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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 | ||
36 | struct tgt_ring { | |
37 | u32 tr_idx; | |
38 | unsigned long tr_pages[TGT_RING_PAGES]; | |
39 | spinlock_t tr_lock; | |
40 | }; | |
41 | ||
42 | /* tx_ring : kernel->user, rx_ring : user->kernel */ | |
43 | static struct tgt_ring tx_ring, rx_ring; | |
44 | static DECLARE_WAIT_QUEUE_HEAD(tgt_poll_wait); | |
45 | ||
46 | static inline void tgt_ring_idx_inc(struct tgt_ring *ring) | |
47 | { | |
48 | if (ring->tr_idx == TGT_MAX_EVENTS - 1) | |
49 | ring->tr_idx = 0; | |
50 | else | |
51 | ring->tr_idx++; | |
52 | } | |
53 | ||
54 | static struct tgt_event *tgt_head_event(struct tgt_ring *ring, u32 idx) | |
55 | { | |
56 | u32 pidx, off; | |
57 | ||
58 | pidx = idx / TGT_EVENT_PER_PAGE; | |
59 | off = idx % TGT_EVENT_PER_PAGE; | |
60 | ||
61 | return (struct tgt_event *) | |
62 | (ring->tr_pages[pidx] + sizeof(struct tgt_event) * off); | |
63 | } | |
64 | ||
65 | static int tgt_uspace_send_event(u32 type, struct tgt_event *p) | |
66 | { | |
67 | struct tgt_event *ev; | |
68 | struct tgt_ring *ring = &tx_ring; | |
69 | unsigned long flags; | |
70 | int err = 0; | |
71 | ||
72 | spin_lock_irqsave(&ring->tr_lock, flags); | |
73 | ||
74 | ev = tgt_head_event(ring, ring->tr_idx); | |
75 | if (!ev->hdr.status) | |
76 | tgt_ring_idx_inc(ring); | |
77 | else | |
78 | err = -BUSY; | |
79 | ||
80 | spin_unlock_irqrestore(&ring->tr_lock, flags); | |
81 | ||
82 | if (err) | |
83 | return err; | |
84 | ||
85 | memcpy(ev, p, sizeof(*ev)); | |
86 | ev->hdr.type = type; | |
87 | mb(); | |
88 | ev->hdr.status = 1; | |
89 | ||
90 | flush_dcache_page(virt_to_page(ev)); | |
91 | ||
92 | wake_up_interruptible(&tgt_poll_wait); | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
97 | int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 tag) | |
98 | { | |
99 | struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); | |
100 | struct tgt_event ev; | |
101 | int err; | |
102 | ||
103 | memset(&ev, 0, sizeof(ev)); | |
104 | ev.p.cmd_req.host_no = shost->host_no; | |
105 | ev.p.cmd_req.data_len = cmd->request_bufflen; | |
106 | memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb)); | |
107 | memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun)); | |
108 | ev.p.cmd_req.attribute = cmd->tag; | |
109 | ev.p.cmd_req.tag = tag; | |
110 | ||
111 | dprintk("%p %d %u %x %llx\n", cmd, shost->host_no, | |
112 | ev.p.cmd_req.data_len, cmd->tag, | |
113 | (unsigned long long) ev.p.cmd_req.tag); | |
114 | ||
115 | err = tgt_uspace_send_event(TGT_KEVENT_CMD_REQ, &ev); | |
116 | if (err) | |
117 | eprintk("tx buf is full, could not send\n"); | |
118 | ||
119 | return err; | |
120 | } | |
121 | ||
122 | int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag) | |
123 | { | |
124 | struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd); | |
125 | struct tgt_event ev; | |
126 | int err; | |
127 | ||
128 | memset(&ev, 0, sizeof(ev)); | |
129 | ev.p.cmd_done.host_no = shost->host_no; | |
130 | ev.p.cmd_done.tag = tag; | |
131 | ev.p.cmd_done.result = cmd->result; | |
132 | ||
133 | dprintk("%p %d %llu %u %x\n", cmd, shost->host_no, | |
134 | (unsigned long long) ev.p.cmd_req.tag, | |
135 | ev.p.cmd_req.data_len, cmd->tag); | |
136 | ||
137 | err = tgt_uspace_send_event(TGT_KEVENT_CMD_DONE, &ev); | |
138 | if (err) | |
139 | eprintk("tx buf is full, could not send\n"); | |
140 | ||
141 | return err; | |
142 | } | |
143 | ||
144 | int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag, | |
145 | struct scsi_lun *scsilun, void *data) | |
146 | { | |
147 | struct tgt_event ev; | |
148 | int err; | |
149 | ||
150 | memset(&ev, 0, sizeof(ev)); | |
151 | ev.p.tsk_mgmt_req.host_no = host_no; | |
152 | ev.p.tsk_mgmt_req.function = function; | |
153 | ev.p.tsk_mgmt_req.tag = tag; | |
154 | memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun)); | |
155 | ev.p.tsk_mgmt_req.mid = (u64) (unsigned long) data; | |
156 | ||
157 | dprintk("%d %x %llx %llx\n", host_no, function, (unsigned long long) tag, | |
158 | (unsigned long long) ev.p.tsk_mgmt_req.mid); | |
159 | ||
160 | err = tgt_uspace_send_event(TGT_KEVENT_TSK_MGMT_REQ, &ev); | |
161 | if (err) | |
162 | eprintk("tx buf is full, could not send\n"); | |
163 | ||
164 | return err; | |
165 | } | |
166 | ||
167 | static int event_recv_msg(struct tgt_event *ev) | |
168 | { | |
169 | int err = 0; | |
170 | ||
171 | switch (ev->hdr.type) { | |
172 | case TGT_UEVENT_CMD_RSP: | |
173 | err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no, | |
174 | ev->p.cmd_rsp.tag, | |
175 | ev->p.cmd_rsp.result, | |
176 | ev->p.cmd_rsp.len, | |
177 | ev->p.cmd_rsp.uaddr, | |
178 | ev->p.cmd_rsp.rw); | |
179 | break; | |
180 | case TGT_UEVENT_TSK_MGMT_RSP: | |
181 | err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no, | |
182 | ev->p.tsk_mgmt_rsp.mid, | |
183 | ev->p.tsk_mgmt_rsp.result); | |
184 | break; | |
185 | default: | |
186 | eprintk("unknown type %d\n", ev->hdr.type); | |
187 | err = -EINVAL; | |
188 | } | |
189 | ||
190 | return err; | |
191 | } | |
192 | ||
193 | static ssize_t tgt_write(struct file *file, const char __user * buffer, | |
194 | size_t count, loff_t * ppos) | |
195 | { | |
196 | struct tgt_event *ev; | |
197 | struct tgt_ring *ring = &rx_ring; | |
198 | ||
199 | while (1) { | |
200 | ev = tgt_head_event(ring, ring->tr_idx); | |
201 | /* do we need this? */ | |
202 | flush_dcache_page(virt_to_page(ev)); | |
203 | ||
204 | if (!ev->hdr.status) | |
205 | break; | |
206 | ||
207 | tgt_ring_idx_inc(ring); | |
208 | event_recv_msg(ev); | |
209 | ev->hdr.status = 0; | |
210 | }; | |
211 | ||
212 | return count; | |
213 | } | |
214 | ||
215 | static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait) | |
216 | { | |
217 | struct tgt_event *ev; | |
218 | struct tgt_ring *ring = &tx_ring; | |
219 | unsigned long flags; | |
220 | unsigned int mask = 0; | |
221 | u32 idx; | |
222 | ||
223 | poll_wait(file, &tgt_poll_wait, wait); | |
224 | ||
225 | spin_lock_irqsave(&ring->tr_lock, flags); | |
226 | ||
227 | idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1; | |
228 | ev = tgt_head_event(ring, idx); | |
229 | if (ev->hdr.status) | |
230 | mask |= POLLIN | POLLRDNORM; | |
231 | ||
232 | spin_unlock_irqrestore(&ring->tr_lock, flags); | |
233 | ||
234 | return mask; | |
235 | } | |
236 | ||
237 | static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr, | |
238 | struct tgt_ring *ring) | |
239 | { | |
240 | int i, err; | |
241 | ||
242 | for (i = 0; i < TGT_RING_PAGES; i++) { | |
243 | struct page *page = virt_to_page(ring->tr_pages[i]); | |
244 | err = vm_insert_page(vma, addr, page); | |
245 | if (err) | |
246 | return err; | |
247 | addr += PAGE_SIZE; | |
248 | } | |
249 | ||
250 | return 0; | |
251 | } | |
252 | ||
253 | static int tgt_mmap(struct file *filp, struct vm_area_struct *vma) | |
254 | { | |
255 | unsigned long addr; | |
256 | int err; | |
257 | ||
258 | if (vma->vm_pgoff) | |
259 | return -EINVAL; | |
260 | ||
261 | if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) { | |
262 | eprintk("mmap size must be %lu, not %lu \n", | |
263 | TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start); | |
264 | return -EINVAL; | |
265 | } | |
266 | ||
267 | addr = vma->vm_start; | |
268 | err = uspace_ring_map(vma, addr, &tx_ring); | |
269 | if (err) | |
270 | return err; | |
271 | err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring); | |
272 | ||
273 | return err; | |
274 | } | |
275 | ||
276 | static int tgt_open(struct inode *inode, struct file *file) | |
277 | { | |
278 | tx_ring.tr_idx = rx_ring.tr_idx = 0; | |
279 | ||
280 | return 0; | |
281 | } | |
282 | ||
00977a59 | 283 | static const struct file_operations tgt_fops = { |
97f78759 FT |
284 | .owner = THIS_MODULE, |
285 | .open = tgt_open, | |
286 | .poll = tgt_poll, | |
287 | .write = tgt_write, | |
288 | .mmap = tgt_mmap, | |
289 | }; | |
290 | ||
291 | static struct miscdevice tgt_miscdev = { | |
292 | .minor = MISC_DYNAMIC_MINOR, | |
293 | .name = "tgt", | |
294 | .fops = &tgt_fops, | |
295 | }; | |
296 | ||
297 | static void tgt_ring_exit(struct tgt_ring *ring) | |
298 | { | |
299 | int i; | |
300 | ||
301 | for (i = 0; i < TGT_RING_PAGES; i++) | |
302 | free_page(ring->tr_pages[i]); | |
303 | } | |
304 | ||
305 | static int tgt_ring_init(struct tgt_ring *ring) | |
306 | { | |
307 | int i; | |
308 | ||
309 | spin_lock_init(&ring->tr_lock); | |
310 | ||
311 | for (i = 0; i < TGT_RING_PAGES; i++) { | |
312 | ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL); | |
313 | if (!ring->tr_pages[i]) { | |
314 | eprintk("out of memory\n"); | |
315 | return -ENOMEM; | |
316 | } | |
317 | } | |
318 | ||
319 | return 0; | |
320 | } | |
321 | ||
322 | void scsi_tgt_if_exit(void) | |
323 | { | |
324 | tgt_ring_exit(&tx_ring); | |
325 | tgt_ring_exit(&rx_ring); | |
326 | misc_deregister(&tgt_miscdev); | |
327 | } | |
328 | ||
329 | int scsi_tgt_if_init(void) | |
330 | { | |
331 | int err; | |
332 | ||
333 | err = tgt_ring_init(&tx_ring); | |
334 | if (err) | |
335 | return err; | |
336 | ||
337 | err = tgt_ring_init(&rx_ring); | |
338 | if (err) | |
339 | goto free_tx_ring; | |
340 | ||
341 | err = misc_register(&tgt_miscdev); | |
342 | if (err) | |
343 | goto free_rx_ring; | |
344 | ||
345 | return 0; | |
346 | free_rx_ring: | |
347 | tgt_ring_exit(&rx_ring); | |
348 | free_tx_ring: | |
349 | tgt_ring_exit(&tx_ring); | |
350 | ||
351 | return err; | |
352 | } |