, with DMA addresses mapped
 25	 * for pages the pages in page_list. The lower two bits designate
 26	 * access permissions. See ODP_READ_ALLOWED_BIT and
 27	 * ODP_WRITE_ALLOWED_BIT.
 28	 */
 29	dma_addr_t		*dma_list;
 30	/*
 31	 * The umem_mutex protects the page_list and dma_list fields of an ODP
 32	 * umem, allowing only a single thread to map/unmap pages. The mutex
 33	 * also protects access to the mmu notifier counters.
 34	 */
 35	struct mutex		umem_mutex;
 36	void			*private; /* for the HW driver to use. */
 37
 38	int npages;
 39
 40	/*
 41	 * An implicit odp umem cannot be DMA mapped, has 0 length, and serves
 42	 * only as an anchor for the driver to hold onto the per_mm. FIXME:
 43	 * This should be removed and drivers should work with the per_mm
 44	 * directly.
 45	 */
 46	bool is_implicit_odp;
 47
 48	unsigned int		page_shift;
 49};
 50
 51static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
 52{
 53	return container_of(umem, struct ib_umem_odp, umem);
 54}
 55
 56/* Returns the first page of an ODP umem. */
 57static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
 58{
 59	return umem_odp->notifier.interval_tree.start;
 60}
 61
 62/* Returns the address of the page after the last one of an ODP umem. */
 63static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
 64{
 65	return umem_odp->notifier.interval_tree.last + 1;
 66}
 67
 68static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
 69{
 70	return (ib_umem_end(umem_odp) - ib_umem_start(umem_odp)) >>
 71	       umem_odp->page_shift;
 72}
 73
 74/*
 75 * The lower 2 bits of the DMA address signal the R/W permissions for
 76 * the entry. To upgrade the permissions, provide the appropriate
 77 * bitmask to the map_dma_pages function.
 78 *
 79 * Be aware that upgrading a mapped address might result in change of
 80 * the DMA address for the page.
 81 */
 82#define ODP_READ_ALLOWED_BIT  (1<<0ULL)
 83#define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
 84
 85#define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
 86
 87#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
 88
 89struct ib_umem_odp *
 90ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
 91		int access, const struct mmu_interval_notifier_ops *ops);
 92struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_device *device,
 93					       int access);
 94struct ib_umem_odp *
 95ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
 96			size_t size,
 97			const struct mmu_interval_notifier_ops *ops);
 98void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
 99
100int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
101			      u64 bcnt, u64 access_mask,
102			      unsigned long current_seq);
103
104void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
105				 u64 bound);
106
107#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
108
109static inline struct ib_umem_odp *
110ib_umem_odp_get(struct ib_device *device, unsigned long addr, size_t size,
111		int access, const struct mmu_interval_notifier_ops *ops)
112{
113	return ERR_PTR(-EINVAL);
114}
115
116static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
117
118#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
119
120#endif /* IB_UMEM_ODP_H */