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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 | ||
105 | int 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 | ||
130 | int 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 | ||
152 | int 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 | ||
175 | static 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.tag, | |
183 | ev->p.cmd_rsp.result, | |
184 | ev->p.cmd_rsp.len, | |
185 | ev->p.cmd_rsp.uaddr, | |
186 | ev->p.cmd_rsp.rw); | |
187 | break; | |
188 | case TGT_UEVENT_TSK_MGMT_RSP: | |
189 | err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no, | |
190 | ev->p.tsk_mgmt_rsp.mid, | |
191 | ev->p.tsk_mgmt_rsp.result); | |
192 | break; | |
193 | default: | |
194 | eprintk("unknown type %d\n", ev->hdr.type); | |
195 | err = -EINVAL; | |
196 | } | |
197 | ||
198 | return err; | |
199 | } | |
200 | ||
201 | static ssize_t tgt_write(struct file *file, const char __user * buffer, | |
202 | size_t count, loff_t * ppos) | |
203 | { | |
204 | struct tgt_event *ev; | |
205 | struct tgt_ring *ring = &rx_ring; | |
206 | ||
207 | while (1) { | |
208 | ev = tgt_head_event(ring, ring->tr_idx); | |
209 | /* do we need this? */ | |
210 | flush_dcache_page(virt_to_page(ev)); | |
211 | ||
212 | if (!ev->hdr.status) | |
213 | break; | |
214 | ||
215 | tgt_ring_idx_inc(ring); | |
216 | event_recv_msg(ev); | |
217 | ev->hdr.status = 0; | |
218 | }; | |
219 | ||
220 | return count; | |
221 | } | |
222 | ||
223 | static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait) | |
224 | { | |
225 | struct tgt_event *ev; | |
226 | struct tgt_ring *ring = &tx_ring; | |
227 | unsigned long flags; | |
228 | unsigned int mask = 0; | |
229 | u32 idx; | |
230 | ||
231 | poll_wait(file, &tgt_poll_wait, wait); | |
232 | ||
233 | spin_lock_irqsave(&ring->tr_lock, flags); | |
234 | ||
235 | idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1; | |
236 | ev = tgt_head_event(ring, idx); | |
237 | if (ev->hdr.status) | |
238 | mask |= POLLIN | POLLRDNORM; | |
239 | ||
240 | spin_unlock_irqrestore(&ring->tr_lock, flags); | |
241 | ||
242 | return mask; | |
243 | } | |
244 | ||
245 | static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr, | |
246 | struct tgt_ring *ring) | |
247 | { | |
248 | int i, err; | |
249 | ||
250 | for (i = 0; i < TGT_RING_PAGES; i++) { | |
251 | struct page *page = virt_to_page(ring->tr_pages[i]); | |
252 | err = vm_insert_page(vma, addr, page); | |
253 | if (err) | |
254 | return err; | |
255 | addr += PAGE_SIZE; | |
256 | } | |
257 | ||
258 | return 0; | |
259 | } | |
260 | ||
261 | static int tgt_mmap(struct file *filp, struct vm_area_struct *vma) | |
262 | { | |
263 | unsigned long addr; | |
264 | int err; | |
265 | ||
266 | if (vma->vm_pgoff) | |
267 | return -EINVAL; | |
268 | ||
269 | if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) { | |
270 | eprintk("mmap size must be %lu, not %lu \n", | |
271 | TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start); | |
272 | return -EINVAL; | |
273 | } | |
274 | ||
275 | addr = vma->vm_start; | |
276 | err = uspace_ring_map(vma, addr, &tx_ring); | |
277 | if (err) | |
278 | return err; | |
279 | err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring); | |
280 | ||
281 | return err; | |
282 | } | |
283 | ||
284 | static int tgt_open(struct inode *inode, struct file *file) | |
285 | { | |
286 | tx_ring.tr_idx = rx_ring.tr_idx = 0; | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
00977a59 | 291 | static const struct file_operations tgt_fops = { |
97f78759 FT |
292 | .owner = THIS_MODULE, |
293 | .open = tgt_open, | |
294 | .poll = tgt_poll, | |
295 | .write = tgt_write, | |
296 | .mmap = tgt_mmap, | |
297 | }; | |
298 | ||
299 | static struct miscdevice tgt_miscdev = { | |
300 | .minor = MISC_DYNAMIC_MINOR, | |
301 | .name = "tgt", | |
302 | .fops = &tgt_fops, | |
303 | }; | |
304 | ||
305 | static void tgt_ring_exit(struct tgt_ring *ring) | |
306 | { | |
307 | int i; | |
308 | ||
309 | for (i = 0; i < TGT_RING_PAGES; i++) | |
310 | free_page(ring->tr_pages[i]); | |
311 | } | |
312 | ||
313 | static int tgt_ring_init(struct tgt_ring *ring) | |
314 | { | |
315 | int i; | |
316 | ||
317 | spin_lock_init(&ring->tr_lock); | |
318 | ||
319 | for (i = 0; i < TGT_RING_PAGES; i++) { | |
320 | ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL); | |
321 | if (!ring->tr_pages[i]) { | |
322 | eprintk("out of memory\n"); | |
323 | return -ENOMEM; | |
324 | } | |
325 | } | |
326 | ||
327 | return 0; | |
328 | } | |
329 | ||
330 | void scsi_tgt_if_exit(void) | |
331 | { | |
332 | tgt_ring_exit(&tx_ring); | |
333 | tgt_ring_exit(&rx_ring); | |
334 | misc_deregister(&tgt_miscdev); | |
335 | } | |
336 | ||
337 | int scsi_tgt_if_init(void) | |
338 | { | |
339 | int err; | |
340 | ||
341 | err = tgt_ring_init(&tx_ring); | |
342 | if (err) | |
343 | return err; | |
344 | ||
345 | err = tgt_ring_init(&rx_ring); | |
346 | if (err) | |
347 | goto free_tx_ring; | |
348 | ||
349 | err = misc_register(&tgt_miscdev); | |
350 | if (err) | |
351 | goto free_rx_ring; | |
352 | ||
353 | return 0; | |
354 | free_rx_ring: | |
355 | tgt_ring_exit(&rx_ring); | |
356 | free_tx_ring: | |
357 | tgt_ring_exit(&tx_ring); | |
358 | ||
359 | return err; | |
360 | } |