linux/include/rdma/ib_umem_odp.h
Shiraz Saleem d10bcf947a RDMA/umem: Combine contiguous PAGE_SIZE regions in SGEs
Combine contiguous regions of PAGE_SIZE pages into single scatter list
entry while building the scatter table for a umem. This minimizes the
number of the entries in the scatter list and reduces the DMA mapping
overhead, particularly with the IOMMU.

Set default max_seg_size in core for IB devices to 2G and do not combine
if we exceed this limit.

Also, purge npages in struct ib_umem as we now DMA map the umem SGL with
sg_nents and npage computation is not needed. Drivers should now be using
ib_umem_num_pages(), so fix the last stragglers.

Move npages tracking to ib_umem_odp as ODP drivers still need it.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Tested-by: Gal Pressman <galpress@amazon.com>
Tested-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-04-08 13:05:24 -03:00

178 lines
5.3 KiB
C

/*
* Copyright (c) 2014 Mellanox Technologies. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef IB_UMEM_ODP_H
#define IB_UMEM_ODP_H
#include <rdma/ib_umem.h>
#include <rdma/ib_verbs.h>
#include <linux/interval_tree.h>
struct umem_odp_node {
u64 __subtree_last;
struct rb_node rb;
};
struct ib_umem_odp {
struct ib_umem umem;
struct ib_ucontext_per_mm *per_mm;
/*
* An array of the pages included in the on-demand paging umem.
* Indices of pages that are currently not mapped into the device will
* contain NULL.
*/
struct page **page_list;
/*
* An array of the same size as page_list, with DMA addresses mapped
* for pages the pages in page_list. The lower two bits designate
* access permissions. See ODP_READ_ALLOWED_BIT and
* ODP_WRITE_ALLOWED_BIT.
*/
dma_addr_t *dma_list;
/*
* The umem_mutex protects the page_list and dma_list fields of an ODP
* umem, allowing only a single thread to map/unmap pages. The mutex
* also protects access to the mmu notifier counters.
*/
struct mutex umem_mutex;
void *private; /* for the HW driver to use. */
int notifiers_seq;
int notifiers_count;
int npages;
/* Tree tracking */
struct umem_odp_node interval_tree;
struct completion notifier_completion;
int dying;
struct work_struct work;
};
static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
{
return container_of(umem, struct ib_umem_odp, umem);
}
/*
* The lower 2 bits of the DMA address signal the R/W permissions for
* the entry. To upgrade the permissions, provide the appropriate
* bitmask to the map_dma_pages function.
*
* Be aware that upgrading a mapped address might result in change of
* the DMA address for the page.
*/
#define ODP_READ_ALLOWED_BIT (1<<0ULL)
#define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
#define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
struct ib_ucontext_per_mm {
struct ib_ucontext *context;
struct mm_struct *mm;
struct pid *tgid;
bool active;
struct rb_root_cached umem_tree;
/* Protects umem_tree */
struct rw_semaphore umem_rwsem;
struct mmu_notifier mn;
unsigned int odp_mrs_count;
struct list_head ucontext_list;
struct rcu_head rcu;
};
int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access);
struct ib_umem_odp *ib_alloc_odp_umem(struct ib_umem_odp *root_umem,
unsigned long addr, size_t size);
void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
u64 bcnt, u64 access_mask,
unsigned long current_seq);
void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
u64 bound);
typedef int (*umem_call_back)(struct ib_umem_odp *item, u64 start, u64 end,
void *cookie);
/*
* Call the callback on each ib_umem in the range. Returns the logical or of
* the return values of the functions called.
*/
int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
u64 start, u64 end,
umem_call_back cb,
bool blockable, void *cookie);
/*
* Find first region intersecting with address range.
* Return NULL if not found
*/
struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
u64 addr, u64 length);
static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp,
unsigned long mmu_seq)
{
/*
* This code is strongly based on the KVM code from
* mmu_notifier_retry. Should be called with
* the relevant locks taken (umem_odp->umem_mutex
* and the ucontext umem_mutex semaphore locked for read).
*/
if (unlikely(umem_odp->notifiers_count))
return 1;
if (umem_odp->notifiers_seq != mmu_seq)
return 1;
return 0;
}
#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
static inline int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access)
{
return -EINVAL;
}
static inline void ib_umem_odp_release(struct ib_umem_odp *umem_odp) {}
#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
#endif /* IB_UMEM_ODP_H */