1 /*- 2 * Copyright (c) 2013 Peter Grehan <grehan@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 /* 30 * The block API to be used by acrn-dm block-device emulations. The routines 31 * are thread safe, with no assumptions about the context of the completion 32 * callback - it may occur in the caller's context, or asynchronously in 33 * another thread. 34 */ 35 36 #ifndef _BLOCK_IF_H_ 37 #define _BLOCK_IF_H_ 38 39 #include <sys/uio.h> 40 #include <sys/unistd.h> 41 42 #include "iothread.h" 43 44 #define BLOCKIF_IOV_MAX 256 /* not practical to be IOV_MAX */ 45 46 /* 47 * |<------------------------------------- bounced_size --------------------------------->| 48 * |<-------- alignment ------->| |<-------- alignment ------->| 49 * |<--- head --->|<------------------------ org_size ---------------------->|<-- tail -->| 50 * | | | | | | 51 * *--------------$-------------*----------- ... ------------*---------------$------------* 52 * | | | | | | 53 * | start end | 54 * aligned_dn_start aligned_dn_end 55 * |__________head_area_________| |__________tail_area_________| 56 * |<--- head --->| | |<-- end_rmd -->|<-- tail -->| 57 * |<-------- alignment ------->| |<-------- alignment ------->| 58 * 59 */ 60 struct br_align_info { 61 uint32_t alignment; 62 63 bool is_iov_base_aligned; 64 bool is_iov_len_aligned; 65 bool is_offset_aligned; 66 67 /* 68 * Needs to convert the misaligned request to an aligned one when 69 * O_DIRECT is used, but the request (either buffer address/length, or offset) is not aligned. 70 */ 71 bool need_conversion; 72 73 uint32_t head; 74 uint32_t tail; 75 uint32_t org_size; 76 uint32_t bounced_size; 77 78 off_t aligned_dn_start; 79 off_t aligned_dn_end; 80 81 /* 82 * A bounce_iov for aligned read/write access. 83 * bounce_iov.iov_base is aligned to @alignment 84 * bounce_iov.iov_len is @bounced_size (@head + @org_size + @tail) 85 */ 86 struct iovec bounce_iov; 87 }; 88 89 struct blockif_req { 90 struct iovec iov[BLOCKIF_IOV_MAX]; 91 int iovcnt; 92 off_t offset; 93 ssize_t resid; 94 void (*callback)(struct blockif_req *req, int err); 95 void *param; 96 int qidx; 97 98 struct br_align_info align_info; 99 }; 100 101 struct blockif_ctxt; 102 struct blockif_ctxt *blockif_open(const char *optstr, const char *ident, int queue_num, 103 struct iothreads_info *iothrds_info); 104 off_t blockif_size(struct blockif_ctxt *bc); 105 void blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, 106 uint8_t *s); 107 int blockif_sectsz(struct blockif_ctxt *bc); 108 void blockif_psectsz(struct blockif_ctxt *bc, int *size, int *off); 109 int blockif_queuesz(struct blockif_ctxt *bc); 110 int blockif_is_ro(struct blockif_ctxt *bc); 111 int blockif_candiscard(struct blockif_ctxt *bc); 112 int blockif_read(struct blockif_ctxt *bc, struct blockif_req *breq); 113 int blockif_write(struct blockif_ctxt *bc, struct blockif_req *breq); 114 int blockif_flush(struct blockif_ctxt *bc, struct blockif_req *breq); 115 int blockif_discard(struct blockif_ctxt *bc, struct blockif_req *breq); 116 int blockif_cancel(struct blockif_ctxt *bc, struct blockif_req *breq); 117 int blockif_close(struct blockif_ctxt *bc); 118 uint8_t blockif_get_wce(struct blockif_ctxt *bc); 119 void blockif_set_wce(struct blockif_ctxt *bc, uint8_t wce); 120 int blockif_flush_all(struct blockif_ctxt *bc); 121 int blockif_max_discard_sectors(struct blockif_ctxt *bc); 122 int blockif_max_discard_seg(struct blockif_ctxt *bc); 123 int blockif_discard_sector_alignment(struct blockif_ctxt *bc); 124 125 #endif /* _BLOCK_IF_H_ */ 126