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a665aca89a
ib_umem_num_pages() should only be used by things working with the SGL in CPU pages directly. Drivers building DMA lists should use the new ib_num_dma_blocks() which returns the number of blocks rdma_umem_for_each_block() will return. To make this general for DMA drivers requires a different implementation. Computing DMA block count based on umem->address only works if the requested page size is < PAGE_SIZE and/or the IOVA == umem->address. Instead the number of DMA pages should be computed in the IOVA address space, not umem->address. Thus the IOVA has to be stored inside the umem so it can be used for these calculations. For now set it to umem->address by default and fix it up if ib_umem_find_best_pgsz() was called. This allows drivers to be converted to ib_umem_num_dma_blocks() safely. Link: https://lore.kernel.org/r/6-v2-270386b7e60b+28f4-umem_1_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
110 lines
3.0 KiB
C
110 lines
3.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
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/*
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* Copyright (c) 2007 Cisco Systems. All rights reserved.
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*/
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#ifndef IB_UMEM_H
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#define IB_UMEM_H
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#include <linux/list.h>
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#include <linux/scatterlist.h>
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#include <linux/workqueue.h>
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#include <rdma/ib_verbs.h>
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struct ib_ucontext;
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struct ib_umem_odp;
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struct ib_umem {
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struct ib_device *ibdev;
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struct mm_struct *owning_mm;
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u64 iova;
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size_t length;
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unsigned long address;
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u32 writable : 1;
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u32 is_odp : 1;
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struct work_struct work;
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struct sg_table sg_head;
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int nmap;
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unsigned int sg_nents;
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};
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/* Returns the offset of the umem start relative to the first page. */
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static inline int ib_umem_offset(struct ib_umem *umem)
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{
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return umem->address & ~PAGE_MASK;
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}
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static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
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unsigned long pgsz)
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{
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return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
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ALIGN_DOWN(umem->iova, pgsz))) /
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pgsz;
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}
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static inline size_t ib_umem_num_pages(struct ib_umem *umem)
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{
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return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
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}
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static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
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struct ib_umem *umem,
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unsigned long pgsz)
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{
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__rdma_block_iter_start(biter, umem->sg_head.sgl, umem->nmap, pgsz);
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}
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/**
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* rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
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* @umem: umem to iterate over
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* @pgsz: Page size to split the list into
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*
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* pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
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* returned DMA blocks will be aligned to pgsz and span the range:
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* ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
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*
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* Performs exactly ib_umem_num_dma_blocks() iterations.
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*/
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#define rdma_umem_for_each_dma_block(umem, biter, pgsz) \
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for (__rdma_umem_block_iter_start(biter, umem, pgsz); \
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__rdma_block_iter_next(biter);)
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#ifdef CONFIG_INFINIBAND_USER_MEM
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struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
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size_t size, int access);
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void ib_umem_release(struct ib_umem *umem);
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int ib_umem_page_count(struct ib_umem *umem);
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int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
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size_t length);
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unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
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unsigned long pgsz_bitmap,
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unsigned long virt);
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#else /* CONFIG_INFINIBAND_USER_MEM */
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#include <linux/err.h>
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static inline struct ib_umem *ib_umem_get(struct ib_device *device,
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unsigned long addr, size_t size,
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int access)
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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_release(struct ib_umem *umem) { }
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static inline int ib_umem_page_count(struct ib_umem *umem) { return 0; }
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static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
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size_t length) {
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return -EINVAL;
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}
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static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
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unsigned long pgsz_bitmap,
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unsigned long virt)
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{
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return 0;
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}
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#endif /* CONFIG_INFINIBAND_USER_MEM */
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#endif /* IB_UMEM_H */
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