1
2
3
4
5
6
7
8
9
10
11
12#include <linux/blkdev.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/kernel.h>
16#include <linux/timer.h>
17#include <asm/irq.h>
18#include "hpsim_ssc.h"
19
20#include <scsi/scsi.h>
21#include <scsi/scsi_cmnd.h>
22#include <scsi/scsi_device.h>
23#include <scsi/scsi_host.h>
24
25#define DEBUG_SIMSCSI 0
26
27#define SIMSCSI_REQ_QUEUE_LEN 64
28#define DEFAULT_SIMSCSI_ROOT "/var/ski-disks/sd"
29
30
31
32#define SSC_OPEN 50
33#define SSC_CLOSE 51
34#define SSC_READ 52
35#define SSC_WRITE 53
36#define SSC_GET_COMPLETION 54
37#define SSC_WAIT_COMPLETION 55
38
39#define SSC_WRITE_ACCESS 2
40#define SSC_READ_ACCESS 1
41
42#if DEBUG_SIMSCSI
43 int simscsi_debug;
44# define DBG simscsi_debug
45#else
46# define DBG 0
47#endif
48
49static struct Scsi_Host *host;
50
51static void simscsi_interrupt (unsigned long val);
52static DECLARE_TASKLET(simscsi_tasklet, simscsi_interrupt, 0);
53
54struct disk_req {
55 unsigned long addr;
56 unsigned len;
57};
58
59struct disk_stat {
60 int fd;
61 unsigned count;
62};
63
64static int desc[16] = {
65 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
66};
67
68static struct queue_entry {
69 struct scsi_cmnd *sc;
70} queue[SIMSCSI_REQ_QUEUE_LEN];
71
72static int rd, wr;
73static atomic_t num_reqs = ATOMIC_INIT(0);
74
75
76static char *simscsi_root = DEFAULT_SIMSCSI_ROOT;
77
78#define MAX_ROOT_LEN 128
79
80
81
82
83
84
85static int __init
86simscsi_setup (char *s)
87{
88
89 if (strlen(s) > MAX_ROOT_LEN) {
90 printk(KERN_ERR "simscsi_setup: prefix too long---using default %s\n",
91 simscsi_root);
92 } else
93 simscsi_root = s;
94 return 1;
95}
96
97__setup("simscsi=", simscsi_setup);
98
99static void
100simscsi_interrupt (unsigned long val)
101{
102 struct scsi_cmnd *sc;
103
104 while ((sc = queue[rd].sc) != NULL) {
105 atomic_dec(&num_reqs);
106 queue[rd].sc = NULL;
107 if (DBG)
108 printk("simscsi_interrupt: done with %ld\n", sc->serial_number);
109 (*sc->scsi_done)(sc);
110 rd = (rd + 1) % SIMSCSI_REQ_QUEUE_LEN;
111 }
112}
113
114static int
115simscsi_biosparam (struct scsi_device *sdev, struct block_device *n,
116 sector_t capacity, int ip[])
117{
118 ip[0] = 64;
119 ip[1] = 32;
120 ip[2] = capacity >> 11;
121 return 0;
122}
123
124static void
125simscsi_sg_readwrite (struct scsi_cmnd *sc, int mode, unsigned long offset)
126{
127 int i;
128 struct scatterlist *sl;
129 struct disk_stat stat;
130 struct disk_req req;
131
132 stat.fd = desc[sc->device->id];
133
134 scsi_for_each_sg(sc, sl, scsi_sg_count(sc), i) {
135 req.addr = __pa(sg_virt(sl));
136 req.len = sl->length;
137 if (DBG)
138 printk("simscsi_sg_%s @ %lx (off %lx) use_sg=%d len=%d\n",
139 mode == SSC_READ ? "read":"write", req.addr, offset,
140 scsi_sg_count(sc) - i, sl->length);
141 ia64_ssc(stat.fd, 1, __pa(&req), offset, mode);
142 ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
143
144
145 if (stat.count != req.len) {
146 sc->result = DID_ERROR << 16;
147 return;
148 }
149 offset += sl->length;
150 }
151 sc->result = GOOD;
152}
153
154
155
156
157
158
159static void
160simscsi_readwrite6 (struct scsi_cmnd *sc, int mode)
161{
162 unsigned long offset;
163
164 offset = (((sc->cmnd[1] & 0x1f) << 16) | (sc->cmnd[2] << 8) | sc->cmnd[3])*512;
165 simscsi_sg_readwrite(sc, mode, offset);
166}
167
168static size_t
169simscsi_get_disk_size (int fd)
170{
171 struct disk_stat stat;
172 size_t bit, sectors = 0;
173 struct disk_req req;
174 char buf[512];
175
176
177
178
179
180
181 for (bit = (128UL << 30)/512; bit != 0; bit >>= 1) {
182 req.addr = __pa(&buf);
183 req.len = sizeof(buf);
184 ia64_ssc(fd, 1, __pa(&req), ((sectors | bit) - 1)*512, SSC_READ);
185 stat.fd = fd;
186 ia64_ssc(__pa(&stat), 0, 0, 0, SSC_WAIT_COMPLETION);
187 if (stat.count == sizeof(buf))
188 sectors |= bit;
189 }
190 return sectors - 1;
191}
192
193static void
194simscsi_readwrite10 (struct scsi_cmnd *sc, int mode)
195{
196 unsigned long offset;
197
198 offset = (((unsigned long)sc->cmnd[2] << 24)
199 | ((unsigned long)sc->cmnd[3] << 16)
200 | ((unsigned long)sc->cmnd[4] << 8)
201 | ((unsigned long)sc->cmnd[5] << 0))*512UL;
202 simscsi_sg_readwrite(sc, mode, offset);
203}
204
205static int
206simscsi_queuecommand_lck (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
207{
208 unsigned int target_id = sc->device->id;
209 char fname[MAX_ROOT_LEN+16];
210 size_t disk_size;
211 char *buf;
212 char localbuf[36];
213#if DEBUG_SIMSCSI
214 register long sp asm ("sp");
215
216 if (DBG)
217 printk("simscsi_queuecommand: target=%d,cmnd=%u,sc=%lu,sp=%lx,done=%p\n",
218 target_id, sc->cmnd[0], sc->serial_number, sp, done);
219#endif
220
221 sc->result = DID_BAD_TARGET << 16;
222 sc->scsi_done = done;
223 if (target_id <= 15 && sc->device->lun == 0) {
224 switch (sc->cmnd[0]) {
225 case INQUIRY:
226 if (scsi_bufflen(sc) < 35) {
227 break;
228 }
229 sprintf (fname, "%s%c", simscsi_root, 'a' + target_id);
230 desc[target_id] = ia64_ssc(__pa(fname), SSC_READ_ACCESS|SSC_WRITE_ACCESS,
231 0, 0, SSC_OPEN);
232 if (desc[target_id] < 0) {
233
234 break;
235 }
236 buf = localbuf;
237 buf[0] = 0;
238 buf[1] = 0;
239 buf[2] = 2;
240 buf[3] = 2;
241 buf[4] = 31;
242 buf[5] = 0;
243 buf[6] = 0;
244 buf[7] = 0;
245 memcpy(buf + 8, "HP SIMULATED DISK 0.00", 28);
246 scsi_sg_copy_from_buffer(sc, buf, 36);
247 sc->result = GOOD;
248 break;
249
250 case TEST_UNIT_READY:
251 sc->result = GOOD;
252 break;
253
254 case READ_6:
255 if (desc[target_id] < 0 )
256 break;
257 simscsi_readwrite6(sc, SSC_READ);
258 break;
259
260 case READ_10:
261 if (desc[target_id] < 0 )
262 break;
263 simscsi_readwrite10(sc, SSC_READ);
264 break;
265
266 case WRITE_6:
267 if (desc[target_id] < 0)
268 break;
269 simscsi_readwrite6(sc, SSC_WRITE);
270 break;
271
272 case WRITE_10:
273 if (desc[target_id] < 0)
274 break;
275 simscsi_readwrite10(sc, SSC_WRITE);
276 break;
277
278 case READ_CAPACITY:
279 if (desc[target_id] < 0 || scsi_bufflen(sc) < 8) {
280 break;
281 }
282 buf = localbuf;
283 disk_size = simscsi_get_disk_size(desc[target_id]);
284
285 buf[0] = (disk_size >> 24) & 0xff;
286 buf[1] = (disk_size >> 16) & 0xff;
287 buf[2] = (disk_size >> 8) & 0xff;
288 buf[3] = (disk_size >> 0) & 0xff;
289
290 buf[4] = 0;
291 buf[5] = 0;
292 buf[6] = 2;
293 buf[7] = 0;
294 scsi_sg_copy_from_buffer(sc, buf, 8);
295 sc->result = GOOD;
296 break;
297
298 case MODE_SENSE:
299 case MODE_SENSE_10:
300
301 scsi_sg_copy_from_buffer(sc, (char *)empty_zero_page,
302 PAGE_SIZE);
303 sc->result = GOOD;
304 break;
305
306 case START_STOP:
307 printk(KERN_ERR "START_STOP\n");
308 break;
309
310 default:
311 panic("simscsi: unknown SCSI command %u\n", sc->cmnd[0]);
312 }
313 }
314 if (sc->result == DID_BAD_TARGET) {
315 sc->result |= DRIVER_SENSE << 24;
316 sc->sense_buffer[0] = 0x70;
317 sc->sense_buffer[2] = 0x00;
318 }
319 if (atomic_read(&num_reqs) >= SIMSCSI_REQ_QUEUE_LEN) {
320 panic("Attempt to queue command while command is pending!!");
321 }
322 atomic_inc(&num_reqs);
323 queue[wr].sc = sc;
324 wr = (wr + 1) % SIMSCSI_REQ_QUEUE_LEN;
325
326 tasklet_schedule(&simscsi_tasklet);
327 return 0;
328}
329
330static DEF_SCSI_QCMD(simscsi_queuecommand)
331
332static int
333simscsi_host_reset (struct scsi_cmnd *sc)
334{
335 printk(KERN_ERR "simscsi_host_reset: not implemented\n");
336 return 0;
337}
338
339static struct scsi_host_template driver_template = {
340 .name = "simulated SCSI host adapter",
341 .proc_name = "simscsi",
342 .queuecommand = simscsi_queuecommand,
343 .eh_host_reset_handler = simscsi_host_reset,
344 .bios_param = simscsi_biosparam,
345 .can_queue = SIMSCSI_REQ_QUEUE_LEN,
346 .this_id = -1,
347 .sg_tablesize = SG_ALL,
348 .max_sectors = 1024,
349 .cmd_per_lun = SIMSCSI_REQ_QUEUE_LEN,
350 .use_clustering = DISABLE_CLUSTERING,
351};
352
353static int __init
354simscsi_init(void)
355{
356 int error;
357
358 host = scsi_host_alloc(&driver_template, 0);
359 if (!host)
360 return -ENOMEM;
361
362 error = scsi_add_host(host, NULL);
363 if (error)
364 goto free_host;
365 scsi_scan_host(host);
366 return 0;
367
368 free_host:
369 scsi_host_put(host);
370 return error;
371}
372device_initcall(simscsi_init);
373
