1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2014 Gleb Smirnoff <glebius@FreeBSD.org> 5 * Copyright (c) 2003-2004 Alan L. Cox <alc@cs.rice.edu> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#ifndef _SYS_SF_BUF_H_ 31#define _SYS_SF_BUF_H_ 32 33struct sfstat { /* sendfile statistics */ 34 uint64_t sf_syscalls; /* times sendfile was called */ 35 uint64_t sf_noiocnt; /* times sendfile didn't require I/O */ 36 uint64_t sf_iocnt; /* times sendfile had to do disk I/O */ 37 uint64_t sf_pages_read; /* pages read as part of a request */ 38 uint64_t sf_pages_valid; /* pages were valid for a request */ 39 uint64_t sf_rhpages_requested; /* readahead pages requested */ 40 uint64_t sf_rhpages_read; /* readahead pages read */ 41 uint64_t sf_busy; /* times aborted on a busy page */ 42 uint64_t sf_allocfail; /* times sfbuf allocation failed */ 43 uint64_t sf_allocwait; /* times sfbuf allocation had to wait */ 44 uint64_t sf_pages_bogus; /* times bogus page was used */ 45}; 46 47#ifdef _KERNEL 48#include <sys/types.h> 49#include <sys/systm.h> 50#include <sys/counter.h> 51#include <vm/vm.h> 52#include <vm/vm_param.h> 53#include <vm/vm_page.h> 54 55/* 56 * Sf_bufs, or sendfile(2) buffers provide a vm_page that is mapped 57 * into kernel address space. Note, that they aren't used only 58 * by sendfile(2)! 59 * 60 * Sf_bufs could be implemented as a feature of vm_page_t, but that 61 * would require growth of the structure. That's why they are implemented 62 * as a separate hash indexed by vm_page address. Implementation lives in 63 * kern/subr_sfbuf.c. Meanwhile, most 64-bit machines have a physical map, 64 * so they don't require this hash at all, thus ignore subr_sfbuf.c. 65 * 66 * Different 32-bit architectures demand different requirements on sf_buf 67 * hash and functions. They request features in machine/vmparam.h, which 68 * enable parts of this file. They can also optionally provide helpers in 69 * machine/sf_buf.h 70 * 71 * Defines are: 72 * SFBUF This machine requires sf_buf hash. 73 * subr_sfbuf.c should be compiled. 74 * SFBUF_CPUSET This machine can perform SFB_CPUPRIVATE mappings, 75 * that do no invalidate cache on the rest of CPUs. 76 * SFBUF_NOMD This machine doesn't have machine/sf_buf.h 77 * 78 * SFBUF_MAP This machine provides its own sf_buf_map() and 79 * sf_buf_unmap(). 80 * SFBUF_PROCESS_PAGE This machine provides sf_buf_process_page() 81 * function. 82 */ 83 84#ifdef SFBUF 85#if defined(SMP) && defined(SFBUF_CPUSET) 86#include <sys/_cpuset.h> 87#endif 88#include <sys/queue.h> 89 90struct sf_buf { 91 LIST_ENTRY(sf_buf) list_entry; /* list of buffers */ 92 TAILQ_ENTRY(sf_buf) free_entry; /* list of buffers */ 93 vm_page_t m; /* currently mapped page */ 94 vm_offset_t kva; /* va of mapping */ 95 int ref_count; /* usage of this mapping */ 96#if defined(SMP) && defined(SFBUF_CPUSET) 97 cpuset_t cpumask; /* where mapping is valid */ 98#endif 99}; 100#else /* ! SFBUF */ 101struct sf_buf; 102#endif /* SFBUF */ 103 104#ifndef SFBUF_NOMD 105#include <machine/sf_buf.h> 106#endif 107 108#ifdef SFBUF 109struct sf_buf *sf_buf_alloc(struct vm_page *, int); 110void sf_buf_free(struct sf_buf *); 111void sf_buf_ref(struct sf_buf *); 112 113static inline vm_offset_t 114sf_buf_kva(struct sf_buf *sf) 115{ 116 if (PMAP_HAS_DMAP) 117 return (PHYS_TO_DMAP(VM_PAGE_TO_PHYS((vm_page_t)sf))); 118 119 return (sf->kva); 120} 121 122static inline vm_page_t 123sf_buf_page(struct sf_buf *sf) 124{ 125 if (PMAP_HAS_DMAP) 126 return ((vm_page_t)sf); 127 128 return (sf->m); 129} 130 131#ifndef SFBUF_MAP 132#include <vm/pmap.h> 133 134static inline void 135sf_buf_map(struct sf_buf *sf, int flags) 136{ 137 138 pmap_qenter(sf->kva, &sf->m, 1); 139} 140 141static inline int 142sf_buf_unmap(struct sf_buf *sf) 143{ 144 145 return (0); 146} 147#endif /* SFBUF_MAP */ 148 149#if defined(SMP) && defined(SFBUF_CPUSET) 150void sf_buf_shootdown(struct sf_buf *, int); 151#endif 152 153#ifdef SFBUF_PROCESS_PAGE 154boolean_t sf_buf_process_page(vm_page_t, void (*)(struct sf_buf *)); 155#endif 156 157#else /* ! SFBUF */ 158 159static inline struct sf_buf * 160sf_buf_alloc(struct vm_page *m, int pri) 161{ 162 163 return ((struct sf_buf *)m); 164} 165 166static inline void 167sf_buf_free(struct sf_buf *sf) 168{ 169} 170 171static inline void 172sf_buf_ref(struct sf_buf *sf) 173{ 174} 175#endif /* SFBUF */ 176 177/* 178 * Options to sf_buf_alloc() are specified through its flags argument. This 179 * argument's value should be the result of a bitwise or'ing of one or more 180 * of the following values. 181 */ 182#define SFB_CATCH 1 /* Check signals if the allocation 183 sleeps. */ 184#define SFB_CPUPRIVATE 2 /* Create a CPU private mapping. */ 185#define SFB_DEFAULT 0 186#define SFB_NOWAIT 4 /* Return NULL if all bufs are used. */ 187 188extern counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; 189#define SFSTAT_ADD(name, val) \ 190 counter_u64_add(sfstat[offsetof(struct sfstat, name) / sizeof(uint64_t)],\ 191 (val)) 192#define SFSTAT_INC(name) SFSTAT_ADD(name, 1) 193#endif /* _KERNEL */ 194#endif /* !_SYS_SF_BUF_H_ */ 195