/*
* 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 {
/*
* 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. */
/* When false, use the notifier counter in the ucontext struct. */
bool mn_counters_active;
int notifiers_seq;
int notifiers_count;
/* A linked list of umems that don't have private mmu notifier
* counters yet. */
struct list_head no_private_counters;
struct ib_umem *umem;
/* Tree tracking */
struct umem_odp_node interval_tree;
struct completion notifier_completion;
int dying;
struct work_struct work;
};
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem,
int access);
struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context,
unsigned long addr,
size_t size);
void ib_umem_odp_release(struct ib_umem *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))
int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 start_offset, u64 bcnt,
u64 access_mask, unsigned long current_seq);
void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 start_offset,
u64 bound);
void rbt_ib_umem_insert(struct umem_odp_node *node, struct rb_root *root);
void rbt_ib_umem_remove(struct umem_odp_node *node, struct rb_root *root);
typedef int (*umem_call_back)(struct ib_umem *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 *root, u64 start, u64 end,
umem_call_back cb, 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 *root,
u64 addr, u64 length);
static inline int ib_umem_mmu_notifier_retry(struct ib_umem *item,
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 (item->odp_data->umem_mutex
* and the ucontext umem_mutex semaphore locked for read).
*/
/* Do not allow page faults while the new ib_umem hasn't seen a state
* with zero notifiers yet, and doesn't have its own valid set of
* private counters. */
if (!item->odp_data->mn_counters_active)
return 1;
if (unlikely(item->odp_data->notifiers_count))
return 1;
if (item->odp_data->notifiers_seq != mmu_seq)
return 1;
return 0;
}
#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
static inline int ib_umem_odp_get(struct ib_ucontext *context,
struct ib_umem *umem,
int access)
{
return -EINVAL;
}
static inline struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context,
unsigned long addr,
size_t size)
{
return ERR_PTR(-EINVAL);
}
static inline void ib_umem_odp_release(struct ib_umem *umem) {}
#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
#endif /* IB_UMEM_ODP_H */
