xref: /linux/drivers/scsi/sg.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20 
21 static int sg_version_num = 30533;	/* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.33"
23 
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32 
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/smp_lock.h>
45 #include <linux/moduleparam.h>
46 #include <linux/cdev.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/scatterlist.h>
51 
52 #include "scsi.h"
53 #include <scsi/scsi_dbg.h>
54 #include <scsi/scsi_host.h>
55 #include <scsi/scsi_driver.h>
56 #include <scsi/scsi_ioctl.h>
57 #include <scsi/sg.h>
58 
59 #include "scsi_logging.h"
60 
61 #ifdef CONFIG_SCSI_PROC_FS
62 #include <linux/proc_fs.h>
63 static char *sg_version_date = "20050908";
64 
65 static int sg_proc_init(void);
66 static void sg_proc_cleanup(void);
67 #endif
68 
69 #define SG_ALLOW_DIO_DEF 0
70 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
71 
72 #define SG_MAX_DEVS 32768
73 
74 /*
75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
76  * Then when using 32 bit integers x * m may overflow during the calculation.
77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
78  * calculates the same, but prevents the overflow when both m and d
79  * are "small" numbers (like HZ and USER_HZ).
80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
81  * in 32 bits.
82  */
83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
84 
85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
86 
87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
88 /* N.B. This variable is readable and writeable via
89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
90    of this size (or less if there is not enough memory) will be reserved
91    for use by this file descriptor. [Deprecated usage: this variable is also
92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
93    the kernel (i.e. it is not a module).] */
94 static int def_reserved_size = -1;	/* picks up init parameter */
95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
96 
97 #define SG_SECTOR_SZ 512
98 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
99 
100 #define SG_DEV_ARR_LUMP 32	/* amount to over allocate sg_dev_arr by */
101 
102 static int sg_add(struct class_device *, struct class_interface *);
103 static void sg_remove(struct class_device *, struct class_interface *);
104 
105 static DEFINE_RWLOCK(sg_dev_arr_lock);	/* Also used to lock
106 							   file descriptor list for device */
107 
108 static struct class_interface sg_interface = {
109 	.add		= sg_add,
110 	.remove		= sg_remove,
111 };
112 
113 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
114 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
115 	unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
116 	unsigned bufflen;	/* Size of (aggregate) data buffer */
117 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
118 	struct scatterlist *buffer;/* scatter list */
119 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
120 	unsigned char cmd_opcode; /* first byte of command */
121 } Sg_scatter_hold;
122 
123 struct sg_device;		/* forward declarations */
124 struct sg_fd;
125 
126 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
127 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
128 	struct sg_fd *parentfp;	/* NULL -> not in use */
129 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
130 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
131 	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
132 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
133 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
134 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
135 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
136 } Sg_request;
137 
138 typedef struct sg_fd {		/* holds the state of a file descriptor */
139 	struct sg_fd *nextfp;	/* NULL when last opened fd on this device */
140 	struct sg_device *parentdp;	/* owning device */
141 	wait_queue_head_t read_wait;	/* queue read until command done */
142 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
143 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
144 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
145 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
146 	unsigned save_scat_len;	/* original length of trunc. scat. element */
147 	Sg_request *headrp;	/* head of request slist, NULL->empty */
148 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
149 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
150 	char low_dma;		/* as in parent but possibly overridden to 1 */
151 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
152 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
153 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
154 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
155 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
156 	char mmap_called;	/* 0 -> mmap() never called on this fd */
157 } Sg_fd;
158 
159 typedef struct sg_device { /* holds the state of each scsi generic device */
160 	struct scsi_device *device;
161 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
162 	int sg_tablesize;	/* adapter's max scatter-gather table size */
163 	Sg_fd *headfp;		/* first open fd belonging to this device */
164 	volatile char detached;	/* 0->attached, 1->detached pending removal */
165 	volatile char exclude;	/* opened for exclusive access */
166 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
167 	struct gendisk *disk;
168 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
169 } Sg_device;
170 
171 static int sg_fasync(int fd, struct file *filp, int mode);
172 /* tasklet or soft irq callback */
173 static void sg_cmd_done(void *data, char *sense, int result, int resid);
174 static int sg_start_req(Sg_request * srp);
175 static void sg_finish_rem_req(Sg_request * srp);
176 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
177 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
178 			 int tablesize);
179 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
180 			   Sg_request * srp);
181 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
182 			    int blocking, int read_only, Sg_request ** o_srp);
183 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
184 			   unsigned char *cmnd, int timeout, int blocking);
185 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
186 		      int wr_xf, int *countp, unsigned char __user **up);
187 static int sg_write_xfer(Sg_request * srp);
188 static int sg_read_xfer(Sg_request * srp);
189 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
190 static void sg_remove_scat(Sg_scatter_hold * schp);
191 static void sg_build_reserve(Sg_fd * sfp, int req_size);
192 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
193 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
194 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
195 static void sg_page_free(struct page *page, int size);
196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
197 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
198 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
199 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
200 static Sg_request *sg_add_request(Sg_fd * sfp);
201 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
202 static int sg_res_in_use(Sg_fd * sfp);
203 static int sg_allow_access(unsigned char opcode, char dev_type);
204 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
205 static Sg_device *sg_get_dev(int dev);
206 #ifdef CONFIG_SCSI_PROC_FS
207 static int sg_last_dev(void);
208 #endif
209 
210 static Sg_device **sg_dev_arr = NULL;
211 static int sg_dev_max;
212 static int sg_nr_dev;
213 
214 #define SZ_SG_HEADER sizeof(struct sg_header)
215 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
216 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
217 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
218 
219 static int
220 sg_open(struct inode *inode, struct file *filp)
221 {
222 	int dev = iminor(inode);
223 	int flags = filp->f_flags;
224 	struct request_queue *q;
225 	Sg_device *sdp;
226 	Sg_fd *sfp;
227 	int res;
228 	int retval;
229 
230 	nonseekable_open(inode, filp);
231 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
232 	sdp = sg_get_dev(dev);
233 	if ((!sdp) || (!sdp->device))
234 		return -ENXIO;
235 	if (sdp->detached)
236 		return -ENODEV;
237 
238 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
239 	/* Prevent the device driver from vanishing while we sleep */
240 	retval = scsi_device_get(sdp->device);
241 	if (retval)
242 		return retval;
243 
244 	if (!((flags & O_NONBLOCK) ||
245 	      scsi_block_when_processing_errors(sdp->device))) {
246 		retval = -ENXIO;
247 		/* we are in error recovery for this device */
248 		goto error_out;
249 	}
250 
251 	if (flags & O_EXCL) {
252 		if (O_RDONLY == (flags & O_ACCMODE)) {
253 			retval = -EPERM; /* Can't lock it with read only access */
254 			goto error_out;
255 		}
256 		if (sdp->headfp && (flags & O_NONBLOCK)) {
257 			retval = -EBUSY;
258 			goto error_out;
259 		}
260 		res = 0;
261 		__wait_event_interruptible(sdp->o_excl_wait,
262 			((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
263 		if (res) {
264 			retval = res;	/* -ERESTARTSYS because signal hit process */
265 			goto error_out;
266 		}
267 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
268 		if (flags & O_NONBLOCK) {
269 			retval = -EBUSY;
270 			goto error_out;
271 		}
272 		res = 0;
273 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
274 					   res);
275 		if (res) {
276 			retval = res;	/* -ERESTARTSYS because signal hit process */
277 			goto error_out;
278 		}
279 	}
280 	if (sdp->detached) {
281 		retval = -ENODEV;
282 		goto error_out;
283 	}
284 	if (!sdp->headfp) {	/* no existing opens on this device */
285 		sdp->sgdebug = 0;
286 		q = sdp->device->request_queue;
287 		sdp->sg_tablesize = min(q->max_hw_segments,
288 					q->max_phys_segments);
289 	}
290 	if ((sfp = sg_add_sfp(sdp, dev)))
291 		filp->private_data = sfp;
292 	else {
293 		if (flags & O_EXCL)
294 			sdp->exclude = 0;	/* undo if error */
295 		retval = -ENOMEM;
296 		goto error_out;
297 	}
298 	return 0;
299 
300       error_out:
301 	scsi_device_put(sdp->device);
302 	return retval;
303 }
304 
305 /* Following function was formerly called 'sg_close' */
306 static int
307 sg_release(struct inode *inode, struct file *filp)
308 {
309 	Sg_device *sdp;
310 	Sg_fd *sfp;
311 
312 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
313 		return -ENXIO;
314 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
315 	sg_fasync(-1, filp, 0);	/* remove filp from async notification list */
316 	if (0 == sg_remove_sfp(sdp, sfp)) {	/* Returns 1 when sdp gone */
317 		if (!sdp->detached) {
318 			scsi_device_put(sdp->device);
319 		}
320 		sdp->exclude = 0;
321 		wake_up_interruptible(&sdp->o_excl_wait);
322 	}
323 	return 0;
324 }
325 
326 static ssize_t
327 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
328 {
329 	Sg_device *sdp;
330 	Sg_fd *sfp;
331 	Sg_request *srp;
332 	int req_pack_id = -1;
333 	sg_io_hdr_t *hp;
334 	struct sg_header *old_hdr = NULL;
335 	int retval = 0;
336 
337 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
338 		return -ENXIO;
339 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
340 				   sdp->disk->disk_name, (int) count));
341 
342 	if (!access_ok(VERIFY_WRITE, buf, count))
343 		return -EFAULT;
344 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
345 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
346 		if (!old_hdr)
347 			return -ENOMEM;
348 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
349 			retval = -EFAULT;
350 			goto free_old_hdr;
351 		}
352 		if (old_hdr->reply_len < 0) {
353 			if (count >= SZ_SG_IO_HDR) {
354 				sg_io_hdr_t *new_hdr;
355 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
356 				if (!new_hdr) {
357 					retval = -ENOMEM;
358 					goto free_old_hdr;
359 				}
360 				retval =__copy_from_user
361 				    (new_hdr, buf, SZ_SG_IO_HDR);
362 				req_pack_id = new_hdr->pack_id;
363 				kfree(new_hdr);
364 				if (retval) {
365 					retval = -EFAULT;
366 					goto free_old_hdr;
367 				}
368 			}
369 		} else
370 			req_pack_id = old_hdr->pack_id;
371 	}
372 	srp = sg_get_rq_mark(sfp, req_pack_id);
373 	if (!srp) {		/* now wait on packet to arrive */
374 		if (sdp->detached) {
375 			retval = -ENODEV;
376 			goto free_old_hdr;
377 		}
378 		if (filp->f_flags & O_NONBLOCK) {
379 			retval = -EAGAIN;
380 			goto free_old_hdr;
381 		}
382 		while (1) {
383 			retval = 0; /* following macro beats race condition */
384 			__wait_event_interruptible(sfp->read_wait,
385 				(sdp->detached ||
386 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
387 				retval);
388 			if (sdp->detached) {
389 				retval = -ENODEV;
390 				goto free_old_hdr;
391 			}
392 			if (0 == retval)
393 				break;
394 
395 			/* -ERESTARTSYS as signal hit process */
396 			goto free_old_hdr;
397 		}
398 	}
399 	if (srp->header.interface_id != '\0') {
400 		retval = sg_new_read(sfp, buf, count, srp);
401 		goto free_old_hdr;
402 	}
403 
404 	hp = &srp->header;
405 	if (old_hdr == NULL) {
406 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
407 		if (! old_hdr) {
408 			retval = -ENOMEM;
409 			goto free_old_hdr;
410 		}
411 	}
412 	memset(old_hdr, 0, SZ_SG_HEADER);
413 	old_hdr->reply_len = (int) hp->timeout;
414 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
415 	old_hdr->pack_id = hp->pack_id;
416 	old_hdr->twelve_byte =
417 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
418 	old_hdr->target_status = hp->masked_status;
419 	old_hdr->host_status = hp->host_status;
420 	old_hdr->driver_status = hp->driver_status;
421 	if ((CHECK_CONDITION & hp->masked_status) ||
422 	    (DRIVER_SENSE & hp->driver_status))
423 		memcpy(old_hdr->sense_buffer, srp->sense_b,
424 		       sizeof (old_hdr->sense_buffer));
425 	switch (hp->host_status) {
426 	/* This setup of 'result' is for backward compatibility and is best
427 	   ignored by the user who should use target, host + driver status */
428 	case DID_OK:
429 	case DID_PASSTHROUGH:
430 	case DID_SOFT_ERROR:
431 		old_hdr->result = 0;
432 		break;
433 	case DID_NO_CONNECT:
434 	case DID_BUS_BUSY:
435 	case DID_TIME_OUT:
436 		old_hdr->result = EBUSY;
437 		break;
438 	case DID_BAD_TARGET:
439 	case DID_ABORT:
440 	case DID_PARITY:
441 	case DID_RESET:
442 	case DID_BAD_INTR:
443 		old_hdr->result = EIO;
444 		break;
445 	case DID_ERROR:
446 		old_hdr->result = (srp->sense_b[0] == 0 &&
447 				  hp->masked_status == GOOD) ? 0 : EIO;
448 		break;
449 	default:
450 		old_hdr->result = EIO;
451 		break;
452 	}
453 
454 	/* Now copy the result back to the user buffer.  */
455 	if (count >= SZ_SG_HEADER) {
456 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
457 			retval = -EFAULT;
458 			goto free_old_hdr;
459 		}
460 		buf += SZ_SG_HEADER;
461 		if (count > old_hdr->reply_len)
462 			count = old_hdr->reply_len;
463 		if (count > SZ_SG_HEADER) {
464 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
465 				retval = -EFAULT;
466 				goto free_old_hdr;
467 			}
468 		}
469 	} else
470 		count = (old_hdr->result == 0) ? 0 : -EIO;
471 	sg_finish_rem_req(srp);
472 	retval = count;
473 free_old_hdr:
474 	kfree(old_hdr);
475 	return retval;
476 }
477 
478 static ssize_t
479 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
480 {
481 	sg_io_hdr_t *hp = &srp->header;
482 	int err = 0;
483 	int len;
484 
485 	if (count < SZ_SG_IO_HDR) {
486 		err = -EINVAL;
487 		goto err_out;
488 	}
489 	hp->sb_len_wr = 0;
490 	if ((hp->mx_sb_len > 0) && hp->sbp) {
491 		if ((CHECK_CONDITION & hp->masked_status) ||
492 		    (DRIVER_SENSE & hp->driver_status)) {
493 			int sb_len = SCSI_SENSE_BUFFERSIZE;
494 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
495 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
496 			len = (len > sb_len) ? sb_len : len;
497 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
498 				err = -EFAULT;
499 				goto err_out;
500 			}
501 			hp->sb_len_wr = len;
502 		}
503 	}
504 	if (hp->masked_status || hp->host_status || hp->driver_status)
505 		hp->info |= SG_INFO_CHECK;
506 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
507 		err = -EFAULT;
508 		goto err_out;
509 	}
510 	err = sg_read_xfer(srp);
511       err_out:
512 	sg_finish_rem_req(srp);
513 	return (0 == err) ? count : err;
514 }
515 
516 static ssize_t
517 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
518 {
519 	int mxsize, cmd_size, k;
520 	int input_size, blocking;
521 	unsigned char opcode;
522 	Sg_device *sdp;
523 	Sg_fd *sfp;
524 	Sg_request *srp;
525 	struct sg_header old_hdr;
526 	sg_io_hdr_t *hp;
527 	unsigned char cmnd[MAX_COMMAND_SIZE];
528 
529 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
530 		return -ENXIO;
531 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
532 				   sdp->disk->disk_name, (int) count));
533 	if (sdp->detached)
534 		return -ENODEV;
535 	if (!((filp->f_flags & O_NONBLOCK) ||
536 	      scsi_block_when_processing_errors(sdp->device)))
537 		return -ENXIO;
538 
539 	if (!access_ok(VERIFY_READ, buf, count))
540 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
541 	if (count < SZ_SG_HEADER)
542 		return -EIO;
543 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
544 		return -EFAULT;
545 	blocking = !(filp->f_flags & O_NONBLOCK);
546 	if (old_hdr.reply_len < 0)
547 		return sg_new_write(sfp, buf, count, blocking, 0, NULL);
548 	if (count < (SZ_SG_HEADER + 6))
549 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
550 
551 	if (!(srp = sg_add_request(sfp))) {
552 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
553 		return -EDOM;
554 	}
555 	buf += SZ_SG_HEADER;
556 	__get_user(opcode, buf);
557 	if (sfp->next_cmd_len > 0) {
558 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
559 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
560 			sfp->next_cmd_len = 0;
561 			sg_remove_request(sfp, srp);
562 			return -EIO;
563 		}
564 		cmd_size = sfp->next_cmd_len;
565 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
566 	} else {
567 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
568 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
569 			cmd_size = 12;
570 	}
571 	SCSI_LOG_TIMEOUT(4, printk(
572 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
573 /* Determine buffer size.  */
574 	input_size = count - cmd_size;
575 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
576 	mxsize -= SZ_SG_HEADER;
577 	input_size -= SZ_SG_HEADER;
578 	if (input_size < 0) {
579 		sg_remove_request(sfp, srp);
580 		return -EIO;	/* User did not pass enough bytes for this command. */
581 	}
582 	hp = &srp->header;
583 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
584 	hp->cmd_len = (unsigned char) cmd_size;
585 	hp->iovec_count = 0;
586 	hp->mx_sb_len = 0;
587 	if (input_size > 0)
588 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
589 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
590 	else
591 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
592 	hp->dxfer_len = mxsize;
593 	hp->dxferp = (char __user *)buf + cmd_size;
594 	hp->sbp = NULL;
595 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
596 	hp->flags = input_size;	/* structure abuse ... */
597 	hp->pack_id = old_hdr.pack_id;
598 	hp->usr_ptr = NULL;
599 	if (__copy_from_user(cmnd, buf, cmd_size))
600 		return -EFAULT;
601 	/*
602 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
603 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
604 	 * is a non-zero input_size, so emit a warning.
605 	 */
606 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
607 		if (printk_ratelimit())
608 			printk(KERN_WARNING
609 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
610 			       "guessing data in;\n" KERN_WARNING "   "
611 			       "program %s not setting count and/or reply_len properly\n",
612 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
613 			       input_size, (unsigned int) cmnd[0],
614 			       current->comm);
615 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
616 	return (k < 0) ? k : count;
617 }
618 
619 static ssize_t
620 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
621 	     int blocking, int read_only, Sg_request ** o_srp)
622 {
623 	int k;
624 	Sg_request *srp;
625 	sg_io_hdr_t *hp;
626 	unsigned char cmnd[MAX_COMMAND_SIZE];
627 	int timeout;
628 	unsigned long ul_timeout;
629 
630 	if (count < SZ_SG_IO_HDR)
631 		return -EINVAL;
632 	if (!access_ok(VERIFY_READ, buf, count))
633 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
634 
635 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
636 	if (!(srp = sg_add_request(sfp))) {
637 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
638 		return -EDOM;
639 	}
640 	hp = &srp->header;
641 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
642 		sg_remove_request(sfp, srp);
643 		return -EFAULT;
644 	}
645 	if (hp->interface_id != 'S') {
646 		sg_remove_request(sfp, srp);
647 		return -ENOSYS;
648 	}
649 	if (hp->flags & SG_FLAG_MMAP_IO) {
650 		if (hp->dxfer_len > sfp->reserve.bufflen) {
651 			sg_remove_request(sfp, srp);
652 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
653 		}
654 		if (hp->flags & SG_FLAG_DIRECT_IO) {
655 			sg_remove_request(sfp, srp);
656 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
657 		}
658 		if (sg_res_in_use(sfp)) {
659 			sg_remove_request(sfp, srp);
660 			return -EBUSY;	/* reserve buffer already being used */
661 		}
662 	}
663 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
664 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
665 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
666 		sg_remove_request(sfp, srp);
667 		return -EMSGSIZE;
668 	}
669 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
670 		sg_remove_request(sfp, srp);
671 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
672 	}
673 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
674 		sg_remove_request(sfp, srp);
675 		return -EFAULT;
676 	}
677 	if (read_only &&
678 	    (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
679 		sg_remove_request(sfp, srp);
680 		return -EPERM;
681 	}
682 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
683 	if (k < 0)
684 		return k;
685 	if (o_srp)
686 		*o_srp = srp;
687 	return count;
688 }
689 
690 static int
691 sg_common_write(Sg_fd * sfp, Sg_request * srp,
692 		unsigned char *cmnd, int timeout, int blocking)
693 {
694 	int k, data_dir;
695 	Sg_device *sdp = sfp->parentdp;
696 	sg_io_hdr_t *hp = &srp->header;
697 
698 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
699 	hp->status = 0;
700 	hp->masked_status = 0;
701 	hp->msg_status = 0;
702 	hp->info = 0;
703 	hp->host_status = 0;
704 	hp->driver_status = 0;
705 	hp->resid = 0;
706 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
707 			  (int) cmnd[0], (int) hp->cmd_len));
708 
709 	if ((k = sg_start_req(srp))) {
710 		SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
711 		sg_finish_rem_req(srp);
712 		return k;	/* probably out of space --> ENOMEM */
713 	}
714 	if ((k = sg_write_xfer(srp))) {
715 		SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
716 		sg_finish_rem_req(srp);
717 		return k;
718 	}
719 	if (sdp->detached) {
720 		sg_finish_rem_req(srp);
721 		return -ENODEV;
722 	}
723 
724 	switch (hp->dxfer_direction) {
725 	case SG_DXFER_TO_FROM_DEV:
726 	case SG_DXFER_FROM_DEV:
727 		data_dir = DMA_FROM_DEVICE;
728 		break;
729 	case SG_DXFER_TO_DEV:
730 		data_dir = DMA_TO_DEVICE;
731 		break;
732 	case SG_DXFER_UNKNOWN:
733 		data_dir = DMA_BIDIRECTIONAL;
734 		break;
735 	default:
736 		data_dir = DMA_NONE;
737 		break;
738 	}
739 	hp->duration = jiffies_to_msecs(jiffies);
740 /* Now send everything of to mid-level. The next time we hear about this
741    packet is when sg_cmd_done() is called (i.e. a callback). */
742 	if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
743 				hp->dxfer_len, srp->data.k_use_sg, timeout,
744 				SG_DEFAULT_RETRIES, srp, sg_cmd_done,
745 				GFP_ATOMIC)) {
746 		SCSI_LOG_TIMEOUT(1, printk("sg_write: scsi_execute_async failed\n"));
747 		/*
748 		 * most likely out of mem, but could also be a bad map
749 		 */
750 		sg_finish_rem_req(srp);
751 		return -ENOMEM;
752 	} else
753 		return 0;
754 }
755 
756 static int
757 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
758 {
759 	unsigned long iflags;
760 	int done;
761 
762 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
763 	done = srp->done;
764 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
765 	return done;
766 }
767 
768 static int
769 sg_ioctl(struct inode *inode, struct file *filp,
770 	 unsigned int cmd_in, unsigned long arg)
771 {
772 	void __user *p = (void __user *)arg;
773 	int __user *ip = p;
774 	int result, val, read_only;
775 	Sg_device *sdp;
776 	Sg_fd *sfp;
777 	Sg_request *srp;
778 	unsigned long iflags;
779 
780 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
781 		return -ENXIO;
782 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
783 				   sdp->disk->disk_name, (int) cmd_in));
784 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
785 
786 	switch (cmd_in) {
787 	case SG_IO:
788 		{
789 			int blocking = 1;	/* ignore O_NONBLOCK flag */
790 
791 			if (sdp->detached)
792 				return -ENODEV;
793 			if (!scsi_block_when_processing_errors(sdp->device))
794 				return -ENXIO;
795 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
796 				return -EFAULT;
797 			result =
798 			    sg_new_write(sfp, p, SZ_SG_IO_HDR,
799 					 blocking, read_only, &srp);
800 			if (result < 0)
801 				return result;
802 			srp->sg_io_owned = 1;
803 			while (1) {
804 				result = 0;	/* following macro to beat race condition */
805 				__wait_event_interruptible(sfp->read_wait,
806 					(sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
807 							   result);
808 				if (sdp->detached)
809 					return -ENODEV;
810 				if (sfp->closed)
811 					return 0;	/* request packet dropped already */
812 				if (0 == result)
813 					break;
814 				srp->orphan = 1;
815 				return result;	/* -ERESTARTSYS because signal hit process */
816 			}
817 			write_lock_irqsave(&sfp->rq_list_lock, iflags);
818 			srp->done = 2;
819 			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
820 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
821 			return (result < 0) ? result : 0;
822 		}
823 	case SG_SET_TIMEOUT:
824 		result = get_user(val, ip);
825 		if (result)
826 			return result;
827 		if (val < 0)
828 			return -EIO;
829 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
830 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
831 		sfp->timeout_user = val;
832 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
833 
834 		return 0;
835 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
836 				/* strange ..., for backward compatibility */
837 		return sfp->timeout_user;
838 	case SG_SET_FORCE_LOW_DMA:
839 		result = get_user(val, ip);
840 		if (result)
841 			return result;
842 		if (val) {
843 			sfp->low_dma = 1;
844 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
845 				val = (int) sfp->reserve.bufflen;
846 				sg_remove_scat(&sfp->reserve);
847 				sg_build_reserve(sfp, val);
848 			}
849 		} else {
850 			if (sdp->detached)
851 				return -ENODEV;
852 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
853 		}
854 		return 0;
855 	case SG_GET_LOW_DMA:
856 		return put_user((int) sfp->low_dma, ip);
857 	case SG_GET_SCSI_ID:
858 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
859 			return -EFAULT;
860 		else {
861 			sg_scsi_id_t __user *sg_idp = p;
862 
863 			if (sdp->detached)
864 				return -ENODEV;
865 			__put_user((int) sdp->device->host->host_no,
866 				   &sg_idp->host_no);
867 			__put_user((int) sdp->device->channel,
868 				   &sg_idp->channel);
869 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
870 			__put_user((int) sdp->device->lun, &sg_idp->lun);
871 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
872 			__put_user((short) sdp->device->host->cmd_per_lun,
873 				   &sg_idp->h_cmd_per_lun);
874 			__put_user((short) sdp->device->queue_depth,
875 				   &sg_idp->d_queue_depth);
876 			__put_user(0, &sg_idp->unused[0]);
877 			__put_user(0, &sg_idp->unused[1]);
878 			return 0;
879 		}
880 	case SG_SET_FORCE_PACK_ID:
881 		result = get_user(val, ip);
882 		if (result)
883 			return result;
884 		sfp->force_packid = val ? 1 : 0;
885 		return 0;
886 	case SG_GET_PACK_ID:
887 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
888 			return -EFAULT;
889 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
890 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
891 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
892 				read_unlock_irqrestore(&sfp->rq_list_lock,
893 						       iflags);
894 				__put_user(srp->header.pack_id, ip);
895 				return 0;
896 			}
897 		}
898 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
899 		__put_user(-1, ip);
900 		return 0;
901 	case SG_GET_NUM_WAITING:
902 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
903 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
904 			if ((1 == srp->done) && (!srp->sg_io_owned))
905 				++val;
906 		}
907 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
908 		return put_user(val, ip);
909 	case SG_GET_SG_TABLESIZE:
910 		return put_user(sdp->sg_tablesize, ip);
911 	case SG_SET_RESERVED_SIZE:
912 		result = get_user(val, ip);
913 		if (result)
914 			return result;
915                 if (val < 0)
916                         return -EINVAL;
917 		if (val != sfp->reserve.bufflen) {
918 			if (sg_res_in_use(sfp) || sfp->mmap_called)
919 				return -EBUSY;
920 			sg_remove_scat(&sfp->reserve);
921 			sg_build_reserve(sfp, val);
922 		}
923 		return 0;
924 	case SG_GET_RESERVED_SIZE:
925 		val = (int) sfp->reserve.bufflen;
926 		return put_user(val, ip);
927 	case SG_SET_COMMAND_Q:
928 		result = get_user(val, ip);
929 		if (result)
930 			return result;
931 		sfp->cmd_q = val ? 1 : 0;
932 		return 0;
933 	case SG_GET_COMMAND_Q:
934 		return put_user((int) sfp->cmd_q, ip);
935 	case SG_SET_KEEP_ORPHAN:
936 		result = get_user(val, ip);
937 		if (result)
938 			return result;
939 		sfp->keep_orphan = val;
940 		return 0;
941 	case SG_GET_KEEP_ORPHAN:
942 		return put_user((int) sfp->keep_orphan, ip);
943 	case SG_NEXT_CMD_LEN:
944 		result = get_user(val, ip);
945 		if (result)
946 			return result;
947 		sfp->next_cmd_len = (val > 0) ? val : 0;
948 		return 0;
949 	case SG_GET_VERSION_NUM:
950 		return put_user(sg_version_num, ip);
951 	case SG_GET_ACCESS_COUNT:
952 		/* faked - we don't have a real access count anymore */
953 		val = (sdp->device ? 1 : 0);
954 		return put_user(val, ip);
955 	case SG_GET_REQUEST_TABLE:
956 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
957 			return -EFAULT;
958 		else {
959 			sg_req_info_t *rinfo;
960 			unsigned int ms;
961 
962 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
963 								GFP_KERNEL);
964 			if (!rinfo)
965 				return -ENOMEM;
966 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
967 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
968 			     ++val, srp = srp ? srp->nextrp : srp) {
969 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
970 				if (srp) {
971 					rinfo[val].req_state = srp->done + 1;
972 					rinfo[val].problem =
973 					    srp->header.masked_status &
974 					    srp->header.host_status &
975 					    srp->header.driver_status;
976 					if (srp->done)
977 						rinfo[val].duration =
978 							srp->header.duration;
979 					else {
980 						ms = jiffies_to_msecs(jiffies);
981 						rinfo[val].duration =
982 						    (ms > srp->header.duration) ?
983 						    (ms - srp->header.duration) : 0;
984 					}
985 					rinfo[val].orphan = srp->orphan;
986 					rinfo[val].sg_io_owned =
987 							srp->sg_io_owned;
988 					rinfo[val].pack_id =
989 							srp->header.pack_id;
990 					rinfo[val].usr_ptr =
991 							srp->header.usr_ptr;
992 				}
993 			}
994 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
995 			result = __copy_to_user(p, rinfo,
996 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
997 			result = result ? -EFAULT : 0;
998 			kfree(rinfo);
999 			return result;
1000 		}
1001 	case SG_EMULATED_HOST:
1002 		if (sdp->detached)
1003 			return -ENODEV;
1004 		return put_user(sdp->device->host->hostt->emulated, ip);
1005 	case SG_SCSI_RESET:
1006 		if (sdp->detached)
1007 			return -ENODEV;
1008 		if (filp->f_flags & O_NONBLOCK) {
1009 			if (scsi_host_in_recovery(sdp->device->host))
1010 				return -EBUSY;
1011 		} else if (!scsi_block_when_processing_errors(sdp->device))
1012 			return -EBUSY;
1013 		result = get_user(val, ip);
1014 		if (result)
1015 			return result;
1016 		if (SG_SCSI_RESET_NOTHING == val)
1017 			return 0;
1018 		switch (val) {
1019 		case SG_SCSI_RESET_DEVICE:
1020 			val = SCSI_TRY_RESET_DEVICE;
1021 			break;
1022 		case SG_SCSI_RESET_BUS:
1023 			val = SCSI_TRY_RESET_BUS;
1024 			break;
1025 		case SG_SCSI_RESET_HOST:
1026 			val = SCSI_TRY_RESET_HOST;
1027 			break;
1028 		default:
1029 			return -EINVAL;
1030 		}
1031 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1032 			return -EACCES;
1033 		return (scsi_reset_provider(sdp->device, val) ==
1034 			SUCCESS) ? 0 : -EIO;
1035 	case SCSI_IOCTL_SEND_COMMAND:
1036 		if (sdp->detached)
1037 			return -ENODEV;
1038 		if (read_only) {
1039 			unsigned char opcode = WRITE_6;
1040 			Scsi_Ioctl_Command __user *siocp = p;
1041 
1042 			if (copy_from_user(&opcode, siocp->data, 1))
1043 				return -EFAULT;
1044 			if (!sg_allow_access(opcode, sdp->device->type))
1045 				return -EPERM;
1046 		}
1047 		return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1048 	case SG_SET_DEBUG:
1049 		result = get_user(val, ip);
1050 		if (result)
1051 			return result;
1052 		sdp->sgdebug = (char) val;
1053 		return 0;
1054 	case SCSI_IOCTL_GET_IDLUN:
1055 	case SCSI_IOCTL_GET_BUS_NUMBER:
1056 	case SCSI_IOCTL_PROBE_HOST:
1057 	case SG_GET_TRANSFORM:
1058 		if (sdp->detached)
1059 			return -ENODEV;
1060 		return scsi_ioctl(sdp->device, cmd_in, p);
1061 	default:
1062 		if (read_only)
1063 			return -EPERM;	/* don't know so take safe approach */
1064 		return scsi_ioctl(sdp->device, cmd_in, p);
1065 	}
1066 }
1067 
1068 #ifdef CONFIG_COMPAT
1069 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1070 {
1071 	Sg_device *sdp;
1072 	Sg_fd *sfp;
1073 	struct scsi_device *sdev;
1074 
1075 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1076 		return -ENXIO;
1077 
1078 	sdev = sdp->device;
1079 	if (sdev->host->hostt->compat_ioctl) {
1080 		int ret;
1081 
1082 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1083 
1084 		return ret;
1085 	}
1086 
1087 	return -ENOIOCTLCMD;
1088 }
1089 #endif
1090 
1091 static unsigned int
1092 sg_poll(struct file *filp, poll_table * wait)
1093 {
1094 	unsigned int res = 0;
1095 	Sg_device *sdp;
1096 	Sg_fd *sfp;
1097 	Sg_request *srp;
1098 	int count = 0;
1099 	unsigned long iflags;
1100 
1101 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1102 	    || sfp->closed)
1103 		return POLLERR;
1104 	poll_wait(filp, &sfp->read_wait, wait);
1105 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1106 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1107 		/* if any read waiting, flag it */
1108 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1109 			res = POLLIN | POLLRDNORM;
1110 		++count;
1111 	}
1112 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1113 
1114 	if (sdp->detached)
1115 		res |= POLLHUP;
1116 	else if (!sfp->cmd_q) {
1117 		if (0 == count)
1118 			res |= POLLOUT | POLLWRNORM;
1119 	} else if (count < SG_MAX_QUEUE)
1120 		res |= POLLOUT | POLLWRNORM;
1121 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1122 				   sdp->disk->disk_name, (int) res));
1123 	return res;
1124 }
1125 
1126 static int
1127 sg_fasync(int fd, struct file *filp, int mode)
1128 {
1129 	int retval;
1130 	Sg_device *sdp;
1131 	Sg_fd *sfp;
1132 
1133 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1134 		return -ENXIO;
1135 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1136 				   sdp->disk->disk_name, mode));
1137 
1138 	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1139 	return (retval < 0) ? retval : 0;
1140 }
1141 
1142 static struct page *
1143 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1144 {
1145 	Sg_fd *sfp;
1146 	struct page *page = NOPAGE_SIGBUS;
1147 	unsigned long offset, len, sa;
1148 	Sg_scatter_hold *rsv_schp;
1149 	struct scatterlist *sg;
1150 	int k;
1151 
1152 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1153 		return page;
1154 	rsv_schp = &sfp->reserve;
1155 	offset = addr - vma->vm_start;
1156 	if (offset >= rsv_schp->bufflen)
1157 		return page;
1158 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1159 				   offset, rsv_schp->k_use_sg));
1160 	sg = rsv_schp->buffer;
1161 	sa = vma->vm_start;
1162 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1163 	     ++k, ++sg) {
1164 		len = vma->vm_end - sa;
1165 		len = (len < sg->length) ? len : sg->length;
1166 		if (offset < len) {
1167 			page = sg->page;
1168 			get_page(page);	/* increment page count */
1169 			break;
1170 		}
1171 		sa += len;
1172 		offset -= len;
1173 	}
1174 
1175 	if (type)
1176 		*type = VM_FAULT_MINOR;
1177 	return page;
1178 }
1179 
1180 static struct vm_operations_struct sg_mmap_vm_ops = {
1181 	.nopage = sg_vma_nopage,
1182 };
1183 
1184 static int
1185 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1186 {
1187 	Sg_fd *sfp;
1188 	unsigned long req_sz, len, sa;
1189 	Sg_scatter_hold *rsv_schp;
1190 	int k;
1191 	struct scatterlist *sg;
1192 
1193 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1194 		return -ENXIO;
1195 	req_sz = vma->vm_end - vma->vm_start;
1196 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1197 				   (void *) vma->vm_start, (int) req_sz));
1198 	if (vma->vm_pgoff)
1199 		return -EINVAL;	/* want no offset */
1200 	rsv_schp = &sfp->reserve;
1201 	if (req_sz > rsv_schp->bufflen)
1202 		return -ENOMEM;	/* cannot map more than reserved buffer */
1203 
1204 	sa = vma->vm_start;
1205 	sg = rsv_schp->buffer;
1206 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1207 	     ++k, ++sg) {
1208 		len = vma->vm_end - sa;
1209 		len = (len < sg->length) ? len : sg->length;
1210 		sa += len;
1211 	}
1212 
1213 	sfp->mmap_called = 1;
1214 	vma->vm_flags |= VM_RESERVED;
1215 	vma->vm_private_data = sfp;
1216 	vma->vm_ops = &sg_mmap_vm_ops;
1217 	return 0;
1218 }
1219 
1220 /* This function is a "bottom half" handler that is called by the
1221  * mid level when a command is completed (or has failed). */
1222 static void
1223 sg_cmd_done(void *data, char *sense, int result, int resid)
1224 {
1225 	Sg_request *srp = data;
1226 	Sg_device *sdp = NULL;
1227 	Sg_fd *sfp;
1228 	unsigned long iflags;
1229 	unsigned int ms;
1230 
1231 	if (NULL == srp) {
1232 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
1233 		return;
1234 	}
1235 	sfp = srp->parentfp;
1236 	if (sfp)
1237 		sdp = sfp->parentdp;
1238 	if ((NULL == sdp) || sdp->detached) {
1239 		printk(KERN_INFO "sg_cmd_done: device detached\n");
1240 		return;
1241 	}
1242 
1243 
1244 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1245 		sdp->disk->disk_name, srp->header.pack_id, result));
1246 	srp->header.resid = resid;
1247 	ms = jiffies_to_msecs(jiffies);
1248 	srp->header.duration = (ms > srp->header.duration) ?
1249 				(ms - srp->header.duration) : 0;
1250 	if (0 != result) {
1251 		struct scsi_sense_hdr sshdr;
1252 
1253 		memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1254 		srp->header.status = 0xff & result;
1255 		srp->header.masked_status = status_byte(result);
1256 		srp->header.msg_status = msg_byte(result);
1257 		srp->header.host_status = host_byte(result);
1258 		srp->header.driver_status = driver_byte(result);
1259 		if ((sdp->sgdebug > 0) &&
1260 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1261 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1262 			__scsi_print_sense("sg_cmd_done", sense,
1263 					   SCSI_SENSE_BUFFERSIZE);
1264 
1265 		/* Following if statement is a patch supplied by Eric Youngdale */
1266 		if (driver_byte(result) != 0
1267 		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1268 		    && !scsi_sense_is_deferred(&sshdr)
1269 		    && sshdr.sense_key == UNIT_ATTENTION
1270 		    && sdp->device->removable) {
1271 			/* Detected possible disc change. Set the bit - this */
1272 			/* may be used if there are filesystems using this device */
1273 			sdp->device->changed = 1;
1274 		}
1275 	}
1276 	/* Rely on write phase to clean out srp status values, so no "else" */
1277 
1278 	if (sfp->closed) {	/* whoops this fd already released, cleanup */
1279 		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1280 		sg_finish_rem_req(srp);
1281 		srp = NULL;
1282 		if (NULL == sfp->headrp) {
1283 			SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1284 			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
1285 				scsi_device_put(sdp->device);
1286 			}
1287 			sfp = NULL;
1288 		}
1289 	} else if (srp && srp->orphan) {
1290 		if (sfp->keep_orphan)
1291 			srp->sg_io_owned = 0;
1292 		else {
1293 			sg_finish_rem_req(srp);
1294 			srp = NULL;
1295 		}
1296 	}
1297 	if (sfp && srp) {
1298 		/* Now wake up any sg_read() that is waiting for this packet. */
1299 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1300 		write_lock_irqsave(&sfp->rq_list_lock, iflags);
1301 		srp->done = 1;
1302 		wake_up_interruptible(&sfp->read_wait);
1303 		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1304 	}
1305 }
1306 
1307 static struct file_operations sg_fops = {
1308 	.owner = THIS_MODULE,
1309 	.read = sg_read,
1310 	.write = sg_write,
1311 	.poll = sg_poll,
1312 	.ioctl = sg_ioctl,
1313 #ifdef CONFIG_COMPAT
1314 	.compat_ioctl = sg_compat_ioctl,
1315 #endif
1316 	.open = sg_open,
1317 	.mmap = sg_mmap,
1318 	.release = sg_release,
1319 	.fasync = sg_fasync,
1320 };
1321 
1322 static struct class *sg_sysfs_class;
1323 
1324 static int sg_sysfs_valid = 0;
1325 
1326 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1327 {
1328 	struct request_queue *q = scsidp->request_queue;
1329 	Sg_device *sdp;
1330 	unsigned long iflags;
1331 	void *old_sg_dev_arr = NULL;
1332 	int k, error;
1333 
1334 	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1335 	if (!sdp) {
1336 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1337 		return -ENOMEM;
1338 	}
1339 
1340 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1341 	if (unlikely(sg_nr_dev >= sg_dev_max)) {	/* try to resize */
1342 		Sg_device **tmp_da;
1343 		int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1344 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1345 
1346 		tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1347 		if (unlikely(!tmp_da))
1348 			goto expand_failed;
1349 
1350 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
1351 		memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1352 		old_sg_dev_arr = sg_dev_arr;
1353 		sg_dev_arr = tmp_da;
1354 		sg_dev_max = tmp_dev_max;
1355 	}
1356 
1357 	for (k = 0; k < sg_dev_max; k++)
1358 		if (!sg_dev_arr[k])
1359 			break;
1360 	if (unlikely(k >= SG_MAX_DEVS))
1361 		goto overflow;
1362 
1363 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1364 	sprintf(disk->disk_name, "sg%d", k);
1365 	disk->first_minor = k;
1366 	sdp->disk = disk;
1367 	sdp->device = scsidp;
1368 	init_waitqueue_head(&sdp->o_excl_wait);
1369 	sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1370 
1371 	sg_nr_dev++;
1372 	sg_dev_arr[k] = sdp;
1373 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1374 	error = k;
1375 
1376  out:
1377 	if (error < 0)
1378 		kfree(sdp);
1379 	kfree(old_sg_dev_arr);
1380 	return error;
1381 
1382  expand_failed:
1383 	printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1384 	error = -ENOMEM;
1385 	goto out;
1386 
1387  overflow:
1388 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1389 	sdev_printk(KERN_WARNING, scsidp,
1390 		    "Unable to attach sg device type=%d, minor "
1391 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1392 	error = -ENODEV;
1393 	goto out;
1394 }
1395 
1396 static int
1397 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1398 {
1399 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1400 	struct gendisk *disk;
1401 	Sg_device *sdp = NULL;
1402 	struct cdev * cdev = NULL;
1403 	int error, k;
1404 	unsigned long iflags;
1405 
1406 	disk = alloc_disk(1);
1407 	if (!disk) {
1408 		printk(KERN_WARNING "alloc_disk failed\n");
1409 		return -ENOMEM;
1410 	}
1411 	disk->major = SCSI_GENERIC_MAJOR;
1412 
1413 	error = -ENOMEM;
1414 	cdev = cdev_alloc();
1415 	if (!cdev) {
1416 		printk(KERN_WARNING "cdev_alloc failed\n");
1417 		goto out;
1418 	}
1419 	cdev->owner = THIS_MODULE;
1420 	cdev->ops = &sg_fops;
1421 
1422 	error = sg_alloc(disk, scsidp);
1423 	if (error < 0) {
1424 		printk(KERN_WARNING "sg_alloc failed\n");
1425 		goto out;
1426 	}
1427 	k = error;
1428 	sdp = sg_dev_arr[k];
1429 
1430 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1431 	if (error)
1432 		goto cdev_add_err;
1433 
1434 	sdp->cdev = cdev;
1435 	if (sg_sysfs_valid) {
1436 		struct class_device * sg_class_member;
1437 
1438 		sg_class_member = class_device_create(sg_sysfs_class, NULL,
1439 				MKDEV(SCSI_GENERIC_MAJOR, k),
1440 				cl_dev->dev, "%s",
1441 				disk->disk_name);
1442 		if (IS_ERR(sg_class_member))
1443 			printk(KERN_WARNING "sg_add: "
1444 				"class_device_create failed\n");
1445 		class_set_devdata(sg_class_member, sdp);
1446 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1447 					  &sg_class_member->kobj, "generic");
1448 		if (error)
1449 			printk(KERN_ERR "sg_add: unable to make symlink "
1450 					"'generic' back to sg%d\n", k);
1451 	} else
1452 		printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1453 
1454 	sdev_printk(KERN_NOTICE, scsidp,
1455 		    "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1456 
1457 	return 0;
1458 
1459 cdev_add_err:
1460 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1461 	kfree(sg_dev_arr[k]);
1462 	sg_dev_arr[k] = NULL;
1463 	sg_nr_dev--;
1464 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1465 
1466 out:
1467 	put_disk(disk);
1468 	if (cdev)
1469 		cdev_del(cdev);
1470 	return error;
1471 }
1472 
1473 static void
1474 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1475 {
1476 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1477 	Sg_device *sdp = NULL;
1478 	unsigned long iflags;
1479 	Sg_fd *sfp;
1480 	Sg_fd *tsfp;
1481 	Sg_request *srp;
1482 	Sg_request *tsrp;
1483 	int k, delay;
1484 
1485 	if (NULL == sg_dev_arr)
1486 		return;
1487 	delay = 0;
1488 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1489 	for (k = 0; k < sg_dev_max; k++) {
1490 		sdp = sg_dev_arr[k];
1491 		if ((NULL == sdp) || (sdp->device != scsidp))
1492 			continue;	/* dirty but lowers nesting */
1493 		if (sdp->headfp) {
1494 			sdp->detached = 1;
1495 			for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1496 				tsfp = sfp->nextfp;
1497 				for (srp = sfp->headrp; srp; srp = tsrp) {
1498 					tsrp = srp->nextrp;
1499 					if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1500 						sg_finish_rem_req(srp);
1501 				}
1502 				if (sfp->closed) {
1503 					scsi_device_put(sdp->device);
1504 					__sg_remove_sfp(sdp, sfp);
1505 				} else {
1506 					delay = 1;
1507 					wake_up_interruptible(&sfp->read_wait);
1508 					kill_fasync(&sfp->async_qp, SIGPOLL,
1509 						    POLL_HUP);
1510 				}
1511 			}
1512 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1513 			if (NULL == sdp->headfp) {
1514 				sg_dev_arr[k] = NULL;
1515 			}
1516 		} else {	/* nothing active, simple case */
1517 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1518 			sg_dev_arr[k] = NULL;
1519 		}
1520 		sg_nr_dev--;
1521 		break;
1522 	}
1523 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1524 
1525 	if (sdp) {
1526 		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1527 		class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1528 		cdev_del(sdp->cdev);
1529 		sdp->cdev = NULL;
1530 		put_disk(sdp->disk);
1531 		sdp->disk = NULL;
1532 		if (NULL == sdp->headfp)
1533 			kfree((char *) sdp);
1534 	}
1535 
1536 	if (delay)
1537 		msleep(10);	/* dirty detach so delay device destruction */
1538 }
1539 
1540 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1541  * of sysfs parameters (which module_param doesn't yet support).
1542  * Sysfs parameters defined explicitly below.
1543  */
1544 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1545 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1546 
1547 MODULE_AUTHOR("Douglas Gilbert");
1548 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1549 MODULE_LICENSE("GPL");
1550 MODULE_VERSION(SG_VERSION_STR);
1551 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1552 
1553 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1554 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1555 
1556 static int __init
1557 init_sg(void)
1558 {
1559 	int rc;
1560 
1561 	if (def_reserved_size >= 0)
1562 		sg_big_buff = def_reserved_size;
1563 
1564 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1565 				    SG_MAX_DEVS, "sg");
1566 	if (rc)
1567 		return rc;
1568         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1569         if ( IS_ERR(sg_sysfs_class) ) {
1570 		rc = PTR_ERR(sg_sysfs_class);
1571 		goto err_out;
1572         }
1573 	sg_sysfs_valid = 1;
1574 	rc = scsi_register_interface(&sg_interface);
1575 	if (0 == rc) {
1576 #ifdef CONFIG_SCSI_PROC_FS
1577 		sg_proc_init();
1578 #endif				/* CONFIG_SCSI_PROC_FS */
1579 		return 0;
1580 	}
1581 	class_destroy(sg_sysfs_class);
1582 err_out:
1583 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1584 	return rc;
1585 }
1586 
1587 static void __exit
1588 exit_sg(void)
1589 {
1590 #ifdef CONFIG_SCSI_PROC_FS
1591 	sg_proc_cleanup();
1592 #endif				/* CONFIG_SCSI_PROC_FS */
1593 	scsi_unregister_interface(&sg_interface);
1594 	class_destroy(sg_sysfs_class);
1595 	sg_sysfs_valid = 0;
1596 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1597 				 SG_MAX_DEVS);
1598 	kfree((char *)sg_dev_arr);
1599 	sg_dev_arr = NULL;
1600 	sg_dev_max = 0;
1601 }
1602 
1603 static int
1604 sg_start_req(Sg_request * srp)
1605 {
1606 	int res;
1607 	Sg_fd *sfp = srp->parentfp;
1608 	sg_io_hdr_t *hp = &srp->header;
1609 	int dxfer_len = (int) hp->dxfer_len;
1610 	int dxfer_dir = hp->dxfer_direction;
1611 	Sg_scatter_hold *req_schp = &srp->data;
1612 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1613 
1614 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1615 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1616 		return 0;
1617 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1618 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1619 	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1620 		res = sg_build_direct(srp, sfp, dxfer_len);
1621 		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
1622 			return res;
1623 	}
1624 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1625 		sg_link_reserve(sfp, srp, dxfer_len);
1626 	else {
1627 		res = sg_build_indirect(req_schp, sfp, dxfer_len);
1628 		if (res) {
1629 			sg_remove_scat(req_schp);
1630 			return res;
1631 		}
1632 	}
1633 	return 0;
1634 }
1635 
1636 static void
1637 sg_finish_rem_req(Sg_request * srp)
1638 {
1639 	Sg_fd *sfp = srp->parentfp;
1640 	Sg_scatter_hold *req_schp = &srp->data;
1641 
1642 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1643 	if (srp->res_used)
1644 		sg_unlink_reserve(sfp, srp);
1645 	else
1646 		sg_remove_scat(req_schp);
1647 	sg_remove_request(sfp, srp);
1648 }
1649 
1650 static int
1651 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1652 {
1653 	int sg_bufflen = tablesize * sizeof(struct scatterlist);
1654 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1655 
1656 	/*
1657 	 * TODO: test without low_dma, we should not need it since
1658 	 * the block layer will bounce the buffer for us
1659 	 *
1660 	 * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1661 	 */
1662 	if (sfp->low_dma)
1663 		 gfp_flags |= GFP_DMA;
1664 	schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1665 	if (!schp->buffer)
1666 		return -ENOMEM;
1667 	schp->sglist_len = sg_bufflen;
1668 	return tablesize;	/* number of scat_gath elements allocated */
1669 }
1670 
1671 #ifdef SG_ALLOW_DIO_CODE
1672 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1673 	/* TODO: hopefully we can use the generic block layer code */
1674 
1675 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1676    - mapping of all pages not successful
1677    (i.e., either completely successful or fails)
1678 */
1679 static int
1680 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1681 	          unsigned long uaddr, size_t count, int rw)
1682 {
1683 	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1684 	unsigned long start = uaddr >> PAGE_SHIFT;
1685 	const int nr_pages = end - start;
1686 	int res, i, j;
1687 	struct page **pages;
1688 
1689 	/* User attempted Overflow! */
1690 	if ((uaddr + count) < uaddr)
1691 		return -EINVAL;
1692 
1693 	/* Too big */
1694         if (nr_pages > max_pages)
1695 		return -ENOMEM;
1696 
1697 	/* Hmm? */
1698 	if (count == 0)
1699 		return 0;
1700 
1701 	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1702 		return -ENOMEM;
1703 
1704         /* Try to fault in all of the necessary pages */
1705 	down_read(&current->mm->mmap_sem);
1706         /* rw==READ means read from drive, write into memory area */
1707 	res = get_user_pages(
1708 		current,
1709 		current->mm,
1710 		uaddr,
1711 		nr_pages,
1712 		rw == READ,
1713 		0, /* don't force */
1714 		pages,
1715 		NULL);
1716 	up_read(&current->mm->mmap_sem);
1717 
1718 	/* Errors and no page mapped should return here */
1719 	if (res < nr_pages)
1720 		goto out_unmap;
1721 
1722         for (i=0; i < nr_pages; i++) {
1723                 /* FIXME: flush superflous for rw==READ,
1724                  * probably wrong function for rw==WRITE
1725                  */
1726 		flush_dcache_page(pages[i]);
1727 		/* ?? Is locking needed? I don't think so */
1728 		/* if (TestSetPageLocked(pages[i]))
1729 		   goto out_unlock; */
1730         }
1731 
1732 	sgl[0].page = pages[0];
1733 	sgl[0].offset = uaddr & ~PAGE_MASK;
1734 	if (nr_pages > 1) {
1735 		sgl[0].length = PAGE_SIZE - sgl[0].offset;
1736 		count -= sgl[0].length;
1737 		for (i=1; i < nr_pages ; i++) {
1738 			sgl[i].page = pages[i];
1739 			sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1740 			count -= PAGE_SIZE;
1741 		}
1742 	}
1743 	else {
1744 		sgl[0].length = count;
1745 	}
1746 
1747 	kfree(pages);
1748 	return nr_pages;
1749 
1750  out_unmap:
1751 	if (res > 0) {
1752 		for (j=0; j < res; j++)
1753 			page_cache_release(pages[j]);
1754 		res = 0;
1755 	}
1756 	kfree(pages);
1757 	return res;
1758 }
1759 
1760 
1761 /* And unmap them... */
1762 static int
1763 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1764 		    int dirtied)
1765 {
1766 	int i;
1767 
1768 	for (i=0; i < nr_pages; i++) {
1769 		struct page *page = sgl[i].page;
1770 
1771 		if (dirtied)
1772 			SetPageDirty(page);
1773 		/* unlock_page(page); */
1774 		/* FIXME: cache flush missing for rw==READ
1775 		 * FIXME: call the correct reference counting function
1776 		 */
1777 		page_cache_release(page);
1778 	}
1779 
1780 	return 0;
1781 }
1782 
1783 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1784 #endif
1785 
1786 
1787 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1788 static int
1789 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1790 {
1791 #ifdef SG_ALLOW_DIO_CODE
1792 	sg_io_hdr_t *hp = &srp->header;
1793 	Sg_scatter_hold *schp = &srp->data;
1794 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1795 	int mx_sc_elems, res;
1796 	struct scsi_device *sdev = sfp->parentdp->device;
1797 
1798 	if (((unsigned long)hp->dxferp &
1799 			queue_dma_alignment(sdev->request_queue)) != 0)
1800 		return 1;
1801 
1802 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1803         if (mx_sc_elems <= 0) {
1804                 return 1;
1805         }
1806 	res = st_map_user_pages(schp->buffer, mx_sc_elems,
1807 				(unsigned long)hp->dxferp, dxfer_len,
1808 				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1809 	if (res <= 0) {
1810 		sg_remove_scat(schp);
1811 		return 1;
1812 	}
1813 	schp->k_use_sg = res;
1814 	schp->dio_in_use = 1;
1815 	hp->info |= SG_INFO_DIRECT_IO;
1816 	return 0;
1817 #else
1818 	return 1;
1819 #endif
1820 }
1821 
1822 static int
1823 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1824 {
1825 	struct scatterlist *sg;
1826 	int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1827 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1828 	int blk_size = buff_size;
1829 	struct page *p = NULL;
1830 
1831 	if ((blk_size < 0) || (!sfp))
1832 		return -EFAULT;
1833 	if (0 == blk_size)
1834 		++blk_size;	/* don't know why */
1835 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1836 	blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1837 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1838 				   buff_size, blk_size));
1839 
1840 	/* N.B. ret_sz carried into this block ... */
1841 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1842 	if (mx_sc_elems < 0)
1843 		return mx_sc_elems;	/* most likely -ENOMEM */
1844 
1845 	for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1846 	     (rem_sz > 0) && (k < mx_sc_elems);
1847 	     ++k, rem_sz -= ret_sz, ++sg) {
1848 
1849 		num = (rem_sz > SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1850 		p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1851 		if (!p)
1852 			return -ENOMEM;
1853 
1854 		sg->page = p;
1855 		sg->length = ret_sz;
1856 
1857 		SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1858 				  k, p, ret_sz));
1859 	}		/* end of for loop */
1860 
1861 	schp->k_use_sg = k;
1862 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1863 
1864 	schp->bufflen = blk_size;
1865 	if (rem_sz > 0)	/* must have failed */
1866 		return -ENOMEM;
1867 
1868 	return 0;
1869 }
1870 
1871 static int
1872 sg_write_xfer(Sg_request * srp)
1873 {
1874 	sg_io_hdr_t *hp = &srp->header;
1875 	Sg_scatter_hold *schp = &srp->data;
1876 	struct scatterlist *sg = schp->buffer;
1877 	int num_xfer = 0;
1878 	int j, k, onum, usglen, ksglen, res;
1879 	int iovec_count = (int) hp->iovec_count;
1880 	int dxfer_dir = hp->dxfer_direction;
1881 	unsigned char *p;
1882 	unsigned char __user *up;
1883 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1884 
1885 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1886 	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1887 		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1888 		if (schp->bufflen < num_xfer)
1889 			num_xfer = schp->bufflen;
1890 	}
1891 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
1892 	    (new_interface
1893 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1894 		return 0;
1895 
1896 	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1897 			  num_xfer, iovec_count, schp->k_use_sg));
1898 	if (iovec_count) {
1899 		onum = iovec_count;
1900 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1901 			return -EFAULT;
1902 	} else
1903 		onum = 1;
1904 
1905 	ksglen = sg->length;
1906 	p = page_address(sg->page);
1907 	for (j = 0, k = 0; j < onum; ++j) {
1908 		res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1909 		if (res)
1910 			return res;
1911 
1912 		for (; p; ++sg, ksglen = sg->length,
1913 		     p = page_address(sg->page)) {
1914 			if (usglen <= 0)
1915 				break;
1916 			if (ksglen > usglen) {
1917 				if (usglen >= num_xfer) {
1918 					if (__copy_from_user(p, up, num_xfer))
1919 						return -EFAULT;
1920 					return 0;
1921 				}
1922 				if (__copy_from_user(p, up, usglen))
1923 					return -EFAULT;
1924 				p += usglen;
1925 				ksglen -= usglen;
1926 				break;
1927 			} else {
1928 				if (ksglen >= num_xfer) {
1929 					if (__copy_from_user(p, up, num_xfer))
1930 						return -EFAULT;
1931 					return 0;
1932 				}
1933 				if (__copy_from_user(p, up, ksglen))
1934 					return -EFAULT;
1935 				up += ksglen;
1936 				usglen -= ksglen;
1937 			}
1938 			++k;
1939 			if (k >= schp->k_use_sg)
1940 				return 0;
1941 		}
1942 	}
1943 
1944 	return 0;
1945 }
1946 
1947 static int
1948 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1949 	   int wr_xf, int *countp, unsigned char __user **up)
1950 {
1951 	int num_xfer = (int) hp->dxfer_len;
1952 	unsigned char __user *p = hp->dxferp;
1953 	int count;
1954 
1955 	if (0 == sg_num) {
1956 		if (wr_xf && ('\0' == hp->interface_id))
1957 			count = (int) hp->flags;	/* holds "old" input_size */
1958 		else
1959 			count = num_xfer;
1960 	} else {
1961 		sg_iovec_t iovec;
1962 		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1963 			return -EFAULT;
1964 		p = iovec.iov_base;
1965 		count = (int) iovec.iov_len;
1966 	}
1967 	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1968 		return -EFAULT;
1969 	if (up)
1970 		*up = p;
1971 	if (countp)
1972 		*countp = count;
1973 	return 0;
1974 }
1975 
1976 static void
1977 sg_remove_scat(Sg_scatter_hold * schp)
1978 {
1979 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1980 	if (schp->buffer && (schp->sglist_len > 0)) {
1981 		struct scatterlist *sg = schp->buffer;
1982 
1983 		if (schp->dio_in_use) {
1984 #ifdef SG_ALLOW_DIO_CODE
1985 			st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
1986 #endif
1987 		} else {
1988 			int k;
1989 
1990 			for (k = 0; (k < schp->k_use_sg) && sg->page;
1991 			     ++k, ++sg) {
1992 				SCSI_LOG_TIMEOUT(5, printk(
1993 				    "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
1994 				    k, sg->page, sg->length));
1995 				sg_page_free(sg->page, sg->length);
1996 			}
1997 		}
1998 		kfree(schp->buffer);
1999 	}
2000 	memset(schp, 0, sizeof (*schp));
2001 }
2002 
2003 static int
2004 sg_read_xfer(Sg_request * srp)
2005 {
2006 	sg_io_hdr_t *hp = &srp->header;
2007 	Sg_scatter_hold *schp = &srp->data;
2008 	struct scatterlist *sg = schp->buffer;
2009 	int num_xfer = 0;
2010 	int j, k, onum, usglen, ksglen, res;
2011 	int iovec_count = (int) hp->iovec_count;
2012 	int dxfer_dir = hp->dxfer_direction;
2013 	unsigned char *p;
2014 	unsigned char __user *up;
2015 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2016 
2017 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2018 	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2019 		num_xfer = hp->dxfer_len;
2020 		if (schp->bufflen < num_xfer)
2021 			num_xfer = schp->bufflen;
2022 	}
2023 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2024 	    (new_interface
2025 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2026 		return 0;
2027 
2028 	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2029 			  num_xfer, iovec_count, schp->k_use_sg));
2030 	if (iovec_count) {
2031 		onum = iovec_count;
2032 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2033 			return -EFAULT;
2034 	} else
2035 		onum = 1;
2036 
2037 	p = page_address(sg->page);
2038 	ksglen = sg->length;
2039 	for (j = 0, k = 0; j < onum; ++j) {
2040 		res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2041 		if (res)
2042 			return res;
2043 
2044 		for (; p; ++sg, ksglen = sg->length,
2045 		     p = page_address(sg->page)) {
2046 			if (usglen <= 0)
2047 				break;
2048 			if (ksglen > usglen) {
2049 				if (usglen >= num_xfer) {
2050 					if (__copy_to_user(up, p, num_xfer))
2051 						return -EFAULT;
2052 					return 0;
2053 				}
2054 				if (__copy_to_user(up, p, usglen))
2055 					return -EFAULT;
2056 				p += usglen;
2057 				ksglen -= usglen;
2058 				break;
2059 			} else {
2060 				if (ksglen >= num_xfer) {
2061 					if (__copy_to_user(up, p, num_xfer))
2062 						return -EFAULT;
2063 					return 0;
2064 				}
2065 				if (__copy_to_user(up, p, ksglen))
2066 					return -EFAULT;
2067 				up += ksglen;
2068 				usglen -= ksglen;
2069 			}
2070 			++k;
2071 			if (k >= schp->k_use_sg)
2072 				return 0;
2073 		}
2074 	}
2075 
2076 	return 0;
2077 }
2078 
2079 static int
2080 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2081 {
2082 	Sg_scatter_hold *schp = &srp->data;
2083 	struct scatterlist *sg = schp->buffer;
2084 	int k, num;
2085 
2086 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2087 				   num_read_xfer));
2088 	if ((!outp) || (num_read_xfer <= 0))
2089 		return 0;
2090 
2091 	for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2092 		num = sg->length;
2093 		if (num > num_read_xfer) {
2094 			if (__copy_to_user(outp, page_address(sg->page),
2095 					   num_read_xfer))
2096 				return -EFAULT;
2097 			break;
2098 		} else {
2099 			if (__copy_to_user(outp, page_address(sg->page),
2100 					   num))
2101 				return -EFAULT;
2102 			num_read_xfer -= num;
2103 			if (num_read_xfer <= 0)
2104 				break;
2105 			outp += num;
2106 		}
2107 	}
2108 
2109 	return 0;
2110 }
2111 
2112 static void
2113 sg_build_reserve(Sg_fd * sfp, int req_size)
2114 {
2115 	Sg_scatter_hold *schp = &sfp->reserve;
2116 
2117 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2118 	do {
2119 		if (req_size < PAGE_SIZE)
2120 			req_size = PAGE_SIZE;
2121 		if (0 == sg_build_indirect(schp, sfp, req_size))
2122 			return;
2123 		else
2124 			sg_remove_scat(schp);
2125 		req_size >>= 1;	/* divide by 2 */
2126 	} while (req_size > (PAGE_SIZE / 2));
2127 }
2128 
2129 static void
2130 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2131 {
2132 	Sg_scatter_hold *req_schp = &srp->data;
2133 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2134 	struct scatterlist *sg = rsv_schp->buffer;
2135 	int k, num, rem;
2136 
2137 	srp->res_used = 1;
2138 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2139 	rem = size;
2140 
2141 	for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2142 		num = sg->length;
2143 		if (rem <= num) {
2144 			sfp->save_scat_len = num;
2145 			sg->length = rem;
2146 			req_schp->k_use_sg = k + 1;
2147 			req_schp->sglist_len = rsv_schp->sglist_len;
2148 			req_schp->buffer = rsv_schp->buffer;
2149 
2150 			req_schp->bufflen = size;
2151 			req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2152 			break;
2153 		} else
2154 			rem -= num;
2155 	}
2156 
2157 	if (k >= rsv_schp->k_use_sg)
2158 		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2159 }
2160 
2161 static void
2162 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2163 {
2164 	Sg_scatter_hold *req_schp = &srp->data;
2165 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2166 
2167 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2168 				   (int) req_schp->k_use_sg));
2169 	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2170 		struct scatterlist *sg = rsv_schp->buffer;
2171 
2172 		if (sfp->save_scat_len > 0)
2173 			(sg + (req_schp->k_use_sg - 1))->length =
2174 			    (unsigned) sfp->save_scat_len;
2175 		else
2176 			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2177 	}
2178 	req_schp->k_use_sg = 0;
2179 	req_schp->bufflen = 0;
2180 	req_schp->buffer = NULL;
2181 	req_schp->sglist_len = 0;
2182 	sfp->save_scat_len = 0;
2183 	srp->res_used = 0;
2184 }
2185 
2186 static Sg_request *
2187 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2188 {
2189 	Sg_request *resp;
2190 	unsigned long iflags;
2191 
2192 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2193 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2194 		/* look for requests that are ready + not SG_IO owned */
2195 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
2196 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2197 			resp->done = 2;	/* guard against other readers */
2198 			break;
2199 		}
2200 	}
2201 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2202 	return resp;
2203 }
2204 
2205 #ifdef CONFIG_SCSI_PROC_FS
2206 static Sg_request *
2207 sg_get_nth_request(Sg_fd * sfp, int nth)
2208 {
2209 	Sg_request *resp;
2210 	unsigned long iflags;
2211 	int k;
2212 
2213 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2214 	for (k = 0, resp = sfp->headrp; resp && (k < nth);
2215 	     ++k, resp = resp->nextrp) ;
2216 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2217 	return resp;
2218 }
2219 #endif
2220 
2221 /* always adds to end of list */
2222 static Sg_request *
2223 sg_add_request(Sg_fd * sfp)
2224 {
2225 	int k;
2226 	unsigned long iflags;
2227 	Sg_request *resp;
2228 	Sg_request *rp = sfp->req_arr;
2229 
2230 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2231 	resp = sfp->headrp;
2232 	if (!resp) {
2233 		memset(rp, 0, sizeof (Sg_request));
2234 		rp->parentfp = sfp;
2235 		resp = rp;
2236 		sfp->headrp = resp;
2237 	} else {
2238 		if (0 == sfp->cmd_q)
2239 			resp = NULL;	/* command queuing disallowed */
2240 		else {
2241 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2242 				if (!rp->parentfp)
2243 					break;
2244 			}
2245 			if (k < SG_MAX_QUEUE) {
2246 				memset(rp, 0, sizeof (Sg_request));
2247 				rp->parentfp = sfp;
2248 				while (resp->nextrp)
2249 					resp = resp->nextrp;
2250 				resp->nextrp = rp;
2251 				resp = rp;
2252 			} else
2253 				resp = NULL;
2254 		}
2255 	}
2256 	if (resp) {
2257 		resp->nextrp = NULL;
2258 		resp->header.duration = jiffies_to_msecs(jiffies);
2259 	}
2260 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2261 	return resp;
2262 }
2263 
2264 /* Return of 1 for found; 0 for not found */
2265 static int
2266 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2267 {
2268 	Sg_request *prev_rp;
2269 	Sg_request *rp;
2270 	unsigned long iflags;
2271 	int res = 0;
2272 
2273 	if ((!sfp) || (!srp) || (!sfp->headrp))
2274 		return res;
2275 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2276 	prev_rp = sfp->headrp;
2277 	if (srp == prev_rp) {
2278 		sfp->headrp = prev_rp->nextrp;
2279 		prev_rp->parentfp = NULL;
2280 		res = 1;
2281 	} else {
2282 		while ((rp = prev_rp->nextrp)) {
2283 			if (srp == rp) {
2284 				prev_rp->nextrp = rp->nextrp;
2285 				rp->parentfp = NULL;
2286 				res = 1;
2287 				break;
2288 			}
2289 			prev_rp = rp;
2290 		}
2291 	}
2292 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2293 	return res;
2294 }
2295 
2296 #ifdef CONFIG_SCSI_PROC_FS
2297 static Sg_fd *
2298 sg_get_nth_sfp(Sg_device * sdp, int nth)
2299 {
2300 	Sg_fd *resp;
2301 	unsigned long iflags;
2302 	int k;
2303 
2304 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2305 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
2306 	     ++k, resp = resp->nextfp) ;
2307 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2308 	return resp;
2309 }
2310 #endif
2311 
2312 static Sg_fd *
2313 sg_add_sfp(Sg_device * sdp, int dev)
2314 {
2315 	Sg_fd *sfp;
2316 	unsigned long iflags;
2317 
2318 	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2319 	if (!sfp)
2320 		return NULL;
2321 
2322 	init_waitqueue_head(&sfp->read_wait);
2323 	rwlock_init(&sfp->rq_list_lock);
2324 
2325 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2326 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2327 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2328 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2329 	    sdp->device->host->unchecked_isa_dma : 1;
2330 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2331 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2332 	sfp->parentdp = sdp;
2333 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
2334 	if (!sdp->headfp)
2335 		sdp->headfp = sfp;
2336 	else {			/* add to tail of existing list */
2337 		Sg_fd *pfp = sdp->headfp;
2338 		while (pfp->nextfp)
2339 			pfp = pfp->nextfp;
2340 		pfp->nextfp = sfp;
2341 	}
2342 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2343 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2344 	sg_build_reserve(sfp, sg_big_buff);
2345 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2346 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2347 	return sfp;
2348 }
2349 
2350 static void
2351 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2352 {
2353 	Sg_fd *fp;
2354 	Sg_fd *prev_fp;
2355 
2356 	prev_fp = sdp->headfp;
2357 	if (sfp == prev_fp)
2358 		sdp->headfp = prev_fp->nextfp;
2359 	else {
2360 		while ((fp = prev_fp->nextfp)) {
2361 			if (sfp == fp) {
2362 				prev_fp->nextfp = fp->nextfp;
2363 				break;
2364 			}
2365 			prev_fp = fp;
2366 		}
2367 	}
2368 	if (sfp->reserve.bufflen > 0) {
2369 		SCSI_LOG_TIMEOUT(6,
2370 			printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2371 			(int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2372 		sg_remove_scat(&sfp->reserve);
2373 	}
2374 	sfp->parentdp = NULL;
2375 	SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2376 	kfree(sfp);
2377 }
2378 
2379 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2380 static int
2381 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2382 {
2383 	Sg_request *srp;
2384 	Sg_request *tsrp;
2385 	int dirty = 0;
2386 	int res = 0;
2387 
2388 	for (srp = sfp->headrp; srp; srp = tsrp) {
2389 		tsrp = srp->nextrp;
2390 		if (sg_srp_done(srp, sfp))
2391 			sg_finish_rem_req(srp);
2392 		else
2393 			++dirty;
2394 	}
2395 	if (0 == dirty) {
2396 		unsigned long iflags;
2397 
2398 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
2399 		__sg_remove_sfp(sdp, sfp);
2400 		if (sdp->detached && (NULL == sdp->headfp)) {
2401 			int k, maxd;
2402 
2403 			maxd = sg_dev_max;
2404 			for (k = 0; k < maxd; ++k) {
2405 				if (sdp == sg_dev_arr[k])
2406 					break;
2407 			}
2408 			if (k < maxd)
2409 				sg_dev_arr[k] = NULL;
2410 			kfree((char *) sdp);
2411 			res = 1;
2412 		}
2413 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2414 	} else {
2415 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
2416 		/* only bump the access_count if we actually succeeded in
2417 		 * throwing another counter on the host module */
2418 		scsi_device_get(sdp->device);	/* XXX: retval ignored? */
2419 		sfp->closed = 1;	/* flag dirty state on this fd */
2420 		SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2421 				  dirty));
2422 	}
2423 	return res;
2424 }
2425 
2426 static int
2427 sg_res_in_use(Sg_fd * sfp)
2428 {
2429 	const Sg_request *srp;
2430 	unsigned long iflags;
2431 
2432 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2433 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2434 		if (srp->res_used)
2435 			break;
2436 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2437 	return srp ? 1 : 0;
2438 }
2439 
2440 /* If retSzp==NULL want exact size or fail */
2441 static struct page *
2442 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2443 {
2444 	struct page *resp = NULL;
2445 	gfp_t page_mask;
2446 	int order, a_size;
2447 	int resSz = rqSz;
2448 
2449 	if (rqSz <= 0)
2450 		return resp;
2451 
2452 	if (lowDma)
2453 		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2454 	else
2455 		page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2456 
2457 	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2458 	     order++, a_size <<= 1) ;
2459 	resp = alloc_pages(page_mask, order);
2460 	while ((!resp) && order && retSzp) {
2461 		--order;
2462 		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
2463 		resp =  alloc_pages(page_mask, order);	/* try half */
2464 		resSz = a_size;
2465 	}
2466 	if (resp) {
2467 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2468 			memset(page_address(resp), 0, resSz);
2469 		if (retSzp)
2470 			*retSzp = resSz;
2471 	}
2472 	return resp;
2473 }
2474 
2475 static void
2476 sg_page_free(struct page *page, int size)
2477 {
2478 	int order, a_size;
2479 
2480 	if (!page)
2481 		return;
2482 	for (order = 0, a_size = PAGE_SIZE; a_size < size;
2483 	     order++, a_size <<= 1) ;
2484 	__free_pages(page, order);
2485 }
2486 
2487 #ifndef MAINTENANCE_IN_CMD
2488 #define MAINTENANCE_IN_CMD 0xa3
2489 #endif
2490 
2491 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2492 	INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2493 	READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2494 	SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2495 };
2496 
2497 static int
2498 sg_allow_access(unsigned char opcode, char dev_type)
2499 {
2500 	int k;
2501 
2502 	if (TYPE_SCANNER == dev_type)	/* TYPE_ROM maybe burner */
2503 		return 1;
2504 	for (k = 0; k < sizeof (allow_ops); ++k) {
2505 		if (opcode == allow_ops[k])
2506 			return 1;
2507 	}
2508 	return 0;
2509 }
2510 
2511 #ifdef CONFIG_SCSI_PROC_FS
2512 static int
2513 sg_last_dev(void)
2514 {
2515 	int k;
2516 	unsigned long iflags;
2517 
2518 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2519 	for (k = sg_dev_max - 1; k >= 0; --k)
2520 		if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2521 			break;
2522 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2523 	return k + 1;		/* origin 1 */
2524 }
2525 #endif
2526 
2527 static Sg_device *
2528 sg_get_dev(int dev)
2529 {
2530 	Sg_device *sdp = NULL;
2531 	unsigned long iflags;
2532 
2533 	if (sg_dev_arr && (dev >= 0)) {
2534 		read_lock_irqsave(&sg_dev_arr_lock, iflags);
2535 		if (dev < sg_dev_max)
2536 			sdp = sg_dev_arr[dev];
2537 		read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2538 	}
2539 	return sdp;
2540 }
2541 
2542 #ifdef CONFIG_SCSI_PROC_FS
2543 
2544 static struct proc_dir_entry *sg_proc_sgp = NULL;
2545 
2546 static char sg_proc_sg_dirname[] = "scsi/sg";
2547 
2548 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2549 
2550 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2551 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2552 			          size_t count, loff_t *off);
2553 static struct file_operations adio_fops = {
2554 	/* .owner, .read and .llseek added in sg_proc_init() */
2555 	.open = sg_proc_single_open_adio,
2556 	.write = sg_proc_write_adio,
2557 	.release = single_release,
2558 };
2559 
2560 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2561 static ssize_t sg_proc_write_dressz(struct file *filp,
2562 		const char __user *buffer, size_t count, loff_t *off);
2563 static struct file_operations dressz_fops = {
2564 	.open = sg_proc_single_open_dressz,
2565 	.write = sg_proc_write_dressz,
2566 	.release = single_release,
2567 };
2568 
2569 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2570 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2571 static struct file_operations version_fops = {
2572 	.open = sg_proc_single_open_version,
2573 	.release = single_release,
2574 };
2575 
2576 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2577 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2578 static struct file_operations devhdr_fops = {
2579 	.open = sg_proc_single_open_devhdr,
2580 	.release = single_release,
2581 };
2582 
2583 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2584 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2585 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2586 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2587 static void dev_seq_stop(struct seq_file *s, void *v);
2588 static struct file_operations dev_fops = {
2589 	.open = sg_proc_open_dev,
2590 	.release = seq_release,
2591 };
2592 static struct seq_operations dev_seq_ops = {
2593 	.start = dev_seq_start,
2594 	.next  = dev_seq_next,
2595 	.stop  = dev_seq_stop,
2596 	.show  = sg_proc_seq_show_dev,
2597 };
2598 
2599 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2600 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2601 static struct file_operations devstrs_fops = {
2602 	.open = sg_proc_open_devstrs,
2603 	.release = seq_release,
2604 };
2605 static struct seq_operations devstrs_seq_ops = {
2606 	.start = dev_seq_start,
2607 	.next  = dev_seq_next,
2608 	.stop  = dev_seq_stop,
2609 	.show  = sg_proc_seq_show_devstrs,
2610 };
2611 
2612 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2613 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2614 static struct file_operations debug_fops = {
2615 	.open = sg_proc_open_debug,
2616 	.release = seq_release,
2617 };
2618 static struct seq_operations debug_seq_ops = {
2619 	.start = dev_seq_start,
2620 	.next  = dev_seq_next,
2621 	.stop  = dev_seq_stop,
2622 	.show  = sg_proc_seq_show_debug,
2623 };
2624 
2625 
2626 struct sg_proc_leaf {
2627 	const char * name;
2628 	struct file_operations * fops;
2629 };
2630 
2631 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2632 	{"allow_dio", &adio_fops},
2633 	{"debug", &debug_fops},
2634 	{"def_reserved_size", &dressz_fops},
2635 	{"device_hdr", &devhdr_fops},
2636 	{"devices", &dev_fops},
2637 	{"device_strs", &devstrs_fops},
2638 	{"version", &version_fops}
2639 };
2640 
2641 static int
2642 sg_proc_init(void)
2643 {
2644 	int k, mask;
2645 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2646 	struct proc_dir_entry *pdep;
2647 	struct sg_proc_leaf * leaf;
2648 
2649 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2650 	if (!sg_proc_sgp)
2651 		return 1;
2652 	for (k = 0; k < num_leaves; ++k) {
2653 		leaf = &sg_proc_leaf_arr[k];
2654 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2655 		pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2656 		if (pdep) {
2657 			leaf->fops->owner = THIS_MODULE,
2658 			leaf->fops->read = seq_read,
2659 			leaf->fops->llseek = seq_lseek,
2660 			pdep->proc_fops = leaf->fops;
2661 		}
2662 	}
2663 	return 0;
2664 }
2665 
2666 static void
2667 sg_proc_cleanup(void)
2668 {
2669 	int k;
2670 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2671 
2672 	if (!sg_proc_sgp)
2673 		return;
2674 	for (k = 0; k < num_leaves; ++k)
2675 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2676 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2677 }
2678 
2679 
2680 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2681 {
2682 	seq_printf(s, "%d\n", *((int *)s->private));
2683 	return 0;
2684 }
2685 
2686 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2687 {
2688 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2689 }
2690 
2691 static ssize_t
2692 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2693 		   size_t count, loff_t *off)
2694 {
2695 	int num;
2696 	char buff[11];
2697 
2698 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2699 		return -EACCES;
2700 	num = (count < 10) ? count : 10;
2701 	if (copy_from_user(buff, buffer, num))
2702 		return -EFAULT;
2703 	buff[num] = '\0';
2704 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2705 	return count;
2706 }
2707 
2708 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2709 {
2710 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2711 }
2712 
2713 static ssize_t
2714 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2715 		     size_t count, loff_t *off)
2716 {
2717 	int num;
2718 	unsigned long k = ULONG_MAX;
2719 	char buff[11];
2720 
2721 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2722 		return -EACCES;
2723 	num = (count < 10) ? count : 10;
2724 	if (copy_from_user(buff, buffer, num))
2725 		return -EFAULT;
2726 	buff[num] = '\0';
2727 	k = simple_strtoul(buff, NULL, 10);
2728 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2729 		sg_big_buff = k;
2730 		return count;
2731 	}
2732 	return -ERANGE;
2733 }
2734 
2735 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2736 {
2737 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2738 		   sg_version_date);
2739 	return 0;
2740 }
2741 
2742 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2743 {
2744 	return single_open(file, sg_proc_seq_show_version, NULL);
2745 }
2746 
2747 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2748 {
2749 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2750 		   "online\n");
2751 	return 0;
2752 }
2753 
2754 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2755 {
2756 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2757 }
2758 
2759 struct sg_proc_deviter {
2760 	loff_t	index;
2761 	size_t	max;
2762 };
2763 
2764 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2765 {
2766 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2767 
2768 	s->private = it;
2769 	if (! it)
2770 		return NULL;
2771 
2772 	if (NULL == sg_dev_arr)
2773 		return NULL;
2774 	it->index = *pos;
2775 	it->max = sg_last_dev();
2776 	if (it->index >= it->max)
2777 		return NULL;
2778 	return it;
2779 }
2780 
2781 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2782 {
2783 	struct sg_proc_deviter * it = s->private;
2784 
2785 	*pos = ++it->index;
2786 	return (it->index < it->max) ? it : NULL;
2787 }
2788 
2789 static void dev_seq_stop(struct seq_file *s, void *v)
2790 {
2791 	kfree(s->private);
2792 }
2793 
2794 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2795 {
2796         return seq_open(file, &dev_seq_ops);
2797 }
2798 
2799 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2800 {
2801 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2802 	Sg_device *sdp;
2803 	struct scsi_device *scsidp;
2804 
2805 	sdp = it ? sg_get_dev(it->index) : NULL;
2806 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2807 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2808 			      scsidp->host->host_no, scsidp->channel,
2809 			      scsidp->id, scsidp->lun, (int) scsidp->type,
2810 			      1,
2811 			      (int) scsidp->queue_depth,
2812 			      (int) scsidp->device_busy,
2813 			      (int) scsi_device_online(scsidp));
2814 	else
2815 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2816 	return 0;
2817 }
2818 
2819 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2820 {
2821         return seq_open(file, &devstrs_seq_ops);
2822 }
2823 
2824 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2825 {
2826 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2827 	Sg_device *sdp;
2828 	struct scsi_device *scsidp;
2829 
2830 	sdp = it ? sg_get_dev(it->index) : NULL;
2831 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2832 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2833 			   scsidp->vendor, scsidp->model, scsidp->rev);
2834 	else
2835 		seq_printf(s, "<no active device>\n");
2836 	return 0;
2837 }
2838 
2839 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2840 {
2841 	int k, m, new_interface, blen, usg;
2842 	Sg_request *srp;
2843 	Sg_fd *fp;
2844 	const sg_io_hdr_t *hp;
2845 	const char * cp;
2846 	unsigned int ms;
2847 
2848 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2849 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2850 			   "(res)sgat=%d low_dma=%d\n", k + 1,
2851 			   jiffies_to_msecs(fp->timeout),
2852 			   fp->reserve.bufflen,
2853 			   (int) fp->reserve.k_use_sg,
2854 			   (int) fp->low_dma);
2855 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2856 			   (int) fp->cmd_q, (int) fp->force_packid,
2857 			   (int) fp->keep_orphan, (int) fp->closed);
2858 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2859 			hp = &srp->header;
2860 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2861 			if (srp->res_used) {
2862 				if (new_interface &&
2863 				    (SG_FLAG_MMAP_IO & hp->flags))
2864 					cp = "     mmap>> ";
2865 				else
2866 					cp = "     rb>> ";
2867 			} else {
2868 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2869 					cp = "     dio>> ";
2870 				else
2871 					cp = "     ";
2872 			}
2873 			seq_printf(s, cp);
2874 			blen = srp->data.bufflen;
2875 			usg = srp->data.k_use_sg;
2876 			seq_printf(s, srp->done ?
2877 				   ((1 == srp->done) ?  "rcv:" : "fin:")
2878 				   : "act:");
2879 			seq_printf(s, " id=%d blen=%d",
2880 				   srp->header.pack_id, blen);
2881 			if (srp->done)
2882 				seq_printf(s, " dur=%d", hp->duration);
2883 			else {
2884 				ms = jiffies_to_msecs(jiffies);
2885 				seq_printf(s, " t_o/elap=%d/%d",
2886 					(new_interface ? hp->timeout :
2887 						  jiffies_to_msecs(fp->timeout)),
2888 					(ms > hp->duration ? ms - hp->duration : 0));
2889 			}
2890 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2891 				   (int) srp->data.cmd_opcode);
2892 		}
2893 		if (0 == m)
2894 			seq_printf(s, "     No requests active\n");
2895 	}
2896 }
2897 
2898 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2899 {
2900         return seq_open(file, &debug_seq_ops);
2901 }
2902 
2903 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2904 {
2905 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2906 	Sg_device *sdp;
2907 
2908 	if (it && (0 == it->index)) {
2909 		seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2910 			   "(origin 1)\n", sg_dev_max, (int)it->max);
2911 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2912 	}
2913 	sdp = it ? sg_get_dev(it->index) : NULL;
2914 	if (sdp) {
2915 		struct scsi_device *scsidp = sdp->device;
2916 
2917 		if (NULL == scsidp) {
2918 			seq_printf(s, "device %d detached ??\n",
2919 				   (int)it->index);
2920 			return 0;
2921 		}
2922 
2923 		if (sg_get_nth_sfp(sdp, 0)) {
2924 			seq_printf(s, " >>> device=%s ",
2925 				sdp->disk->disk_name);
2926 			if (sdp->detached)
2927 				seq_printf(s, "detached pending close ");
2928 			else
2929 				seq_printf
2930 				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2931 				     scsidp->host->host_no,
2932 				     scsidp->channel, scsidp->id,
2933 				     scsidp->lun,
2934 				     scsidp->host->hostt->emulated);
2935 			seq_printf(s, " sg_tablesize=%d excl=%d\n",
2936 				   sdp->sg_tablesize, sdp->exclude);
2937 		}
2938 		sg_proc_debug_helper(s, sdp);
2939 	}
2940 	return 0;
2941 }
2942 
2943 #endif				/* CONFIG_SCSI_PROC_FS */
2944 
2945 module_init(init_sg);
2946 module_exit(exit_sg);
2947