ide-disk.c

linux设备驱动开发详解（书代码）

}

static unsigned long long idedisk_set_max_address_ext(ide_drive_t *drive, unsigned long long addr_req)
{
	ide_task_t args;
	unsigned long long addr_set = 0;

	addr_req--;
	/* Create IDE/ATA command request structure */
	memset(&args, 0, sizeof(ide_task_t));
	args.tfRegister[IDE_SECTOR_OFFSET]	= ((addr_req >>  0) & 0xff);
	args.tfRegister[IDE_LCYL_OFFSET]	= ((addr_req >>= 8) & 0xff);
	args.tfRegister[IDE_HCYL_OFFSET]	= ((addr_req >>= 8) & 0xff);
	args.tfRegister[IDE_SELECT_OFFSET]      = 0x40;
	args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_SET_MAX_EXT;
	args.hobRegister[IDE_SECTOR_OFFSET]	= (addr_req >>= 8) & 0xff;
	args.hobRegister[IDE_LCYL_OFFSET]	= (addr_req >>= 8) & 0xff;
	args.hobRegister[IDE_HCYL_OFFSET]	= (addr_req >>= 8) & 0xff;
	args.hobRegister[IDE_SELECT_OFFSET]	= 0x40;
	args.hobRegister[IDE_CONTROL_OFFSET_HOB]= (drive->ctl|0x80);
	args.command_type			= IDE_DRIVE_TASK_NO_DATA;
	args.handler				= &task_no_data_intr;
	/* submit command request */
	ide_raw_taskfile(drive, &args, NULL);
	/* if OK, compute maximum address value */
	if ((args.tfRegister[IDE_STATUS_OFFSET] & 0x01) == 0) {
		u32 high = (args.hobRegister[IDE_HCYL_OFFSET] << 16) |
			   (args.hobRegister[IDE_LCYL_OFFSET] <<  8) |
			    args.hobRegister[IDE_SECTOR_OFFSET];
		u32 low  = ((args.tfRegister[IDE_HCYL_OFFSET])<<16) |
			   ((args.tfRegister[IDE_LCYL_OFFSET])<<8) |
			    (args.tfRegister[IDE_SECTOR_OFFSET]);
		addr_set = ((__u64)high << 24) | low;
		addr_set++;
	}
	return addr_set;
}

static unsigned long long sectors_to_MB(unsigned long long n)
{
	n <<= 9;		/* make it bytes */
	do_div(n, 1000000);	/* make it MB */
	return n;
}

/*
 * Bits 10 of command_set_1 and cfs_enable_1 must be equal,
 * so on non-buggy drives we need test only one.
 * However, we should also check whether these fields are valid.
 */
static inline int idedisk_supports_hpa(const struct hd_driveid *id)
{
	return (id->command_set_1 & 0x0400) && (id->cfs_enable_1 & 0x0400);
}

/*
 * The same here.
 */
static inline int idedisk_supports_lba48(const struct hd_driveid *id)
{
	return (id->command_set_2 & 0x0400) && (id->cfs_enable_2 & 0x0400)
	       && id->lba_capacity_2;
}

static void idedisk_check_hpa(ide_drive_t *drive)
{
	unsigned long long capacity, set_max;
	int lba48 = idedisk_supports_lba48(drive->id);

	capacity = drive->capacity64;
	if (lba48)
		set_max = idedisk_read_native_max_address_ext(drive);
	else
		set_max = idedisk_read_native_max_address(drive);

	if (set_max <= capacity)
		return;

	printk(KERN_INFO "%s: Host Protected Area detected.\n"
			 "\tcurrent capacity is %llu sectors (%llu MB)\n"
			 "\tnative  capacity is %llu sectors (%llu MB)\n",
			 drive->name,
			 capacity, sectors_to_MB(capacity),
			 set_max, sectors_to_MB(set_max));

	if (lba48)
		set_max = idedisk_set_max_address_ext(drive, set_max);
	else
		set_max = idedisk_set_max_address(drive, set_max);
	if (set_max) {
		drive->capacity64 = set_max;
		printk(KERN_INFO "%s: Host Protected Area disabled.\n",
				 drive->name);
	}
}

/*
 * Compute drive->capacity, the full capacity of the drive
 * Called with drive->id != NULL.
 *
 * To compute capacity, this uses either of
 *
 *    1. CHS value set by user       (whatever user sets will be trusted)
 *    2. LBA value from target drive (require new ATA feature)
 *    3. LBA value from system BIOS  (new one is OK, old one may break)
 *    4. CHS value from system BIOS  (traditional style)
 *
 * in above order (i.e., if value of higher priority is available,
 * reset will be ignored).
 */
static void init_idedisk_capacity (ide_drive_t  *drive)
{
	struct hd_driveid *id = drive->id;
	/*
	 * If this drive supports the Host Protected Area feature set,
	 * then we may need to change our opinion about the drive's capacity.
	 */
	int hpa = idedisk_supports_hpa(id);

	if (idedisk_supports_lba48(id)) {
		/* drive speaks 48-bit LBA */
		drive->select.b.lba = 1;
		drive->capacity64 = id->lba_capacity_2;
		if (hpa)
			idedisk_check_hpa(drive);
	} else if ((id->capability & 2) && lba_capacity_is_ok(id)) {
		/* drive speaks 28-bit LBA */
		drive->select.b.lba = 1;
		drive->capacity64 = id->lba_capacity;
		if (hpa)
			idedisk_check_hpa(drive);
	} else {
		/* drive speaks boring old 28-bit CHS */
		drive->capacity64 = drive->cyl * drive->head * drive->sect;
	}
}

static sector_t idedisk_capacity (ide_drive_t *drive)
{
	return drive->capacity64 - drive->sect0;
}

#ifdef CONFIG_PROC_FS

static int smart_enable(ide_drive_t *drive)
{
	ide_task_t args;

	memset(&args, 0, sizeof(ide_task_t));
	args.tfRegister[IDE_FEATURE_OFFSET]	= SMART_ENABLE;
	args.tfRegister[IDE_LCYL_OFFSET]	= SMART_LCYL_PASS;
	args.tfRegister[IDE_HCYL_OFFSET]	= SMART_HCYL_PASS;
	args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_SMART;
	args.command_type			= IDE_DRIVE_TASK_NO_DATA;
	args.handler				= &task_no_data_intr;
	return ide_raw_taskfile(drive, &args, NULL);
}

static int get_smart_values(ide_drive_t *drive, u8 *buf)
{
	ide_task_t args;

	memset(&args, 0, sizeof(ide_task_t));
	args.tfRegister[IDE_FEATURE_OFFSET]	= SMART_READ_VALUES;
	args.tfRegister[IDE_NSECTOR_OFFSET]	= 0x01;
	args.tfRegister[IDE_LCYL_OFFSET]	= SMART_LCYL_PASS;
	args.tfRegister[IDE_HCYL_OFFSET]	= SMART_HCYL_PASS;
	args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_SMART;
	args.command_type			= IDE_DRIVE_TASK_IN;
	args.data_phase				= TASKFILE_IN;
	args.handler				= &task_in_intr;
	(void) smart_enable(drive);
	return ide_raw_taskfile(drive, &args, buf);
}

static int get_smart_thresholds(ide_drive_t *drive, u8 *buf)
{
	ide_task_t args;
	memset(&args, 0, sizeof(ide_task_t));
	args.tfRegister[IDE_FEATURE_OFFSET]	= SMART_READ_THRESHOLDS;
	args.tfRegister[IDE_NSECTOR_OFFSET]	= 0x01;
	args.tfRegister[IDE_LCYL_OFFSET]	= SMART_LCYL_PASS;
	args.tfRegister[IDE_HCYL_OFFSET]	= SMART_HCYL_PASS;
	args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_SMART;
	args.command_type			= IDE_DRIVE_TASK_IN;
	args.data_phase				= TASKFILE_IN;
	args.handler				= &task_in_intr;
	(void) smart_enable(drive);
	return ide_raw_taskfile(drive, &args, buf);
}

static int proc_idedisk_read_cache
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *) data;
	char		*out = page;
	int		len;

	if (drive->id_read)
		len = sprintf(out,"%i\n", drive->id->buf_size / 2);
	else
		len = sprintf(out,"(none)\n");
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static int proc_idedisk_read_capacity
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t*drive = (ide_drive_t *)data;
	int len;

	len = sprintf(page,"%llu\n", (long long)idedisk_capacity(drive));
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static int proc_idedisk_read_smart_thresholds
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *)data;
	int		len = 0, i = 0;

	if (!get_smart_thresholds(drive, page)) {
		unsigned short *val = (unsigned short *) page;
		char *out = ((char *)val) + (SECTOR_WORDS * 4);
		page = out;
		do {
			out += sprintf(out, "%04x%c", le16_to_cpu(*val), (++i & 7) ? ' ' : '\n');
			val += 1;
		} while (i < (SECTOR_WORDS * 2));
		len = out - page;
	}
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static int proc_idedisk_read_smart_values
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *)data;
	int		len = 0, i = 0;

	if (!get_smart_values(drive, page)) {
		unsigned short *val = (unsigned short *) page;
		char *out = ((char *)val) + (SECTOR_WORDS * 4);
		page = out;
		do {
			out += sprintf(out, "%04x%c", le16_to_cpu(*val), (++i & 7) ? ' ' : '\n');
			val += 1;
		} while (i < (SECTOR_WORDS * 2));
		len = out - page;
	}
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static ide_proc_entry_t idedisk_proc[] = {
	{ "cache",		S_IFREG|S_IRUGO,	proc_idedisk_read_cache,		NULL },
	{ "capacity",		S_IFREG|S_IRUGO,	proc_idedisk_read_capacity,		NULL },
	{ "geometry",		S_IFREG|S_IRUGO,	proc_ide_read_geometry,			NULL },
	{ "smart_values",	S_IFREG|S_IRUSR,	proc_idedisk_read_smart_values,		NULL },
	{ "smart_thresholds",	S_IFREG|S_IRUSR,	proc_idedisk_read_smart_thresholds,	NULL },
	{ NULL, 0, NULL, NULL }
};

#else

#define	idedisk_proc	NULL

#endif	/* CONFIG_PROC_FS */

static void idedisk_prepare_flush(request_queue_t *q, struct request *rq)
{
	ide_drive_t *drive = q->queuedata;

	memset(rq->cmd, 0, sizeof(rq->cmd));

	if (ide_id_has_flush_cache_ext(drive->id) &&
	    (drive->capacity64 >= (1UL << 28)))
		rq->cmd[0] = WIN_FLUSH_CACHE_EXT;
	else
		rq->cmd[0] = WIN_FLUSH_CACHE;


	rq->flags |= REQ_DRIVE_TASK;
	rq->buffer = rq->cmd;
}

static int idedisk_issue_flush(request_queue_t *q, struct gendisk *disk,
			       sector_t *error_sector)
{
	ide_drive_t *drive = q->queuedata;
	struct request *rq;
	int ret;

	if (!drive->wcache)
		return 0;

	rq = blk_get_request(q, WRITE, __GFP_WAIT);

	idedisk_prepare_flush(q, rq);

	ret = blk_execute_rq(q, disk, rq, 0);

	/*
	 * if we failed and caller wants error offset, get it
	 */
	if (ret && error_sector)
		*error_sector = ide_get_error_location(drive, rq->cmd);

	blk_put_request(rq);
	return ret;
}

/*
 * This is tightly woven into the driver->do_special can not touch.
 * DON'T do it again until a total personality rewrite is committed.
 */
static int set_multcount(ide_drive_t *drive, int arg)
{
	struct request rq;

	if (drive->special.b.set_multmode)
		return -EBUSY;
	ide_init_drive_cmd (&rq);
	rq.flags = REQ_DRIVE_CMD;
	drive->mult_req = arg;
	drive->special.b.set_multmode = 1;
	(void) ide_do_drive_cmd (drive, &rq, ide_wait);
	return (drive->mult_count == arg) ? 0 : -EIO;
}

static int set_nowerr(ide_drive_t *drive, int arg)
{
	if (ide_spin_wait_hwgroup(drive))
		return -EBUSY;
	drive->nowerr = arg;
	drive->bad_wstat = arg ? BAD_R_STAT : BAD_W_STAT;
	spin_unlock_irq(&ide_lock);
	return 0;
}

static void update_ordered(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	unsigned ordered = QUEUE_ORDERED_NONE;
	prepare_flush_fn *prep_fn = NULL;
	issue_flush_fn *issue_fn = NULL;

	if (drive->wcache) {
		unsigned long long capacity;
		int barrier;
		/*
		 * We must avoid issuing commands a drive does not
		 * understand or we may crash it. We check flush cache
		 * is supported. We also check we have the LBA48 flush
		 * cache if the drive capacity is too large. By this
		 * time we have trimmed the drive capacity if LBA48 is
		 * not available so we don't need to recheck that.
		 */
		capacity = idedisk_capacity(drive);
		barrier = ide_id_has_flush_cache(id) &&
			(drive->addressing == 0 || capacity <= (1ULL << 28) ||
			 ide_id_has_flush_cache_ext(id));

		printk(KERN_INFO "%s: cache flushes %ssupported\n",
		       drive->name, barrier ? "" : "not ");

		if (barrier) {
			ordered = QUEUE_ORDERED_DRAIN_FLUSH;
			prep_fn = idedisk_prepare_flush;
			issue_fn = idedisk_issue_flush;
		}
	} else
		ordered = QUEUE_ORDERED_DRAIN;

	blk_queue_ordered(drive->queue, ordered, prep_fn);
	blk_queue_issue_flush_fn(drive->queue, issue_fn);
}

static int write_cache(ide_drive_t *drive, int arg)
{
	ide_task_t args;
	int err = 1;

	if (ide_id_has_flush_cache(drive->id)) {
		memset(&args, 0, sizeof(ide_task_t));
		args.tfRegister[IDE_FEATURE_OFFSET]	= (arg) ?
			SETFEATURES_EN_WCACHE : SETFEATURES_DIS_WCACHE;
		args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_SETFEATURES;
		args.command_type		= IDE_DRIVE_TASK_NO_DATA;
		args.handler			= &task_no_data_intr;
		err = ide_raw_taskfile(drive, &args, NULL);
		if (err == 0)
			drive->wcache = arg;
	}

	update_ordered(drive);

	return err;
}

static int do_idedisk_flushcache (ide_drive_t *drive)
{
	ide_task_t args;

	memset(&args, 0, sizeof(ide_task_t));
	if (ide_id_has_flush_cache_ext(drive->id))
		args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_FLUSH_CACHE_EXT;
	else
		args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_FLUSH_CACHE;
	args.command_type			= IDE_DRIVE_TASK_NO_DATA;
	args.handler				= &task_no_data_intr;
	return ide_raw_taskfile(drive, &args, NULL);
}

static int set_acoustic (ide_drive_t *drive, int arg)
{
	ide_task_t args;