sf_buf.h revision 270201
1/*- 2 * Copyright (c) 2014 Gleb Smirnoff <glebius@FreeBSD.org> 3 * Copyright (c) 2003-2004 Alan L. Cox <alc@cs.rice.edu> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: head/sys/sys/sf_buf.h 270201 2014-08-20 08:02:38Z kib $ 28 */ 29 30#ifndef _SYS_SF_BUF_H_ 31#define _SYS_SF_BUF_H_ 32 33struct sfstat { /* sendfile statistics */ 34 uint64_t sf_iocnt; /* times sendfile had to do disk I/O */ 35 uint64_t sf_allocfail; /* times sfbuf allocation failed */ 36 uint64_t sf_allocwait; /* times sfbuf allocation had to wait */ 37}; 38 39#ifdef _KERNEL 40#include <sys/types.h> 41#include <sys/systm.h> 42#include <sys/counter.h> 43#include <vm/vm.h> 44#include <vm/vm_param.h> 45#include <vm/vm_page.h> 46 47/* 48 * Sf_bufs, or sendfile(2) buffers provide a vm_page that is mapped 49 * into kernel address space. Note, that they aren't used only 50 * by sendfile(2)! 51 * 52 * Sf_bufs could be implemented as a feature of vm_page_t, but that 53 * would require growth of the structure. That's why they are implemented 54 * as a separate hash indexed by vm_page address. Implementation lives in 55 * kern/subr_sfbuf.c. Meanwhile, most 64-bit machines have a physical map, 56 * so they don't require this hash at all, thus ignore subr_sfbuf.c. 57 * 58 * Different 32-bit architectures demand different requirements on sf_buf 59 * hash and functions. They request features in machine/vmparam.h, which 60 * enable parts of this file. They can also optionally provide helpers in 61 * machine/sf_buf.h 62 * 63 * Defines are: 64 * SFBUF This machine requires sf_buf hash. 65 * subr_sfbuf.c should be compiled. 66 * SFBUF_CPUSET This machine can perform SFB_CPUPRIVATE mappings, 67 * that do no invalidate cache on the rest of CPUs. 68 * SFBUF_NOMD This machine doesn't have machine/sf_buf.h 69 * 70 * SFBUF_OPTIONAL_DIRECT_MAP Value of this define is used as boolean 71 * variable that tells whether machine is 72 * capable of direct map or not at runtime. 73 * SFBUF_MAP This machine provides its own sf_buf_map() and 74 * sf_buf_unmap(). 75 * SFBUF_PROCESS_PAGE This machine provides sf_buf_process_page() 76 * function. 77 */ 78 79#ifdef SFBUF 80#if defined(SMP) && defined(SFBUF_CPUSET) 81#include <sys/_cpuset.h> 82#endif 83#include <sys/queue.h> 84 85struct sf_buf { 86 LIST_ENTRY(sf_buf) list_entry; /* list of buffers */ 87 TAILQ_ENTRY(sf_buf) free_entry; /* list of buffers */ 88 vm_page_t m; /* currently mapped page */ 89 vm_offset_t kva; /* va of mapping */ 90 int ref_count; /* usage of this mapping */ 91#if defined(SMP) && defined(SFBUF_CPUSET) 92 cpuset_t cpumask; /* where mapping is valid */ 93#endif 94}; 95#else /* ! SFBUF */ 96struct sf_buf; 97#endif /* SFBUF */ 98 99#ifndef SFBUF_NOMD 100#include <machine/sf_buf.h> 101#endif 102#ifdef SFBUF_OPTIONAL_DIRECT_MAP 103#include <machine/md_var.h> 104#endif 105 106#ifdef SFBUF 107struct sf_buf *sf_buf_alloc(struct vm_page *, int); 108void sf_buf_free(struct sf_buf *); 109void sf_buf_ref(struct sf_buf *); 110 111static inline vm_offset_t 112sf_buf_kva(struct sf_buf *sf) 113{ 114#ifdef SFBUF_OPTIONAL_DIRECT_MAP 115 if (SFBUF_OPTIONAL_DIRECT_MAP) 116 return (SFBUF_PHYS_DMAP(VM_PAGE_TO_PHYS((vm_page_t)sf))); 117#endif 118 119 return (sf->kva); 120} 121 122static inline vm_page_t 123sf_buf_page(struct sf_buf *sf) 124{ 125#ifdef SFBUF_OPTIONAL_DIRECT_MAP 126 if (SFBUF_OPTIONAL_DIRECT_MAP) 127 return ((vm_page_t)sf); 128#endif 129 130 return (sf->m); 131} 132 133#ifndef SFBUF_MAP 134#include <vm/pmap.h> 135 136static inline void 137sf_buf_map(struct sf_buf *sf, int flags) 138{ 139 140 pmap_qenter(sf->kva, &sf->m, 1); 141} 142 143static inline int 144sf_buf_unmap(struct sf_buf *sf) 145{ 146 147 return (0); 148} 149#endif /* SFBUF_MAP */ 150 151#if defined(SMP) && defined(SFBUF_CPUSET) 152void sf_buf_shootdown(struct sf_buf *, int); 153#endif 154 155#ifdef SFBUF_PROCESS_PAGE 156boolean_t sf_buf_process_page(vm_page_t, void (*)(struct sf_buf *)); 157#endif 158 159#else /* ! SFBUF */ 160 161static inline struct sf_buf * 162sf_buf_alloc(struct vm_page *m, int pri) 163{ 164 165 return ((struct sf_buf *)m); 166} 167 168static inline void 169sf_buf_free(struct sf_buf *sf) 170{ 171} 172 173static inline void 174sf_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 190extern 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