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22#include <linux/miscdevice.h>
23#include <linux/gfp.h>
24#include <linux/file.h>
25#include <linux/export.h>
26#include <net/tcp.h>
27#include <scsi/scsi.h>
28#include <scsi/scsi_cmnd.h>
29#include <scsi/scsi_device.h>
30#include <scsi/scsi_host.h>
31#include <scsi/scsi_tgt.h>
32#include <scsi/scsi_tgt_if.h>
33
34#include <asm/cacheflush.h>
35
36#include "scsi_tgt_priv.h"
37
38#if TGT_RING_SIZE < PAGE_SIZE
39# define TGT_RING_SIZE PAGE_SIZE
40#endif
41
42#define TGT_RING_PAGES (TGT_RING_SIZE >> PAGE_SHIFT)
43#define TGT_EVENT_PER_PAGE (PAGE_SIZE / sizeof(struct tgt_event))
44#define TGT_MAX_EVENTS (TGT_EVENT_PER_PAGE * TGT_RING_PAGES)
45
46struct tgt_ring {
47 u32 tr_idx;
48 unsigned long tr_pages[TGT_RING_PAGES];
49 spinlock_t tr_lock;
50};
51
52
53static struct tgt_ring tx_ring, rx_ring;
54static DECLARE_WAIT_QUEUE_HEAD(tgt_poll_wait);
55
56static inline void tgt_ring_idx_inc(struct tgt_ring *ring)
57{
58 if (ring->tr_idx == TGT_MAX_EVENTS - 1)
59 ring->tr_idx = 0;
60 else
61 ring->tr_idx++;
62}
63
64static struct tgt_event *tgt_head_event(struct tgt_ring *ring, u32 idx)
65{
66 u32 pidx, off;
67
68 pidx = idx / TGT_EVENT_PER_PAGE;
69 off = idx % TGT_EVENT_PER_PAGE;
70
71 return (struct tgt_event *)
72 (ring->tr_pages[pidx] + sizeof(struct tgt_event) * off);
73}
74
75static int tgt_uspace_send_event(u32 type, struct tgt_event *p)
76{
77 struct tgt_event *ev;
78 struct tgt_ring *ring = &tx_ring;
79 unsigned long flags;
80 int err = 0;
81
82 spin_lock_irqsave(&ring->tr_lock, flags);
83
84 ev = tgt_head_event(ring, ring->tr_idx);
85 if (!ev->hdr.status)
86 tgt_ring_idx_inc(ring);
87 else
88 err = -BUSY;
89
90 spin_unlock_irqrestore(&ring->tr_lock, flags);
91
92 if (err)
93 return err;
94
95 memcpy(ev, p, sizeof(*ev));
96 ev->hdr.type = type;
97 mb();
98 ev->hdr.status = 1;
99
100 flush_dcache_page(virt_to_page(ev));
101
102 wake_up_interruptible(&tgt_poll_wait);
103
104 return 0;
105}
106
107int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 itn_id,
108 struct scsi_lun *lun, u64 tag)
109{
110 struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
111 struct tgt_event ev;
112 int err;
113
114 memset(&ev, 0, sizeof(ev));
115 ev.p.cmd_req.host_no = shost->host_no;
116 ev.p.cmd_req.itn_id = itn_id;
117 ev.p.cmd_req.data_len = scsi_bufflen(cmd);
118 memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb));
119 memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun));
120 ev.p.cmd_req.attribute = cmd->tag;
121 ev.p.cmd_req.tag = tag;
122
123 dprintk("%p %d %u %x %llx\n", cmd, shost->host_no,
124 ev.p.cmd_req.data_len, cmd->tag,
125 (unsigned long long) ev.p.cmd_req.tag);
126
127 err = tgt_uspace_send_event(TGT_KEVENT_CMD_REQ, &ev);
128 if (err)
129 eprintk("tx buf is full, could not send\n");
130
131 return err;
132}
133
134int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 itn_id, u64 tag)
135{
136 struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
137 struct tgt_event ev;
138 int err;
139
140 memset(&ev, 0, sizeof(ev));
141 ev.p.cmd_done.host_no = shost->host_no;
142 ev.p.cmd_done.itn_id = itn_id;
143 ev.p.cmd_done.tag = tag;
144 ev.p.cmd_done.result = cmd->result;
145
146 dprintk("%p %d %llu %u %x\n", cmd, shost->host_no,
147 (unsigned long long) ev.p.cmd_req.tag,
148 ev.p.cmd_req.data_len, cmd->tag);
149
150 err = tgt_uspace_send_event(TGT_KEVENT_CMD_DONE, &ev);
151 if (err)
152 eprintk("tx buf is full, could not send\n");
153
154 return err;
155}
156
157int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 itn_id, int function,
158 u64 tag, struct scsi_lun *scsilun, void *data)
159{
160 struct tgt_event ev;
161 int err;
162
163 memset(&ev, 0, sizeof(ev));
164 ev.p.tsk_mgmt_req.host_no = host_no;
165 ev.p.tsk_mgmt_req.itn_id = itn_id;
166 ev.p.tsk_mgmt_req.function = function;
167 ev.p.tsk_mgmt_req.tag = tag;
168 memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun));
169 ev.p.tsk_mgmt_req.mid = (u64) (unsigned long) data;
170
171 dprintk("%d %x %llx %llx\n", host_no, function, (unsigned long long) tag,
172 (unsigned long long) ev.p.tsk_mgmt_req.mid);
173
174 err = tgt_uspace_send_event(TGT_KEVENT_TSK_MGMT_REQ, &ev);
175 if (err)
176 eprintk("tx buf is full, could not send\n");
177
178 return err;
179}
180
181int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 itn_id,
182 int function, char *initiator_id)
183{
184 struct tgt_event ev;
185 int err;
186
187 memset(&ev, 0, sizeof(ev));
188 ev.p.it_nexus_req.host_no = host_no;
189 ev.p.it_nexus_req.function = function;
190 ev.p.it_nexus_req.itn_id = itn_id;
191 if (initiator_id)
192 strncpy(ev.p.it_nexus_req.initiator_id, initiator_id,
193 sizeof(ev.p.it_nexus_req.initiator_id));
194
195 dprintk("%d %x %llx\n", host_no, function, (unsigned long long)itn_id);
196
197 err = tgt_uspace_send_event(TGT_KEVENT_IT_NEXUS_REQ, &ev);
198 if (err)
199 eprintk("tx buf is full, could not send\n");
200
201 return err;
202}
203
204static int event_recv_msg(struct tgt_event *ev)
205{
206 int err = 0;
207
208 switch (ev->hdr.type) {
209 case TGT_UEVENT_CMD_RSP:
210 err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no,
211 ev->p.cmd_rsp.itn_id,
212 ev->p.cmd_rsp.result,
213 ev->p.cmd_rsp.tag,
214 ev->p.cmd_rsp.uaddr,
215 ev->p.cmd_rsp.len,
216 ev->p.cmd_rsp.sense_uaddr,
217 ev->p.cmd_rsp.sense_len,
218 ev->p.cmd_rsp.rw);
219 break;
220 case TGT_UEVENT_TSK_MGMT_RSP:
221 err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no,
222 ev->p.tsk_mgmt_rsp.itn_id,
223 ev->p.tsk_mgmt_rsp.mid,
224 ev->p.tsk_mgmt_rsp.result);
225 break;
226 case TGT_UEVENT_IT_NEXUS_RSP:
227 err = scsi_tgt_kspace_it_nexus_rsp(ev->p.it_nexus_rsp.host_no,
228 ev->p.it_nexus_rsp.itn_id,
229 ev->p.it_nexus_rsp.result);
230 break;
231 default:
232 eprintk("unknown type %d\n", ev->hdr.type);
233 err = -EINVAL;
234 }
235
236 return err;
237}
238
239static ssize_t tgt_write(struct file *file, const char __user * buffer,
240 size_t count, loff_t * ppos)
241{
242 struct tgt_event *ev;
243 struct tgt_ring *ring = &rx_ring;
244
245 while (1) {
246 ev = tgt_head_event(ring, ring->tr_idx);
247
248 flush_dcache_page(virt_to_page(ev));
249
250 if (!ev->hdr.status)
251 break;
252
253 tgt_ring_idx_inc(ring);
254 event_recv_msg(ev);
255 ev->hdr.status = 0;
256 };
257
258 return count;
259}
260
261static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait)
262{
263 struct tgt_event *ev;
264 struct tgt_ring *ring = &tx_ring;
265 unsigned long flags;
266 unsigned int mask = 0;
267 u32 idx;
268
269 poll_wait(file, &tgt_poll_wait, wait);
270
271 spin_lock_irqsave(&ring->tr_lock, flags);
272
273 idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1;
274 ev = tgt_head_event(ring, idx);
275 if (ev->hdr.status)
276 mask |= POLLIN | POLLRDNORM;
277
278 spin_unlock_irqrestore(&ring->tr_lock, flags);
279
280 return mask;
281}
282
283static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr,
284 struct tgt_ring *ring)
285{
286 int i, err;
287
288 for (i = 0; i < TGT_RING_PAGES; i++) {
289 struct page *page = virt_to_page(ring->tr_pages[i]);
290 err = vm_insert_page(vma, addr, page);
291 if (err)
292 return err;
293 addr += PAGE_SIZE;
294 }
295
296 return 0;
297}
298
299static int tgt_mmap(struct file *filp, struct vm_area_struct *vma)
300{
301 unsigned long addr;
302 int err;
303
304 if (vma->vm_pgoff)
305 return -EINVAL;
306
307 if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) {
308 eprintk("mmap size must be %lu, not %lu \n",
309 TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start);
310 return -EINVAL;
311 }
312
313 addr = vma->vm_start;
314 err = uspace_ring_map(vma, addr, &tx_ring);
315 if (err)
316 return err;
317 err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring);
318
319 return err;
320}
321
322static int tgt_open(struct inode *inode, struct file *file)
323{
324 tx_ring.tr_idx = rx_ring.tr_idx = 0;
325
326 return 0;
327}
328
329static const struct file_operations tgt_fops = {
330 .owner = THIS_MODULE,
331 .open = tgt_open,
332 .poll = tgt_poll,
333 .write = tgt_write,
334 .mmap = tgt_mmap,
335 .llseek = noop_llseek,
336};
337
338static struct miscdevice tgt_miscdev = {
339 .minor = MISC_DYNAMIC_MINOR,
340 .name = "tgt",
341 .fops = &tgt_fops,
342};
343
344static void tgt_ring_exit(struct tgt_ring *ring)
345{
346 int i;
347
348 for (i = 0; i < TGT_RING_PAGES; i++)
349 free_page(ring->tr_pages[i]);
350}
351
352static int tgt_ring_init(struct tgt_ring *ring)
353{
354 int i;
355
356 spin_lock_init(&ring->tr_lock);
357
358 for (i = 0; i < TGT_RING_PAGES; i++) {
359 ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL);
360 if (!ring->tr_pages[i]) {
361 eprintk("out of memory\n");
362 return -ENOMEM;
363 }
364 }
365
366 return 0;
367}
368
369void scsi_tgt_if_exit(void)
370{
371 tgt_ring_exit(&tx_ring);
372 tgt_ring_exit(&rx_ring);
373 misc_deregister(&tgt_miscdev);
374}
375
376int scsi_tgt_if_init(void)
377{
378 int err;
379
380 err = tgt_ring_init(&tx_ring);
381 if (err)
382 return err;
383
384 err = tgt_ring_init(&rx_ring);
385 if (err)
386 goto free_tx_ring;
387
388 err = misc_register(&tgt_miscdev);
389 if (err)
390 goto free_rx_ring;
391
392 return 0;
393free_rx_ring:
394 tgt_ring_exit(&rx_ring);
395free_tx_ring:
396 tgt_ring_exit(&tx_ring);
397
398 return err;
399}
400
