xref: /linux/drivers/scsi/sg.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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/config.h>
32 #include <linux/module.h>
33 
34 #include <linux/fs.h>
35 #include <linux/kernel.h>
36 #include <linux/sched.h>
37 #include <linux/string.h>
38 #include <linux/mm.h>
39 #include <linux/errno.h>
40 #include <linux/mtio.h>
41 #include <linux/ioctl.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/smp_lock.h>
46 #include <linux/moduleparam.h>
47 #include <linux/devfs_fs_kernel.h>
48 #include <linux/cdev.h>
49 #include <linux/seq_file.h>
50 #include <linux/blkdev.h>
51 #include <linux/delay.h>
52 #include <linux/scatterlist.h>
53 
54 #include "scsi.h"
55 #include <scsi/scsi_dbg.h>
56 #include <scsi/scsi_host.h>
57 #include <scsi/scsi_driver.h>
58 #include <scsi/scsi_ioctl.h>
59 #include <scsi/sg.h>
60 
61 #include "scsi_logging.h"
62 
63 #ifdef CONFIG_SCSI_PROC_FS
64 #include <linux/proc_fs.h>
65 static char *sg_version_date = "20050908";
66 
67 static int sg_proc_init(void);
68 static void sg_proc_cleanup(void);
69 #endif
70 
71 #define SG_ALLOW_DIO_DEF 0
72 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
73 
74 #define SG_MAX_DEVS 32768
75 
76 /*
77  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
78  * Then when using 32 bit integers x * m may overflow during the calculation.
79  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
80  * calculates the same, but prevents the overflow when both m and d
81  * are "small" numbers (like HZ and USER_HZ).
82  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
83  * in 32 bits.
84  */
85 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
86 
87 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
88 
89 int sg_big_buff = SG_DEF_RESERVED_SIZE;
90 /* N.B. This variable is readable and writeable via
91    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
92    of this size (or less if there is not enough memory) will be reserved
93    for use by this file descriptor. [Deprecated usage: this variable is also
94    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
95    the kernel (i.e. it is not a module).] */
96 static int def_reserved_size = -1;	/* picks up init parameter */
97 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
98 
99 #define SG_SECTOR_SZ 512
100 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
101 
102 #define SG_DEV_ARR_LUMP 32	/* amount to over allocate sg_dev_arr by */
103 
104 static int sg_add(struct class_device *, struct class_interface *);
105 static void sg_remove(struct class_device *, struct class_interface *);
106 
107 static Scsi_Request *dummy_cmdp;	/* only used for sizeof */
108 
109 static DEFINE_RWLOCK(sg_dev_arr_lock);	/* Also used to lock
110 							   file descriptor list for device */
111 
112 static struct class_interface sg_interface = {
113 	.add		= sg_add,
114 	.remove		= sg_remove,
115 };
116 
117 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
118 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
119 	unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
120 	unsigned bufflen;	/* Size of (aggregate) data buffer */
121 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
122 	void *buffer;		/* Data buffer or scatter list (k_use_sg>0) */
123 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
124 	unsigned char cmd_opcode; /* first byte of command */
125 } Sg_scatter_hold;
126 
127 struct sg_device;		/* forward declarations */
128 struct sg_fd;
129 
130 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
131 	Scsi_Request *my_cmdp;	/* != 0  when request with lower levels */
132 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
133 	struct sg_fd *parentfp;	/* NULL -> not in use */
134 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
135 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
136 	unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
137 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
138 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
139 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
140 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
141 } Sg_request;
142 
143 typedef struct sg_fd {		/* holds the state of a file descriptor */
144 	struct sg_fd *nextfp;	/* NULL when last opened fd on this device */
145 	struct sg_device *parentdp;	/* owning device */
146 	wait_queue_head_t read_wait;	/* queue read until command done */
147 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
148 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
149 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
150 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
151 	unsigned save_scat_len;	/* original length of trunc. scat. element */
152 	Sg_request *headrp;	/* head of request slist, NULL->empty */
153 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
154 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
155 	char low_dma;		/* as in parent but possibly overridden to 1 */
156 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
157 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
158 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
159 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
160 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
161 	char mmap_called;	/* 0 -> mmap() never called on this fd */
162 } Sg_fd;
163 
164 typedef struct sg_device { /* holds the state of each scsi generic device */
165 	struct scsi_device *device;
166 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
167 	int sg_tablesize;	/* adapter's max scatter-gather table size */
168 	Sg_fd *headfp;		/* first open fd belonging to this device */
169 	volatile char detached;	/* 0->attached, 1->detached pending removal */
170 	volatile char exclude;	/* opened for exclusive access */
171 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
172 	struct gendisk *disk;
173 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
174 } Sg_device;
175 
176 static int sg_fasync(int fd, struct file *filp, int mode);
177 static void sg_cmd_done(Scsi_Cmnd * SCpnt);	/* tasklet or soft irq callback */
178 static int sg_start_req(Sg_request * srp);
179 static void sg_finish_rem_req(Sg_request * srp);
180 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
181 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
182 			 int tablesize);
183 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
184 			   Sg_request * srp);
185 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
186 			    int blocking, int read_only, Sg_request ** o_srp);
187 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
188 			   unsigned char *cmnd, int timeout, int blocking);
189 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
190 		      int wr_xf, int *countp, unsigned char __user **up);
191 static int sg_write_xfer(Sg_request * srp);
192 static int sg_read_xfer(Sg_request * srp);
193 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
194 static void sg_remove_scat(Sg_scatter_hold * schp);
195 static void sg_build_reserve(Sg_fd * sfp, int req_size);
196 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
197 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
198 static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
199 static void sg_page_free(char *buff, int size);
200 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
201 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
202 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
203 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
204 static Sg_request *sg_add_request(Sg_fd * sfp);
205 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
206 static int sg_res_in_use(Sg_fd * sfp);
207 static int sg_allow_access(unsigned char opcode, char dev_type);
208 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
209 static Sg_device *sg_get_dev(int dev);
210 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
211 #ifdef CONFIG_SCSI_PROC_FS
212 static int sg_last_dev(void);
213 #endif
214 
215 static Sg_device **sg_dev_arr = NULL;
216 static int sg_dev_max;
217 static int sg_nr_dev;
218 
219 #define SZ_SG_HEADER sizeof(struct sg_header)
220 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
221 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
222 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
223 
224 static int
225 sg_open(struct inode *inode, struct file *filp)
226 {
227 	int dev = iminor(inode);
228 	int flags = filp->f_flags;
229 	Sg_device *sdp;
230 	Sg_fd *sfp;
231 	int res;
232 	int retval;
233 
234 	nonseekable_open(inode, filp);
235 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
236 	sdp = sg_get_dev(dev);
237 	if ((!sdp) || (!sdp->device))
238 		return -ENXIO;
239 	if (sdp->detached)
240 		return -ENODEV;
241 
242 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
243 	/* Prevent the device driver from vanishing while we sleep */
244 	retval = scsi_device_get(sdp->device);
245 	if (retval)
246 		return retval;
247 
248 	if (!((flags & O_NONBLOCK) ||
249 	      scsi_block_when_processing_errors(sdp->device))) {
250 		retval = -ENXIO;
251 		/* we are in error recovery for this device */
252 		goto error_out;
253 	}
254 
255 	if (flags & O_EXCL) {
256 		if (O_RDONLY == (flags & O_ACCMODE)) {
257 			retval = -EPERM; /* Can't lock it with read only access */
258 			goto error_out;
259 		}
260 		if (sdp->headfp && (flags & O_NONBLOCK)) {
261 			retval = -EBUSY;
262 			goto error_out;
263 		}
264 		res = 0;
265 		__wait_event_interruptible(sdp->o_excl_wait,
266 			((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
267 		if (res) {
268 			retval = res;	/* -ERESTARTSYS because signal hit process */
269 			goto error_out;
270 		}
271 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
272 		if (flags & O_NONBLOCK) {
273 			retval = -EBUSY;
274 			goto error_out;
275 		}
276 		res = 0;
277 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
278 					   res);
279 		if (res) {
280 			retval = res;	/* -ERESTARTSYS because signal hit process */
281 			goto error_out;
282 		}
283 	}
284 	if (sdp->detached) {
285 		retval = -ENODEV;
286 		goto error_out;
287 	}
288 	if (!sdp->headfp) {	/* no existing opens on this device */
289 		sdp->sgdebug = 0;
290 		sdp->sg_tablesize = sdp->device->host->sg_tablesize;
291 	}
292 	if ((sfp = sg_add_sfp(sdp, dev)))
293 		filp->private_data = sfp;
294 	else {
295 		if (flags & O_EXCL)
296 			sdp->exclude = 0;	/* undo if error */
297 		retval = -ENOMEM;
298 		goto error_out;
299 	}
300 	return 0;
301 
302       error_out:
303 	scsi_device_put(sdp->device);
304 	return retval;
305 }
306 
307 /* Following function was formerly called 'sg_close' */
308 static int
309 sg_release(struct inode *inode, struct file *filp)
310 {
311 	Sg_device *sdp;
312 	Sg_fd *sfp;
313 
314 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
315 		return -ENXIO;
316 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
317 	sg_fasync(-1, filp, 0);	/* remove filp from async notification list */
318 	if (0 == sg_remove_sfp(sdp, sfp)) {	/* Returns 1 when sdp gone */
319 		if (!sdp->detached) {
320 			scsi_device_put(sdp->device);
321 		}
322 		sdp->exclude = 0;
323 		wake_up_interruptible(&sdp->o_excl_wait);
324 	}
325 	return 0;
326 }
327 
328 static ssize_t
329 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
330 {
331 	Sg_device *sdp;
332 	Sg_fd *sfp;
333 	Sg_request *srp;
334 	int req_pack_id = -1;
335 	sg_io_hdr_t *hp;
336 	struct sg_header *old_hdr = NULL;
337 	int retval = 0;
338 
339 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
340 		return -ENXIO;
341 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
342 				   sdp->disk->disk_name, (int) count));
343 	if (!access_ok(VERIFY_WRITE, buf, count))
344 		return -EFAULT;
345 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
346 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
347 		if (!old_hdr)
348 			return -ENOMEM;
349 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
350 			retval = -EFAULT;
351 			goto free_old_hdr;
352 		}
353 		if (old_hdr->reply_len < 0) {
354 			if (count >= SZ_SG_IO_HDR) {
355 				sg_io_hdr_t *new_hdr;
356 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
357 				if (!new_hdr) {
358 					retval = -ENOMEM;
359 					goto free_old_hdr;
360 				}
361 				retval =__copy_from_user
362 				    (new_hdr, buf, SZ_SG_IO_HDR);
363 				req_pack_id = new_hdr->pack_id;
364 				kfree(new_hdr);
365 				if (retval) {
366 					retval = -EFAULT;
367 					goto free_old_hdr;
368 				}
369 			}
370 		} else
371 			req_pack_id = old_hdr->pack_id;
372 	}
373 	srp = sg_get_rq_mark(sfp, req_pack_id);
374 	if (!srp) {		/* now wait on packet to arrive */
375 		if (sdp->detached) {
376 			retval = -ENODEV;
377 			goto free_old_hdr;
378 		}
379 		if (filp->f_flags & O_NONBLOCK) {
380 			retval = -EAGAIN;
381 			goto free_old_hdr;
382 		}
383 		while (1) {
384 			retval = 0; /* following macro beats race condition */
385 			__wait_event_interruptible(sfp->read_wait,
386 				(sdp->detached ||
387 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
388 				retval);
389 			if (sdp->detached) {
390 				retval = -ENODEV;
391 				goto free_old_hdr;
392 			}
393 			if (0 == retval)
394 				break;
395 
396 			/* -ERESTARTSYS as signal hit process */
397 			goto free_old_hdr;
398 		}
399 	}
400 	if (srp->header.interface_id != '\0') {
401 		retval = sg_new_read(sfp, buf, count, srp);
402 		goto free_old_hdr;
403 	}
404 
405 	hp = &srp->header;
406 	if (old_hdr == NULL) {
407 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
408 		if (! old_hdr) {
409 			retval = -ENOMEM;
410 			goto free_old_hdr;
411 		}
412 	}
413 	memset(old_hdr, 0, SZ_SG_HEADER);
414 	old_hdr->reply_len = (int) hp->timeout;
415 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
416 	old_hdr->pack_id = hp->pack_id;
417 	old_hdr->twelve_byte =
418 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
419 	old_hdr->target_status = hp->masked_status;
420 	old_hdr->host_status = hp->host_status;
421 	old_hdr->driver_status = hp->driver_status;
422 	if ((CHECK_CONDITION & hp->masked_status) ||
423 	    (DRIVER_SENSE & hp->driver_status))
424 		memcpy(old_hdr->sense_buffer, srp->sense_b,
425 		       sizeof (old_hdr->sense_buffer));
426 	switch (hp->host_status) {
427 	/* This setup of 'result' is for backward compatibility and is best
428 	   ignored by the user who should use target, host + driver status */
429 	case DID_OK:
430 	case DID_PASSTHROUGH:
431 	case DID_SOFT_ERROR:
432 		old_hdr->result = 0;
433 		break;
434 	case DID_NO_CONNECT:
435 	case DID_BUS_BUSY:
436 	case DID_TIME_OUT:
437 		old_hdr->result = EBUSY;
438 		break;
439 	case DID_BAD_TARGET:
440 	case DID_ABORT:
441 	case DID_PARITY:
442 	case DID_RESET:
443 	case DID_BAD_INTR:
444 		old_hdr->result = EIO;
445 		break;
446 	case DID_ERROR:
447 		old_hdr->result = (srp->sense_b[0] == 0 &&
448 				  hp->masked_status == GOOD) ? 0 : EIO;
449 		break;
450 	default:
451 		old_hdr->result = EIO;
452 		break;
453 	}
454 
455 	/* Now copy the result back to the user buffer.  */
456 	if (count >= SZ_SG_HEADER) {
457 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
458 			retval = -EFAULT;
459 			goto free_old_hdr;
460 		}
461 		buf += SZ_SG_HEADER;
462 		if (count > old_hdr->reply_len)
463 			count = old_hdr->reply_len;
464 		if (count > SZ_SG_HEADER) {
465 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
466 				retval = -EFAULT;
467 				goto free_old_hdr;
468 			}
469 		}
470 	} else
471 		count = (old_hdr->result == 0) ? 0 : -EIO;
472 	sg_finish_rem_req(srp);
473 	retval = count;
474 free_old_hdr:
475 	kfree(old_hdr);
476 	return retval;
477 }
478 
479 static ssize_t
480 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
481 {
482 	sg_io_hdr_t *hp = &srp->header;
483 	int err = 0;
484 	int len;
485 
486 	if (count < SZ_SG_IO_HDR) {
487 		err = -EINVAL;
488 		goto err_out;
489 	}
490 	hp->sb_len_wr = 0;
491 	if ((hp->mx_sb_len > 0) && hp->sbp) {
492 		if ((CHECK_CONDITION & hp->masked_status) ||
493 		    (DRIVER_SENSE & hp->driver_status)) {
494 			int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
495 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
496 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
497 			len = (len > sb_len) ? sb_len : len;
498 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
499 				err = -EFAULT;
500 				goto err_out;
501 			}
502 			hp->sb_len_wr = len;
503 		}
504 	}
505 	if (hp->masked_status || hp->host_status || hp->driver_status)
506 		hp->info |= SG_INFO_CHECK;
507 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
508 		err = -EFAULT;
509 		goto err_out;
510 	}
511 	err = sg_read_xfer(srp);
512       err_out:
513 	sg_finish_rem_req(srp);
514 	return (0 == err) ? count : err;
515 }
516 
517 static ssize_t
518 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
519 {
520 	int mxsize, cmd_size, k;
521 	int input_size, blocking;
522 	unsigned char opcode;
523 	Sg_device *sdp;
524 	Sg_fd *sfp;
525 	Sg_request *srp;
526 	struct sg_header old_hdr;
527 	sg_io_hdr_t *hp;
528 	unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
529 
530 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
531 		return -ENXIO;
532 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
533 				   sdp->disk->disk_name, (int) count));
534 	if (sdp->detached)
535 		return -ENODEV;
536 	if (!((filp->f_flags & O_NONBLOCK) ||
537 	      scsi_block_when_processing_errors(sdp->device)))
538 		return -ENXIO;
539 
540 	if (!access_ok(VERIFY_READ, buf, count))
541 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
542 	if (count < SZ_SG_HEADER)
543 		return -EIO;
544 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
545 		return -EFAULT;
546 	blocking = !(filp->f_flags & O_NONBLOCK);
547 	if (old_hdr.reply_len < 0)
548 		return sg_new_write(sfp, buf, count, blocking, 0, NULL);
549 	if (count < (SZ_SG_HEADER + 6))
550 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
551 
552 	if (!(srp = sg_add_request(sfp))) {
553 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
554 		return -EDOM;
555 	}
556 	buf += SZ_SG_HEADER;
557 	__get_user(opcode, buf);
558 	if (sfp->next_cmd_len > 0) {
559 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
560 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
561 			sfp->next_cmd_len = 0;
562 			sg_remove_request(sfp, srp);
563 			return -EIO;
564 		}
565 		cmd_size = sfp->next_cmd_len;
566 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
567 	} else {
568 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
569 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
570 			cmd_size = 12;
571 	}
572 	SCSI_LOG_TIMEOUT(4, printk(
573 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
574 /* Determine buffer size.  */
575 	input_size = count - cmd_size;
576 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
577 	mxsize -= SZ_SG_HEADER;
578 	input_size -= SZ_SG_HEADER;
579 	if (input_size < 0) {
580 		sg_remove_request(sfp, srp);
581 		return -EIO;	/* User did not pass enough bytes for this command. */
582 	}
583 	hp = &srp->header;
584 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
585 	hp->cmd_len = (unsigned char) cmd_size;
586 	hp->iovec_count = 0;
587 	hp->mx_sb_len = 0;
588 	if (input_size > 0)
589 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
590 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
591 	else
592 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
593 	hp->dxfer_len = mxsize;
594 	hp->dxferp = (char __user *)buf + cmd_size;
595 	hp->sbp = NULL;
596 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
597 	hp->flags = input_size;	/* structure abuse ... */
598 	hp->pack_id = old_hdr.pack_id;
599 	hp->usr_ptr = NULL;
600 	if (__copy_from_user(cmnd, buf, cmd_size))
601 		return -EFAULT;
602 	/*
603 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
604 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
605 	 * is a non-zero input_size, so emit a warning.
606 	 */
607 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
608 		if (printk_ratelimit())
609 			printk(KERN_WARNING
610 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
611 			       "guessing data in;\n" KERN_WARNING "   "
612 			       "program %s not setting count and/or reply_len properly\n",
613 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
614 			       input_size, (unsigned int) cmnd[0],
615 			       current->comm);
616 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
617 	return (k < 0) ? k : count;
618 }
619 
620 static ssize_t
621 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
622 	     int blocking, int read_only, Sg_request ** o_srp)
623 {
624 	int k;
625 	Sg_request *srp;
626 	sg_io_hdr_t *hp;
627 	unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
628 	int timeout;
629 	unsigned long ul_timeout;
630 
631 	if (count < SZ_SG_IO_HDR)
632 		return -EINVAL;
633 	if (!access_ok(VERIFY_READ, buf, count))
634 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
635 
636 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
637 	if (!(srp = sg_add_request(sfp))) {
638 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
639 		return -EDOM;
640 	}
641 	hp = &srp->header;
642 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
643 		sg_remove_request(sfp, srp);
644 		return -EFAULT;
645 	}
646 	if (hp->interface_id != 'S') {
647 		sg_remove_request(sfp, srp);
648 		return -ENOSYS;
649 	}
650 	if (hp->flags & SG_FLAG_MMAP_IO) {
651 		if (hp->dxfer_len > sfp->reserve.bufflen) {
652 			sg_remove_request(sfp, srp);
653 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
654 		}
655 		if (hp->flags & SG_FLAG_DIRECT_IO) {
656 			sg_remove_request(sfp, srp);
657 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
658 		}
659 		if (sg_res_in_use(sfp)) {
660 			sg_remove_request(sfp, srp);
661 			return -EBUSY;	/* reserve buffer already being used */
662 		}
663 	}
664 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
665 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
666 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
667 		sg_remove_request(sfp, srp);
668 		return -EMSGSIZE;
669 	}
670 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
671 		sg_remove_request(sfp, srp);
672 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
673 	}
674 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
675 		sg_remove_request(sfp, srp);
676 		return -EFAULT;
677 	}
678 	if (read_only &&
679 	    (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
680 		sg_remove_request(sfp, srp);
681 		return -EPERM;
682 	}
683 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
684 	if (k < 0)
685 		return k;
686 	if (o_srp)
687 		*o_srp = srp;
688 	return count;
689 }
690 
691 static int
692 sg_common_write(Sg_fd * sfp, Sg_request * srp,
693 		unsigned char *cmnd, int timeout, int blocking)
694 {
695 	int k;
696 	Scsi_Request *SRpnt;
697 	Sg_device *sdp = sfp->parentdp;
698 	sg_io_hdr_t *hp = &srp->header;
699 	request_queue_t *q;
700 
701 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
702 	hp->status = 0;
703 	hp->masked_status = 0;
704 	hp->msg_status = 0;
705 	hp->info = 0;
706 	hp->host_status = 0;
707 	hp->driver_status = 0;
708 	hp->resid = 0;
709 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
710 			  (int) cmnd[0], (int) hp->cmd_len));
711 
712 	if ((k = sg_start_req(srp))) {
713 		SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
714 		sg_finish_rem_req(srp);
715 		return k;	/* probably out of space --> ENOMEM */
716 	}
717 	if ((k = sg_write_xfer(srp))) {
718 		SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
719 		sg_finish_rem_req(srp);
720 		return k;
721 	}
722 	if (sdp->detached) {
723 		sg_finish_rem_req(srp);
724 		return -ENODEV;
725 	}
726 	SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
727 	if (SRpnt == NULL) {
728 		SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
729 		sg_finish_rem_req(srp);
730 		return -ENOMEM;
731 	}
732 
733 	srp->my_cmdp = SRpnt;
734 	q = SRpnt->sr_device->request_queue;
735 	SRpnt->sr_request->rq_disk = sdp->disk;
736 	SRpnt->sr_sense_buffer[0] = 0;
737 	SRpnt->sr_cmd_len = hp->cmd_len;
738 	SRpnt->sr_use_sg = srp->data.k_use_sg;
739 	SRpnt->sr_sglist_len = srp->data.sglist_len;
740 	SRpnt->sr_bufflen = srp->data.bufflen;
741 	SRpnt->sr_underflow = 0;
742 	SRpnt->sr_buffer = srp->data.buffer;
743 	switch (hp->dxfer_direction) {
744 	case SG_DXFER_TO_FROM_DEV:
745 	case SG_DXFER_FROM_DEV:
746 		SRpnt->sr_data_direction = DMA_FROM_DEVICE;
747 		break;
748 	case SG_DXFER_TO_DEV:
749 		SRpnt->sr_data_direction = DMA_TO_DEVICE;
750 		break;
751 	case SG_DXFER_UNKNOWN:
752 		SRpnt->sr_data_direction = DMA_BIDIRECTIONAL;
753 		break;
754 	default:
755 		SRpnt->sr_data_direction = DMA_NONE;
756 		break;
757 	}
758 	SRpnt->upper_private_data = srp;
759 	srp->data.k_use_sg = 0;
760 	srp->data.sglist_len = 0;
761 	srp->data.bufflen = 0;
762 	srp->data.buffer = NULL;
763 	hp->duration = jiffies_to_msecs(jiffies);
764 /* Now send everything of to mid-level. The next time we hear about this
765    packet is when sg_cmd_done() is called (i.e. a callback). */
766 	scsi_do_req(SRpnt, (void *) cmnd,
767 		    (void *) SRpnt->sr_buffer, hp->dxfer_len,
768 		    sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
769 	/* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
770 	return 0;
771 }
772 
773 static int
774 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
775 {
776 	unsigned long iflags;
777 	int done;
778 
779 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
780 	done = srp->done;
781 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
782 	return done;
783 }
784 
785 static int
786 sg_ioctl(struct inode *inode, struct file *filp,
787 	 unsigned int cmd_in, unsigned long arg)
788 {
789 	void __user *p = (void __user *)arg;
790 	int __user *ip = p;
791 	int result, val, read_only;
792 	Sg_device *sdp;
793 	Sg_fd *sfp;
794 	Sg_request *srp;
795 	unsigned long iflags;
796 
797 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
798 		return -ENXIO;
799 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
800 				   sdp->disk->disk_name, (int) cmd_in));
801 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
802 
803 	switch (cmd_in) {
804 	case SG_IO:
805 		{
806 			int blocking = 1;	/* ignore O_NONBLOCK flag */
807 
808 			if (sdp->detached)
809 				return -ENODEV;
810 			if (!scsi_block_when_processing_errors(sdp->device))
811 				return -ENXIO;
812 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
813 				return -EFAULT;
814 			result =
815 			    sg_new_write(sfp, p, SZ_SG_IO_HDR,
816 					 blocking, read_only, &srp);
817 			if (result < 0)
818 				return result;
819 			srp->sg_io_owned = 1;
820 			while (1) {
821 				result = 0;	/* following macro to beat race condition */
822 				__wait_event_interruptible(sfp->read_wait,
823 					(sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
824 							   result);
825 				if (sdp->detached)
826 					return -ENODEV;
827 				if (sfp->closed)
828 					return 0;	/* request packet dropped already */
829 				if (0 == result)
830 					break;
831 				srp->orphan = 1;
832 				return result;	/* -ERESTARTSYS because signal hit process */
833 			}
834 			write_lock_irqsave(&sfp->rq_list_lock, iflags);
835 			srp->done = 2;
836 			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
837 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
838 			return (result < 0) ? result : 0;
839 		}
840 	case SG_SET_TIMEOUT:
841 		result = get_user(val, ip);
842 		if (result)
843 			return result;
844 		if (val < 0)
845 			return -EIO;
846 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
847 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
848 		sfp->timeout_user = val;
849 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
850 
851 		return 0;
852 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
853 				/* strange ..., for backward compatibility */
854 		return sfp->timeout_user;
855 	case SG_SET_FORCE_LOW_DMA:
856 		result = get_user(val, ip);
857 		if (result)
858 			return result;
859 		if (val) {
860 			sfp->low_dma = 1;
861 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
862 				val = (int) sfp->reserve.bufflen;
863 				sg_remove_scat(&sfp->reserve);
864 				sg_build_reserve(sfp, val);
865 			}
866 		} else {
867 			if (sdp->detached)
868 				return -ENODEV;
869 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
870 		}
871 		return 0;
872 	case SG_GET_LOW_DMA:
873 		return put_user((int) sfp->low_dma, ip);
874 	case SG_GET_SCSI_ID:
875 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
876 			return -EFAULT;
877 		else {
878 			sg_scsi_id_t __user *sg_idp = p;
879 
880 			if (sdp->detached)
881 				return -ENODEV;
882 			__put_user((int) sdp->device->host->host_no,
883 				   &sg_idp->host_no);
884 			__put_user((int) sdp->device->channel,
885 				   &sg_idp->channel);
886 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
887 			__put_user((int) sdp->device->lun, &sg_idp->lun);
888 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
889 			__put_user((short) sdp->device->host->cmd_per_lun,
890 				   &sg_idp->h_cmd_per_lun);
891 			__put_user((short) sdp->device->queue_depth,
892 				   &sg_idp->d_queue_depth);
893 			__put_user(0, &sg_idp->unused[0]);
894 			__put_user(0, &sg_idp->unused[1]);
895 			return 0;
896 		}
897 	case SG_SET_FORCE_PACK_ID:
898 		result = get_user(val, ip);
899 		if (result)
900 			return result;
901 		sfp->force_packid = val ? 1 : 0;
902 		return 0;
903 	case SG_GET_PACK_ID:
904 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
905 			return -EFAULT;
906 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
907 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
908 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
909 				read_unlock_irqrestore(&sfp->rq_list_lock,
910 						       iflags);
911 				__put_user(srp->header.pack_id, ip);
912 				return 0;
913 			}
914 		}
915 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
916 		__put_user(-1, ip);
917 		return 0;
918 	case SG_GET_NUM_WAITING:
919 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
920 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
921 			if ((1 == srp->done) && (!srp->sg_io_owned))
922 				++val;
923 		}
924 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
925 		return put_user(val, ip);
926 	case SG_GET_SG_TABLESIZE:
927 		return put_user(sdp->sg_tablesize, ip);
928 	case SG_SET_RESERVED_SIZE:
929 		result = get_user(val, ip);
930 		if (result)
931 			return result;
932                 if (val < 0)
933                         return -EINVAL;
934 		if (val != sfp->reserve.bufflen) {
935 			if (sg_res_in_use(sfp) || sfp->mmap_called)
936 				return -EBUSY;
937 			sg_remove_scat(&sfp->reserve);
938 			sg_build_reserve(sfp, val);
939 		}
940 		return 0;
941 	case SG_GET_RESERVED_SIZE:
942 		val = (int) sfp->reserve.bufflen;
943 		return put_user(val, ip);
944 	case SG_SET_COMMAND_Q:
945 		result = get_user(val, ip);
946 		if (result)
947 			return result;
948 		sfp->cmd_q = val ? 1 : 0;
949 		return 0;
950 	case SG_GET_COMMAND_Q:
951 		return put_user((int) sfp->cmd_q, ip);
952 	case SG_SET_KEEP_ORPHAN:
953 		result = get_user(val, ip);
954 		if (result)
955 			return result;
956 		sfp->keep_orphan = val;
957 		return 0;
958 	case SG_GET_KEEP_ORPHAN:
959 		return put_user((int) sfp->keep_orphan, ip);
960 	case SG_NEXT_CMD_LEN:
961 		result = get_user(val, ip);
962 		if (result)
963 			return result;
964 		sfp->next_cmd_len = (val > 0) ? val : 0;
965 		return 0;
966 	case SG_GET_VERSION_NUM:
967 		return put_user(sg_version_num, ip);
968 	case SG_GET_ACCESS_COUNT:
969 		/* faked - we don't have a real access count anymore */
970 		val = (sdp->device ? 1 : 0);
971 		return put_user(val, ip);
972 	case SG_GET_REQUEST_TABLE:
973 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
974 			return -EFAULT;
975 		else {
976 			sg_req_info_t *rinfo;
977 			unsigned int ms;
978 
979 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
980 								GFP_KERNEL);
981 			if (!rinfo)
982 				return -ENOMEM;
983 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
984 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
985 			     ++val, srp = srp ? srp->nextrp : srp) {
986 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
987 				if (srp) {
988 					rinfo[val].req_state = srp->done + 1;
989 					rinfo[val].problem =
990 					    srp->header.masked_status &
991 					    srp->header.host_status &
992 					    srp->header.driver_status;
993 					if (srp->done)
994 						rinfo[val].duration =
995 							srp->header.duration;
996 					else {
997 						ms = jiffies_to_msecs(jiffies);
998 						rinfo[val].duration =
999 						    (ms > srp->header.duration) ?
1000 						    (ms - srp->header.duration) : 0;
1001 					}
1002 					rinfo[val].orphan = srp->orphan;
1003 					rinfo[val].sg_io_owned =
1004 							srp->sg_io_owned;
1005 					rinfo[val].pack_id =
1006 							srp->header.pack_id;
1007 					rinfo[val].usr_ptr =
1008 							srp->header.usr_ptr;
1009 				}
1010 			}
1011 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1012 			result = __copy_to_user(p, rinfo,
1013 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1014 			result = result ? -EFAULT : 0;
1015 			kfree(rinfo);
1016 			return result;
1017 		}
1018 	case SG_EMULATED_HOST:
1019 		if (sdp->detached)
1020 			return -ENODEV;
1021 		return put_user(sdp->device->host->hostt->emulated, ip);
1022 	case SG_SCSI_RESET:
1023 		if (sdp->detached)
1024 			return -ENODEV;
1025 		if (filp->f_flags & O_NONBLOCK) {
1026 			if (scsi_host_in_recovery(sdp->device->host))
1027 				return -EBUSY;
1028 		} else if (!scsi_block_when_processing_errors(sdp->device))
1029 			return -EBUSY;
1030 		result = get_user(val, ip);
1031 		if (result)
1032 			return result;
1033 		if (SG_SCSI_RESET_NOTHING == val)
1034 			return 0;
1035 		switch (val) {
1036 		case SG_SCSI_RESET_DEVICE:
1037 			val = SCSI_TRY_RESET_DEVICE;
1038 			break;
1039 		case SG_SCSI_RESET_BUS:
1040 			val = SCSI_TRY_RESET_BUS;
1041 			break;
1042 		case SG_SCSI_RESET_HOST:
1043 			val = SCSI_TRY_RESET_HOST;
1044 			break;
1045 		default:
1046 			return -EINVAL;
1047 		}
1048 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1049 			return -EACCES;
1050 		return (scsi_reset_provider(sdp->device, val) ==
1051 			SUCCESS) ? 0 : -EIO;
1052 	case SCSI_IOCTL_SEND_COMMAND:
1053 		if (sdp->detached)
1054 			return -ENODEV;
1055 		if (read_only) {
1056 			unsigned char opcode = WRITE_6;
1057 			Scsi_Ioctl_Command __user *siocp = p;
1058 
1059 			if (copy_from_user(&opcode, siocp->data, 1))
1060 				return -EFAULT;
1061 			if (!sg_allow_access(opcode, sdp->device->type))
1062 				return -EPERM;
1063 		}
1064 		return scsi_ioctl_send_command(sdp->device, p);
1065 	case SG_SET_DEBUG:
1066 		result = get_user(val, ip);
1067 		if (result)
1068 			return result;
1069 		sdp->sgdebug = (char) val;
1070 		return 0;
1071 	case SCSI_IOCTL_GET_IDLUN:
1072 	case SCSI_IOCTL_GET_BUS_NUMBER:
1073 	case SCSI_IOCTL_PROBE_HOST:
1074 	case SG_GET_TRANSFORM:
1075 		if (sdp->detached)
1076 			return -ENODEV;
1077 		return scsi_ioctl(sdp->device, cmd_in, p);
1078 	default:
1079 		if (read_only)
1080 			return -EPERM;	/* don't know so take safe approach */
1081 		return scsi_ioctl(sdp->device, cmd_in, p);
1082 	}
1083 }
1084 
1085 #ifdef CONFIG_COMPAT
1086 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1087 {
1088 	Sg_device *sdp;
1089 	Sg_fd *sfp;
1090 	struct scsi_device *sdev;
1091 
1092 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1093 		return -ENXIO;
1094 
1095 	sdev = sdp->device;
1096 	if (sdev->host->hostt->compat_ioctl) {
1097 		int ret;
1098 
1099 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1100 
1101 		return ret;
1102 	}
1103 
1104 	return -ENOIOCTLCMD;
1105 }
1106 #endif
1107 
1108 static unsigned int
1109 sg_poll(struct file *filp, poll_table * wait)
1110 {
1111 	unsigned int res = 0;
1112 	Sg_device *sdp;
1113 	Sg_fd *sfp;
1114 	Sg_request *srp;
1115 	int count = 0;
1116 	unsigned long iflags;
1117 
1118 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1119 	    || sfp->closed)
1120 		return POLLERR;
1121 	poll_wait(filp, &sfp->read_wait, wait);
1122 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1123 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1124 		/* if any read waiting, flag it */
1125 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1126 			res = POLLIN | POLLRDNORM;
1127 		++count;
1128 	}
1129 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1130 
1131 	if (sdp->detached)
1132 		res |= POLLHUP;
1133 	else if (!sfp->cmd_q) {
1134 		if (0 == count)
1135 			res |= POLLOUT | POLLWRNORM;
1136 	} else if (count < SG_MAX_QUEUE)
1137 		res |= POLLOUT | POLLWRNORM;
1138 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1139 				   sdp->disk->disk_name, (int) res));
1140 	return res;
1141 }
1142 
1143 static int
1144 sg_fasync(int fd, struct file *filp, int mode)
1145 {
1146 	int retval;
1147 	Sg_device *sdp;
1148 	Sg_fd *sfp;
1149 
1150 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1151 		return -ENXIO;
1152 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1153 				   sdp->disk->disk_name, mode));
1154 
1155 	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1156 	return (retval < 0) ? retval : 0;
1157 }
1158 
1159 static inline unsigned char *
1160 sg_scatg2virt(const struct scatterlist *sclp)
1161 {
1162 	return (sclp && sclp->page) ?
1163 	    (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1164 }
1165 
1166 /* When startFinish==1 increments page counts for pages other than the
1167    first of scatter gather elements obtained from __get_free_pages().
1168    When startFinish==0 decrements ... */
1169 static void
1170 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1171 {
1172 	void *page_ptr;
1173 	struct page *page;
1174 	int k, m;
1175 
1176 	SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1177 				   startFinish, rsv_schp->k_use_sg));
1178 	/* N.B. correction _not_ applied to base page of each allocation */
1179 	if (rsv_schp->k_use_sg) {	/* reserve buffer is a scatter gather list */
1180 		struct scatterlist *sclp = rsv_schp->buffer;
1181 
1182 		for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1183 			for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1184 				page_ptr = sg_scatg2virt(sclp) + m;
1185 				page = virt_to_page(page_ptr);
1186 				if (startFinish)
1187 					get_page(page);
1188 				else {
1189 					if (page_count(page) > 0)
1190 						__put_page(page);
1191 				}
1192 			}
1193 		}
1194 	} else {		/* reserve buffer is just a single allocation */
1195 		for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1196 			page_ptr = (unsigned char *) rsv_schp->buffer + m;
1197 			page = virt_to_page(page_ptr);
1198 			if (startFinish)
1199 				get_page(page);
1200 			else {
1201 				if (page_count(page) > 0)
1202 					__put_page(page);
1203 			}
1204 		}
1205 	}
1206 }
1207 
1208 static struct page *
1209 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1210 {
1211 	Sg_fd *sfp;
1212 	struct page *page = NOPAGE_SIGBUS;
1213 	void *page_ptr = NULL;
1214 	unsigned long offset;
1215 	Sg_scatter_hold *rsv_schp;
1216 
1217 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1218 		return page;
1219 	rsv_schp = &sfp->reserve;
1220 	offset = addr - vma->vm_start;
1221 	if (offset >= rsv_schp->bufflen)
1222 		return page;
1223 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1224 				   offset, rsv_schp->k_use_sg));
1225 	if (rsv_schp->k_use_sg) {	/* reserve buffer is a scatter gather list */
1226 		int k;
1227 		unsigned long sa = vma->vm_start;
1228 		unsigned long len;
1229 		struct scatterlist *sclp = rsv_schp->buffer;
1230 
1231 		for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1232 		     ++k, ++sclp) {
1233 			len = vma->vm_end - sa;
1234 			len = (len < sclp->length) ? len : sclp->length;
1235 			if (offset < len) {
1236 				page_ptr = sg_scatg2virt(sclp) + offset;
1237 				page = virt_to_page(page_ptr);
1238 				get_page(page);	/* increment page count */
1239 				break;
1240 			}
1241 			sa += len;
1242 			offset -= len;
1243 		}
1244 	} else {		/* reserve buffer is just a single allocation */
1245 		page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1246 		page = virt_to_page(page_ptr);
1247 		get_page(page);	/* increment page count */
1248 	}
1249 	if (type)
1250 		*type = VM_FAULT_MINOR;
1251 	return page;
1252 }
1253 
1254 static struct vm_operations_struct sg_mmap_vm_ops = {
1255 	.nopage = sg_vma_nopage,
1256 };
1257 
1258 static int
1259 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1260 {
1261 	Sg_fd *sfp;
1262 	unsigned long req_sz;
1263 	Sg_scatter_hold *rsv_schp;
1264 
1265 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1266 		return -ENXIO;
1267 	req_sz = vma->vm_end - vma->vm_start;
1268 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1269 				   (void *) vma->vm_start, (int) req_sz));
1270 	if (vma->vm_pgoff)
1271 		return -EINVAL;	/* want no offset */
1272 	rsv_schp = &sfp->reserve;
1273 	if (req_sz > rsv_schp->bufflen)
1274 		return -ENOMEM;	/* cannot map more than reserved buffer */
1275 
1276 	if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1277 		int k;
1278 		unsigned long sa = vma->vm_start;
1279 		unsigned long len;
1280 		struct scatterlist *sclp = rsv_schp->buffer;
1281 
1282 		for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1283 		     ++k, ++sclp) {
1284 			if (0 != sclp->offset)
1285 				return -EFAULT;	/* non page aligned memory ?? */
1286 			len = vma->vm_end - sa;
1287 			len = (len < sclp->length) ? len : sclp->length;
1288 			sa += len;
1289 		}
1290 	} else {	/* reserve buffer is just a single allocation */
1291 		if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1292 			return -EFAULT;	/* non page aligned memory ?? */
1293 	}
1294 	if (0 == sfp->mmap_called) {
1295 		sg_rb_correct4mmap(rsv_schp, 1);	/* do only once per fd lifetime */
1296 		sfp->mmap_called = 1;
1297 	}
1298 	vma->vm_flags |= VM_RESERVED;
1299 	vma->vm_private_data = sfp;
1300 	vma->vm_ops = &sg_mmap_vm_ops;
1301 	return 0;
1302 }
1303 
1304 /* This function is a "bottom half" handler that is called by the
1305  * mid level when a command is completed (or has failed). */
1306 static void
1307 sg_cmd_done(Scsi_Cmnd * SCpnt)
1308 {
1309 	Scsi_Request *SRpnt = NULL;
1310 	Sg_device *sdp = NULL;
1311 	Sg_fd *sfp;
1312 	Sg_request *srp = NULL;
1313 	unsigned long iflags;
1314 	unsigned int ms;
1315 
1316 	if (SCpnt && (SRpnt = SCpnt->sc_request))
1317 		srp = (Sg_request *) SRpnt->upper_private_data;
1318 	if (NULL == srp) {
1319 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
1320 		if (SRpnt)
1321 			scsi_release_request(SRpnt);
1322 		return;
1323 	}
1324 	sfp = srp->parentfp;
1325 	if (sfp)
1326 		sdp = sfp->parentdp;
1327 	if ((NULL == sdp) || sdp->detached) {
1328 		printk(KERN_INFO "sg_cmd_done: device detached\n");
1329 		scsi_release_request(SRpnt);
1330 		return;
1331 	}
1332 
1333 	/* First transfer ownership of data buffers to sg_device object. */
1334 	srp->data.k_use_sg = SRpnt->sr_use_sg;
1335 	srp->data.sglist_len = SRpnt->sr_sglist_len;
1336 	srp->data.bufflen = SRpnt->sr_bufflen;
1337 	srp->data.buffer = SRpnt->sr_buffer;
1338 	/* now clear out request structure */
1339 	SRpnt->sr_use_sg = 0;
1340 	SRpnt->sr_sglist_len = 0;
1341 	SRpnt->sr_bufflen = 0;
1342 	SRpnt->sr_buffer = NULL;
1343 	SRpnt->sr_underflow = 0;
1344 	SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1345 
1346 	srp->my_cmdp = NULL;
1347 
1348 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1349 		sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1350 	srp->header.resid = SCpnt->resid;
1351 	ms = jiffies_to_msecs(jiffies);
1352 	srp->header.duration = (ms > srp->header.duration) ?
1353 				(ms - srp->header.duration) : 0;
1354 	if (0 != SRpnt->sr_result) {
1355 		struct scsi_sense_hdr sshdr;
1356 
1357 		memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1358 		       sizeof (srp->sense_b));
1359 		srp->header.status = 0xff & SRpnt->sr_result;
1360 		srp->header.masked_status = status_byte(SRpnt->sr_result);
1361 		srp->header.msg_status = msg_byte(SRpnt->sr_result);
1362 		srp->header.host_status = host_byte(SRpnt->sr_result);
1363 		srp->header.driver_status = driver_byte(SRpnt->sr_result);
1364 		if ((sdp->sgdebug > 0) &&
1365 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1366 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1367 			scsi_print_req_sense("sg_cmd_done", SRpnt);
1368 
1369 		/* Following if statement is a patch supplied by Eric Youngdale */
1370 		if (driver_byte(SRpnt->sr_result) != 0
1371 		    && scsi_command_normalize_sense(SCpnt, &sshdr)
1372 		    && !scsi_sense_is_deferred(&sshdr)
1373 		    && sshdr.sense_key == UNIT_ATTENTION
1374 		    && sdp->device->removable) {
1375 			/* Detected possible disc change. Set the bit - this */
1376 			/* may be used if there are filesystems using this device */
1377 			sdp->device->changed = 1;
1378 		}
1379 	}
1380 	/* Rely on write phase to clean out srp status values, so no "else" */
1381 
1382 	scsi_release_request(SRpnt);
1383 	SRpnt = NULL;
1384 	if (sfp->closed) {	/* whoops this fd already released, cleanup */
1385 		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1386 		sg_finish_rem_req(srp);
1387 		srp = NULL;
1388 		if (NULL == sfp->headrp) {
1389 			SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1390 			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
1391 				scsi_device_put(sdp->device);
1392 			}
1393 			sfp = NULL;
1394 		}
1395 	} else if (srp && srp->orphan) {
1396 		if (sfp->keep_orphan)
1397 			srp->sg_io_owned = 0;
1398 		else {
1399 			sg_finish_rem_req(srp);
1400 			srp = NULL;
1401 		}
1402 	}
1403 	if (sfp && srp) {
1404 		/* Now wake up any sg_read() that is waiting for this packet. */
1405 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1406 		write_lock_irqsave(&sfp->rq_list_lock, iflags);
1407 		srp->done = 1;
1408 		wake_up_interruptible(&sfp->read_wait);
1409 		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1410 	}
1411 }
1412 
1413 static struct file_operations sg_fops = {
1414 	.owner = THIS_MODULE,
1415 	.read = sg_read,
1416 	.write = sg_write,
1417 	.poll = sg_poll,
1418 	.ioctl = sg_ioctl,
1419 #ifdef CONFIG_COMPAT
1420 	.compat_ioctl = sg_compat_ioctl,
1421 #endif
1422 	.open = sg_open,
1423 	.mmap = sg_mmap,
1424 	.release = sg_release,
1425 	.fasync = sg_fasync,
1426 };
1427 
1428 static struct class *sg_sysfs_class;
1429 
1430 static int sg_sysfs_valid = 0;
1431 
1432 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1433 {
1434 	Sg_device *sdp;
1435 	unsigned long iflags;
1436 	void *old_sg_dev_arr = NULL;
1437 	int k, error;
1438 
1439 	sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1440 	if (!sdp) {
1441 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1442 		return -ENOMEM;
1443 	}
1444 
1445 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1446 	if (unlikely(sg_nr_dev >= sg_dev_max)) {	/* try to resize */
1447 		Sg_device **tmp_da;
1448 		int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1449 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1450 
1451 		tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1452 		if (unlikely(!tmp_da))
1453 			goto expand_failed;
1454 
1455 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
1456 		memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1457 		memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1458 		old_sg_dev_arr = sg_dev_arr;
1459 		sg_dev_arr = tmp_da;
1460 		sg_dev_max = tmp_dev_max;
1461 	}
1462 
1463 	for (k = 0; k < sg_dev_max; k++)
1464 		if (!sg_dev_arr[k])
1465 			break;
1466 	if (unlikely(k >= SG_MAX_DEVS))
1467 		goto overflow;
1468 
1469 	memset(sdp, 0, sizeof(*sdp));
1470 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1471 	sprintf(disk->disk_name, "sg%d", k);
1472 	disk->first_minor = k;
1473 	sdp->disk = disk;
1474 	sdp->device = scsidp;
1475 	init_waitqueue_head(&sdp->o_excl_wait);
1476 	sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1477 
1478 	sg_nr_dev++;
1479 	sg_dev_arr[k] = sdp;
1480 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1481 	error = k;
1482 
1483  out:
1484 	if (error < 0)
1485 		kfree(sdp);
1486 	kfree(old_sg_dev_arr);
1487 	return error;
1488 
1489  expand_failed:
1490 	printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1491 	error = -ENOMEM;
1492 	goto out;
1493 
1494  overflow:
1495 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1496 	sdev_printk(KERN_WARNING, scsidp,
1497 		    "Unable to attach sg device type=%d, minor "
1498 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1499 	error = -ENODEV;
1500 	goto out;
1501 }
1502 
1503 static int
1504 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1505 {
1506 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1507 	struct gendisk *disk;
1508 	Sg_device *sdp = NULL;
1509 	struct cdev * cdev = NULL;
1510 	int error, k;
1511 
1512 	disk = alloc_disk(1);
1513 	if (!disk) {
1514 		printk(KERN_WARNING "alloc_disk failed\n");
1515 		return -ENOMEM;
1516 	}
1517 	disk->major = SCSI_GENERIC_MAJOR;
1518 
1519 	error = -ENOMEM;
1520 	cdev = cdev_alloc();
1521 	if (!cdev) {
1522 		printk(KERN_WARNING "cdev_alloc failed\n");
1523 		goto out;
1524 	}
1525 	cdev->owner = THIS_MODULE;
1526 	cdev->ops = &sg_fops;
1527 
1528 	error = sg_alloc(disk, scsidp);
1529 	if (error < 0) {
1530 		printk(KERN_WARNING "sg_alloc failed\n");
1531 		goto out;
1532 	}
1533 	k = error;
1534 	sdp = sg_dev_arr[k];
1535 
1536 	devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1537 			S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1538 			"%s/generic", scsidp->devfs_name);
1539 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1540 	if (error) {
1541 		devfs_remove("%s/generic", scsidp->devfs_name);
1542 		goto out;
1543 	}
1544 	sdp->cdev = cdev;
1545 	if (sg_sysfs_valid) {
1546 		struct class_device * sg_class_member;
1547 
1548 		sg_class_member = class_device_create(sg_sysfs_class, NULL,
1549 				MKDEV(SCSI_GENERIC_MAJOR, k),
1550 				cl_dev->dev, "%s",
1551 				disk->disk_name);
1552 		if (IS_ERR(sg_class_member))
1553 			printk(KERN_WARNING "sg_add: "
1554 				"class_device_create failed\n");
1555 		class_set_devdata(sg_class_member, sdp);
1556 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1557 					  &sg_class_member->kobj, "generic");
1558 		if (error)
1559 			printk(KERN_ERR "sg_add: unable to make symlink "
1560 					"'generic' back to sg%d\n", k);
1561 	} else
1562 		printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1563 
1564 	sdev_printk(KERN_NOTICE, scsidp,
1565 		    "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1566 
1567 	return 0;
1568 
1569 out:
1570 	put_disk(disk);
1571 	if (cdev)
1572 		cdev_del(cdev);
1573 	return error;
1574 }
1575 
1576 static void
1577 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1578 {
1579 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1580 	Sg_device *sdp = NULL;
1581 	unsigned long iflags;
1582 	Sg_fd *sfp;
1583 	Sg_fd *tsfp;
1584 	Sg_request *srp;
1585 	Sg_request *tsrp;
1586 	int k, delay;
1587 
1588 	if (NULL == sg_dev_arr)
1589 		return;
1590 	delay = 0;
1591 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1592 	for (k = 0; k < sg_dev_max; k++) {
1593 		sdp = sg_dev_arr[k];
1594 		if ((NULL == sdp) || (sdp->device != scsidp))
1595 			continue;	/* dirty but lowers nesting */
1596 		if (sdp->headfp) {
1597 			sdp->detached = 1;
1598 			for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1599 				tsfp = sfp->nextfp;
1600 				for (srp = sfp->headrp; srp; srp = tsrp) {
1601 					tsrp = srp->nextrp;
1602 					if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1603 						sg_finish_rem_req(srp);
1604 				}
1605 				if (sfp->closed) {
1606 					scsi_device_put(sdp->device);
1607 					__sg_remove_sfp(sdp, sfp);
1608 				} else {
1609 					delay = 1;
1610 					wake_up_interruptible(&sfp->read_wait);
1611 					kill_fasync(&sfp->async_qp, SIGPOLL,
1612 						    POLL_HUP);
1613 				}
1614 			}
1615 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1616 			if (NULL == sdp->headfp) {
1617 				sg_dev_arr[k] = NULL;
1618 			}
1619 		} else {	/* nothing active, simple case */
1620 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1621 			sg_dev_arr[k] = NULL;
1622 		}
1623 		sg_nr_dev--;
1624 		break;
1625 	}
1626 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1627 
1628 	if (sdp) {
1629 		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1630 		class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1631 		cdev_del(sdp->cdev);
1632 		sdp->cdev = NULL;
1633 		devfs_remove("%s/generic", scsidp->devfs_name);
1634 		put_disk(sdp->disk);
1635 		sdp->disk = NULL;
1636 		if (NULL == sdp->headfp)
1637 			kfree((char *) sdp);
1638 	}
1639 
1640 	if (delay)
1641 		msleep(10);	/* dirty detach so delay device destruction */
1642 }
1643 
1644 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1645  * of sysfs parameters (which module_param doesn't yet support).
1646  * Sysfs parameters defined explicitly below.
1647  */
1648 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1649 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1650 
1651 MODULE_AUTHOR("Douglas Gilbert");
1652 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1653 MODULE_LICENSE("GPL");
1654 MODULE_VERSION(SG_VERSION_STR);
1655 
1656 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1657 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1658 
1659 static int __init
1660 init_sg(void)
1661 {
1662 	int rc;
1663 
1664 	if (def_reserved_size >= 0)
1665 		sg_big_buff = def_reserved_size;
1666 
1667 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1668 				    SG_MAX_DEVS, "sg");
1669 	if (rc)
1670 		return rc;
1671         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1672         if ( IS_ERR(sg_sysfs_class) ) {
1673 		rc = PTR_ERR(sg_sysfs_class);
1674 		goto err_out;
1675         }
1676 	sg_sysfs_valid = 1;
1677 	rc = scsi_register_interface(&sg_interface);
1678 	if (0 == rc) {
1679 #ifdef CONFIG_SCSI_PROC_FS
1680 		sg_proc_init();
1681 #endif				/* CONFIG_SCSI_PROC_FS */
1682 		return 0;
1683 	}
1684 	class_destroy(sg_sysfs_class);
1685 err_out:
1686 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1687 	return rc;
1688 }
1689 
1690 static void __exit
1691 exit_sg(void)
1692 {
1693 #ifdef CONFIG_SCSI_PROC_FS
1694 	sg_proc_cleanup();
1695 #endif				/* CONFIG_SCSI_PROC_FS */
1696 	scsi_unregister_interface(&sg_interface);
1697 	class_destroy(sg_sysfs_class);
1698 	sg_sysfs_valid = 0;
1699 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1700 				 SG_MAX_DEVS);
1701 	kfree((char *)sg_dev_arr);
1702 	sg_dev_arr = NULL;
1703 	sg_dev_max = 0;
1704 }
1705 
1706 static int
1707 sg_start_req(Sg_request * srp)
1708 {
1709 	int res;
1710 	Sg_fd *sfp = srp->parentfp;
1711 	sg_io_hdr_t *hp = &srp->header;
1712 	int dxfer_len = (int) hp->dxfer_len;
1713 	int dxfer_dir = hp->dxfer_direction;
1714 	Sg_scatter_hold *req_schp = &srp->data;
1715 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1716 
1717 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1718 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1719 		return 0;
1720 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1721 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1722 	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1723 		res = sg_build_direct(srp, sfp, dxfer_len);
1724 		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
1725 			return res;
1726 	}
1727 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1728 		sg_link_reserve(sfp, srp, dxfer_len);
1729 	else {
1730 		res = sg_build_indirect(req_schp, sfp, dxfer_len);
1731 		if (res) {
1732 			sg_remove_scat(req_schp);
1733 			return res;
1734 		}
1735 	}
1736 	return 0;
1737 }
1738 
1739 static void
1740 sg_finish_rem_req(Sg_request * srp)
1741 {
1742 	Sg_fd *sfp = srp->parentfp;
1743 	Sg_scatter_hold *req_schp = &srp->data;
1744 
1745 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1746 	if (srp->res_used)
1747 		sg_unlink_reserve(sfp, srp);
1748 	else
1749 		sg_remove_scat(req_schp);
1750 	sg_remove_request(sfp, srp);
1751 }
1752 
1753 static int
1754 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1755 {
1756 	int ret_sz;
1757 	int elem_sz = sizeof (struct scatterlist);
1758 	int sg_bufflen = tablesize * elem_sz;
1759 	int mx_sc_elems = tablesize;
1760 
1761 	schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1762 	if (!schp->buffer)
1763 		return -ENOMEM;
1764 	else if (ret_sz != sg_bufflen) {
1765 		sg_bufflen = ret_sz;
1766 		mx_sc_elems = sg_bufflen / elem_sz;
1767 	}
1768 	schp->sglist_len = sg_bufflen;
1769 	memset(schp->buffer, 0, sg_bufflen);
1770 	return mx_sc_elems;	/* number of scat_gath elements allocated */
1771 }
1772 
1773 #ifdef SG_ALLOW_DIO_CODE
1774 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1775 	/* hopefully this generic code will moved to a library */
1776 
1777 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1778    - mapping of all pages not successful
1779    - any page is above max_pfn
1780    (i.e., either completely successful or fails)
1781 */
1782 static int
1783 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1784 	          unsigned long uaddr, size_t count, int rw,
1785 	          unsigned long max_pfn)
1786 {
1787 	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1788 	unsigned long start = uaddr >> PAGE_SHIFT;
1789 	const int nr_pages = end - start;
1790 	int res, i, j;
1791 	struct page **pages;
1792 
1793 	/* User attempted Overflow! */
1794 	if ((uaddr + count) < uaddr)
1795 		return -EINVAL;
1796 
1797 	/* Too big */
1798         if (nr_pages > max_pages)
1799 		return -ENOMEM;
1800 
1801 	/* Hmm? */
1802 	if (count == 0)
1803 		return 0;
1804 
1805 	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1806 		return -ENOMEM;
1807 
1808         /* Try to fault in all of the necessary pages */
1809 	down_read(&current->mm->mmap_sem);
1810         /* rw==READ means read from drive, write into memory area */
1811 	res = get_user_pages(
1812 		current,
1813 		current->mm,
1814 		uaddr,
1815 		nr_pages,
1816 		rw == READ,
1817 		0, /* don't force */
1818 		pages,
1819 		NULL);
1820 	up_read(&current->mm->mmap_sem);
1821 
1822 	/* Errors and no page mapped should return here */
1823 	if (res < nr_pages)
1824 		goto out_unmap;
1825 
1826         for (i=0; i < nr_pages; i++) {
1827                 /* FIXME: flush superflous for rw==READ,
1828                  * probably wrong function for rw==WRITE
1829                  */
1830 		flush_dcache_page(pages[i]);
1831 		if (page_to_pfn(pages[i]) > max_pfn)
1832 			goto out_unlock;
1833 		/* ?? Is locking needed? I don't think so */
1834 		/* if (TestSetPageLocked(pages[i]))
1835 		   goto out_unlock; */
1836         }
1837 
1838 	/* Populate the scatter/gather list */
1839 	sgl[0].page = pages[0];
1840 	sgl[0].offset = uaddr & ~PAGE_MASK;
1841 	if (nr_pages > 1) {
1842 		sgl[0].length = PAGE_SIZE - sgl[0].offset;
1843 		count -= sgl[0].length;
1844 		for (i=1; i < nr_pages ; i++) {
1845 			sgl[i].offset = 0;
1846 			sgl[i].page = pages[i];
1847 			sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1848 			count -= PAGE_SIZE;
1849 		}
1850 	}
1851 	else {
1852 		sgl[0].length = count;
1853 	}
1854 
1855 	kfree(pages);
1856 	return nr_pages;
1857 
1858  out_unlock:
1859 	/* for (j=0; j < i; j++)
1860 	   unlock_page(pages[j]); */
1861 	res = 0;
1862  out_unmap:
1863 	if (res > 0) {
1864 		for (j=0; j < res; j++)
1865 			page_cache_release(pages[j]);
1866 		res = 0;
1867 	}
1868 	kfree(pages);
1869 	return res;
1870 }
1871 
1872 
1873 /* And unmap them... */
1874 static int
1875 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1876 		    int dirtied)
1877 {
1878 	int i;
1879 
1880 	for (i=0; i < nr_pages; i++) {
1881 		struct page *page = sgl[i].page;
1882 
1883 		if (dirtied)
1884 			SetPageDirty(page);
1885 		/* unlock_page(page); */
1886 		/* FIXME: cache flush missing for rw==READ
1887 		 * FIXME: call the correct reference counting function
1888 		 */
1889 		page_cache_release(page);
1890 	}
1891 
1892 	return 0;
1893 }
1894 
1895 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1896 #endif
1897 
1898 
1899 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1900 static int
1901 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1902 {
1903 #ifdef SG_ALLOW_DIO_CODE
1904 	sg_io_hdr_t *hp = &srp->header;
1905 	Sg_scatter_hold *schp = &srp->data;
1906 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1907 	struct scatterlist *sgl;
1908 	int mx_sc_elems, res;
1909 	struct scsi_device *sdev = sfp->parentdp->device;
1910 
1911 	if (((unsigned long)hp->dxferp &
1912 			queue_dma_alignment(sdev->request_queue)) != 0)
1913 		return 1;
1914 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1915         if (mx_sc_elems <= 0) {
1916                 return 1;
1917         }
1918 	sgl = (struct scatterlist *)schp->buffer;
1919 	res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len,
1920 				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1921 	if (res <= 0)
1922 		return 1;
1923 	schp->k_use_sg = res;
1924 	schp->dio_in_use = 1;
1925 	hp->info |= SG_INFO_DIRECT_IO;
1926 	return 0;
1927 #else
1928 	return 1;
1929 #endif
1930 }
1931 
1932 static int
1933 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1934 {
1935 	int ret_sz;
1936 	int blk_size = buff_size;
1937 	unsigned char *p = NULL;
1938 
1939 	if ((blk_size < 0) || (!sfp))
1940 		return -EFAULT;
1941 	if (0 == blk_size)
1942 		++blk_size;	/* don't know why */
1943 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1944 	blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1945 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1946 				   buff_size, blk_size));
1947 	if (blk_size <= SG_SCATTER_SZ) {
1948 		p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1949 		if (!p)
1950 			return -ENOMEM;
1951 		if (blk_size == ret_sz) {	/* got it on the first attempt */
1952 			schp->k_use_sg = 0;
1953 			schp->buffer = p;
1954 			schp->bufflen = blk_size;
1955 			schp->b_malloc_len = blk_size;
1956 			return 0;
1957 		}
1958 	} else {
1959 		p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1960 		if (!p)
1961 			return -ENOMEM;
1962 	}
1963 /* Want some local declarations, so start new block ... */
1964 	{			/* lets try and build a scatter gather list */
1965 		struct scatterlist *sclp;
1966 		int k, rem_sz, num;
1967 		int mx_sc_elems;
1968 		int sg_tablesize = sfp->parentdp->sg_tablesize;
1969 		int first = 1;
1970 
1971 		/* N.B. ret_sz carried into this block ... */
1972 		mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1973 		if (mx_sc_elems < 0)
1974 			return mx_sc_elems;	/* most likely -ENOMEM */
1975 
1976 		for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1977 		     (rem_sz > 0) && (k < mx_sc_elems);
1978 		     ++k, rem_sz -= ret_sz, ++sclp) {
1979 			if (first)
1980 				first = 0;
1981 			else {
1982 				num =
1983 				    (rem_sz >
1984 				     SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1985 				p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1986 				if (!p)
1987 					break;
1988 			}
1989 			sg_set_buf(sclp, p, ret_sz);
1990 
1991 			SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1992 					  k, sg_scatg2virt(sclp), ret_sz));
1993 		}		/* end of for loop */
1994 		schp->k_use_sg = k;
1995 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1996 		schp->bufflen = blk_size;
1997 		if (rem_sz > 0)	/* must have failed */
1998 			return -ENOMEM;
1999 	}
2000 	return 0;
2001 }
2002 
2003 static int
2004 sg_write_xfer(Sg_request * srp)
2005 {
2006 	sg_io_hdr_t *hp = &srp->header;
2007 	Sg_scatter_hold *schp = &srp->data;
2008 	int num_xfer = 0;
2009 	int j, k, onum, usglen, ksglen, res;
2010 	int iovec_count = (int) hp->iovec_count;
2011 	int dxfer_dir = hp->dxfer_direction;
2012 	unsigned char *p;
2013 	unsigned char __user *up;
2014 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2015 
2016 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
2017 	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2018 		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
2019 		if (schp->bufflen < num_xfer)
2020 			num_xfer = schp->bufflen;
2021 	}
2022 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2023 	    (new_interface
2024 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2025 		return 0;
2026 
2027 	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2028 			  num_xfer, iovec_count, schp->k_use_sg));
2029 	if (iovec_count) {
2030 		onum = iovec_count;
2031 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2032 			return -EFAULT;
2033 	} else
2034 		onum = 1;
2035 
2036 	if (0 == schp->k_use_sg) {	/* kernel has single buffer */
2037 		for (j = 0, p = schp->buffer; j < onum; ++j) {
2038 			res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
2039 			if (res)
2040 				return res;
2041 			usglen = (num_xfer > usglen) ? usglen : num_xfer;
2042 			if (__copy_from_user(p, up, usglen))
2043 				return -EFAULT;
2044 			p += usglen;
2045 			num_xfer -= usglen;
2046 			if (num_xfer <= 0)
2047 				return 0;
2048 		}
2049 	} else {		/* kernel using scatter gather list */
2050 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2051 
2052 		ksglen = (int) sclp->length;
2053 		p = sg_scatg2virt(sclp);
2054 		for (j = 0, k = 0; j < onum; ++j) {
2055 			res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
2056 			if (res)
2057 				return res;
2058 
2059 			for (; p; ++sclp, ksglen = (int) sclp->length,
2060 				  p = sg_scatg2virt(sclp)) {
2061 				if (usglen <= 0)
2062 					break;
2063 				if (ksglen > usglen) {
2064 					if (usglen >= num_xfer) {
2065 						if (__copy_from_user
2066 						    (p, up, num_xfer))
2067 							return -EFAULT;
2068 						return 0;
2069 					}
2070 					if (__copy_from_user(p, up, usglen))
2071 						return -EFAULT;
2072 					p += usglen;
2073 					ksglen -= usglen;
2074 					break;
2075 				} else {
2076 					if (ksglen >= num_xfer) {
2077 						if (__copy_from_user
2078 						    (p, up, num_xfer))
2079 							return -EFAULT;
2080 						return 0;
2081 					}
2082 					if (__copy_from_user(p, up, ksglen))
2083 						return -EFAULT;
2084 					up += ksglen;
2085 					usglen -= ksglen;
2086 				}
2087 				++k;
2088 				if (k >= schp->k_use_sg)
2089 					return 0;
2090 			}
2091 		}
2092 	}
2093 	return 0;
2094 }
2095 
2096 static int
2097 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
2098 	   int wr_xf, int *countp, unsigned char __user **up)
2099 {
2100 	int num_xfer = (int) hp->dxfer_len;
2101 	unsigned char __user *p = hp->dxferp;
2102 	int count;
2103 
2104 	if (0 == sg_num) {
2105 		if (wr_xf && ('\0' == hp->interface_id))
2106 			count = (int) hp->flags;	/* holds "old" input_size */
2107 		else
2108 			count = num_xfer;
2109 	} else {
2110 		sg_iovec_t iovec;
2111 		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2112 			return -EFAULT;
2113 		p = iovec.iov_base;
2114 		count = (int) iovec.iov_len;
2115 	}
2116 	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
2117 		return -EFAULT;
2118 	if (up)
2119 		*up = p;
2120 	if (countp)
2121 		*countp = count;
2122 	return 0;
2123 }
2124 
2125 static void
2126 sg_remove_scat(Sg_scatter_hold * schp)
2127 {
2128 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2129 	if (schp->buffer && (schp->sglist_len > 0)) {
2130 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2131 
2132 		if (schp->dio_in_use) {
2133 #ifdef SG_ALLOW_DIO_CODE
2134 			st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2135 #endif
2136 		} else {
2137 			int k;
2138 
2139 			for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2140 			     ++k, ++sclp) {
2141 				SCSI_LOG_TIMEOUT(5, printk(
2142 				    "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2143 				    k, sg_scatg2virt(sclp), sclp->length));
2144 				sg_page_free(sg_scatg2virt(sclp), sclp->length);
2145 				sclp->page = NULL;
2146 				sclp->offset = 0;
2147 				sclp->length = 0;
2148 			}
2149 		}
2150 		sg_page_free(schp->buffer, schp->sglist_len);
2151 	} else if (schp->buffer)
2152 		sg_page_free(schp->buffer, schp->b_malloc_len);
2153 	memset(schp, 0, sizeof (*schp));
2154 }
2155 
2156 static int
2157 sg_read_xfer(Sg_request * srp)
2158 {
2159 	sg_io_hdr_t *hp = &srp->header;
2160 	Sg_scatter_hold *schp = &srp->data;
2161 	int num_xfer = 0;
2162 	int j, k, onum, usglen, ksglen, res;
2163 	int iovec_count = (int) hp->iovec_count;
2164 	int dxfer_dir = hp->dxfer_direction;
2165 	unsigned char *p;
2166 	unsigned char __user *up;
2167 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2168 
2169 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2170 	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2171 		num_xfer = hp->dxfer_len;
2172 		if (schp->bufflen < num_xfer)
2173 			num_xfer = schp->bufflen;
2174 	}
2175 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2176 	    (new_interface
2177 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2178 		return 0;
2179 
2180 	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2181 			  num_xfer, iovec_count, schp->k_use_sg));
2182 	if (iovec_count) {
2183 		onum = iovec_count;
2184 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2185 			return -EFAULT;
2186 	} else
2187 		onum = 1;
2188 
2189 	if (0 == schp->k_use_sg) {	/* kernel has single buffer */
2190 		for (j = 0, p = schp->buffer; j < onum; ++j) {
2191 			res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2192 			if (res)
2193 				return res;
2194 			usglen = (num_xfer > usglen) ? usglen : num_xfer;
2195 			if (__copy_to_user(up, p, usglen))
2196 				return -EFAULT;
2197 			p += usglen;
2198 			num_xfer -= usglen;
2199 			if (num_xfer <= 0)
2200 				return 0;
2201 		}
2202 	} else {		/* kernel using scatter gather list */
2203 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2204 
2205 		ksglen = (int) sclp->length;
2206 		p = sg_scatg2virt(sclp);
2207 		for (j = 0, k = 0; j < onum; ++j) {
2208 			res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2209 			if (res)
2210 				return res;
2211 
2212 			for (; p; ++sclp, ksglen = (int) sclp->length,
2213 				  p = sg_scatg2virt(sclp)) {
2214 				if (usglen <= 0)
2215 					break;
2216 				if (ksglen > usglen) {
2217 					if (usglen >= num_xfer) {
2218 						if (__copy_to_user
2219 						    (up, p, num_xfer))
2220 							return -EFAULT;
2221 						return 0;
2222 					}
2223 					if (__copy_to_user(up, p, usglen))
2224 						return -EFAULT;
2225 					p += usglen;
2226 					ksglen -= usglen;
2227 					break;
2228 				} else {
2229 					if (ksglen >= num_xfer) {
2230 						if (__copy_to_user
2231 						    (up, p, num_xfer))
2232 							return -EFAULT;
2233 						return 0;
2234 					}
2235 					if (__copy_to_user(up, p, ksglen))
2236 						return -EFAULT;
2237 					up += ksglen;
2238 					usglen -= ksglen;
2239 				}
2240 				++k;
2241 				if (k >= schp->k_use_sg)
2242 					return 0;
2243 			}
2244 		}
2245 	}
2246 	return 0;
2247 }
2248 
2249 static int
2250 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2251 {
2252 	Sg_scatter_hold *schp = &srp->data;
2253 
2254 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2255 				   num_read_xfer));
2256 	if ((!outp) || (num_read_xfer <= 0))
2257 		return 0;
2258 	if (schp->k_use_sg > 0) {
2259 		int k, num;
2260 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2261 
2262 		for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2263 		     ++k, ++sclp) {
2264 			num = (int) sclp->length;
2265 			if (num > num_read_xfer) {
2266 				if (__copy_to_user
2267 				    (outp, sg_scatg2virt(sclp), num_read_xfer))
2268 					return -EFAULT;
2269 				break;
2270 			} else {
2271 				if (__copy_to_user
2272 				    (outp, sg_scatg2virt(sclp), num))
2273 					return -EFAULT;
2274 				num_read_xfer -= num;
2275 				if (num_read_xfer <= 0)
2276 					break;
2277 				outp += num;
2278 			}
2279 		}
2280 	} else {
2281 		if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2282 			return -EFAULT;
2283 	}
2284 	return 0;
2285 }
2286 
2287 static void
2288 sg_build_reserve(Sg_fd * sfp, int req_size)
2289 {
2290 	Sg_scatter_hold *schp = &sfp->reserve;
2291 
2292 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2293 	do {
2294 		if (req_size < PAGE_SIZE)
2295 			req_size = PAGE_SIZE;
2296 		if (0 == sg_build_indirect(schp, sfp, req_size))
2297 			return;
2298 		else
2299 			sg_remove_scat(schp);
2300 		req_size >>= 1;	/* divide by 2 */
2301 	} while (req_size > (PAGE_SIZE / 2));
2302 }
2303 
2304 static void
2305 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2306 {
2307 	Sg_scatter_hold *req_schp = &srp->data;
2308 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2309 
2310 	srp->res_used = 1;
2311 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2312 	size = (size + 1) & (~1);	/* round to even for aha1542 */
2313 	if (rsv_schp->k_use_sg > 0) {
2314 		int k, num;
2315 		int rem = size;
2316 		struct scatterlist *sclp =
2317 		    (struct scatterlist *) rsv_schp->buffer;
2318 
2319 		for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2320 			num = (int) sclp->length;
2321 			if (rem <= num) {
2322 				if (0 == k) {
2323 					req_schp->k_use_sg = 0;
2324 					req_schp->buffer = sg_scatg2virt(sclp);
2325 				} else {
2326 					sfp->save_scat_len = num;
2327 					sclp->length = (unsigned) rem;
2328 					req_schp->k_use_sg = k + 1;
2329 					req_schp->sglist_len =
2330 					    rsv_schp->sglist_len;
2331 					req_schp->buffer = rsv_schp->buffer;
2332 				}
2333 				req_schp->bufflen = size;
2334 				req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2335 				break;
2336 			} else
2337 				rem -= num;
2338 		}
2339 		if (k >= rsv_schp->k_use_sg)
2340 			SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2341 	} else {
2342 		req_schp->k_use_sg = 0;
2343 		req_schp->bufflen = size;
2344 		req_schp->buffer = rsv_schp->buffer;
2345 		req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2346 	}
2347 }
2348 
2349 static void
2350 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2351 {
2352 	Sg_scatter_hold *req_schp = &srp->data;
2353 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2354 
2355 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2356 				   (int) req_schp->k_use_sg));
2357 	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2358 		struct scatterlist *sclp =
2359 		    (struct scatterlist *) rsv_schp->buffer;
2360 
2361 		if (sfp->save_scat_len > 0)
2362 			(sclp + (req_schp->k_use_sg - 1))->length =
2363 			    (unsigned) sfp->save_scat_len;
2364 		else
2365 			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2366 	}
2367 	req_schp->k_use_sg = 0;
2368 	req_schp->bufflen = 0;
2369 	req_schp->buffer = NULL;
2370 	req_schp->sglist_len = 0;
2371 	sfp->save_scat_len = 0;
2372 	srp->res_used = 0;
2373 }
2374 
2375 static Sg_request *
2376 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2377 {
2378 	Sg_request *resp;
2379 	unsigned long iflags;
2380 
2381 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2382 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2383 		/* look for requests that are ready + not SG_IO owned */
2384 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
2385 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2386 			resp->done = 2;	/* guard against other readers */
2387 			break;
2388 		}
2389 	}
2390 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2391 	return resp;
2392 }
2393 
2394 #ifdef CONFIG_SCSI_PROC_FS
2395 static Sg_request *
2396 sg_get_nth_request(Sg_fd * sfp, int nth)
2397 {
2398 	Sg_request *resp;
2399 	unsigned long iflags;
2400 	int k;
2401 
2402 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2403 	for (k = 0, resp = sfp->headrp; resp && (k < nth);
2404 	     ++k, resp = resp->nextrp) ;
2405 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2406 	return resp;
2407 }
2408 #endif
2409 
2410 /* always adds to end of list */
2411 static Sg_request *
2412 sg_add_request(Sg_fd * sfp)
2413 {
2414 	int k;
2415 	unsigned long iflags;
2416 	Sg_request *resp;
2417 	Sg_request *rp = sfp->req_arr;
2418 
2419 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2420 	resp = sfp->headrp;
2421 	if (!resp) {
2422 		memset(rp, 0, sizeof (Sg_request));
2423 		rp->parentfp = sfp;
2424 		resp = rp;
2425 		sfp->headrp = resp;
2426 	} else {
2427 		if (0 == sfp->cmd_q)
2428 			resp = NULL;	/* command queuing disallowed */
2429 		else {
2430 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2431 				if (!rp->parentfp)
2432 					break;
2433 			}
2434 			if (k < SG_MAX_QUEUE) {
2435 				memset(rp, 0, sizeof (Sg_request));
2436 				rp->parentfp = sfp;
2437 				while (resp->nextrp)
2438 					resp = resp->nextrp;
2439 				resp->nextrp = rp;
2440 				resp = rp;
2441 			} else
2442 				resp = NULL;
2443 		}
2444 	}
2445 	if (resp) {
2446 		resp->nextrp = NULL;
2447 		resp->header.duration = jiffies_to_msecs(jiffies);
2448 		resp->my_cmdp = NULL;
2449 	}
2450 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2451 	return resp;
2452 }
2453 
2454 /* Return of 1 for found; 0 for not found */
2455 static int
2456 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2457 {
2458 	Sg_request *prev_rp;
2459 	Sg_request *rp;
2460 	unsigned long iflags;
2461 	int res = 0;
2462 
2463 	if ((!sfp) || (!srp) || (!sfp->headrp))
2464 		return res;
2465 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2466 	if (srp->my_cmdp)
2467 		srp->my_cmdp->upper_private_data = NULL;
2468 	prev_rp = sfp->headrp;
2469 	if (srp == prev_rp) {
2470 		sfp->headrp = prev_rp->nextrp;
2471 		prev_rp->parentfp = NULL;
2472 		res = 1;
2473 	} else {
2474 		while ((rp = prev_rp->nextrp)) {
2475 			if (srp == rp) {
2476 				prev_rp->nextrp = rp->nextrp;
2477 				rp->parentfp = NULL;
2478 				res = 1;
2479 				break;
2480 			}
2481 			prev_rp = rp;
2482 		}
2483 	}
2484 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2485 	return res;
2486 }
2487 
2488 #ifdef CONFIG_SCSI_PROC_FS
2489 static Sg_fd *
2490 sg_get_nth_sfp(Sg_device * sdp, int nth)
2491 {
2492 	Sg_fd *resp;
2493 	unsigned long iflags;
2494 	int k;
2495 
2496 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2497 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
2498 	     ++k, resp = resp->nextfp) ;
2499 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2500 	return resp;
2501 }
2502 #endif
2503 
2504 static Sg_fd *
2505 sg_add_sfp(Sg_device * sdp, int dev)
2506 {
2507 	Sg_fd *sfp;
2508 	unsigned long iflags;
2509 
2510 	sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
2511 	if (!sfp)
2512 		return NULL;
2513 	memset(sfp, 0, sizeof (Sg_fd));
2514 	init_waitqueue_head(&sfp->read_wait);
2515 	rwlock_init(&sfp->rq_list_lock);
2516 
2517 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2518 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2519 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2520 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2521 	    sdp->device->host->unchecked_isa_dma : 1;
2522 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2523 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2524 	sfp->parentdp = sdp;
2525 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
2526 	if (!sdp->headfp)
2527 		sdp->headfp = sfp;
2528 	else {			/* add to tail of existing list */
2529 		Sg_fd *pfp = sdp->headfp;
2530 		while (pfp->nextfp)
2531 			pfp = pfp->nextfp;
2532 		pfp->nextfp = sfp;
2533 	}
2534 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2535 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2536 	sg_build_reserve(sfp, sg_big_buff);
2537 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2538 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2539 	return sfp;
2540 }
2541 
2542 static void
2543 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2544 {
2545 	Sg_fd *fp;
2546 	Sg_fd *prev_fp;
2547 
2548 	prev_fp = sdp->headfp;
2549 	if (sfp == prev_fp)
2550 		sdp->headfp = prev_fp->nextfp;
2551 	else {
2552 		while ((fp = prev_fp->nextfp)) {
2553 			if (sfp == fp) {
2554 				prev_fp->nextfp = fp->nextfp;
2555 				break;
2556 			}
2557 			prev_fp = fp;
2558 		}
2559 	}
2560 	if (sfp->reserve.bufflen > 0) {
2561 		SCSI_LOG_TIMEOUT(6,
2562 			printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2563 			(int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2564 		if (sfp->mmap_called)
2565 			sg_rb_correct4mmap(&sfp->reserve, 0);	/* undo correction */
2566 		sg_remove_scat(&sfp->reserve);
2567 	}
2568 	sfp->parentdp = NULL;
2569 	SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2570 	sg_page_free((char *) sfp, sizeof (Sg_fd));
2571 }
2572 
2573 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2574 static int
2575 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2576 {
2577 	Sg_request *srp;
2578 	Sg_request *tsrp;
2579 	int dirty = 0;
2580 	int res = 0;
2581 
2582 	for (srp = sfp->headrp; srp; srp = tsrp) {
2583 		tsrp = srp->nextrp;
2584 		if (sg_srp_done(srp, sfp))
2585 			sg_finish_rem_req(srp);
2586 		else
2587 			++dirty;
2588 	}
2589 	if (0 == dirty) {
2590 		unsigned long iflags;
2591 
2592 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
2593 		__sg_remove_sfp(sdp, sfp);
2594 		if (sdp->detached && (NULL == sdp->headfp)) {
2595 			int k, maxd;
2596 
2597 			maxd = sg_dev_max;
2598 			for (k = 0; k < maxd; ++k) {
2599 				if (sdp == sg_dev_arr[k])
2600 					break;
2601 			}
2602 			if (k < maxd)
2603 				sg_dev_arr[k] = NULL;
2604 			kfree((char *) sdp);
2605 			res = 1;
2606 		}
2607 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2608 	} else {
2609 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
2610 		/* only bump the access_count if we actually succeeded in
2611 		 * throwing another counter on the host module */
2612 		scsi_device_get(sdp->device);	/* XXX: retval ignored? */
2613 		sfp->closed = 1;	/* flag dirty state on this fd */
2614 		SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2615 				  dirty));
2616 	}
2617 	return res;
2618 }
2619 
2620 static int
2621 sg_res_in_use(Sg_fd * sfp)
2622 {
2623 	const Sg_request *srp;
2624 	unsigned long iflags;
2625 
2626 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2627 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2628 		if (srp->res_used)
2629 			break;
2630 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2631 	return srp ? 1 : 0;
2632 }
2633 
2634 /* If retSzp==NULL want exact size or fail */
2635 static char *
2636 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2637 {
2638 	char *resp = NULL;
2639 	gfp_t page_mask;
2640 	int order, a_size;
2641 	int resSz = rqSz;
2642 
2643 	if (rqSz <= 0)
2644 		return resp;
2645 
2646 	if (lowDma)
2647 		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2648 	else
2649 		page_mask = GFP_ATOMIC | __GFP_NOWARN;
2650 
2651 	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2652 	     order++, a_size <<= 1) ;
2653 	resp = (char *) __get_free_pages(page_mask, order);
2654 	while ((!resp) && order && retSzp) {
2655 		--order;
2656 		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
2657 		resp = (char *) __get_free_pages(page_mask, order);	/* try half */
2658 		resSz = a_size;
2659 	}
2660 	if (resp) {
2661 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2662 			memset(resp, 0, resSz);
2663 		if (retSzp)
2664 			*retSzp = resSz;
2665 	}
2666 	return resp;
2667 }
2668 
2669 static void
2670 sg_page_free(char *buff, int size)
2671 {
2672 	int order, a_size;
2673 
2674 	if (!buff)
2675 		return;
2676 	for (order = 0, a_size = PAGE_SIZE; a_size < size;
2677 	     order++, a_size <<= 1) ;
2678 	free_pages((unsigned long) buff, order);
2679 }
2680 
2681 #ifndef MAINTENANCE_IN_CMD
2682 #define MAINTENANCE_IN_CMD 0xa3
2683 #endif
2684 
2685 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2686 	INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2687 	READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2688 	SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2689 };
2690 
2691 static int
2692 sg_allow_access(unsigned char opcode, char dev_type)
2693 {
2694 	int k;
2695 
2696 	if (TYPE_SCANNER == dev_type)	/* TYPE_ROM maybe burner */
2697 		return 1;
2698 	for (k = 0; k < sizeof (allow_ops); ++k) {
2699 		if (opcode == allow_ops[k])
2700 			return 1;
2701 	}
2702 	return 0;
2703 }
2704 
2705 #ifdef CONFIG_SCSI_PROC_FS
2706 static int
2707 sg_last_dev(void)
2708 {
2709 	int k;
2710 	unsigned long iflags;
2711 
2712 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2713 	for (k = sg_dev_max - 1; k >= 0; --k)
2714 		if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2715 			break;
2716 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2717 	return k + 1;		/* origin 1 */
2718 }
2719 #endif
2720 
2721 static Sg_device *
2722 sg_get_dev(int dev)
2723 {
2724 	Sg_device *sdp = NULL;
2725 	unsigned long iflags;
2726 
2727 	if (sg_dev_arr && (dev >= 0)) {
2728 		read_lock_irqsave(&sg_dev_arr_lock, iflags);
2729 		if (dev < sg_dev_max)
2730 			sdp = sg_dev_arr[dev];
2731 		read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2732 	}
2733 	return sdp;
2734 }
2735 
2736 #ifdef CONFIG_SCSI_PROC_FS
2737 
2738 static struct proc_dir_entry *sg_proc_sgp = NULL;
2739 
2740 static char sg_proc_sg_dirname[] = "scsi/sg";
2741 
2742 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2743 
2744 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2745 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2746 			          size_t count, loff_t *off);
2747 static struct file_operations adio_fops = {
2748 	/* .owner, .read and .llseek added in sg_proc_init() */
2749 	.open = sg_proc_single_open_adio,
2750 	.write = sg_proc_write_adio,
2751 	.release = single_release,
2752 };
2753 
2754 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2755 static ssize_t sg_proc_write_dressz(struct file *filp,
2756 		const char __user *buffer, size_t count, loff_t *off);
2757 static struct file_operations dressz_fops = {
2758 	.open = sg_proc_single_open_dressz,
2759 	.write = sg_proc_write_dressz,
2760 	.release = single_release,
2761 };
2762 
2763 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2764 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2765 static struct file_operations version_fops = {
2766 	.open = sg_proc_single_open_version,
2767 	.release = single_release,
2768 };
2769 
2770 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2771 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2772 static struct file_operations devhdr_fops = {
2773 	.open = sg_proc_single_open_devhdr,
2774 	.release = single_release,
2775 };
2776 
2777 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2778 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2779 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2780 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2781 static void dev_seq_stop(struct seq_file *s, void *v);
2782 static struct file_operations dev_fops = {
2783 	.open = sg_proc_open_dev,
2784 	.release = seq_release,
2785 };
2786 static struct seq_operations dev_seq_ops = {
2787 	.start = dev_seq_start,
2788 	.next  = dev_seq_next,
2789 	.stop  = dev_seq_stop,
2790 	.show  = sg_proc_seq_show_dev,
2791 };
2792 
2793 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2794 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2795 static struct file_operations devstrs_fops = {
2796 	.open = sg_proc_open_devstrs,
2797 	.release = seq_release,
2798 };
2799 static struct seq_operations devstrs_seq_ops = {
2800 	.start = dev_seq_start,
2801 	.next  = dev_seq_next,
2802 	.stop  = dev_seq_stop,
2803 	.show  = sg_proc_seq_show_devstrs,
2804 };
2805 
2806 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2807 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2808 static struct file_operations debug_fops = {
2809 	.open = sg_proc_open_debug,
2810 	.release = seq_release,
2811 };
2812 static struct seq_operations debug_seq_ops = {
2813 	.start = dev_seq_start,
2814 	.next  = dev_seq_next,
2815 	.stop  = dev_seq_stop,
2816 	.show  = sg_proc_seq_show_debug,
2817 };
2818 
2819 
2820 struct sg_proc_leaf {
2821 	const char * name;
2822 	struct file_operations * fops;
2823 };
2824 
2825 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2826 	{"allow_dio", &adio_fops},
2827 	{"debug", &debug_fops},
2828 	{"def_reserved_size", &dressz_fops},
2829 	{"device_hdr", &devhdr_fops},
2830 	{"devices", &dev_fops},
2831 	{"device_strs", &devstrs_fops},
2832 	{"version", &version_fops}
2833 };
2834 
2835 static int
2836 sg_proc_init(void)
2837 {
2838 	int k, mask;
2839 	int num_leaves =
2840 	    sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2841 	struct proc_dir_entry *pdep;
2842 	struct sg_proc_leaf * leaf;
2843 
2844 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2845 	if (!sg_proc_sgp)
2846 		return 1;
2847 	for (k = 0; k < num_leaves; ++k) {
2848 		leaf = &sg_proc_leaf_arr[k];
2849 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2850 		pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2851 		if (pdep) {
2852 			leaf->fops->owner = THIS_MODULE,
2853 			leaf->fops->read = seq_read,
2854 			leaf->fops->llseek = seq_lseek,
2855 			pdep->proc_fops = leaf->fops;
2856 		}
2857 	}
2858 	return 0;
2859 }
2860 
2861 static void
2862 sg_proc_cleanup(void)
2863 {
2864 	int k;
2865 	int num_leaves =
2866 	    sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2867 
2868 	if (!sg_proc_sgp)
2869 		return;
2870 	for (k = 0; k < num_leaves; ++k)
2871 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2872 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2873 }
2874 
2875 
2876 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2877 {
2878 	seq_printf(s, "%d\n", *((int *)s->private));
2879 	return 0;
2880 }
2881 
2882 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2883 {
2884 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2885 }
2886 
2887 static ssize_t
2888 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2889 		   size_t count, loff_t *off)
2890 {
2891 	int num;
2892 	char buff[11];
2893 
2894 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2895 		return -EACCES;
2896 	num = (count < 10) ? count : 10;
2897 	if (copy_from_user(buff, buffer, num))
2898 		return -EFAULT;
2899 	buff[num] = '\0';
2900 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2901 	return count;
2902 }
2903 
2904 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2905 {
2906 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2907 }
2908 
2909 static ssize_t
2910 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2911 		     size_t count, loff_t *off)
2912 {
2913 	int num;
2914 	unsigned long k = ULONG_MAX;
2915 	char buff[11];
2916 
2917 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2918 		return -EACCES;
2919 	num = (count < 10) ? count : 10;
2920 	if (copy_from_user(buff, buffer, num))
2921 		return -EFAULT;
2922 	buff[num] = '\0';
2923 	k = simple_strtoul(buff, NULL, 10);
2924 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2925 		sg_big_buff = k;
2926 		return count;
2927 	}
2928 	return -ERANGE;
2929 }
2930 
2931 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2932 {
2933 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2934 		   sg_version_date);
2935 	return 0;
2936 }
2937 
2938 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2939 {
2940 	return single_open(file, sg_proc_seq_show_version, NULL);
2941 }
2942 
2943 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2944 {
2945 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2946 		   "online\n");
2947 	return 0;
2948 }
2949 
2950 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2951 {
2952 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2953 }
2954 
2955 struct sg_proc_deviter {
2956 	loff_t	index;
2957 	size_t	max;
2958 };
2959 
2960 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2961 {
2962 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2963 
2964 	s->private = it;
2965 	if (! it)
2966 		return NULL;
2967 
2968 	if (NULL == sg_dev_arr)
2969 		return NULL;
2970 	it->index = *pos;
2971 	it->max = sg_last_dev();
2972 	if (it->index >= it->max)
2973 		return NULL;
2974 	return it;
2975 }
2976 
2977 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2978 {
2979 	struct sg_proc_deviter * it = s->private;
2980 
2981 	*pos = ++it->index;
2982 	return (it->index < it->max) ? it : NULL;
2983 }
2984 
2985 static void dev_seq_stop(struct seq_file *s, void *v)
2986 {
2987 	kfree(s->private);
2988 }
2989 
2990 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2991 {
2992         return seq_open(file, &dev_seq_ops);
2993 }
2994 
2995 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2996 {
2997 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2998 	Sg_device *sdp;
2999 	struct scsi_device *scsidp;
3000 
3001 	sdp = it ? sg_get_dev(it->index) : NULL;
3002 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
3003 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
3004 			      scsidp->host->host_no, scsidp->channel,
3005 			      scsidp->id, scsidp->lun, (int) scsidp->type,
3006 			      1,
3007 			      (int) scsidp->queue_depth,
3008 			      (int) scsidp->device_busy,
3009 			      (int) scsi_device_online(scsidp));
3010 	else
3011 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
3012 	return 0;
3013 }
3014 
3015 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
3016 {
3017         return seq_open(file, &devstrs_seq_ops);
3018 }
3019 
3020 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
3021 {
3022 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3023 	Sg_device *sdp;
3024 	struct scsi_device *scsidp;
3025 
3026 	sdp = it ? sg_get_dev(it->index) : NULL;
3027 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
3028 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
3029 			   scsidp->vendor, scsidp->model, scsidp->rev);
3030 	else
3031 		seq_printf(s, "<no active device>\n");
3032 	return 0;
3033 }
3034 
3035 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
3036 {
3037 	int k, m, new_interface, blen, usg;
3038 	Sg_request *srp;
3039 	Sg_fd *fp;
3040 	const sg_io_hdr_t *hp;
3041 	const char * cp;
3042 	unsigned int ms;
3043 
3044 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
3045 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
3046 			   "(res)sgat=%d low_dma=%d\n", k + 1,
3047 			   jiffies_to_msecs(fp->timeout),
3048 			   fp->reserve.bufflen,
3049 			   (int) fp->reserve.k_use_sg,
3050 			   (int) fp->low_dma);
3051 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
3052 			   (int) fp->cmd_q, (int) fp->force_packid,
3053 			   (int) fp->keep_orphan, (int) fp->closed);
3054 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
3055 			hp = &srp->header;
3056 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
3057 			if (srp->res_used) {
3058 				if (new_interface &&
3059 				    (SG_FLAG_MMAP_IO & hp->flags))
3060 					cp = "     mmap>> ";
3061 				else
3062 					cp = "     rb>> ";
3063 			} else {
3064 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
3065 					cp = "     dio>> ";
3066 				else
3067 					cp = "     ";
3068 			}
3069 			seq_printf(s, cp);
3070 			blen = srp->my_cmdp ?
3071 				srp->my_cmdp->sr_bufflen : srp->data.bufflen;
3072 			usg = srp->my_cmdp ?
3073 				srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
3074 			seq_printf(s, srp->done ?
3075 				   ((1 == srp->done) ?  "rcv:" : "fin:")
3076 				   : (srp->my_cmdp ? "act:" : "prior:"));
3077 			seq_printf(s, " id=%d blen=%d",
3078 				   srp->header.pack_id, blen);
3079 			if (srp->done)
3080 				seq_printf(s, " dur=%d", hp->duration);
3081 			else {
3082 				ms = jiffies_to_msecs(jiffies);
3083 				seq_printf(s, " t_o/elap=%d/%d",
3084 					(new_interface ? hp->timeout :
3085 						  jiffies_to_msecs(fp->timeout)),
3086 					(ms > hp->duration ? ms - hp->duration : 0));
3087 			}
3088 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
3089 				   (int) srp->data.cmd_opcode);
3090 		}
3091 		if (0 == m)
3092 			seq_printf(s, "     No requests active\n");
3093 	}
3094 }
3095 
3096 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3097 {
3098         return seq_open(file, &debug_seq_ops);
3099 }
3100 
3101 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3102 {
3103 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3104 	Sg_device *sdp;
3105 
3106 	if (it && (0 == it->index)) {
3107 		seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3108 			   "(origin 1)\n", sg_dev_max, (int)it->max);
3109 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3110 	}
3111 	sdp = it ? sg_get_dev(it->index) : NULL;
3112 	if (sdp) {
3113 		struct scsi_device *scsidp = sdp->device;
3114 
3115 		if (NULL == scsidp) {
3116 			seq_printf(s, "device %d detached ??\n",
3117 				   (int)it->index);
3118 			return 0;
3119 		}
3120 
3121 		if (sg_get_nth_sfp(sdp, 0)) {
3122 			seq_printf(s, " >>> device=%s ",
3123 				sdp->disk->disk_name);
3124 			if (sdp->detached)
3125 				seq_printf(s, "detached pending close ");
3126 			else
3127 				seq_printf
3128 				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3129 				     scsidp->host->host_no,
3130 				     scsidp->channel, scsidp->id,
3131 				     scsidp->lun,
3132 				     scsidp->host->hostt->emulated);
3133 			seq_printf(s, " sg_tablesize=%d excl=%d\n",
3134 				   sdp->sg_tablesize, sdp->exclude);
3135 		}
3136 		sg_proc_debug_helper(s, sdp);
3137 	}
3138 	return 0;
3139 }
3140 
3141 #endif				/* CONFIG_SCSI_PROC_FS */
3142 
3143 module_init(init_sg);
3144 module_exit(exit_sg);
3145 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
3146