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| 1 | /* Driver for USB Mass Storage compliant devices | |||
| 2 | * | |||
| 3 | * $Id: protocol.c,v 1.14 2002/04/22 03:39:43 mdharm Exp $ | |||
| 4 | * | |||
| 5 | * Current development and maintenance by: | |||
| 6 | * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net) | |||
| 7 | * | |||
| 8 | * Developed with the assistance of: | |||
| 9 | * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org) | |||
| 10 | * (c) 2002 Alan Stern (stern@rowland.org) | |||
| 11 | * | |||
| 12 | * Initial work by: | |||
| 13 | * (c) 1999 Michael Gee (michael@linuxspecific.com) | |||
| 14 | * | |||
| 15 | * This driver is based on the 'USB Mass Storage Class' document. This | |||
| 16 | * describes in detail the protocol used to communicate with such | |||
| 17 | * devices. Clearly, the designers had SCSI and ATAPI commands in | |||
| 18 | * mind when they created this document. The commands are all very | |||
| 19 | * similar to commands in the SCSI-II and ATAPI specifications. | |||
| 20 | * | |||
| 21 | * It is important to note that in a number of cases this class | |||
| 22 | * exhibits class-specific exemptions from the USB specification. | |||
| 23 | * Notably the usage of NAK, STALL and ACK differs from the norm, in | |||
| 24 | * that they are used to communicate wait, failed and OK on commands. | |||
| 25 | * | |||
| 26 | * Also, for certain devices, the interrupt endpoint is used to convey | |||
| 27 | * status of a command. | |||
| 28 | * | |||
| 29 | * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more | |||
| 30 | * information about this driver. | |||
| 31 | * | |||
| 32 | * This program is free software; you can redistribute it and/or modify it | |||
| 33 | * under the terms of the GNU General Public License as published by the | |||
| 34 | * Free Software Foundation; either version 2, or (at your option) any | |||
| 35 | * later version. | |||
| 36 | * | |||
| 37 | * This program is distributed in the hope that it will be useful, but | |||
| 38 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |||
| 39 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |||
| 40 | * General Public License for more details. | |||
| 41 | * | |||
| 42 | * You should have received a copy of the GNU General Public License along | |||
| 43 | * with this program; if not, write to the Free Software Foundation, Inc., | |||
| 44 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |||
| 45 | */ | |||
| 46 | ||||
| 47 | #include <linux/highmem.h> | |||
| 48 | #include <scsi/scsi.h> | |||
| 49 | #include <scsi/scsi_cmnd.h> | |||
| 50 | ||||
| 51 | #include "usb.h" | |||
| 52 | #include "protocol.h" | |||
| 53 | #include "debug.h" | |||
| 54 | #include "scsiglue.h" | |||
| 55 | #include "transport.h" | |||
| 56 | ||||
| 57 | /*********************************************************************** | |||
| 58 | * Protocol routines | |||
| 59 | ***********************************************************************/ | |||
| 60 | ||||
| 0 | 0 | - | 61 | void usb_stor_qic157_command(struct scsi_cmnd *srb, struct us_data *us) |
| 62 | { | |||
| 63 | /* Pad the ATAPI command with zeros | |||
| 64 | * | |||
| 65 | * NOTE: This only works because a scsi_cmnd struct field contains | |||
| 66 | * a unsigned char cmnd[16], so we know we have storage available | |||
| 67 | */ | |||
| 0 | 0 | - | 68 | for (; srb->cmd_len<12; srb->cmd_len++) |
| 69 | srb->cmnd[srb->cmd_len] = 0; | |||
| 70 | ||||
| 71 | /* set command length to 12 bytes */ | |||
| 72 | srb->cmd_len = 12; | |||
| 73 | ||||
| 74 | /* send the command to the transport layer */ | |||
| 75 | usb_stor_invoke_transport(srb, us); | |||
| 76 | } | |||
| 77 | ||||
| 0 | 0 | - | 78 | void usb_stor_ATAPI_command(struct scsi_cmnd *srb, struct us_data *us) |
| 79 | { | |||
| 80 | /* Pad the ATAPI command with zeros | |||
| 81 | * | |||
| 82 | * NOTE: This only works because a scsi_cmnd struct field contains | |||
| 83 | * a unsigned char cmnd[16], so we know we have storage available | |||
| 84 | */ | |||
| 85 | ||||
| 86 | /* Pad the ATAPI command with zeros */ | |||
| 0 | 0 | - | 87 | for (; srb->cmd_len<12; srb->cmd_len++) |
| 88 | srb->cmnd[srb->cmd_len] = 0; | |||
| 89 | ||||
| 90 | /* set command length to 12 bytes */ | |||
| 91 | srb->cmd_len = 12; | |||
| 92 | ||||
| 93 | /* send the command to the transport layer */ | |||
| 94 | usb_stor_invoke_transport(srb, us); | |||
| 95 | } | |||
| 96 | ||||
| 97 | ||||
| 0 | 0 | - | 98 | void usb_stor_ufi_command(struct scsi_cmnd *srb, struct us_data *us) |
| 99 | { | |||
| 100 | /* fix some commands -- this is a form of mode translation | |||
| 101 | * UFI devices only accept 12 byte long commands | |||
| 102 | * | |||
| 103 | * NOTE: This only works because a scsi_cmnd struct field contains | |||
| 104 | * a unsigned char cmnd[16], so we know we have storage available | |||
| 105 | */ | |||
| 106 | ||||
| 107 | /* Pad the ATAPI command with zeros */ | |||
| 0 | 0 | - | 108 | for (; srb->cmd_len<12; srb->cmd_len++) |
| 109 | srb->cmnd[srb->cmd_len] = 0; | |||
| 110 | ||||
| 111 | /* set command length to 12 bytes (this affects the transport layer) */ | |||
| 112 | srb->cmd_len = 12; | |||
| 113 | ||||
| 114 | /* XXX We should be constantly re-evaluating the need for these */ | |||
| 115 | ||||
| 116 | /* determine the correct data length for these commands */ | |||
| 117 | switch (srb->cmnd[0]) { | |||
| 118 | ||||
| 119 | /* for INQUIRY, UFI devices only ever return 36 bytes */ | |||
| 0 | - | 120 | case INQUIRY: | |
| 121 | srb->cmnd[4] = 36; | |||
| 0 | - | 122 | break; | |
| 123 | ||||
| 124 | /* again, for MODE_SENSE_10, we get the minimum (8) */ | |||
| 0 | - | 125 | case MODE_SENSE_10: | |
| 126 | srb->cmnd[7] = 0; | |||
| 127 | srb->cmnd[8] = 8; | |||
| 0 | - | 128 | break; | |
| 129 | ||||
| 130 | /* for REQUEST_SENSE, UFI devices only ever return 18 bytes */ | |||
| 0 | - | 131 | case REQUEST_SENSE: | |
| 132 | srb->cmnd[4] = 18; | |||
| 0 | - | 133 | break; | |
| 134 | } /* end switch on cmnd[0] */ | |||
| 135 | ||||
| 136 | /* send the command to the transport layer */ | |||
| 137 | usb_stor_invoke_transport(srb, us); | |||
| 138 | } | |||
| 139 | ||||
| 2056 | 2056 | 140 | void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb, | |
| 141 | struct us_data *us) | |||
| 142 | { | |||
| 143 | /* send the command to the transport layer */ | |||
| 144 | usb_stor_invoke_transport(srb, us); | |||
| 145 | } | |||
| 146 | ||||
| 147 | /*********************************************************************** | |||
| 148 | * Scatter-gather transfer buffer access routines | |||
| 149 | ***********************************************************************/ | |||
| 150 | ||||
| 151 | /* Copy a buffer of length buflen to/from the srb's transfer buffer. | |||
| 152 | * (Note: for scatter-gather transfers (srb->use_sg > 0), srb->request_buffer | |||
| 153 | * points to a list of s-g entries and we ignore srb->request_bufflen. | |||
| 154 | * For non-scatter-gather transfers, srb->request_buffer points to the | |||
| 155 | * transfer buffer itself and srb->request_bufflen is the buffer's length.) | |||
| 156 | * Update the *index and *offset variables so that the next copy will | |||
| 157 | * pick up from where this one left off. */ | |||
| 158 | ||||
| 0 | 0 | - | 159 | unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, |
| 160 | unsigned int buflen, struct scsi_cmnd *srb, unsigned int *index, | |||
| 161 | unsigned int *offset, enum xfer_buf_dir dir) | |||
| 162 | { | |||
| 163 | unsigned int cnt; | |||
| 164 | ||||
| 165 | /* If not using scatter-gather, just transfer the data directly. | |||
| 166 | * Make certain it will fit in the available buffer space. */ | |||
| 0 | 0 | - | 167 | if (srb->use_sg == 0) { |
| 0 | 0 | - | 168 | if (*offset >= srb->request_bufflen) |
| 0 | - | 169 | return 0; | |
| 170 | cnt = min(buflen, srb->request_bufflen - *offset); | |||
| 0 | 0 | - | 171 | if (dir == TO_XFER_BUF) |
| 172 | memcpy((unsigned char *) srb->request_buffer + *offset, | |||
| 173 | buffer, cnt); | |||
| 174 | else | |||
| 175 | memcpy(buffer, (unsigned char *) srb->request_buffer + | |||
| 176 | *offset, cnt); | |||
| 177 | *offset += cnt; | |||
| 178 | ||||
| 179 | /* Using scatter-gather. We have to go through the list one entry | |||
| 180 | * at a time. Each s-g entry contains some number of pages, and | |||
| 181 | * each page has to be kmap()'ed separately. If the page is already | |||
| 182 | * in kernel-addressable memory then kmap() will return its address. | |||
| 183 | * If the page is not directly accessible -- such as a user buffer | |||
| 184 | * located in high memory -- then kmap() will map it to a temporary | |||
| 185 | * position in the kernel's virtual address space. */ | |||
| 186 | } else { | |||
| 187 | struct scatterlist *sg = | |||
| 188 | (struct scatterlist *) srb->request_buffer | |||
| 189 | + *index; | |||
| 190 | ||||
| 191 | /* This loop handles a single s-g list entry, which may | |||
| 192 | * include multiple pages. Find the initial page structure | |||
| 193 | * and the starting offset within the page, and update | |||
| 194 | * the *offset and *index values for the next loop. */ | |||
| 195 | cnt = 0; | |||
| 0 | 0 | - | 196 | while (cnt < buflen && *index < srb->use_sg) { |
| 0 | - | 196 | T && T | |
| 0 | - | 196 | T && F | |
| 0 | - | 196 | F && _ | |
| 197 | struct page *page = sg->page + | |||
| 198 | ((sg->offset + *offset) >> PAGE_SHIFT); | |||
| 199 | unsigned int poff = | |||
| 200 | (sg->offset + *offset) & (PAGE_SIZE-1); | |||
| 201 | unsigned int sglen = sg->length - *offset; | |||
| 202 | ||||
| 0 | 0 | - | 203 | if (sglen > buflen - cnt) { |
| 204 | ||||
| 205 | /* Transfer ends within this s-g entry */ | |||
| 206 | sglen = buflen - cnt; | |||
| 207 | *offset += sglen; | |||
| 208 | } else { | |||
| 209 | ||||
| 210 | /* Transfer continues to next s-g entry */ | |||
| 211 | *offset = 0; | |||
| 212 | ++*index; | |||
| 213 | ++sg; | |||
| 214 | } | |||
| 215 | ||||
| 216 | /* Transfer the data for all the pages in this | |||
| 217 | * s-g entry. For each page: call kmap(), do the | |||
| 218 | * transfer, and call kunmap() immediately after. */ | |||
| 0 | 0 | - | 219 | while (sglen > 0) { |
| 220 | unsigned int plen = min(sglen, (unsigned int) | |||
| 221 | PAGE_SIZE - poff); | |||
| 222 | unsigned char *ptr = kmap(page); | |||
| 223 | ||||
| 0 | 0 | - | 224 | if (dir == TO_XFER_BUF) |
| 225 | memcpy(ptr + poff, buffer + cnt, plen); | |||
| 226 | else | |||
| 227 | memcpy(buffer + cnt, ptr + poff, plen); | |||
| 228 | kunmap(page); | |||
| 0 | 0 | - | 228 | do-while (0) |
| 229 | ||||
| 230 | /* Start at the beginning of the next page */ | |||
| 231 | poff = 0; | |||
| 232 | ++page; | |||
| 233 | cnt += plen; | |||
| 234 | sglen -= plen; | |||
| 235 | } | |||
| 236 | } | |||
| 237 | } | |||
| 238 | ||||
| 239 | /* Return the amount actually transferred */ | |||
| 0 | - | 240 | return cnt; | |
| 241 | } | |||
| 242 | ||||
| 243 | /* Store the contents of buffer into srb's transfer buffer and set the | |||
| 244 | * SCSI residue. */ | |||
| 0 | 0 | - | 245 | void usb_stor_set_xfer_buf(unsigned char *buffer, |
| 246 | unsigned int buflen, struct scsi_cmnd *srb) | |||
| 247 | { | |||
| 248 | unsigned int index = 0, offset = 0; | |||
| 249 | ||||
| 250 | usb_stor_access_xfer_buf(buffer, buflen, srb, &index, &offset, | |||
| 251 | TO_XFER_BUF); | |||
| 0 | 0 | - | 252 | if (buflen < srb->request_bufflen) |
| 253 | srb->resid = srb->request_bufflen - buflen; | |||
| 254 | } | |||
| ***TER 2% (1/41) of SOURCE FILE protocol.c | ||||