1269577Sglebius/*- 2269577Sglebius * Copyright (c) 2014 Gleb Smirnoff <glebius@FreeBSD.org> 3269577Sglebius * Copyright (c) 2003, 2005 Alan L. Cox <alc@cs.rice.edu> 4269577Sglebius * All rights reserved. 5269577Sglebius * 6269577Sglebius * Redistribution and use in source and binary forms, with or without 7269577Sglebius * modification, are permitted provided that the following conditions 8269577Sglebius * are met: 9269577Sglebius * 1. Redistributions of source code must retain the above copyright 10269577Sglebius * notice, this list of conditions and the following disclaimer. 11269577Sglebius * 2. Redistributions in binary form must reproduce the above copyright 12269577Sglebius * notice, this list of conditions and the following disclaimer in the 13269577Sglebius * documentation and/or other materials provided with the distribution. 14269577Sglebius * 15269577Sglebius * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16269577Sglebius * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17269577Sglebius * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18269577Sglebius * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19269577Sglebius * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20269577Sglebius * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21269577Sglebius * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22269577Sglebius * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23269577Sglebius * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24269577Sglebius * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25269577Sglebius * SUCH DAMAGE. 26269577Sglebius */ 27269577Sglebius 28269577Sglebius#include <sys/cdefs.h> 29269577Sglebius__FBSDID("$FreeBSD: stable/11/sys/kern/subr_sfbuf.c 313989 2017-02-20 10:44:24Z kib $"); 30269577Sglebius 31269577Sglebius#include <sys/param.h> 32269577Sglebius#include <sys/kernel.h> 33269577Sglebius#include <sys/lock.h> 34269577Sglebius#include <sys/malloc.h> 35269577Sglebius#include <sys/mutex.h> 36313989Skib#include <sys/proc.h> 37269577Sglebius#include <sys/sf_buf.h> 38269577Sglebius#include <sys/smp.h> 39269577Sglebius#include <sys/sysctl.h> 40269577Sglebius 41269577Sglebius#include <vm/vm.h> 42269577Sglebius#include <vm/vm_extern.h> 43269577Sglebius#include <vm/vm_page.h> 44269577Sglebius 45269577Sglebius#ifndef NSFBUFS 46269577Sglebius#define NSFBUFS (512 + maxusers * 16) 47269577Sglebius#endif 48269577Sglebius 49269577Sglebiusstatic int nsfbufs; 50269577Sglebiusstatic int nsfbufspeak; 51269577Sglebiusstatic int nsfbufsused; 52269577Sglebius 53269577SglebiusSYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufs, CTLFLAG_RDTUN, &nsfbufs, 0, 54269577Sglebius "Maximum number of sendfile(2) sf_bufs available"); 55269577SglebiusSYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufspeak, CTLFLAG_RD, &nsfbufspeak, 0, 56269577Sglebius "Number of sendfile(2) sf_bufs at peak usage"); 57269577SglebiusSYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufsused, CTLFLAG_RD, &nsfbufsused, 0, 58269577Sglebius "Number of sendfile(2) sf_bufs in use"); 59269577Sglebius 60269577Sglebiusstatic void sf_buf_init(void *arg); 61269577SglebiusSYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL); 62269577Sglebius 63269577SglebiusLIST_HEAD(sf_head, sf_buf); 64269577Sglebius 65269577Sglebius/* 66269577Sglebius * A hash table of active sendfile(2) buffers 67269577Sglebius */ 68269577Sglebiusstatic struct sf_head *sf_buf_active; 69269577Sglebiusstatic u_long sf_buf_hashmask; 70269577Sglebius 71269577Sglebius#define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask) 72269577Sglebius 73269577Sglebiusstatic TAILQ_HEAD(, sf_buf) sf_buf_freelist; 74269577Sglebiusstatic u_int sf_buf_alloc_want; 75269577Sglebius 76269577Sglebius/* 77269577Sglebius * A lock used to synchronize access to the hash table and free list 78269577Sglebius */ 79269577Sglebiusstatic struct mtx sf_buf_lock; 80269577Sglebius 81269577Sglebius/* 82269577Sglebius * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-)) 83269577Sglebius */ 84269577Sglebiusstatic void 85269577Sglebiussf_buf_init(void *arg) 86269577Sglebius{ 87269577Sglebius struct sf_buf *sf_bufs; 88269577Sglebius vm_offset_t sf_base; 89269577Sglebius int i; 90269577Sglebius 91269577Sglebius#ifdef SFBUF_OPTIONAL_DIRECT_MAP 92269577Sglebius if (SFBUF_OPTIONAL_DIRECT_MAP) 93269577Sglebius return; 94269577Sglebius#endif 95269577Sglebius 96269577Sglebius nsfbufs = NSFBUFS; 97269577Sglebius TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs); 98269577Sglebius 99269577Sglebius sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask); 100269577Sglebius TAILQ_INIT(&sf_buf_freelist); 101269577Sglebius sf_base = kva_alloc(nsfbufs * PAGE_SIZE); 102269577Sglebius sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, 103269808Sglebius M_WAITOK | M_ZERO); 104269577Sglebius for (i = 0; i < nsfbufs; i++) { 105269577Sglebius sf_bufs[i].kva = sf_base + i * PAGE_SIZE; 106269577Sglebius TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry); 107269577Sglebius } 108269577Sglebius sf_buf_alloc_want = 0; 109269577Sglebius mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF); 110269577Sglebius} 111269577Sglebius 112269577Sglebius/* 113269577Sglebius * Get an sf_buf from the freelist. May block if none are available. 114269577Sglebius */ 115269577Sglebiusstruct sf_buf * 116269577Sglebiussf_buf_alloc(struct vm_page *m, int flags) 117269577Sglebius{ 118269577Sglebius struct sf_head *hash_list; 119269577Sglebius struct sf_buf *sf; 120269577Sglebius int error; 121269577Sglebius 122269577Sglebius#ifdef SFBUF_OPTIONAL_DIRECT_MAP 123269577Sglebius if (SFBUF_OPTIONAL_DIRECT_MAP) 124269577Sglebius return ((struct sf_buf *)m); 125269577Sglebius#endif 126269577Sglebius 127269577Sglebius KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0, 128269577Sglebius ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned")); 129269577Sglebius hash_list = &sf_buf_active[SF_BUF_HASH(m)]; 130269577Sglebius mtx_lock(&sf_buf_lock); 131269577Sglebius LIST_FOREACH(sf, hash_list, list_entry) { 132269577Sglebius if (sf->m == m) { 133269577Sglebius sf->ref_count++; 134269577Sglebius if (sf->ref_count == 1) { 135269577Sglebius TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 136269577Sglebius nsfbufsused++; 137269577Sglebius nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 138269577Sglebius } 139269577Sglebius#if defined(SMP) && defined(SFBUF_CPUSET) 140269577Sglebius sf_buf_shootdown(sf, flags); 141269577Sglebius#endif 142269577Sglebius goto done; 143269577Sglebius } 144269577Sglebius } 145269577Sglebius while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) { 146269577Sglebius if (flags & SFB_NOWAIT) 147269577Sglebius goto done; 148269577Sglebius sf_buf_alloc_want++; 149269577Sglebius SFSTAT_INC(sf_allocwait); 150269577Sglebius error = msleep(&sf_buf_freelist, &sf_buf_lock, 151269577Sglebius (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0); 152269577Sglebius sf_buf_alloc_want--; 153269577Sglebius 154269577Sglebius /* 155269577Sglebius * If we got a signal, don't risk going back to sleep. 156269577Sglebius */ 157269577Sglebius if (error) 158269577Sglebius goto done; 159269577Sglebius } 160269577Sglebius TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 161269577Sglebius if (sf->m != NULL) 162269577Sglebius LIST_REMOVE(sf, list_entry); 163269577Sglebius LIST_INSERT_HEAD(hash_list, sf, list_entry); 164269577Sglebius sf->ref_count = 1; 165269577Sglebius sf->m = m; 166269577Sglebius nsfbufsused++; 167269577Sglebius nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 168269577Sglebius sf_buf_map(sf, flags); 169269577Sglebiusdone: 170269577Sglebius mtx_unlock(&sf_buf_lock); 171269577Sglebius return (sf); 172269577Sglebius} 173269577Sglebius 174269577Sglebius/* 175269577Sglebius * Remove a reference from the given sf_buf, adding it to the free 176269577Sglebius * list when its reference count reaches zero. A freed sf_buf still, 177269577Sglebius * however, retains its virtual-to-physical mapping until it is 178269577Sglebius * recycled or reactivated by sf_buf_alloc(9). 179269577Sglebius */ 180269577Sglebiusvoid 181269577Sglebiussf_buf_free(struct sf_buf *sf) 182269577Sglebius{ 183269577Sglebius 184269577Sglebius#ifdef SFBUF_OPTIONAL_DIRECT_MAP 185269577Sglebius if (SFBUF_OPTIONAL_DIRECT_MAP) 186269577Sglebius return; 187269577Sglebius#endif 188269577Sglebius 189269577Sglebius mtx_lock(&sf_buf_lock); 190269577Sglebius sf->ref_count--; 191269577Sglebius if (sf->ref_count == 0) { 192269577Sglebius TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry); 193269577Sglebius nsfbufsused--; 194269577Sglebius if (sf_buf_unmap(sf)) { 195269577Sglebius sf->m = NULL; 196269577Sglebius LIST_REMOVE(sf, list_entry); 197269577Sglebius } 198269577Sglebius if (sf_buf_alloc_want > 0) 199269577Sglebius wakeup(&sf_buf_freelist); 200269577Sglebius } 201269577Sglebius mtx_unlock(&sf_buf_lock); 202269577Sglebius} 203269577Sglebius 204269807Sglebiusvoid 205269807Sglebiussf_buf_ref(struct sf_buf *sf) 206269807Sglebius{ 207269807Sglebius 208269807Sglebius#ifdef SFBUF_OPTIONAL_DIRECT_MAP 209269807Sglebius if (SFBUF_OPTIONAL_DIRECT_MAP) 210269807Sglebius return; 211269807Sglebius#endif 212269807Sglebius 213269813Sglebius mtx_lock(&sf_buf_lock); 214269807Sglebius KASSERT(sf->ref_count > 0, ("%s: sf %p not allocated", __func__, sf)); 215269807Sglebius sf->ref_count++; 216269807Sglebius mtx_unlock(&sf_buf_lock); 217269807Sglebius} 218269807Sglebius 219269577Sglebius#ifdef SFBUF_PROCESS_PAGE 220269577Sglebius/* 221269577Sglebius * Run callback function on sf_buf that holds a certain page. 222269577Sglebius */ 223269577Sglebiusboolean_t 224269577Sglebiussf_buf_process_page(vm_page_t m, void (*cb)(struct sf_buf *)) 225269577Sglebius{ 226269577Sglebius struct sf_head *hash_list; 227269577Sglebius struct sf_buf *sf; 228269577Sglebius 229269577Sglebius hash_list = &sf_buf_active[SF_BUF_HASH(m)]; 230269577Sglebius mtx_lock(&sf_buf_lock); 231269577Sglebius LIST_FOREACH(sf, hash_list, list_entry) { 232269577Sglebius if (sf->m == m) { 233269577Sglebius cb(sf); 234269577Sglebius mtx_unlock(&sf_buf_lock); 235269577Sglebius return (TRUE); 236269577Sglebius } 237269577Sglebius } 238269577Sglebius mtx_unlock(&sf_buf_lock); 239269577Sglebius return (FALSE); 240269577Sglebius} 241269577Sglebius#endif /* SFBUF_PROCESS_PAGE */ 242