| /* |
| * Copyright (c) 2004, 2005 Topspin Communications. All rights reserved. |
| * Copyright (c) 2006 Cisco Systems, Inc. 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. |
| */ |
| |
| #if HAVE_CONFIG_H |
| # include <config.h> |
| #endif /* HAVE_CONFIG_H */ |
| |
| #include <errno.h> |
| #include <sys/mman.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <dirent.h> |
| #include <limits.h> |
| #include <inttypes.h> |
| |
| #include "ibverbs.h" |
| |
| /* |
| * Most distro's headers don't have these yet. |
| */ |
| #ifndef MADV_DONTFORK |
| #define MADV_DONTFORK 10 |
| #endif |
| |
| #ifndef MADV_DOFORK |
| #define MADV_DOFORK 11 |
| #endif |
| |
| struct ibv_mem_node { |
| enum { |
| IBV_RED, |
| IBV_BLACK |
| } color; |
| struct ibv_mem_node *parent; |
| struct ibv_mem_node *left, *right; |
| uintptr_t start, end; |
| int refcnt; |
| }; |
| |
| static struct ibv_mem_node *mm_root; |
| static pthread_mutex_t mm_mutex = PTHREAD_MUTEX_INITIALIZER; |
| static int page_size; |
| static int huge_page_enabled; |
| static int too_late; |
| |
| static unsigned long smaps_page_size(FILE *file) |
| { |
| int n; |
| unsigned long size = page_size; |
| char buf[1024]; |
| |
| while (fgets(buf, sizeof(buf), file) != NULL) { |
| if (!strstr(buf, "KernelPageSize:")) |
| continue; |
| |
| n = sscanf(buf, "%*s %lu", &size); |
| if (n < 1) |
| continue; |
| |
| /* page size is printed in Kb */ |
| size = size * 1024; |
| |
| break; |
| } |
| |
| return size; |
| } |
| |
| static unsigned long get_page_size(void *base) |
| { |
| unsigned long ret = page_size; |
| pid_t pid; |
| FILE *file; |
| char buf[1024]; |
| |
| pid = getpid(); |
| snprintf(buf, sizeof(buf), "/proc/%d/smaps", pid); |
| |
| file = fopen(buf, "r" STREAM_CLOEXEC); |
| if (!file) |
| goto out; |
| |
| while (fgets(buf, sizeof(buf), file) != NULL) { |
| int n; |
| uintptr_t range_start, range_end; |
| |
| n = sscanf(buf, "%" SCNxPTR "-%" SCNxPTR, &range_start, &range_end); |
| |
| if (n < 2) |
| continue; |
| |
| if ((uintptr_t) base >= range_start && (uintptr_t) base < range_end) { |
| ret = smaps_page_size(file); |
| break; |
| } |
| } |
| |
| fclose(file); |
| |
| out: |
| return ret; |
| } |
| |
| int ibv_fork_init(void) |
| { |
| void *tmp, *tmp_aligned; |
| int ret; |
| unsigned long size; |
| |
| if (getenv("RDMAV_HUGEPAGES_SAFE")) |
| huge_page_enabled = 1; |
| |
| if (mm_root) |
| return 0; |
| |
| if (too_late) |
| return EINVAL; |
| |
| page_size = sysconf(_SC_PAGESIZE); |
| if (page_size < 0) |
| return errno; |
| |
| if (posix_memalign(&tmp, page_size, page_size)) |
| return ENOMEM; |
| |
| if (huge_page_enabled) { |
| size = get_page_size(tmp); |
| tmp_aligned = (void *) ((uintptr_t) tmp & ~(size - 1)); |
| } else { |
| size = page_size; |
| tmp_aligned = tmp; |
| } |
| |
| ret = madvise(tmp_aligned, size, MADV_DONTFORK) || |
| madvise(tmp_aligned, size, MADV_DOFORK); |
| |
| free(tmp); |
| |
| if (ret) |
| return ENOSYS; |
| |
| mm_root = malloc(sizeof *mm_root); |
| if (!mm_root) |
| return ENOMEM; |
| |
| mm_root->parent = NULL; |
| mm_root->left = NULL; |
| mm_root->right = NULL; |
| mm_root->color = IBV_BLACK; |
| mm_root->start = 0; |
| mm_root->end = UINTPTR_MAX; |
| mm_root->refcnt = 0; |
| |
| return 0; |
| } |
| |
| static struct ibv_mem_node *__mm_prev(struct ibv_mem_node *node) |
| { |
| if (node->left) { |
| node = node->left; |
| while (node->right) |
| node = node->right; |
| } else { |
| while (node->parent && node == node->parent->left) |
| node = node->parent; |
| |
| node = node->parent; |
| } |
| |
| return node; |
| } |
| |
| static struct ibv_mem_node *__mm_next(struct ibv_mem_node *node) |
| { |
| if (node->right) { |
| node = node->right; |
| while (node->left) |
| node = node->left; |
| } else { |
| while (node->parent && node == node->parent->right) |
| node = node->parent; |
| |
| node = node->parent; |
| } |
| |
| return node; |
| } |
| |
| static void __mm_rotate_right(struct ibv_mem_node *node) |
| { |
| struct ibv_mem_node *tmp; |
| |
| tmp = node->left; |
| |
| node->left = tmp->right; |
| if (node->left) |
| node->left->parent = node; |
| |
| if (node->parent) { |
| if (node->parent->right == node) |
| node->parent->right = tmp; |
| else |
| node->parent->left = tmp; |
| } else |
| mm_root = tmp; |
| |
| tmp->parent = node->parent; |
| |
| tmp->right = node; |
| node->parent = tmp; |
| } |
| |
| static void __mm_rotate_left(struct ibv_mem_node *node) |
| { |
| struct ibv_mem_node *tmp; |
| |
| tmp = node->right; |
| |
| node->right = tmp->left; |
| if (node->right) |
| node->right->parent = node; |
| |
| if (node->parent) { |
| if (node->parent->right == node) |
| node->parent->right = tmp; |
| else |
| node->parent->left = tmp; |
| } else |
| mm_root = tmp; |
| |
| tmp->parent = node->parent; |
| |
| tmp->left = node; |
| node->parent = tmp; |
| } |
| |
| #if 0 |
| static int verify(struct ibv_mem_node *node) |
| { |
| int hl, hr; |
| |
| if (!node) |
| return 1; |
| |
| hl = verify(node->left); |
| hr = verify(node->left); |
| |
| if (!hl || !hr) |
| return 0; |
| if (hl != hr) |
| return 0; |
| |
| if (node->color == IBV_RED) { |
| if (node->left && node->left->color != IBV_BLACK) |
| return 0; |
| if (node->right && node->right->color != IBV_BLACK) |
| return 0; |
| return hl; |
| } |
| |
| return hl + 1; |
| } |
| #endif |
| |
| static void __mm_add_rebalance(struct ibv_mem_node *node) |
| { |
| struct ibv_mem_node *parent, *gp, *uncle; |
| |
| while (node->parent && node->parent->color == IBV_RED) { |
| parent = node->parent; |
| gp = node->parent->parent; |
| |
| if (parent == gp->left) { |
| uncle = gp->right; |
| |
| if (uncle && uncle->color == IBV_RED) { |
| parent->color = IBV_BLACK; |
| uncle->color = IBV_BLACK; |
| gp->color = IBV_RED; |
| |
| node = gp; |
| } else { |
| if (node == parent->right) { |
| __mm_rotate_left(parent); |
| node = parent; |
| parent = node->parent; |
| } |
| |
| parent->color = IBV_BLACK; |
| gp->color = IBV_RED; |
| |
| __mm_rotate_right(gp); |
| } |
| } else { |
| uncle = gp->left; |
| |
| if (uncle && uncle->color == IBV_RED) { |
| parent->color = IBV_BLACK; |
| uncle->color = IBV_BLACK; |
| gp->color = IBV_RED; |
| |
| node = gp; |
| } else { |
| if (node == parent->left) { |
| __mm_rotate_right(parent); |
| node = parent; |
| parent = node->parent; |
| } |
| |
| parent->color = IBV_BLACK; |
| gp->color = IBV_RED; |
| |
| __mm_rotate_left(gp); |
| } |
| } |
| } |
| |
| mm_root->color = IBV_BLACK; |
| } |
| |
| static void __mm_add(struct ibv_mem_node *new) |
| { |
| struct ibv_mem_node *node, *parent = NULL; |
| |
| node = mm_root; |
| while (node) { |
| parent = node; |
| if (node->start < new->start) |
| node = node->right; |
| else |
| node = node->left; |
| } |
| |
| if (parent->start < new->start) |
| parent->right = new; |
| else |
| parent->left = new; |
| |
| new->parent = parent; |
| new->left = NULL; |
| new->right = NULL; |
| |
| new->color = IBV_RED; |
| __mm_add_rebalance(new); |
| } |
| |
| static void __mm_remove(struct ibv_mem_node *node) |
| { |
| struct ibv_mem_node *child, *parent, *sib, *tmp; |
| int nodecol; |
| |
| if (node->left && node->right) { |
| tmp = node->left; |
| while (tmp->right) |
| tmp = tmp->right; |
| |
| nodecol = tmp->color; |
| child = tmp->left; |
| tmp->color = node->color; |
| |
| if (tmp->parent != node) { |
| parent = tmp->parent; |
| parent->right = tmp->left; |
| if (tmp->left) |
| tmp->left->parent = parent; |
| |
| tmp->left = node->left; |
| node->left->parent = tmp; |
| } else |
| parent = tmp; |
| |
| tmp->right = node->right; |
| node->right->parent = tmp; |
| |
| tmp->parent = node->parent; |
| if (node->parent) { |
| if (node->parent->left == node) |
| node->parent->left = tmp; |
| else |
| node->parent->right = tmp; |
| } else |
| mm_root = tmp; |
| } else { |
| nodecol = node->color; |
| |
| child = node->left ? node->left : node->right; |
| parent = node->parent; |
| |
| if (child) |
| child->parent = parent; |
| if (parent) { |
| if (parent->left == node) |
| parent->left = child; |
| else |
| parent->right = child; |
| } else |
| mm_root = child; |
| } |
| |
| free(node); |
| |
| if (nodecol == IBV_RED) |
| return; |
| |
| while ((!child || child->color == IBV_BLACK) && child != mm_root) { |
| if (parent->left == child) { |
| sib = parent->right; |
| |
| if (sib->color == IBV_RED) { |
| parent->color = IBV_RED; |
| sib->color = IBV_BLACK; |
| __mm_rotate_left(parent); |
| sib = parent->right; |
| } |
| |
| if ((!sib->left || sib->left->color == IBV_BLACK) && |
| (!sib->right || sib->right->color == IBV_BLACK)) { |
| sib->color = IBV_RED; |
| child = parent; |
| parent = child->parent; |
| } else { |
| if (!sib->right || sib->right->color == IBV_BLACK) { |
| if (sib->left) |
| sib->left->color = IBV_BLACK; |
| sib->color = IBV_RED; |
| __mm_rotate_right(sib); |
| sib = parent->right; |
| } |
| |
| sib->color = parent->color; |
| parent->color = IBV_BLACK; |
| if (sib->right) |
| sib->right->color = IBV_BLACK; |
| __mm_rotate_left(parent); |
| child = mm_root; |
| break; |
| } |
| } else { |
| sib = parent->left; |
| |
| if (sib->color == IBV_RED) { |
| parent->color = IBV_RED; |
| sib->color = IBV_BLACK; |
| __mm_rotate_right(parent); |
| sib = parent->left; |
| } |
| |
| if ((!sib->left || sib->left->color == IBV_BLACK) && |
| (!sib->right || sib->right->color == IBV_BLACK)) { |
| sib->color = IBV_RED; |
| child = parent; |
| parent = child->parent; |
| } else { |
| if (!sib->left || sib->left->color == IBV_BLACK) { |
| if (sib->right) |
| sib->right->color = IBV_BLACK; |
| sib->color = IBV_RED; |
| __mm_rotate_left(sib); |
| sib = parent->left; |
| } |
| |
| sib->color = parent->color; |
| parent->color = IBV_BLACK; |
| if (sib->left) |
| sib->left->color = IBV_BLACK; |
| __mm_rotate_right(parent); |
| child = mm_root; |
| break; |
| } |
| } |
| } |
| |
| if (child) |
| child->color = IBV_BLACK; |
| } |
| |
| static struct ibv_mem_node *__mm_find_start(uintptr_t start, uintptr_t end) |
| { |
| struct ibv_mem_node *node = mm_root; |
| |
| while (node) { |
| if (node->start <= start && node->end >= start) |
| break; |
| |
| if (node->start < start) |
| node = node->right; |
| else |
| node = node->left; |
| } |
| |
| return node; |
| } |
| |
| static struct ibv_mem_node *merge_ranges(struct ibv_mem_node *node, |
| struct ibv_mem_node *prev) |
| { |
| prev->end = node->end; |
| prev->refcnt = node->refcnt; |
| __mm_remove(node); |
| |
| return prev; |
| } |
| |
| static struct ibv_mem_node *split_range(struct ibv_mem_node *node, |
| uintptr_t cut_line) |
| { |
| struct ibv_mem_node *new_node = NULL; |
| |
| new_node = malloc(sizeof *new_node); |
| if (!new_node) |
| return NULL; |
| new_node->start = cut_line; |
| new_node->end = node->end; |
| new_node->refcnt = node->refcnt; |
| node->end = cut_line - 1; |
| __mm_add(new_node); |
| |
| return new_node; |
| } |
| |
| static struct ibv_mem_node *get_start_node(uintptr_t start, uintptr_t end, |
| int inc) |
| { |
| struct ibv_mem_node *node, *tmp = NULL; |
| |
| node = __mm_find_start(start, end); |
| if (node->start < start) |
| node = split_range(node, start); |
| else { |
| tmp = __mm_prev(node); |
| if (tmp && tmp->refcnt == node->refcnt + inc) |
| node = merge_ranges(node, tmp); |
| } |
| return node; |
| } |
| |
| /* |
| * This function is called if madvise() fails to undo merging/splitting |
| * operations performed on the node. |
| */ |
| static struct ibv_mem_node *undo_node(struct ibv_mem_node *node, |
| uintptr_t start, int inc) |
| { |
| struct ibv_mem_node *tmp = NULL; |
| |
| /* |
| * This condition can be true only if we merged this |
| * node with the previous one, so we need to split them. |
| */ |
| if (start > node->start) { |
| tmp = split_range(node, start); |
| if (tmp) { |
| node->refcnt += inc; |
| node = tmp; |
| } else |
| return NULL; |
| } |
| |
| tmp = __mm_prev(node); |
| if (tmp && tmp->refcnt == node->refcnt) |
| node = merge_ranges(node, tmp); |
| |
| tmp = __mm_next(node); |
| if (tmp && tmp->refcnt == node->refcnt) |
| node = merge_ranges(tmp, node); |
| |
| return node; |
| } |
| |
| static int ibv_madvise_range(void *base, size_t size, int advice) |
| { |
| uintptr_t start, end; |
| struct ibv_mem_node *node, *tmp; |
| int inc; |
| int rolling_back = 0; |
| int ret = 0; |
| unsigned long range_page_size; |
| |
| if (!size) |
| return 0; |
| |
| if (huge_page_enabled) |
| range_page_size = get_page_size(base); |
| else |
| range_page_size = page_size; |
| |
| start = (uintptr_t) base & ~(range_page_size - 1); |
| end = ((uintptr_t) (base + size + range_page_size - 1) & |
| ~(range_page_size - 1)) - 1; |
| |
| pthread_mutex_lock(&mm_mutex); |
| again: |
| inc = advice == MADV_DONTFORK ? 1 : -1; |
| |
| node = get_start_node(start, end, inc); |
| if (!node) { |
| ret = -1; |
| goto out; |
| } |
| |
| while (node && node->start <= end) { |
| if (node->end > end) { |
| if (!split_range(node, end + 1)) { |
| ret = -1; |
| goto out; |
| } |
| } |
| |
| if ((inc == -1 && node->refcnt == 1) || |
| (inc == 1 && node->refcnt == 0)) { |
| /* |
| * If this is the first time through the loop, |
| * and we merged this node with the previous |
| * one, then we only want to do the madvise() |
| * on start ... node->end (rather than |
| * starting at node->start). |
| * |
| * Otherwise we end up doing madvise() on |
| * bigger region than we're being asked to, |
| * and that may lead to a spurious failure. |
| */ |
| if (start > node->start) |
| ret = madvise((void *) start, node->end - start + 1, |
| advice); |
| else |
| ret = madvise((void *) node->start, |
| node->end - node->start + 1, |
| advice); |
| if (ret) { |
| node = undo_node(node, start, inc); |
| |
| if (rolling_back || !node) |
| goto out; |
| |
| /* madvise failed, roll back previous changes */ |
| rolling_back = 1; |
| advice = advice == MADV_DONTFORK ? |
| MADV_DOFORK : MADV_DONTFORK; |
| tmp = __mm_prev(node); |
| if (!tmp || start > tmp->end) |
| goto out; |
| end = tmp->end; |
| goto again; |
| } |
| } |
| |
| node->refcnt += inc; |
| node = __mm_next(node); |
| } |
| |
| if (node) { |
| tmp = __mm_prev(node); |
| if (tmp && node->refcnt == tmp->refcnt) |
| node = merge_ranges(node, tmp); |
| } |
| |
| out: |
| if (rolling_back) |
| ret = -1; |
| |
| pthread_mutex_unlock(&mm_mutex); |
| |
| return ret; |
| } |
| |
| int ibv_dontfork_range(void *base, size_t size) |
| { |
| if (mm_root) |
| return ibv_madvise_range(base, size, MADV_DONTFORK); |
| else { |
| too_late = 1; |
| return 0; |
| } |
| } |
| |
| int ibv_dofork_range(void *base, size_t size) |
| { |
| if (mm_root) |
| return ibv_madvise_range(base, size, MADV_DOFORK); |
| else { |
| too_late = 1; |
| return 0; |
| } |
| } |