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