1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 30 */ 31 32 #ifndef _SYS_SF_BUF_H_ 33 #define _SYS_SF_BUF_H_ 34 35 struct sfstat { /* sendfile statistics */ 36 uint64_t sf_syscalls; /* times sendfile was called */ 37 uint64_t sf_noiocnt; /* times sendfile didn't require I/O */ 38 uint64_t sf_iocnt; /* times sendfile had to do disk I/O */ 39 uint64_t sf_pages_read; /* pages read as part of a request */ 40 uint64_t sf_pages_valid; /* pages were valid for a request */ 41 uint64_t sf_rhpages_requested; /* readahead pages requested */ 42 uint64_t sf_rhpages_read; /* readahead pages read */ 43 uint64_t sf_busy; /* times aborted on a busy page */ 44 uint64_t sf_allocfail; /* times sfbuf allocation failed */ 45 uint64_t sf_allocwait; /* times sfbuf allocation had to wait */ 46 uint64_t sf_pages_bogus; /* times bogus page was used */ 47 }; 48 49 #ifdef _KERNEL 50 #include <sys/types.h> 51 #include <sys/systm.h> 52 #include <sys/counter.h> 53 #include <vm/vm.h> 54 #include <vm/vm_param.h> 55 #include <vm/vm_page.h> 56 57 /* 58 * Sf_bufs, or sendfile(2) buffers provide a vm_page that is mapped 59 * into kernel address space. Note, that they aren't used only 60 * by sendfile(2)! 61 * 62 * Sf_bufs could be implemented as a feature of vm_page_t, but that 63 * would require growth of the structure. That's why they are implemented 64 * as a separate hash indexed by vm_page address. Implementation lives in 65 * kern/subr_sfbuf.c. Meanwhile, most 64-bit machines have a physical map, 66 * so they don't require this hash at all, thus ignore subr_sfbuf.c. 67 * 68 * Different 32-bit architectures demand different requirements on sf_buf 69 * hash and functions. They request features in machine/vmparam.h, which 70 * enable parts of this file. They can also optionally provide helpers in 71 * machine/sf_buf.h 72 * 73 * Defines are: 74 * SFBUF This machine requires sf_buf hash. 75 * subr_sfbuf.c should be compiled. 76 * SFBUF_CPUSET This machine can perform SFB_CPUPRIVATE mappings, 77 * that do no invalidate cache on the rest of CPUs. 78 * SFBUF_NOMD This machine doesn't have machine/sf_buf.h 79 * 80 * SFBUF_MAP This machine provides its own sf_buf_map() and 81 * sf_buf_unmap(). 82 * SFBUF_PROCESS_PAGE This machine provides sf_buf_process_page() 83 * function. 84 */ 85 86 #ifdef SFBUF 87 #if defined(SMP) && defined(SFBUF_CPUSET) 88 #include <sys/_cpuset.h> 89 #endif 90 #include <sys/queue.h> 91 92 struct sf_buf { 93 LIST_ENTRY(sf_buf) list_entry; /* list of buffers */ 94 TAILQ_ENTRY(sf_buf) free_entry; /* list of buffers */ 95 vm_page_t m; /* currently mapped page */ 96 vm_offset_t kva; /* va of mapping */ 97 int ref_count; /* usage of this mapping */ 98 #if defined(SMP) && defined(SFBUF_CPUSET) 99 cpuset_t cpumask; /* where mapping is valid */ 100 #endif 101 }; 102 #else /* ! SFBUF */ 103 struct sf_buf; 104 #endif /* SFBUF */ 105 106 #ifndef SFBUF_NOMD 107 #include <machine/sf_buf.h> 108 #endif 109 110 #ifdef SFBUF 111 struct sf_buf *sf_buf_alloc(struct vm_page *, int); 112 void sf_buf_free(struct sf_buf *); 113 void sf_buf_ref(struct sf_buf *); 114 115 static inline vm_offset_t 116 sf_buf_kva(struct sf_buf *sf) 117 { 118 if (PMAP_HAS_DMAP) 119 return (PHYS_TO_DMAP(VM_PAGE_TO_PHYS((vm_page_t)sf))); 120 121 return (sf->kva); 122 } 123 124 static inline vm_page_t 125 sf_buf_page(struct sf_buf *sf) 126 { 127 if (PMAP_HAS_DMAP) 128 return ((vm_page_t)sf); 129 130 return (sf->m); 131 } 132 133 #ifndef SFBUF_MAP 134 #include <vm/pmap.h> 135 136 static inline void 137 sf_buf_map(struct sf_buf *sf, int flags) 138 { 139 140 pmap_qenter(sf->kva, &sf->m, 1); 141 } 142 143 static inline int 144 sf_buf_unmap(struct sf_buf *sf) 145 { 146 147 return (0); 148 } 149 #endif /* SFBUF_MAP */ 150 151 #if defined(SMP) && defined(SFBUF_CPUSET) 152 void sf_buf_shootdown(struct sf_buf *, int); 153 #endif 154 155 #ifdef SFBUF_PROCESS_PAGE 156 boolean_t sf_buf_process_page(vm_page_t, void (*)(struct sf_buf *)); 157 #endif 158 159 #else /* ! SFBUF */ 160 161 static inline struct sf_buf * 162 sf_buf_alloc(struct vm_page *m, int pri) 163 { 164 165 return ((struct sf_buf *)m); 166 } 167 168 static inline void 169 sf_buf_free(struct sf_buf *sf) 170 { 171 } 172 173 static inline void 174 sf_buf_ref(struct sf_buf *sf) 175 { 176 } 177 #endif /* SFBUF */ 178 179 /* 180 * Options to sf_buf_alloc() are specified through its flags argument. This 181 * argument's value should be the result of a bitwise or'ing of one or more 182 * of the following values. 183 */ 184 #define SFB_CATCH 1 /* Check signals if the allocation 185 sleeps. */ 186 #define SFB_CPUPRIVATE 2 /* Create a CPU private mapping. */ 187 #define SFB_DEFAULT 0 188 #define SFB_NOWAIT 4 /* Return NULL if all bufs are used. */ 189 190 extern counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; 191 #define SFSTAT_ADD(name, val) \ 192 counter_u64_add(sfstat[offsetof(struct sfstat, name) / sizeof(uint64_t)],\ 193 (val)) 194 #define SFSTAT_INC(name) SFSTAT_ADD(name, 1) 195 #endif /* _KERNEL */ 196 #endif /* !_SYS_SF_BUF_H_ */ 197