forked from Minki/linux
99f80d2f5f
Profiling shows that the key validation is susceptible to cache line trading when accessing the lkey table. Fix by separating out the read mostly fields from the write fields. In addition the shift amount, which is function of the lkey table size, is precomputed and stored with the table pointer. Since both the shift and table pointer are in the same read mostly cacheline, this saves a cache line in this hot path. Reviewed-by: Sebastian Sanchez <sebastian.sanchez@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
145 lines
4.8 KiB
C
145 lines
4.8 KiB
C
#ifndef DEF_RDMAVT_INCMR_H
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#define DEF_RDMAVT_INCMR_H
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/*
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* Copyright(c) 2016 Intel Corporation.
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*
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* This file is provided under a dual BSD/GPLv2 license. When using or
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* redistributing this file, you may do so under either license.
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*
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* GPL LICENSE SUMMARY
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* BSD LICENSE
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of Intel Corporation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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/*
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* For Memory Regions. This stuff should probably be moved into rdmavt/mr.h once
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* drivers no longer need access to the MR directly.
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*/
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/*
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* A segment is a linear region of low physical memory.
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* Used by the verbs layer.
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*/
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struct rvt_seg {
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void *vaddr;
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size_t length;
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};
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/* The number of rvt_segs that fit in a page. */
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#define RVT_SEGSZ (PAGE_SIZE / sizeof(struct rvt_seg))
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struct rvt_segarray {
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struct rvt_seg segs[RVT_SEGSZ];
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};
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struct rvt_mregion {
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struct ib_pd *pd; /* shares refcnt of ibmr.pd */
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u64 user_base; /* User's address for this region */
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u64 iova; /* IB start address of this region */
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size_t length;
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u32 lkey;
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u32 offset; /* offset (bytes) to start of region */
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int access_flags;
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u32 max_segs; /* number of rvt_segs in all the arrays */
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u32 mapsz; /* size of the map array */
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u8 page_shift; /* 0 - non unform/non powerof2 sizes */
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u8 lkey_published; /* in global table */
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atomic_t lkey_invalid; /* true if current lkey is invalid */
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struct completion comp; /* complete when refcount goes to zero */
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atomic_t refcount;
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struct rvt_segarray *map[0]; /* the segments */
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};
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#define RVT_MAX_LKEY_TABLE_BITS 23
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struct rvt_lkey_table {
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/* read mostly fields */
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u32 max; /* size of the table */
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u32 shift; /* lkey/rkey shift */
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struct rvt_mregion __rcu **table;
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/* writeable fields */
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/* protect changes in this struct */
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spinlock_t lock ____cacheline_aligned_in_smp;
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u32 next; /* next unused index (speeds search) */
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u32 gen; /* generation count */
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};
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/*
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* These keep track of the copy progress within a memory region.
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* Used by the verbs layer.
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*/
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struct rvt_sge {
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struct rvt_mregion *mr;
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void *vaddr; /* kernel virtual address of segment */
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u32 sge_length; /* length of the SGE */
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u32 length; /* remaining length of the segment */
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u16 m; /* current index: mr->map[m] */
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u16 n; /* current index: mr->map[m]->segs[n] */
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};
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struct rvt_sge_state {
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struct rvt_sge *sg_list; /* next SGE to be used if any */
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struct rvt_sge sge; /* progress state for the current SGE */
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u32 total_len;
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u8 num_sge;
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};
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static inline void rvt_put_mr(struct rvt_mregion *mr)
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{
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if (unlikely(atomic_dec_and_test(&mr->refcount)))
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complete(&mr->comp);
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}
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static inline void rvt_get_mr(struct rvt_mregion *mr)
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{
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atomic_inc(&mr->refcount);
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}
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static inline void rvt_put_ss(struct rvt_sge_state *ss)
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{
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while (ss->num_sge) {
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rvt_put_mr(ss->sge.mr);
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if (--ss->num_sge)
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ss->sge = *ss->sg_list++;
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}
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}
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#endif /* DEF_RDMAVT_INCMRH */
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