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11#include <linux/blkdev.h>
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/kernel.h>
15#include <linux/timer.h>
16#include <asm/irq.h>
17#include "hpsim_ssc.h"
18
19#include <scsi/scsi.h>
20#include <scsi/scsi_cmnd.h>
21#include <scsi/scsi_device.h>
22#include <scsi/scsi_host.h>
23
24#define DEBUG_SIMSCSI 0
25
26#define SIMSCSI_REQ_QUEUE_LEN 64
27#define DEFAULT_SIMSCSI_ROOT "/var/ski-disks/sd"
28
29
30
31#define SSC_OPEN 50
32#define SSC_CLOSE 51
33#define SSC_READ 52
34#define SSC_WRITE 53
35#define SSC_GET_COMPLETION 54
36#define SSC_WAIT_COMPLETION 55
37
38#define SSC_WRITE_ACCESS 2
39#define SSC_READ_ACCESS 1
40
41#if DEBUG_SIMSCSI
42 int simscsi_debug;
43# define DBG simscsi_debug
44#else
45# define DBG 0
46#endif
47
48static struct Scsi_Host *host;
49
50static void simscsi_interrupt (unsigned long val);
51static DECLARE_TASKLET(simscsi_tasklet, simscsi_interrupt, 0);
52
53struct disk_req {
54 unsigned long addr;
55 unsigned len;
56};
57
58struct disk_stat {
59 int fd;
60 unsigned count;
61};
62
63static int desc[16] = {
64 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
65};
66
67static struct queue_entry {
68 struct scsi_cmnd *sc;
69} queue[SIMSCSI_REQ_QUEUE_LEN];
70
71static int rd, wr;
72static atomic_t num_reqs = ATOMIC_INIT(0);
73
74
75static char *simscsi_root = DEFAULT_SIMSCSI_ROOT;
76
77#define MAX_ROOT_LEN 128
78
79
80
81
82
83
84static int __init
85simscsi_setup (char *s)
86{
87
88 if (strlen(s) > MAX_ROOT_LEN) {
89 printk(KERN_ERR "simscsi_setup: prefix too long---using default %s\n",
90 simscsi_root);
91 }
92 simscsi_root = s;
93 return 1;
94}
95
96__setup("simscsi=", simscsi_setup);
97
98static void
99simscsi_interrupt (unsigned long val)
100{
101 struct scsi_cmnd *sc;
102
103 while ((sc = queue[rd].sc) != NULL) {
104 atomic_dec(&num_reqs);
105 queue[rd].sc = NULL;
106 if (DBG)
107 printk("simscsi_interrupt: done with %ld\n", sc->serial_number);
108 (*sc->scsi_done)(sc);
109 rd = (rd + 1) % SIMSCSI_REQ_QUEUE_LEN;
110 }
111}
112
113static int
114simscsi_biosparam (struct scsi_device *sdev, struct block_device *n,
115 sector_t capacity, int ip[])
116{
117 ip[0] = 64;
118 ip[1] = 32;
119 ip[2] = capacity >> 11;
120 return 0;
121}
122
123static void
124simscsi_sg_readwrite (struct scsi_cmnd *sc, int mode, unsigned long offset)
125{
126 int i;
127 struct scatterlist *sl;
128 struct disk_stat stat;
129 struct disk_req req;
130
131 stat.fd = desc[sc->device->id];
132
133 scsi_for_each_sg(sc, sl, scsi_sg_count(sc), i) {
134 req.addr = __pa(sg_virt(sl));
135 req.len = sl->length;
136 if (DBG)
137 printk("simscsi_sg_%s @ %lx (off %lx) use_sg=%d len=%d\n",
138 mode == SSC_READ ? "read":"write", req.addr, offset,
139 scsi_sg_count(sc) - i, sl->length);
140 ia64_ssc(stat.fd, 1, __pa(&req), offset, mode);
141 ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
142
143
144 if (stat.count != req.len) {
145 sc->result = DID_ERROR << 16;
146 return;
147 }
148 offset += sl->length;
149 }
150 sc->result = GOOD;
151}
152
153
154
155
156
157
158static void
159simscsi_readwrite6 (struct scsi_cmnd *sc, int mode)
160{
161 unsigned long offset;
162
163 offset = (((sc->cmnd[1] & 0x1f) << 16) | (sc->cmnd[2] << 8) | sc->cmnd[3])*512;
164 simscsi_sg_readwrite(sc, mode, offset);
165}
166
167static size_t
168simscsi_get_disk_size (int fd)
169{
170 struct disk_stat stat;
171 size_t bit, sectors = 0;
172 struct disk_req req;
173 char buf[512];
174
175
176
177
178
179
180 for (bit = (128UL << 30)/512; bit != 0; bit >>= 1) {
181 req.addr = __pa(&buf);
182 req.len = sizeof(buf);
183 ia64_ssc(fd, 1, __pa(&req), ((sectors | bit) - 1)*512, SSC_READ);
184 stat.fd = fd;
185 ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
186 if (stat.count == sizeof(buf))
187 sectors |= bit;
188 }
189 return sectors - 1;
190}
191
192static void
193simscsi_readwrite10 (struct scsi_cmnd *sc, int mode)
194{
195 unsigned long offset;
196
197 offset = (((unsigned long)sc->cmnd[2] << 24)
198 | ((unsigned long)sc->cmnd[3] << 16)
199 | ((unsigned long)sc->cmnd[4] << 8)
200 | ((unsigned long)sc->cmnd[5] << 0))*512UL;
201 simscsi_sg_readwrite(sc, mode, offset);
202}
203
204static int
205simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
206{
207 unsigned int target_id = sc->device->id;
208 char fname[MAX_ROOT_LEN+16];
209 size_t disk_size;
210 char *buf;
211 char localbuf[36];
212#if DEBUG_SIMSCSI
213 register long sp asm ("sp");
214
215 if (DBG)
216 printk("simscsi_queuecommand: target=%d,cmnd=%u,sc=%lu,sp=%lx,done=%p\n",
217 target_id, sc->cmnd[0], sc->serial_number, sp, done);
218#endif
219
220 sc->result = DID_BAD_TARGET << 16;
221 sc->scsi_done = done;
222 if (target_id <= 15 && sc->device->lun == 0) {
223 switch (sc->cmnd[0]) {
224 case INQUIRY:
225 if (scsi_bufflen(sc) < 35) {
226 break;
227 }
228 sprintf (fname, "%s%c", simscsi_root, 'a' + target_id);
229 desc[target_id] = ia64_ssc(__pa(fname), SSC_READ_ACCESS|SSC_WRITE_ACCESS,
230 0, 0, SSC_OPEN);
231 if (desc[target_id] < 0) {
232
233 break;
234 }
235 buf = localbuf;
236 buf[0] = 0;
237 buf[1] = 0;
238 buf[2] = 2;
239 buf[3] = 2;
240 buf[4] = 31;
241 buf[5] = 0;
242 buf[6] = 0;
243 buf[7] = 0;
244 memcpy(buf + 8, "HP SIMULATED DISK 0.00", 28);
245 scsi_sg_copy_from_buffer(sc, buf, 36);
246 sc->result = GOOD;
247 break;
248
249 case TEST_UNIT_READY:
250 sc->result = GOOD;
251 break;
252
253 case READ_6:
254 if (desc[target_id] < 0 )
255 break;
256 simscsi_readwrite6(sc, SSC_READ);
257 break;
258
259 case READ_10:
260 if (desc[target_id] < 0 )
261 break;
262 simscsi_readwrite10(sc, SSC_READ);
263 break;
264
265 case WRITE_6:
266 if (desc[target_id] < 0)
267 break;
268 simscsi_readwrite6(sc, SSC_WRITE);
269 break;
270
271 case WRITE_10:
272 if (desc[target_id] < 0)
273 break;
274 simscsi_readwrite10(sc, SSC_WRITE);
275 break;
276
277 case READ_CAPACITY:
278 if (desc[target_id] < 0 || scsi_bufflen(sc) < 8) {
279 break;
280 }
281 buf = localbuf;
282 disk_size = simscsi_get_disk_size(desc[target_id]);
283
284 buf[0] = (disk_size >> 24) & 0xff;
285 buf[1] = (disk_size >> 16) & 0xff;
286 buf[2] = (disk_size >> 8) & 0xff;
287 buf[3] = (disk_size >> 0) & 0xff;
288
289 buf[4] = 0;
290 buf[5] = 0;
291 buf[6] = 2;
292 buf[7] = 0;
293 scsi_sg_copy_from_buffer(sc, buf, 8);
294 sc->result = GOOD;
295 break;
296
297 case MODE_SENSE:
298 case MODE_SENSE_10:
299
300 scsi_sg_copy_from_buffer(sc, (char *)empty_zero_page,
301 PAGE_SIZE);
302 sc->result = GOOD;
303 break;
304
305 case START_STOP:
306 printk(KERN_ERR "START_STOP\n");
307 break;
308
309 default:
310 panic("simscsi: unknown SCSI command %u\n", sc->cmnd[0]);
311 }
312 }
313 if (sc->result == DID_BAD_TARGET) {
314 sc->result |= DRIVER_SENSE << 24;
315 sc->sense_buffer[0] = 0x70;
316 sc->sense_buffer[2] = 0x00;
317 }
318 if (atomic_read(&num_reqs) >= SIMSCSI_REQ_QUEUE_LEN) {
319 panic("Attempt to queue command while command is pending!!");
320 }
321 atomic_inc(&num_reqs);
322 queue[wr].sc = sc;
323 wr = (wr + 1) % SIMSCSI_REQ_QUEUE_LEN;
324
325 tasklet_schedule(&simscsi_tasklet);
326 return 0;
327}
328
329static int
330simscsi_host_reset (struct scsi_cmnd *sc)
331{
332 printk(KERN_ERR "simscsi_host_reset: not implemented\n");
333 return 0;
334}
335
336static struct scsi_host_template driver_template = {
337 .name = "simulated SCSI host adapter",
338 .proc_name = "simscsi",
339 .queuecommand = simscsi_queuecommand,
340 .eh_host_reset_handler = simscsi_host_reset,
341 .bios_param = simscsi_biosparam,
342 .can_queue = SIMSCSI_REQ_QUEUE_LEN,
343 .this_id = -1,
344 .sg_tablesize = SG_ALL,
345 .max_sectors = 1024,
346 .cmd_per_lun = SIMSCSI_REQ_QUEUE_LEN,
347 .use_clustering = DISABLE_CLUSTERING,
348};
349
350static int __init
351simscsi_init(void)
352{
353 int error;
354
355 host = scsi_host_alloc(&driver_template, 0);
356 if (!host)
357 return -ENOMEM;
358
359 error = scsi_add_host(host, NULL);
360 if (error)
361 goto free_host;
362 scsi_scan_host(host);
363 return 0;
364
365 free_host:
366 scsi_host_put(host);
367 return error;
368}
369
370static void __exit
371simscsi_exit(void)
372{
373 scsi_remove_host(host);
374 scsi_host_put(host);
375}
376
377module_init(simscsi_init);
378module_exit(simscsi_exit);
379
