linux/include/rdma/ib_umem.h
Jason Gunthorpe b045db62f6 RDMA/mlx5: Use ib_umem_find_best_pgoff() for SRQ
SRQ uses a quantized and scaled page_offset, which is another variation of
ib_umem_find_best_pgsz(). Add mlx5_umem_find_best_quantized_pgoff() to
perform this calculation for each mailbox. A macro shows how the
calculation is directly connected to the mailbox format.

This new routine replaces the limited mlx5_ib_cont_pages() and
mlx5_ib_get_buf_offset() pairing which would reject valid configurations
rather than adjust the page_size to make it work.

In turn this is much more aggressive about choosing large page sizes for
these objects and when THP is enabled it will now often find a single page
solution.

Link: https://lore.kernel.org/r/20201115114311.136250-2-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-11-16 16:53:29 -04:00

150 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
/*
* Copyright (c) 2007 Cisco Systems. 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 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;
struct work_struct work;
struct sg_table sg_head;
int nmap;
unsigned int sg_nents;
};
/* 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 unsigned long ib_umem_dma_offset(struct ib_umem *umem,
unsigned long pgsz)
{
return (sg_dma_address(umem->sg_head.sgl) + ib_umem_offset(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->sg_head.sgl, umem->nmap, pgsz);
}
/**
* 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_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)
{
struct scatterlist *sg = umem->sg_head.sgl;
dma_addr_t dma_addr;
dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
dma_addr & pgoff_bitmask);
}
#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(-EINVAL);
}
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 -EINVAL;
}
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;
}
#endif /* CONFIG_INFINIBAND_USER_MEM */
#endif /* IB_UMEM_H */