include/rdma/ib_umem.h

/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
/*
 * Copyright (c) 2007 Cisco Systems.  All rights reserved.
 * Copyright (c) 2020 Intel Corporation.  All rights reserved.
 */

#ifndef IB_UMEM_H
#define IB_UMEM_H

#include <linux/scatterlist.h>

struct ib_device;
struct dma_buf_attach_ops;

struct ib_umem {
	struct ib_device       *ibdev;
	struct mm_struct       *owning_mm;
	u64 iova;
	size_t			length;
	unsigned long		address;
	unsigned long		dma_attrs;
	u32 writable : 1;
	u32 is_odp : 1;
	u32 is_dmabuf : 1;
	struct sg_append_table sgt_append;
};

struct ib_umem_dmabuf {
	struct ib_umem umem;
	struct dma_buf_attachment *attach;
	struct sg_table *sgt;
	struct scatterlist *first_sg;
	struct scatterlist *last_sg;
	unsigned long first_sg_offset;
	unsigned long last_sg_trim;
	void (*pinned_revoke)(void *priv);
	void *private;
	u8 pinned : 1;
	u8 revoked : 1;
};

static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
{
	return container_of(umem, struct ib_umem_dmabuf, umem);
}

/* Returns the offset of the umem start relative to the first page. */
static inline int ib_umem_offset(struct ib_umem *umem)
{
	return umem->address & ~PAGE_MASK;
}

static inline dma_addr_t ib_umem_start_dma_addr(struct ib_umem *umem)
{
	return sg_dma_address(umem->sgt_append.sgt.sgl) + ib_umem_offset(umem);
}

static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
					       unsigned long pgsz)
{
	return ib_umem_start_dma_addr(umem) & (pgsz - 1);
}

static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
					    unsigned long pgsz)
{
	return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
			 ALIGN_DOWN(umem->iova, pgsz))) /
	       pgsz;
}

static inline size_t ib_umem_num_pages(struct ib_umem *umem)
{
	return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
}

struct ib_udata;
struct ib_uverbs_buffer_desc;
struct uverbs_attr_bundle;

#ifdef CONFIG_INFINIBAND_USER_MEM

struct ib_umem *ib_umem_get_desc(struct ib_device *device,
				 const struct ib_uverbs_buffer_desc *desc,
				 int access);
struct ib_umem *ib_umem_get_attr(struct ib_device *device,
				 const struct uverbs_attr_bundle *attrs,
				 u16 attr_id, size_t size, int access);
struct ib_umem *ib_umem_get_attr_or_va(struct ib_device *device,
				       const struct uverbs_attr_bundle *attrs,
				       u16 attr_id, u64 addr, size_t size,
				       int access);
struct ib_umem *ib_umem_get_cq_buf(struct ib_device *device,
				   const struct uverbs_attr_bundle *attrs,
				   size_t size, int access);
struct ib_umem *ib_umem_get_cq_buf_or_va(struct ib_device *device,
					 const struct uverbs_attr_bundle *attrs,
					 u64 addr, size_t size, int access);

static inline struct ib_umem *ib_umem_get_va(struct ib_device *device,
					     unsigned long addr, size_t size,
					     int access)
{
	return ib_umem_get_attr_or_va(device, NULL, 0, addr, size, access);
}

void ib_umem_release(struct ib_umem *umem);
int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
		      size_t length);
unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
				     unsigned long pgsz_bitmap,
				     u64 virt);

/**
 * ib_umem_find_best_pgoff - Find best HW page size
 *
 * @umem: umem struct
 * @pgsz_bitmap: bitmap of HW supported page sizes
 * @pgoff_bitmask: Mask of bits that can be represented with an offset
 *
 * This is very similar to ib_umem_find_best_pgsz() except instead of accepting
 * an IOVA it accepts a bitmask specifying what address bits can be represented
 * with a page offset.
 *
 * For instance if the HW has multiple page sizes, requires 64 byte alignemnt,
 * and can support aligned offsets up to 4032 then pgoff_bitmask would be
 * "111111000000".
 *
 * If the pgoff_bitmask requires either alignment in the low bit or an
 * unavailable page size for the high bits, this function returns 0.
 *
 * Returns: best HW page size for the parameters or 0 if none available
 *   for the given parameters.
 */
static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
						    unsigned long pgsz_bitmap,
						    u64 pgoff_bitmask)
{
	dma_addr_t dma_addr;

	dma_addr = ib_umem_start_dma_addr(umem);
	return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
				      dma_addr & pgoff_bitmask);
}

static inline bool ib_umem_is_contiguous(struct ib_umem *umem)
{
	unsigned long pgsz;

	pgsz = ib_umem_find_best_pgsz(umem, ULONG_MAX,
				      ib_umem_start_dma_addr(umem));
	return pgsz && ib_umem_num_dma_blocks(umem, pgsz) == 1;
}

struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
					  unsigned long offset, size_t size,
					  int fd, int access,
					  const struct dma_buf_attach_ops *ops);
struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device,
						 unsigned long offset,
						 size_t size, int fd,
						 int access);
struct ib_umem_dmabuf *
ib_umem_dmabuf_get_pinned_revocable_and_lock(struct ib_device *device,
					     unsigned long offset, size_t size,
					     int fd, int access);
void ib_umem_dmabuf_set_revoke_locked(struct ib_umem_dmabuf *umem_dmabuf,
				      void (*revoke)(void *priv), void *priv);
struct ib_umem_dmabuf *
ib_umem_dmabuf_get_pinned_with_dma_device(struct ib_device *device,
					  struct device *dma_device,
					  unsigned long offset, size_t size,
					  int fd, int access);
int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
void ib_umem_dmabuf_revoke_lock(struct ib_umem_dmabuf *umem_dmabuf);
void ib_umem_dmabuf_revoke_unlock(struct ib_umem_dmabuf *umem_dmabuf);
void ib_umem_dmabuf_revoke(struct ib_umem_dmabuf *umem_dmabuf);

int ib_umem_check_rereg(struct ib_umem *umem, int flags, int new_access_flags);

#else /* CONFIG_INFINIBAND_USER_MEM */

#include <linux/err.h>

static inline struct ib_umem *
ib_umem_get_desc(struct ib_device *device,
		 const struct ib_uverbs_buffer_desc *desc, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline struct ib_umem *ib_umem_get_va(struct ib_device *device,
					     unsigned long addr, size_t size,
					     int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline struct ib_umem *
ib_umem_get_attr(struct ib_device *device,
		 const struct uverbs_attr_bundle *attrs, u16 attr_id,
		 size_t size, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline struct ib_umem *
ib_umem_get_attr_or_va(struct ib_device *device,
		       const struct uverbs_attr_bundle *attrs, u16 attr_id,
		       u64 addr, size_t size, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline struct ib_umem *
ib_umem_get_cq_buf(struct ib_device *device,
		   const struct uverbs_attr_bundle *attrs, size_t size,
		   int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline struct ib_umem *
ib_umem_get_cq_buf_or_va(struct ib_device *device,
			 const struct uverbs_attr_bundle *attrs, u64 addr,
			 size_t size, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline void ib_umem_release(struct ib_umem *umem) { }
static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
		      		    size_t length) {
	return -EOPNOTSUPP;
}
static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
						   unsigned long pgsz_bitmap,
						   u64 virt)
{
	return 0;
}
static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
						    unsigned long pgsz_bitmap,
						    u64 pgoff_bitmask)
{
	return 0;
}
static inline bool ib_umem_is_contiguous(struct ib_umem *umem)
{
	return false;
}
static inline
struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
					  unsigned long offset,
					  size_t size, int fd,
					  int access,
					  const struct dma_buf_attach_ops *ops)
{
	return ERR_PTR(-EOPNOTSUPP);
}
static inline struct ib_umem_dmabuf *
ib_umem_dmabuf_get_pinned(struct ib_device *device, unsigned long offset,
			  size_t size, int fd, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline struct ib_umem_dmabuf *
ib_umem_dmabuf_get_pinned_revocable_and_lock(struct ib_device *device,
					     unsigned long offset, size_t size,
					     int fd, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline void
ib_umem_dmabuf_set_revoke_locked(struct ib_umem_dmabuf *umem_dmabuf,
				 void (*revoke)(void *priv), void *priv) {}

static inline struct ib_umem_dmabuf *
ib_umem_dmabuf_get_pinned_with_dma_device(struct ib_device *device,
					  struct device *dma_device,
					  unsigned long offset, size_t size,
					  int fd, int access)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
{
	return -EOPNOTSUPP;
}
static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
static inline void ib_umem_dmabuf_revoke_lock(struct ib_umem_dmabuf *umem_dmabuf) {}
static inline void ib_umem_dmabuf_revoke_unlock(struct ib_umem_dmabuf *umem_dmabuf) {}
static inline void ib_umem_dmabuf_revoke(struct ib_umem_dmabuf *umem_dmabuf) {}

static inline int ib_umem_check_rereg(struct ib_umem *umem, int flags,
				      int new_access_flags)
{
	return -EOPNOTSUPP;
}

#endif /* CONFIG_INFINIBAND_USER_MEM */
#endif /* IB_UMEM_H */