1/*
2 * storage_common.c -- Common definitions for mass storage functionality
3 *
4 * Copyright (C) 2003-2008 Alan Stern
5 * Copyeight (C) 2009 Samsung Electronics
6 * Author: Michal Nazarewicz (mina86@mina86.com)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14
15/*
16 * This file requires the following identifiers used in USB strings to
17 * be defined (each of type pointer to char):
18 *  - fsg_string_manufacturer -- name of the manufacturer
19 *  - fsg_string_product      -- name of the product
20 *  - fsg_string_config       -- name of the configuration
21 *  - fsg_string_interface    -- name of the interface
22 * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
23 * macro is defined prior to including this file.
24 */
25
26/*
27 * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
28 * fsg_hs_intr_in_desc objects as well as
29 * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
30 * macros are not defined.
31 *
32 * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
33 * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
34 * defined (as well as corresponding entries in string tables are
35 * missing) and FSG_STRING_INTERFACE has value of zero.
36 *
37 * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
38 */
39
40/*
41 * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included
42 * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN
43 * characters rather then a pointer to void.
44 */
45
46/*
47 * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
48 * sets the number of pipeline buffers (length of the fsg_buffhd array).
49 * The valid range of num_buffers is: num >= 2 && num <= 4.
50 */
51
52
53#include <linux/usb/storage.h>
54#include <scsi/scsi.h>
55#include <asm/unaligned.h>
56
57
58/*
59 * Thanks to NetChip Technologies for donating this product ID.
60 *
61 * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
62 * Instead:  allocate your own, using normal USB-IF procedures.
63 */
64#define FSG_VENDOR_ID	0x0525	/* NetChip */
65#define FSG_PRODUCT_ID	0xa4a5	/* Linux-USB File-backed Storage Gadget */
66
67
68/*-------------------------------------------------------------------------*/
69
70
71#ifndef DEBUG
72#undef VERBOSE_DEBUG
73#undef DUMP_MSGS
74#endif /* !DEBUG */
75
76#ifdef VERBOSE_DEBUG
77#define VLDBG	LDBG
78#else
79#define VLDBG(lun, fmt, args...) do { } while (0)
80#endif /* VERBOSE_DEBUG */
81
82#define LDBG(lun, fmt, args...)   dev_dbg (&(lun)->dev, fmt, ## args)
83#define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
84#define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
85#define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
86
87/*
88 * Keep those macros in sync with those in
89 * include/linux/usb/composite.h or else GCC will complain.  If they
90 * are identical (the same names of arguments, white spaces in the
91 * same places) GCC will allow redefinition otherwise (even if some
92 * white space is removed or added) warning will be issued.
93 *
94 * Those macros are needed here because File Storage Gadget does not
95 * include the composite.h header.  For composite gadgets those macros
96 * are redundant since composite.h is included any way.
97 *
98 * One could check whether those macros are already defined (which
99 * would indicate composite.h had been included) or not (which would
100 * indicate we were in FSG) but this is not done because a warning is
101 * desired if definitions here differ from the ones in composite.h.
102 *
103 * We want the definitions to match and be the same in File Storage
104 * Gadget as well as Mass Storage Function (and so composite gadgets
105 * using MSF).  If someone changes them in composite.h it will produce
106 * a warning in this file when building MSF.
107 */
108#define DBG(d, fmt, args...)     dev_dbg(&(d)->gadget->dev , fmt , ## args)
109#define VDBG(d, fmt, args...)    dev_vdbg(&(d)->gadget->dev , fmt , ## args)
110#define ERROR(d, fmt, args...)   dev_err(&(d)->gadget->dev , fmt , ## args)
111#define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
112#define INFO(d, fmt, args...)    dev_info(&(d)->gadget->dev , fmt , ## args)
113
114
115
116#ifdef DUMP_MSGS
117
118#  define dump_msg(fsg, /* const char * */ label,			\
119		   /* const u8 * */ buf, /* unsigned */ length) do {	\
120	if (length < 512) {						\
121		DBG(fsg, "%s, length %u:\n", label, length);		\
122		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,	\
123			       16, 1, buf, length, 0);			\
124	}								\
125} while (0)
126
127#  define dump_cdb(fsg) do { } while (0)
128
129#else
130
131#  define dump_msg(fsg, /* const char * */ label, \
132		   /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
133
134#  ifdef VERBOSE_DEBUG
135
136#    define dump_cdb(fsg)						\
137	print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,	\
138		       16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)		\
139
140#  else
141
142#    define dump_cdb(fsg) do { } while (0)
143
144#  endif /* VERBOSE_DEBUG */
145
146#endif /* DUMP_MSGS */
147
148/*-------------------------------------------------------------------------*/
149
150/* CBI Interrupt data structure */
151struct interrupt_data {
152	u8	bType;
153	u8	bValue;
154};
155
156#define CBI_INTERRUPT_DATA_LEN		2
157
158/* CBI Accept Device-Specific Command request */
159#define USB_CBI_ADSC_REQUEST		0x00
160
161
162/* Length of a SCSI Command Data Block */
163#define MAX_COMMAND_SIZE	16
164
165/* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
166#define SS_NO_SENSE				0
167#define SS_COMMUNICATION_FAILURE		0x040800
168#define SS_INVALID_COMMAND			0x052000
169#define SS_INVALID_FIELD_IN_CDB			0x052400
170#define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE	0x052100
171#define SS_LOGICAL_UNIT_NOT_SUPPORTED		0x052500
172#define SS_MEDIUM_NOT_PRESENT			0x023a00
173#define SS_MEDIUM_REMOVAL_PREVENTED		0x055302
174#define SS_NOT_READY_TO_READY_TRANSITION	0x062800
175#define SS_RESET_OCCURRED			0x062900
176#define SS_SAVING_PARAMETERS_NOT_SUPPORTED	0x053900
177#define SS_UNRECOVERED_READ_ERROR		0x031100
178#define SS_WRITE_ERROR				0x030c02
179#define SS_WRITE_PROTECTED			0x072700
180
181#define SK(x)		((u8) ((x) >> 16))	/* Sense Key byte, etc. */
182#define ASC(x)		((u8) ((x) >> 8))
183#define ASCQ(x)		((u8) (x))
184
185
186/*-------------------------------------------------------------------------*/
187
188
189struct fsg_lun {
190	struct file	*filp;
191	loff_t		file_length;
192	loff_t		num_sectors;
193
194	unsigned int	initially_ro:1;
195	unsigned int	ro:1;
196	unsigned int	removable:1;
197	unsigned int	cdrom:1;
198	unsigned int	prevent_medium_removal:1;
199	unsigned int	registered:1;
200	unsigned int	info_valid:1;
201	unsigned int	nofua:1;
202
203	u32		sense_data;
204	u32		sense_data_info;
205	u32		unit_attention_data;
206
207	unsigned int	blkbits;	/* Bits of logical block size of bound block device */
208	unsigned int	blksize;	/* logical block size of bound block device */
209	struct device	dev;
210};
211
212#define fsg_lun_is_open(curlun)	((curlun)->filp != NULL)
213
214static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
215{
216	return container_of(dev, struct fsg_lun, dev);
217}
218
219
220/* Big enough to hold our biggest descriptor */
221#define EP0_BUFSIZE	256
222#define DELAYED_STATUS	(EP0_BUFSIZE + 999)	/* An impossibly large value */
223
224#ifdef CONFIG_USB_GADGET_DEBUG_FILES
225
226static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
227module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
228MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
229
230#else
231
232/*
233 * Number of buffers we will use.
234 * 2 is usually enough for good buffering pipeline
235 */
236#define fsg_num_buffers	CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
237
238#endif /* CONFIG_USB_DEBUG */
239
240/* check if fsg_num_buffers is within a valid range */
241static inline int fsg_num_buffers_validate(void)
242{
243	if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
244		return 0;
245	pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
246	       fsg_num_buffers, 2 ,4);
247	return -EINVAL;
248}
249
250/* Default size of buffer length. */
251#define FSG_BUFLEN	((u32)16384)
252
253/* Maximal number of LUNs supported in mass storage function */
254#define FSG_MAX_LUNS	8
255
256enum fsg_buffer_state {
257	BUF_STATE_EMPTY = 0,
258	BUF_STATE_FULL,
259	BUF_STATE_BUSY
260};
261
262struct fsg_buffhd {
263#ifdef FSG_BUFFHD_STATIC_BUFFER
264	char				buf[FSG_BUFLEN];
265#else
266	void				*buf;
267#endif
268	enum fsg_buffer_state		state;
269	struct fsg_buffhd		*next;
270
271	/*
272	 * The NetChip 2280 is faster, and handles some protocol faults
273	 * better, if we don't submit any short bulk-out read requests.
274	 * So we will record the intended request length here.
275	 */
276	unsigned int			bulk_out_intended_length;
277
278	struct usb_request		*inreq;
279	int				inreq_busy;
280	struct usb_request		*outreq;
281	int				outreq_busy;
282};
283
284enum fsg_state {
285	/* This one isn't used anywhere */
286	FSG_STATE_COMMAND_PHASE = -10,
287	FSG_STATE_DATA_PHASE,
288	FSG_STATE_STATUS_PHASE,
289
290	FSG_STATE_IDLE = 0,
291	FSG_STATE_ABORT_BULK_OUT,
292	FSG_STATE_RESET,
293	FSG_STATE_INTERFACE_CHANGE,
294	FSG_STATE_CONFIG_CHANGE,
295	FSG_STATE_DISCONNECT,
296	FSG_STATE_EXIT,
297	FSG_STATE_TERMINATED
298};
299
300enum data_direction {
301	DATA_DIR_UNKNOWN = 0,
302	DATA_DIR_FROM_HOST,
303	DATA_DIR_TO_HOST,
304	DATA_DIR_NONE
305};
306
307
308/*-------------------------------------------------------------------------*/
309
310
311static inline u32 get_unaligned_be24(u8 *buf)
312{
313	return 0xffffff & (u32) get_unaligned_be32(buf - 1);
314}
315
316
317/*-------------------------------------------------------------------------*/
318
319
320enum {
321#ifndef FSG_NO_DEVICE_STRINGS
322	FSG_STRING_MANUFACTURER	= 1,
323	FSG_STRING_PRODUCT,
324	FSG_STRING_SERIAL,
325	FSG_STRING_CONFIG,
326#endif
327	FSG_STRING_INTERFACE
328};
329
330
331#ifndef FSG_NO_OTG
332static struct usb_otg_descriptor
333fsg_otg_desc = {
334	.bLength =		sizeof fsg_otg_desc,
335	.bDescriptorType =	USB_DT_OTG,
336
337	.bmAttributes =		USB_OTG_SRP,
338};
339#endif
340
341/* There is only one interface. */
342
343static struct usb_interface_descriptor
344fsg_intf_desc = {
345	.bLength =		sizeof fsg_intf_desc,
346	.bDescriptorType =	USB_DT_INTERFACE,
347
348	.bNumEndpoints =	2,		/* Adjusted during fsg_bind() */
349	.bInterfaceClass =	USB_CLASS_MASS_STORAGE,
350	.bInterfaceSubClass =	USB_SC_SCSI,	/* Adjusted during fsg_bind() */
351	.bInterfaceProtocol =	USB_PR_BULK,	/* Adjusted during fsg_bind() */
352	.iInterface =		FSG_STRING_INTERFACE,
353};
354
355/*
356 * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
357 * interrupt-in.
358 */
359
360static struct usb_endpoint_descriptor
361fsg_fs_bulk_in_desc = {
362	.bLength =		USB_DT_ENDPOINT_SIZE,
363	.bDescriptorType =	USB_DT_ENDPOINT,
364
365	.bEndpointAddress =	USB_DIR_IN,
366	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
367	/* wMaxPacketSize set by autoconfiguration */
368};
369
370static struct usb_endpoint_descriptor
371fsg_fs_bulk_out_desc = {
372	.bLength =		USB_DT_ENDPOINT_SIZE,
373	.bDescriptorType =	USB_DT_ENDPOINT,
374
375	.bEndpointAddress =	USB_DIR_OUT,
376	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
377	/* wMaxPacketSize set by autoconfiguration */
378};
379
380#ifndef FSG_NO_INTR_EP
381
382static struct usb_endpoint_descriptor
383fsg_fs_intr_in_desc = {
384	.bLength =		USB_DT_ENDPOINT_SIZE,
385	.bDescriptorType =	USB_DT_ENDPOINT,
386
387	.bEndpointAddress =	USB_DIR_IN,
388	.bmAttributes =		USB_ENDPOINT_XFER_INT,
389	.wMaxPacketSize =	cpu_to_le16(2),
390	.bInterval =		32,	/* frames -> 32 ms */
391};
392
393#ifndef FSG_NO_OTG
394#  define FSG_FS_FUNCTION_PRE_EP_ENTRIES	2
395#else
396#  define FSG_FS_FUNCTION_PRE_EP_ENTRIES	1
397#endif
398
399#endif
400
401static struct usb_descriptor_header *fsg_fs_function[] = {
402#ifndef FSG_NO_OTG
403	(struct usb_descriptor_header *) &fsg_otg_desc,
404#endif
405	(struct usb_descriptor_header *) &fsg_intf_desc,
406	(struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
407	(struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
408#ifndef FSG_NO_INTR_EP
409	(struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
410#endif
411	NULL,
412};
413
414
415/*
416 * USB 2.0 devices need to expose both high speed and full speed
417 * descriptors, unless they only run at full speed.
418 *
419 * That means alternate endpoint descriptors (bigger packets)
420 * and a "device qualifier" ... plus more construction options
421 * for the configuration descriptor.
422 */
423static struct usb_endpoint_descriptor
424fsg_hs_bulk_in_desc = {
425	.bLength =		USB_DT_ENDPOINT_SIZE,
426	.bDescriptorType =	USB_DT_ENDPOINT,
427
428	/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
429	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
430	.wMaxPacketSize =	cpu_to_le16(512),
431};
432
433static struct usb_endpoint_descriptor
434fsg_hs_bulk_out_desc = {
435	.bLength =		USB_DT_ENDPOINT_SIZE,
436	.bDescriptorType =	USB_DT_ENDPOINT,
437
438	/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
439	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
440	.wMaxPacketSize =	cpu_to_le16(512),
441	.bInterval =		1,	/* NAK every 1 uframe */
442};
443
444#ifndef FSG_NO_INTR_EP
445
446static struct usb_endpoint_descriptor
447fsg_hs_intr_in_desc = {
448	.bLength =		USB_DT_ENDPOINT_SIZE,
449	.bDescriptorType =	USB_DT_ENDPOINT,
450
451	/* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
452	.bmAttributes =		USB_ENDPOINT_XFER_INT,
453	.wMaxPacketSize =	cpu_to_le16(2),
454	.bInterval =		9,	/* 2**(9-1) = 256 uframes -> 32 ms */
455};
456
457#ifndef FSG_NO_OTG
458#  define FSG_HS_FUNCTION_PRE_EP_ENTRIES	2
459#else
460#  define FSG_HS_FUNCTION_PRE_EP_ENTRIES	1
461#endif
462
463#endif
464
465static struct usb_descriptor_header *fsg_hs_function[] = {
466#ifndef FSG_NO_OTG
467	(struct usb_descriptor_header *) &fsg_otg_desc,
468#endif
469	(struct usb_descriptor_header *) &fsg_intf_desc,
470	(struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
471	(struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
472#ifndef FSG_NO_INTR_EP
473	(struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
474#endif
475	NULL,
476};
477
478static struct usb_endpoint_descriptor
479fsg_ss_bulk_in_desc = {
480	.bLength =		USB_DT_ENDPOINT_SIZE,
481	.bDescriptorType =	USB_DT_ENDPOINT,
482
483	/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
484	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
485	.wMaxPacketSize =	cpu_to_le16(1024),
486};
487
488static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
489	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
490	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
491
492	/*.bMaxBurst =		DYNAMIC, */
493};
494
495static struct usb_endpoint_descriptor
496fsg_ss_bulk_out_desc = {
497	.bLength =		USB_DT_ENDPOINT_SIZE,
498	.bDescriptorType =	USB_DT_ENDPOINT,
499
500	/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
501	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
502	.wMaxPacketSize =	cpu_to_le16(1024),
503};
504
505static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
506	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
507	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
508
509	/*.bMaxBurst =		DYNAMIC, */
510};
511
512#ifndef FSG_NO_INTR_EP
513
514static struct usb_endpoint_descriptor
515fsg_ss_intr_in_desc = {
516	.bLength =		USB_DT_ENDPOINT_SIZE,
517	.bDescriptorType =	USB_DT_ENDPOINT,
518
519	/* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
520	.bmAttributes =		USB_ENDPOINT_XFER_INT,
521	.wMaxPacketSize =	cpu_to_le16(2),
522	.bInterval =		9,	/* 2**(9-1) = 256 uframes -> 32 ms */
523};
524
525static struct usb_ss_ep_comp_descriptor fsg_ss_intr_in_comp_desc = {
526	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
527	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
528
529	.wBytesPerInterval =	cpu_to_le16(2),
530};
531
532#ifndef FSG_NO_OTG
533#  define FSG_SS_FUNCTION_PRE_EP_ENTRIES	2
534#else
535#  define FSG_SS_FUNCTION_PRE_EP_ENTRIES	1
536#endif
537
538#endif
539
540static __maybe_unused struct usb_ext_cap_descriptor fsg_ext_cap_desc = {
541	.bLength =		USB_DT_USB_EXT_CAP_SIZE,
542	.bDescriptorType =	USB_DT_DEVICE_CAPABILITY,
543	.bDevCapabilityType =	USB_CAP_TYPE_EXT,
544
545	.bmAttributes =		cpu_to_le32(USB_LPM_SUPPORT),
546};
547
548static __maybe_unused struct usb_ss_cap_descriptor fsg_ss_cap_desc = {
549	.bLength =		USB_DT_USB_SS_CAP_SIZE,
550	.bDescriptorType =	USB_DT_DEVICE_CAPABILITY,
551	.bDevCapabilityType =	USB_SS_CAP_TYPE,
552
553	/* .bmAttributes = LTM is not supported yet */
554
555	.wSpeedSupported =	cpu_to_le16(USB_LOW_SPEED_OPERATION
556		| USB_FULL_SPEED_OPERATION
557		| USB_HIGH_SPEED_OPERATION
558		| USB_5GBPS_OPERATION),
559	.bFunctionalitySupport = USB_LOW_SPEED_OPERATION,
560	.bU1devExitLat =	USB_DEFAULT_U1_DEV_EXIT_LAT,
561	.bU2DevExitLat =	cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT),
562};
563
564static __maybe_unused struct usb_bos_descriptor fsg_bos_desc = {
565	.bLength =		USB_DT_BOS_SIZE,
566	.bDescriptorType =	USB_DT_BOS,
567
568	.wTotalLength =		cpu_to_le16(USB_DT_BOS_SIZE
569				+ USB_DT_USB_EXT_CAP_SIZE
570				+ USB_DT_USB_SS_CAP_SIZE),
571
572	.bNumDeviceCaps =	2,
573};
574
575static struct usb_descriptor_header *fsg_ss_function[] = {
576#ifndef FSG_NO_OTG
577	(struct usb_descriptor_header *) &fsg_otg_desc,
578#endif
579	(struct usb_descriptor_header *) &fsg_intf_desc,
580	(struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
581	(struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
582	(struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
583	(struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
584#ifndef FSG_NO_INTR_EP
585	(struct usb_descriptor_header *) &fsg_ss_intr_in_desc,
586	(struct usb_descriptor_header *) &fsg_ss_intr_in_comp_desc,
587#endif
588	NULL,
589};
590
591/* Maxpacket and other transfer characteristics vary by speed. */
592static __maybe_unused struct usb_endpoint_descriptor *
593fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
594		struct usb_endpoint_descriptor *hs,
595		struct usb_endpoint_descriptor *ss)
596{
597	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
598		return ss;
599	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
600		return hs;
601	return fs;
602}
603
604
605/* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
606static struct usb_string		fsg_strings[] = {
607#ifndef FSG_NO_DEVICE_STRINGS
608	{FSG_STRING_MANUFACTURER,	fsg_string_manufacturer},
609	{FSG_STRING_PRODUCT,		fsg_string_product},
610	{FSG_STRING_SERIAL,		""},
611	{FSG_STRING_CONFIG,		fsg_string_config},
612#endif
613	{FSG_STRING_INTERFACE,		fsg_string_interface},
614	{}
615};
616
617static struct usb_gadget_strings	fsg_stringtab = {
618	.language	= 0x0409,		/* en-us */
619	.strings	= fsg_strings,
620};
621
622
623 /*-------------------------------------------------------------------------*/
624
625/*
626 * If the next two routines are called while the gadget is registered,
627 * the caller must own fsg->filesem for writing.
628 */
629
630static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
631{
632	int				ro;
633	struct file			*filp = NULL;
634	int				rc = -EINVAL;
635	struct inode			*inode = NULL;
636	loff_t				size;
637	loff_t				num_sectors;
638	loff_t				min_sectors;
639
640	/* R/W if we can, R/O if we must */
641	ro = curlun->initially_ro;
642	if (!ro) {
643		filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
644		if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
645			ro = 1;
646	}
647	if (ro)
648		filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
649	if (IS_ERR(filp)) {
650		LINFO(curlun, "unable to open backing file: %s\n", filename);
651		return PTR_ERR(filp);
652	}
653
654	if (!(filp->f_mode & FMODE_WRITE))
655		ro = 1;
656
657	if (filp->f_path.dentry)
658		inode = filp->f_path.dentry->d_inode;
659	if (!inode || (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
660		LINFO(curlun, "invalid file type: %s\n", filename);
661		goto out;
662	}
663
664	/*
665	 * If we can't read the file, it's no good.
666	 * If we can't write the file, use it read-only.
667	 */
668	if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
669		LINFO(curlun, "file not readable: %s\n", filename);
670		goto out;
671	}
672	if (!(filp->f_op->write || filp->f_op->aio_write))
673		ro = 1;
674
675	size = i_size_read(inode->i_mapping->host);
676	if (size < 0) {
677		LINFO(curlun, "unable to find file size: %s\n", filename);
678		rc = (int) size;
679		goto out;
680	}
681
682	if (curlun->cdrom) {
683		curlun->blksize = 2048;
684		curlun->blkbits = 11;
685	} else if (inode->i_bdev) {
686		curlun->blksize = bdev_logical_block_size(inode->i_bdev);
687		curlun->blkbits = blksize_bits(curlun->blksize);
688	} else {
689		curlun->blksize = 512;
690		curlun->blkbits = 9;
691	}
692
693	num_sectors = size >> curlun->blkbits; /* File size in logic-block-size blocks */
694	min_sectors = 1;
695	if (curlun->cdrom) {
696		min_sectors = 300;	/* Smallest track is 300 frames */
697		if (num_sectors >= 256*60*75) {
698			num_sectors = 256*60*75 - 1;
699			LINFO(curlun, "file too big: %s\n", filename);
700			LINFO(curlun, "using only first %d blocks\n",
701					(int) num_sectors);
702		}
703	}
704	if (num_sectors < min_sectors) {
705		LINFO(curlun, "file too small: %s\n", filename);
706		rc = -ETOOSMALL;
707		goto out;
708	}
709
710	get_file(filp);
711	curlun->ro = ro;
712	curlun->filp = filp;
713	curlun->file_length = size;
714	curlun->num_sectors = num_sectors;
715	LDBG(curlun, "open backing file: %s\n", filename);
716	rc = 0;
717
718out:
719	filp_close(filp, current->files);
720	return rc;
721}
722
723
724static void fsg_lun_close(struct fsg_lun *curlun)
725{
726	if (curlun->filp) {
727		LDBG(curlun, "close backing file\n");
728		fput(curlun->filp);
729		curlun->filp = NULL;
730	}
731}
732
733
734/*-------------------------------------------------------------------------*/
735
736/*
737 * Sync the file data, don't bother with the metadata.
738 * This code was copied from fs/buffer.c:sys_fdatasync().
739 */
740static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
741{
742	struct file	*filp = curlun->filp;
743
744	if (curlun->ro || !filp)
745		return 0;
746	return vfs_fsync(filp, 1);
747}
748
749static void store_cdrom_address(u8 *dest, int msf, u32 addr)
750{
751	if (msf) {
752		/* Convert to Minutes-Seconds-Frames */
753		addr >>= 2;		/* Convert to 2048-byte frames */
754		addr += 2*75;		/* Lead-in occupies 2 seconds */
755		dest[3] = addr % 75;	/* Frames */
756		addr /= 75;
757		dest[2] = addr % 60;	/* Seconds */
758		addr /= 60;
759		dest[1] = addr;		/* Minutes */
760		dest[0] = 0;		/* Reserved */
761	} else {
762		/* Absolute sector */
763		put_unaligned_be32(addr, dest);
764	}
765}
766
767
768/*-------------------------------------------------------------------------*/
769
770
771static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
772			   char *buf)
773{
774	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
775
776	return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
777				  ? curlun->ro
778				  : curlun->initially_ro);
779}
780
781static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
782			      char *buf)
783{
784	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
785
786	return sprintf(buf, "%u\n", curlun->nofua);
787}
788
789static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
790			     char *buf)
791{
792	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
793	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
794	char		*p;
795	ssize_t		rc;
796
797	down_read(filesem);
798	if (fsg_lun_is_open(curlun)) {	/* Get the complete pathname */
799		p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
800		if (IS_ERR(p))
801			rc = PTR_ERR(p);
802		else {
803			rc = strlen(p);
804			memmove(buf, p, rc);
805			buf[rc] = '\n';		/* Add a newline */
806			buf[++rc] = 0;
807		}
808	} else {				/* No file, return 0 bytes */
809		*buf = 0;
810		rc = 0;
811	}
812	up_read(filesem);
813	return rc;
814}
815
816
817static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
818			    const char *buf, size_t count)
819{
820	ssize_t		rc;
821	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
822	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
823	unsigned	ro;
824
825	rc = kstrtouint(buf, 2, &ro);
826	if (rc)
827		return rc;
828
829	/*
830	 * Allow the write-enable status to change only while the
831	 * backing file is closed.
832	 */
833	down_read(filesem);
834	if (fsg_lun_is_open(curlun)) {
835		LDBG(curlun, "read-only status change prevented\n");
836		rc = -EBUSY;
837	} else {
838		curlun->ro = ro;
839		curlun->initially_ro = ro;
840		LDBG(curlun, "read-only status set to %d\n", curlun->ro);
841		rc = count;
842	}
843	up_read(filesem);
844	return rc;
845}
846
847static ssize_t fsg_store_nofua(struct device *dev,
848			       struct device_attribute *attr,
849			       const char *buf, size_t count)
850{
851	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
852	unsigned	nofua;
853	int		ret;
854
855	ret = kstrtouint(buf, 2, &nofua);
856	if (ret)
857		return ret;
858
859	/* Sync data when switching from async mode to sync */
860	if (!nofua && curlun->nofua)
861		fsg_lun_fsync_sub(curlun);
862
863	curlun->nofua = nofua;
864
865	return count;
866}
867
868static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
869			      const char *buf, size_t count)
870{
871	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
872	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
873	int		rc = 0;
874
875	if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
876		LDBG(curlun, "eject attempt prevented\n");
877		return -EBUSY;				/* "Door is locked" */
878	}
879
880	/* Remove a trailing newline */
881	if (count > 0 && buf[count-1] == '\n')
882		((char *) buf)[count-1] = 0;		/* Ugh! */
883
884	/* Eject current medium */
885	down_write(filesem);
886	if (fsg_lun_is_open(curlun)) {
887		fsg_lun_close(curlun);
888		curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
889	}
890
891	/* Load new medium */
892	if (count > 0 && buf[0]) {
893		rc = fsg_lun_open(curlun, buf);
894		if (rc == 0)
895			curlun->unit_attention_data =
896					SS_NOT_READY_TO_READY_TRANSITION;
897	}
898	up_write(filesem);
899	return (rc < 0 ? rc : count);
900}
901