From 8ada2c1c0c1d75a60723cd2ca7d49c594a146af6 Mon Sep 17 00:00:00 2001 From: Shachar Raindel Date: Thu, 11 Dec 2014 17:04:17 +0200 Subject: IB/core: Add support for on demand paging regions * Extend the umem struct to keep the ODP related data. * Allocate and initialize the ODP related information in the umem (page_list, dma_list) and freeing as needed in the end of the run. * Store a reference to the process PID struct in the ucontext. Used to safely obtain the task_struct and the mm during fault handling, without preventing the task destruction if needed. * Add 2 helper functions: ib_umem_odp_map_dma_pages and ib_umem_odp_unmap_dma_pages. These functions get the DMA addresses of specific pages of the umem (and, currently, pin them). * Support for page faults only - IB core will keep the reference on the pages used and call put_page when freeing an ODP umem area. Invalidations support will be added in a later patch. Signed-off-by: Sagi Grimberg Signed-off-by: Shachar Raindel Signed-off-by: Haggai Eran Signed-off-by: Majd Dibbiny Signed-off-by: Roland Dreier --- include/rdma/ib_umem.h | 2 + include/rdma/ib_umem_odp.h | 97 ++++++++++++++++++++++++++++++++++++++++++++++ include/rdma/ib_verbs.h | 2 + 3 files changed, 101 insertions(+) create mode 100644 include/rdma/ib_umem_odp.h (limited to 'include/rdma') diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index a51f4091489a..2d83cfd7e6ce 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -38,6 +38,7 @@ #include struct ib_ucontext; +struct ib_umem_odp; struct ib_umem { struct ib_ucontext *context; @@ -50,6 +51,7 @@ struct ib_umem { struct pid *pid; struct mm_struct *mm; unsigned long diff; + struct ib_umem_odp *odp_data; struct sg_table sg_head; int nmap; int npages; diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h new file mode 100644 index 000000000000..b5a2df1923b7 --- /dev/null +++ b/include/rdma/ib_umem_odp.h @@ -0,0 +1,97 @@ +/* + * 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 + +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. + */ + struct mutex umem_mutex; + void *private; /* for the HW driver to use. */ +}; + +#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING + +int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem); + +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); + +#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ + +static inline int ib_umem_odp_get(struct ib_ucontext *context, + struct ib_umem *umem) +{ + return -EINVAL; +} + +static inline void ib_umem_odp_release(struct ib_umem *umem) {} + +#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ + +#endif /* IB_UMEM_ODP_H */ diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index a41bc5a39ebf..3af5dcad1b69 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -1151,6 +1151,8 @@ struct ib_ucontext { struct list_head xrcd_list; struct list_head rule_list; int closing; + + struct pid *tgid; }; struct ib_uobject { -- cgit v1.2.3