1/* 2 * SCSI target kernel/user interface functions 3 * 4 * Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org> 5 * Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License as 9 * published by the Free Software Foundation; either version 2 of the 10 * License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 20 * 02110-1301 USA 21 */ 22#include <linux/miscdevice.h> 23#include <linux/file.h> 24#include <net/tcp.h> 25#include <scsi/scsi.h> 26#include <scsi/scsi_cmnd.h> 27#include <scsi/scsi_device.h> 28#include <scsi/scsi_host.h> 29#include <scsi/scsi_tgt.h> 30#include <scsi/scsi_tgt_if.h> 31 32#include <asm/cacheflush.h> 33 34#include "scsi_tgt_priv.h" 35 36#if TGT_RING_SIZE < PAGE_SIZE 37# define TGT_RING_SIZE PAGE_SIZE 38#endif 39 40#define TGT_RING_PAGES (TGT_RING_SIZE >> PAGE_SHIFT) 41#define TGT_EVENT_PER_PAGE (PAGE_SIZE / sizeof(struct tgt_event)) 42#define TGT_MAX_EVENTS (TGT_EVENT_PER_PAGE * TGT_RING_PAGES) 43 44struct tgt_ring { 45 u32 tr_idx; 46 unsigned long tr_pages[TGT_RING_PAGES]; 47 spinlock_t tr_lock; 48}; 49 50/* tx_ring : kernel->user, rx_ring : user->kernel */ 51static struct tgt_ring tx_ring, rx_ring; 52static DECLARE_WAIT_QUEUE_HEAD(tgt_poll_wait); 53 54static inline void tgt_ring_idx_inc(struct tgt_ring *ring) 55{ 56 if (ring->tr_idx == TGT_MAX_EVENTS - 1) 57 ring->tr_idx = 0; 58 else 59 ring->tr_idx++; 60} 61 62static struct tgt_event *tgt_head_event(struct tgt_ring *ring, u32 idx) 63{ 64 u32 pidx, off; 65 66 pidx = idx / TGT_EVENT_PER_PAGE; 67 off = idx % TGT_EVENT_PER_PAGE; 68 69 return (struct tgt_event *) 70 (ring->tr_pages[pidx] + sizeof(struct tgt_event) * off); 71} 72 73static int tgt_uspace_send_event(u32 type, struct tgt_event *p) 74{ 75 struct tgt_event *ev; 76 struct tgt_ring *ring = &tx_ring; 77 unsigned long flags; 78 int err = 0; 79 80 spin_lock_irqsave(&ring->tr_lock, flags); 81 82 ev = tgt_head_event(ring, ring->tr_idx); 83 if (!ev->hdr.status) 84 tgt_ring_idx_inc(ring); 85 else 86 err = -BUSY; 87 88 spin_unlock_irqrestore(&ring->tr_lock, flags); 89 90 if (err) 91 return err; 92 93 memcpy(ev, p, sizeof(*ev)); 94 ev->hdr.type = type; 95 mb(); 96 ev->hdr.status = 1; 97 98 flush_dcache_page(virt_to_page(ev)); 99 100 wake_up_interruptible(&tgt_poll_wait); 101 102 return 0; 103} 104 105int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 tag) 106{ 107 struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); 108 struct tgt_event ev; 109 int err; 110 111 memset(&ev, 0, sizeof(ev)); 112 ev.p.cmd_req.host_no = shost->host_no; 113 ev.p.cmd_req.data_len = cmd->request_bufflen; 114 memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb)); 115 memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun)); 116 ev.p.cmd_req.attribute = cmd->tag; 117 ev.p.cmd_req.tag = tag; 118 119 dprintk("%p %d %u %x %llx\n", cmd, shost->host_no, 120 ev.p.cmd_req.data_len, cmd->tag, 121 (unsigned long long) ev.p.cmd_req.tag); 122 123 err = tgt_uspace_send_event(TGT_KEVENT_CMD_REQ, &ev); 124 if (err) 125 eprintk("tx buf is full, could not send\n"); 126 127 return err; 128} 129 130int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag) 131{ 132 struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); 133 struct tgt_event ev; 134 int err; 135 136 memset(&ev, 0, sizeof(ev)); 137 ev.p.cmd_done.host_no = shost->host_no; 138 ev.p.cmd_done.tag = tag; 139 ev.p.cmd_done.result = cmd->result; 140 141 dprintk("%p %d %llu %u %x\n", cmd, shost->host_no, 142 (unsigned long long) ev.p.cmd_req.tag, 143 ev.p.cmd_req.data_len, cmd->tag); 144 145 err = tgt_uspace_send_event(TGT_KEVENT_CMD_DONE, &ev); 146 if (err) 147 eprintk("tx buf is full, could not send\n"); 148 149 return err; 150} 151 152int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag, 153 struct scsi_lun *scsilun, void *data) 154{ 155 struct tgt_event ev; 156 int err; 157 158 memset(&ev, 0, sizeof(ev)); 159 ev.p.tsk_mgmt_req.host_no = host_no; 160 ev.p.tsk_mgmt_req.function = function; 161 ev.p.tsk_mgmt_req.tag = tag; 162 memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun)); 163 ev.p.tsk_mgmt_req.mid = (u64) (unsigned long) data; 164 165 dprintk("%d %x %llx %llx\n", host_no, function, (unsigned long long) tag, 166 (unsigned long long) ev.p.tsk_mgmt_req.mid); 167 168 err = tgt_uspace_send_event(TGT_KEVENT_TSK_MGMT_REQ, &ev); 169 if (err) 170 eprintk("tx buf is full, could not send\n"); 171 172 return err; 173} 174 175static int event_recv_msg(struct tgt_event *ev) 176{ 177 int err = 0; 178 179 switch (ev->hdr.type) { 180 case TGT_UEVENT_CMD_RSP: 181 err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no, 182 ev->p.cmd_rsp.result, 183 ev->p.cmd_rsp.tag, 184 ev->p.cmd_rsp.uaddr, 185 ev->p.cmd_rsp.len, 186 ev->p.cmd_rsp.sense_uaddr, 187 ev->p.cmd_rsp.sense_len, 188 ev->p.cmd_rsp.rw); 189 break; 190 case TGT_UEVENT_TSK_MGMT_RSP: 191 err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no, 192 ev->p.tsk_mgmt_rsp.mid, 193 ev->p.tsk_mgmt_rsp.result); 194 break; 195 default: 196 eprintk("unknown type %d\n", ev->hdr.type); 197 err = -EINVAL; 198 } 199 200 return err; 201} 202 203static ssize_t tgt_write(struct file *file, const char __user * buffer, 204 size_t count, loff_t * ppos) 205{ 206 struct tgt_event *ev; 207 struct tgt_ring *ring = &rx_ring; 208 209 while (1) { 210 ev = tgt_head_event(ring, ring->tr_idx); 211 /* do we need this? */ 212 flush_dcache_page(virt_to_page(ev)); 213 214 if (!ev->hdr.status) 215 break; 216 217 tgt_ring_idx_inc(ring); 218 event_recv_msg(ev); 219 ev->hdr.status = 0; 220 }; 221 222 return count; 223} 224 225static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait) 226{ 227 struct tgt_event *ev; 228 struct tgt_ring *ring = &tx_ring; 229 unsigned long flags; 230 unsigned int mask = 0; 231 u32 idx; 232 233 poll_wait(file, &tgt_poll_wait, wait); 234 235 spin_lock_irqsave(&ring->tr_lock, flags); 236 237 idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1; 238 ev = tgt_head_event(ring, idx); 239 if (ev->hdr.status) 240 mask |= POLLIN | POLLRDNORM; 241 242 spin_unlock_irqrestore(&ring->tr_lock, flags); 243 244 return mask; 245} 246 247static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr, 248 struct tgt_ring *ring) 249{ 250 int i, err; 251 252 for (i = 0; i < TGT_RING_PAGES; i++) { 253 struct page *page = virt_to_page(ring->tr_pages[i]); 254 err = vm_insert_page(vma, addr, page); 255 if (err) 256 return err; 257 addr += PAGE_SIZE; 258 } 259 260 return 0; 261} 262 263static int tgt_mmap(struct file *filp, struct vm_area_struct *vma) 264{ 265 unsigned long addr; 266 int err; 267 268 if (vma->vm_pgoff) 269 return -EINVAL; 270 271 if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) { 272 eprintk("mmap size must be %lu, not %lu \n", 273 TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start); 274 return -EINVAL; 275 } 276 277 addr = vma->vm_start; 278 err = uspace_ring_map(vma, addr, &tx_ring); 279 if (err) 280 return err; 281 err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring); 282 283 return err; 284} 285 286static int tgt_open(struct inode *inode, struct file *file) 287{ 288 tx_ring.tr_idx = rx_ring.tr_idx = 0; 289 290 return 0; 291} 292 293static const struct file_operations tgt_fops = { 294 .owner = THIS_MODULE, 295 .open = tgt_open, 296 .poll = tgt_poll, 297 .write = tgt_write, 298 .mmap = tgt_mmap, 299}; 300 301static struct miscdevice tgt_miscdev = { 302 .minor = MISC_DYNAMIC_MINOR, 303 .name = "tgt", 304 .fops = &tgt_fops, 305}; 306 307static void tgt_ring_exit(struct tgt_ring *ring) 308{ 309 int i; 310 311 for (i = 0; i < TGT_RING_PAGES; i++) 312 free_page(ring->tr_pages[i]); 313} 314 315static int tgt_ring_init(struct tgt_ring *ring) 316{ 317 int i; 318 319 spin_lock_init(&ring->tr_lock); 320 321 for (i = 0; i < TGT_RING_PAGES; i++) { 322 ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL); 323 if (!ring->tr_pages[i]) { 324 eprintk("out of memory\n"); 325 return -ENOMEM; 326 } 327 } 328 329 return 0; 330} 331 332void scsi_tgt_if_exit(void) 333{ 334 tgt_ring_exit(&tx_ring); 335 tgt_ring_exit(&rx_ring); 336 misc_deregister(&tgt_miscdev); 337} 338 339int scsi_tgt_if_init(void) 340{ 341 int err; 342 343 err = tgt_ring_init(&tx_ring); 344 if (err) 345 return err; 346 347 err = tgt_ring_init(&rx_ring); 348 if (err) 349 goto free_tx_ring; 350 351 err = misc_register(&tgt_miscdev); 352 if (err) 353 goto free_rx_ring; 354 355 return 0; 356free_rx_ring: 357 tgt_ring_exit(&rx_ring); 358free_tx_ring: 359 tgt_ring_exit(&tx_ring); 360 361 return err; 362} 363