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FUJITA Tomonori97f78752006-11-16 19:24:16 +09001/*
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
akpm@osdl.orge42ebef2006-12-04 23:06:48 -080032#include <asm/cacheflush.h>
33
FUJITA Tomonori97f78752006-11-16 19:24:16 +090034#include "scsi_tgt_priv.h"
35
FUJITA Tomonori930e99b2007-02-13 23:21:52 +090036#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
FUJITA Tomonori97f78752006-11-16 19:24:16 +090044struct 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,
FUJITA Tomonori97f78752006-11-16 19:24:16 +0900182 ev->p.cmd_rsp.result,
FUJITA Tomonoribc7e3802007-03-03 09:55:54 +0900183 ev->p.cmd_rsp.tag,
FUJITA Tomonori97f78752006-11-16 19:24:16 +0900184 ev->p.cmd_rsp.uaddr,
FUJITA Tomonoribc7e3802007-03-03 09:55:54 +0900185 ev->p.cmd_rsp.len,
186 ev->p.cmd_rsp.sense_uaddr,
187 ev->p.cmd_rsp.sense_len,
FUJITA Tomonori97f78752006-11-16 19:24:16 +0900188 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
Arjan van de Ven00977a52007-02-12 00:55:34 -0800293static const struct file_operations tgt_fops = {
FUJITA Tomonori97f78752006-11-16 19:24:16 +0900294 .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}