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97f78759 FT |
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 | ||
e42ebefe | 32 | #include <asm/cacheflush.h> |
33 | ||
97f78759 FT |
34 | #include "scsi_tgt_priv.h" |
35 | ||
930e99bd FT |
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 | ||
97f78759 FT |
44 | struct 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 */ | |
51 | static struct tgt_ring tx_ring, rx_ring; | |
52 | static DECLARE_WAIT_QUEUE_HEAD(tgt_poll_wait); | |
53 | ||
54 | static 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 | ||
62 | static 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 | ||
73 | static 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 | ||
2c47f9ef FT |
105 | int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 itn_id, |
106 | struct scsi_lun *lun, u64 tag) | |
97f78759 FT |
107 | { |
108 | struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); | |
109 | struct tgt_event ev; | |
110 | int err; | |
111 | ||
112 | memset(&ev, 0, sizeof(ev)); | |
113 | ev.p.cmd_req.host_no = shost->host_no; | |
2c47f9ef | 114 | ev.p.cmd_req.itn_id = itn_id; |
f10ab66f | 115 | ev.p.cmd_req.data_len = scsi_bufflen(cmd); |
97f78759 FT |
116 | memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb)); |
117 | memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun)); | |
118 | ev.p.cmd_req.attribute = cmd->tag; | |
119 | ev.p.cmd_req.tag = tag; | |
120 | ||
121 | dprintk("%p %d %u %x %llx\n", cmd, shost->host_no, | |
122 | ev.p.cmd_req.data_len, cmd->tag, | |
123 | (unsigned long long) ev.p.cmd_req.tag); | |
124 | ||
125 | err = tgt_uspace_send_event(TGT_KEVENT_CMD_REQ, &ev); | |
126 | if (err) | |
127 | eprintk("tx buf is full, could not send\n"); | |
128 | ||
129 | return err; | |
130 | } | |
131 | ||
2c47f9ef | 132 | int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 itn_id, u64 tag) |
97f78759 FT |
133 | { |
134 | struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); | |
135 | struct tgt_event ev; | |
136 | int err; | |
137 | ||
138 | memset(&ev, 0, sizeof(ev)); | |
139 | ev.p.cmd_done.host_no = shost->host_no; | |
2c47f9ef | 140 | ev.p.cmd_done.itn_id = itn_id; |
97f78759 FT |
141 | ev.p.cmd_done.tag = tag; |
142 | ev.p.cmd_done.result = cmd->result; | |
143 | ||
144 | dprintk("%p %d %llu %u %x\n", cmd, shost->host_no, | |
145 | (unsigned long long) ev.p.cmd_req.tag, | |
146 | ev.p.cmd_req.data_len, cmd->tag); | |
147 | ||
148 | err = tgt_uspace_send_event(TGT_KEVENT_CMD_DONE, &ev); | |
149 | if (err) | |
150 | eprintk("tx buf is full, could not send\n"); | |
151 | ||
152 | return err; | |
153 | } | |
154 | ||
2c47f9ef FT |
155 | int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 itn_id, int function, |
156 | u64 tag, struct scsi_lun *scsilun, void *data) | |
97f78759 FT |
157 | { |
158 | struct tgt_event ev; | |
159 | int err; | |
160 | ||
161 | memset(&ev, 0, sizeof(ev)); | |
162 | ev.p.tsk_mgmt_req.host_no = host_no; | |
2c47f9ef | 163 | ev.p.tsk_mgmt_req.itn_id = itn_id; |
97f78759 FT |
164 | ev.p.tsk_mgmt_req.function = function; |
165 | ev.p.tsk_mgmt_req.tag = tag; | |
166 | memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun)); | |
167 | ev.p.tsk_mgmt_req.mid = (u64) (unsigned long) data; | |
168 | ||
169 | dprintk("%d %x %llx %llx\n", host_no, function, (unsigned long long) tag, | |
170 | (unsigned long long) ev.p.tsk_mgmt_req.mid); | |
171 | ||
172 | err = tgt_uspace_send_event(TGT_KEVENT_TSK_MGMT_REQ, &ev); | |
173 | if (err) | |
174 | eprintk("tx buf is full, could not send\n"); | |
175 | ||
176 | return err; | |
177 | } | |
178 | ||
2c47f9ef FT |
179 | int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 itn_id, |
180 | int function, char *initiator_id) | |
181 | { | |
182 | struct tgt_event ev; | |
183 | int err; | |
184 | ||
185 | memset(&ev, 0, sizeof(ev)); | |
186 | ev.p.it_nexus_req.host_no = host_no; | |
187 | ev.p.it_nexus_req.function = function; | |
188 | ev.p.it_nexus_req.itn_id = itn_id; | |
189 | if (initiator_id) | |
190 | strncpy(ev.p.it_nexus_req.initiator_id, initiator_id, | |
191 | sizeof(ev.p.it_nexus_req.initiator_id)); | |
192 | ||
193 | dprintk("%d %x %llx\n", host_no, function, (unsigned long long)itn_id); | |
194 | ||
195 | err = tgt_uspace_send_event(TGT_KEVENT_IT_NEXUS_REQ, &ev); | |
196 | if (err) | |
197 | eprintk("tx buf is full, could not send\n"); | |
198 | ||
199 | return err; | |
200 | } | |
201 | ||
97f78759 FT |
202 | static int event_recv_msg(struct tgt_event *ev) |
203 | { | |
204 | int err = 0; | |
205 | ||
206 | switch (ev->hdr.type) { | |
207 | case TGT_UEVENT_CMD_RSP: | |
208 | err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no, | |
2c47f9ef | 209 | ev->p.cmd_rsp.itn_id, |
97f78759 | 210 | ev->p.cmd_rsp.result, |
bc7e380a | 211 | ev->p.cmd_rsp.tag, |
97f78759 | 212 | ev->p.cmd_rsp.uaddr, |
bc7e380a FT |
213 | ev->p.cmd_rsp.len, |
214 | ev->p.cmd_rsp.sense_uaddr, | |
215 | ev->p.cmd_rsp.sense_len, | |
97f78759 FT |
216 | ev->p.cmd_rsp.rw); |
217 | break; | |
218 | case TGT_UEVENT_TSK_MGMT_RSP: | |
219 | err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no, | |
2c47f9ef | 220 | ev->p.tsk_mgmt_rsp.itn_id, |
97f78759 FT |
221 | ev->p.tsk_mgmt_rsp.mid, |
222 | ev->p.tsk_mgmt_rsp.result); | |
223 | break; | |
2c47f9ef FT |
224 | case TGT_UEVENT_IT_NEXUS_RSP: |
225 | err = scsi_tgt_kspace_it_nexus_rsp(ev->p.it_nexus_rsp.host_no, | |
226 | ev->p.it_nexus_rsp.itn_id, | |
227 | ev->p.it_nexus_rsp.result); | |
228 | break; | |
97f78759 FT |
229 | default: |
230 | eprintk("unknown type %d\n", ev->hdr.type); | |
231 | err = -EINVAL; | |
232 | } | |
233 | ||
234 | return err; | |
235 | } | |
236 | ||
237 | static ssize_t tgt_write(struct file *file, const char __user * buffer, | |
238 | size_t count, loff_t * ppos) | |
239 | { | |
240 | struct tgt_event *ev; | |
241 | struct tgt_ring *ring = &rx_ring; | |
242 | ||
243 | while (1) { | |
244 | ev = tgt_head_event(ring, ring->tr_idx); | |
245 | /* do we need this? */ | |
246 | flush_dcache_page(virt_to_page(ev)); | |
247 | ||
248 | if (!ev->hdr.status) | |
249 | break; | |
250 | ||
251 | tgt_ring_idx_inc(ring); | |
252 | event_recv_msg(ev); | |
253 | ev->hdr.status = 0; | |
254 | }; | |
255 | ||
256 | return count; | |
257 | } | |
258 | ||
259 | static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait) | |
260 | { | |
261 | struct tgt_event *ev; | |
262 | struct tgt_ring *ring = &tx_ring; | |
263 | unsigned long flags; | |
264 | unsigned int mask = 0; | |
265 | u32 idx; | |
266 | ||
267 | poll_wait(file, &tgt_poll_wait, wait); | |
268 | ||
269 | spin_lock_irqsave(&ring->tr_lock, flags); | |
270 | ||
271 | idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1; | |
272 | ev = tgt_head_event(ring, idx); | |
273 | if (ev->hdr.status) | |
274 | mask |= POLLIN | POLLRDNORM; | |
275 | ||
276 | spin_unlock_irqrestore(&ring->tr_lock, flags); | |
277 | ||
278 | return mask; | |
279 | } | |
280 | ||
281 | static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr, | |
282 | struct tgt_ring *ring) | |
283 | { | |
284 | int i, err; | |
285 | ||
286 | for (i = 0; i < TGT_RING_PAGES; i++) { | |
287 | struct page *page = virt_to_page(ring->tr_pages[i]); | |
288 | err = vm_insert_page(vma, addr, page); | |
289 | if (err) | |
290 | return err; | |
291 | addr += PAGE_SIZE; | |
292 | } | |
293 | ||
294 | return 0; | |
295 | } | |
296 | ||
297 | static int tgt_mmap(struct file *filp, struct vm_area_struct *vma) | |
298 | { | |
299 | unsigned long addr; | |
300 | int err; | |
301 | ||
302 | if (vma->vm_pgoff) | |
303 | return -EINVAL; | |
304 | ||
305 | if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) { | |
306 | eprintk("mmap size must be %lu, not %lu \n", | |
307 | TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start); | |
308 | return -EINVAL; | |
309 | } | |
310 | ||
311 | addr = vma->vm_start; | |
312 | err = uspace_ring_map(vma, addr, &tx_ring); | |
313 | if (err) | |
314 | return err; | |
315 | err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring); | |
316 | ||
317 | return err; | |
318 | } | |
319 | ||
320 | static int tgt_open(struct inode *inode, struct file *file) | |
321 | { | |
322 | tx_ring.tr_idx = rx_ring.tr_idx = 0; | |
323 | ||
324 | return 0; | |
325 | } | |
326 | ||
00977a59 | 327 | static const struct file_operations tgt_fops = { |
97f78759 FT |
328 | .owner = THIS_MODULE, |
329 | .open = tgt_open, | |
330 | .poll = tgt_poll, | |
331 | .write = tgt_write, | |
332 | .mmap = tgt_mmap, | |
333 | }; | |
334 | ||
335 | static struct miscdevice tgt_miscdev = { | |
336 | .minor = MISC_DYNAMIC_MINOR, | |
337 | .name = "tgt", | |
338 | .fops = &tgt_fops, | |
339 | }; | |
340 | ||
341 | static void tgt_ring_exit(struct tgt_ring *ring) | |
342 | { | |
343 | int i; | |
344 | ||
345 | for (i = 0; i < TGT_RING_PAGES; i++) | |
346 | free_page(ring->tr_pages[i]); | |
347 | } | |
348 | ||
349 | static int tgt_ring_init(struct tgt_ring *ring) | |
350 | { | |
351 | int i; | |
352 | ||
353 | spin_lock_init(&ring->tr_lock); | |
354 | ||
355 | for (i = 0; i < TGT_RING_PAGES; i++) { | |
356 | ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL); | |
357 | if (!ring->tr_pages[i]) { | |
358 | eprintk("out of memory\n"); | |
359 | return -ENOMEM; | |
360 | } | |
361 | } | |
362 | ||
363 | return 0; | |
364 | } | |
365 | ||
366 | void scsi_tgt_if_exit(void) | |
367 | { | |
368 | tgt_ring_exit(&tx_ring); | |
369 | tgt_ring_exit(&rx_ring); | |
370 | misc_deregister(&tgt_miscdev); | |
371 | } | |
372 | ||
373 | int scsi_tgt_if_init(void) | |
374 | { | |
375 | int err; | |
376 | ||
377 | err = tgt_ring_init(&tx_ring); | |
378 | if (err) | |
379 | return err; | |
380 | ||
381 | err = tgt_ring_init(&rx_ring); | |
382 | if (err) | |
383 | goto free_tx_ring; | |
384 | ||
385 | err = misc_register(&tgt_miscdev); | |
386 | if (err) | |
387 | goto free_rx_ring; | |
388 | ||
389 | return 0; | |
390 | free_rx_ring: | |
391 | tgt_ring_exit(&rx_ring); | |
392 | free_tx_ring: | |
393 | tgt_ring_exit(&tx_ring); | |
394 | ||
395 | return err; | |
396 | } |