/* 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/list.h>
#include <linux/scatterlist.h>
#include <linux/workqueue.h>
#include <rdma/ib_verbs.h>

struct ib_ucontext;
struct ib_umem_odp;
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;
        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 *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);
}

static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
                                                struct ib_umem *umem,
                                                unsigned long pgsz)
{
        __rdma_block_iter_start(biter, umem->sgt_append.sgt.sgl,
                                umem->sgt_append.sgt.nents, pgsz);
        biter->__sg_advance = ib_umem_offset(umem) & ~(pgsz - 1);
        biter->__sg_numblocks = ib_umem_num_dma_blocks(umem, pgsz);
}

static inline bool __rdma_umem_block_iter_next(struct ib_block_iter *biter)
{
        return __rdma_block_iter_next(biter) && biter->__sg_numblocks--;
}

/**
 * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
 * @umem: umem to iterate over
 * @pgsz: Page size to split the list into
 *
 * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
 * returned DMA blocks will be aligned to pgsz and span the range:
 * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
 *
 * Performs exactly ib_umem_num_dma_blocks() iterations.
 */
#define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
        for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
             __rdma_umem_block_iter_next(biter);)

#ifdef CONFIG_INFINIBAND_USER_MEM

struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
                            size_t size, int 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,
                                     unsigned long 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.
 */
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)
{
        dma_addr_t dma_addr;
        unsigned long pgsz;

        /*
         * Select the smallest aligned page that can contain the whole umem if
         * it was contiguous.
         */
        dma_addr = ib_umem_start_dma_addr(umem);
        pgsz = roundup_pow_of_two((dma_addr ^ (umem->length - 1 + dma_addr)) + 1);
        return !!ib_umem_find_best_pgoff(umem, pgsz, U64_MAX);
}

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_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(struct ib_umem_dmabuf *umem_dmabuf);

#else /* CONFIG_INFINIBAND_USER_MEM */

#include <linux/err.h>

static inline struct ib_umem *ib_umem_get(struct ib_device *device,
                                          unsigned long 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,
                                                   unsigned long 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
struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
                                          unsigned long offset,
                                          size_t size, int fd,
                                          int access,
                                          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_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(struct ib_umem_dmabuf *umem_dmabuf) {}

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