ide: move IDE settings handling to ide-proc.c

* move
	__ide_add_setting()
	ide_add_setting()
	__ide_remove_setting()
	auto_remove_settings()
	ide_find_setting_by_name()
	ide_read_setting()
	ide_write_setting()
	set_xfer_rate()
	ide_add_generic_settings()
	ide_register_subdriver()
	ide_unregister_subdriver()

  from ide.c to ide-proc.c

* set_{io_32bit,pio_mode,using_dma}() cannot be marked static now, fix it

* rename ide_[un]register_subdriver() to ide_proc_[un]register_driver(),
  update device drivers to use new names

* add CONFIG_IDE_PROC_FS=n versions of ide_proc_[un]register_driver()
  and ide_add_generic_settings()

* make ide_find_setting_by_name(), ide_{read,write}_setting()
  and ide_{add,remove}_proc_entries() static

* cover IDE settings code in device drivers with CONFIG_IDE_PROC_FS #ifdef,
  also while at it cover with CONFIG_IDE_PROC_FS #ifdef ide_driver_t.proc

* remove bogus comment from ide.h

* cover with CONFIG_IDE_PROC_FS #ifdef .proc and .settings in ide_drive_t

Besides saner code this patch results in the IDE core smaller by ~2 kB
(on x86-32) and IDE disk driver by ~1 kB (ditto) when CONFIG_IDE_PROC_FS=n.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 308 insertions, 2 deletions

diff --git a/drivers/ide/ide-proc.c b/drivers/ide/ide-proc.c
index a9e0b30fb1f2..949a6f609d84 100644
--- a/drivers/ide/ide-proc.c
+++ b/drivers/ide/ide-proc.c
@@ -3,6 +3,8 @@
  *
  *  Copyright (C) 1997-1998	Mark Lord
  *  Copyright (C) 2003		Red Hat <alan@redhat.com>
+ *
+ *  Some code was moved here from ide.c, see it for original copyrights.
  */
 
 /*
@@ -121,6 +123,265 @@ static int proc_ide_read_identify
 	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
 }
 
+/**
+ *	__ide_add_setting	-	add an ide setting option
+ *	@drive: drive to use
+ *	@name: setting name
+ *	@rw: true if the function is read write
+ *	@data_type: type of data
+ *	@min: range minimum
+ *	@max: range maximum
+ *	@mul_factor: multiplication scale
+ *	@div_factor: divison scale
+ *	@data: private data field
+ *	@set: setting
+ *	@auto_remove: setting auto removal flag
+ *
+ *	Removes the setting named from the device if it is present.
+ *	The function takes the settings_lock to protect against
+ *	parallel changes. This function must not be called from IRQ
+ *	context. Returns 0 on success or -1 on failure.
+ *
+ *	BUGS: This code is seriously over-engineered. There is also
+ *	magic about how the driver specific features are setup. If
+ *	a driver is attached we assume the driver settings are auto
+ *	remove.
+ */
+
+static int __ide_add_setting(ide_drive_t *drive, const char *name, int rw, int data_type, int min, int max, int mul_factor, int div_factor, void *data, ide_procset_t *set, int auto_remove)
+{
+	ide_settings_t **p = (ide_settings_t **) &drive->settings, *setting = NULL;
+
+	down(&ide_setting_sem);
+	while ((*p) && strcmp((*p)->name, name) < 0)
+		p = &((*p)->next);
+	if ((setting = kzalloc(sizeof(*setting), GFP_KERNEL)) == NULL)
+		goto abort;
+	if ((setting->name = kmalloc(strlen(name) + 1, GFP_KERNEL)) == NULL)
+		goto abort;
+	strcpy(setting->name, name);
+	setting->rw = rw;
+	setting->data_type = data_type;
+	setting->min = min;
+	setting->max = max;
+	setting->mul_factor = mul_factor;
+	setting->div_factor = div_factor;
+	setting->data = data;
+	setting->set = set;
+
+	setting->next = *p;
+	if (auto_remove)
+		setting->auto_remove = 1;
+	*p = setting;
+	up(&ide_setting_sem);
+	return 0;
+abort:
+	up(&ide_setting_sem);
+	kfree(setting);
+	return -1;
+}
+
+int ide_add_setting(ide_drive_t *drive, const char *name, int rw, int data_type, int min, int max, int mul_factor, int div_factor, void *data, ide_procset_t *set)
+{
+	return __ide_add_setting(drive, name, rw, data_type, min, max, mul_factor, div_factor, data, set, 1);
+}
+
+EXPORT_SYMBOL(ide_add_setting);
+
+/**
+ *	__ide_remove_setting	-	remove an ide setting option
+ *	@drive: drive to use
+ *	@name: setting name
+ *
+ *	Removes the setting named from the device if it is present.
+ *	The caller must hold the setting semaphore.
+ */
+
+static void __ide_remove_setting (ide_drive_t *drive, char *name)
+{
+	ide_settings_t **p, *setting;
+
+	p = (ide_settings_t **) &drive->settings;
+
+	while ((*p) && strcmp((*p)->name, name))
+		p = &((*p)->next);
+	if ((setting = (*p)) == NULL)
+		return;
+
+	(*p) = setting->next;
+
+	kfree(setting->name);
+	kfree(setting);
+}
+
+/**
+ *	auto_remove_settings	-	remove driver specific settings
+ *	@drive: drive
+ *
+ *	Automatically remove all the driver specific settings for this
+ *	drive. This function may not be called from IRQ context. The
+ *	caller must hold ide_setting_sem.
+ */
+
+static void auto_remove_settings (ide_drive_t *drive)
+{
+	ide_settings_t *setting;
+repeat:
+	setting = drive->settings;
+	while (setting) {
+		if (setting->auto_remove) {
+			__ide_remove_setting(drive, setting->name);
+			goto repeat;
+		}
+		setting = setting->next;
+	}
+}
+
+/**
+ *	ide_find_setting_by_name	-	find a drive specific setting
+ *	@drive: drive to scan
+ *	@name: setting name
+ *
+ *	Scan's the device setting table for a matching entry and returns
+ *	this or NULL if no entry is found. The caller must hold the
+ *	setting semaphore
+ */
+
+static ide_settings_t *ide_find_setting_by_name(ide_drive_t *drive, char *name)
+{
+	ide_settings_t *setting = drive->settings;
+
+	while (setting) {
+		if (strcmp(setting->name, name) == 0)
+			break;
+		setting = setting->next;
+	}
+	return setting;
+}
+
+/**
+ *	ide_read_setting	-	read an IDE setting
+ *	@drive: drive to read from
+ *	@setting: drive setting
+ *
+ *	Read a drive setting and return the value. The caller
+ *	must hold the ide_setting_sem when making this call.
+ *
+ *	BUGS: the data return and error are the same return value
+ *	so an error -EINVAL and true return of the same value cannot
+ *	be told apart
+ */
+
+static int ide_read_setting(ide_drive_t *drive, ide_settings_t *setting)
+{
+	int		val = -EINVAL;
+	unsigned long	flags;
+
+	if ((setting->rw & SETTING_READ)) {
+		spin_lock_irqsave(&ide_lock, flags);
+		switch(setting->data_type) {
+			case TYPE_BYTE:
+				val = *((u8 *) setting->data);
+				break;
+			case TYPE_SHORT:
+				val = *((u16 *) setting->data);
+				break;
+			case TYPE_INT:
+				val = *((u32 *) setting->data);
+				break;
+		}
+		spin_unlock_irqrestore(&ide_lock, flags);
+	}
+	return val;
+}
+
+/**
+ *	ide_write_setting	-	read an IDE setting
+ *	@drive: drive to read from
+ *	@setting: drive setting
+ *	@val: value
+ *
+ *	Write a drive setting if it is possible. The caller
+ *	must hold the ide_setting_sem when making this call.
+ *
+ *	BUGS: the data return and error are the same return value
+ *	so an error -EINVAL and true return of the same value cannot
+ *	be told apart
+ *
+ *	FIXME:  This should be changed to enqueue a special request
+ *	to the driver to change settings, and then wait on a sema for completion.
+ *	The current scheme of polling is kludgy, though safe enough.
+ */
+
+static int ide_write_setting(ide_drive_t *drive, ide_settings_t *setting, int val)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (setting->set)
+		return setting->set(drive, val);
+	if (!(setting->rw & SETTING_WRITE))
+		return -EPERM;
+	if (val < setting->min || val > setting->max)
+		return -EINVAL;
+	if (ide_spin_wait_hwgroup(drive))
+		return -EBUSY;
+	switch (setting->data_type) {
+		case TYPE_BYTE:
+			*((u8 *) setting->data) = val;
+			break;
+		case TYPE_SHORT:
+			*((u16 *) setting->data) = val;
+			break;
+		case TYPE_INT:
+			*((u32 *) setting->data) = val;
+			break;
+	}
+	spin_unlock_irq(&ide_lock);
+	return 0;
+}
+
+static int set_xfer_rate (ide_drive_t *drive, int arg)
+{
+	int err;
+
+	if (arg < 0 || arg > 70)
+		return -EINVAL;
+
+	err = ide_wait_cmd(drive,
+			WIN_SETFEATURES, (u8) arg,
+			SETFEATURES_XFER, 0, NULL);
+
+	if (!err && arg) {
+		ide_set_xfer_rate(drive, (u8) arg);
+		ide_driveid_update(drive);
+	}
+	return err;
+}
+
+/**
+ *	ide_add_generic_settings	-	generic ide settings
+ *	@drive: drive being configured
+ *
+ *	Add the generic parts of the system settings to the /proc files.
+ *	The caller must not be holding the ide_setting_sem.
+ */
+
+void ide_add_generic_settings (ide_drive_t *drive)
+{
+/*
+ *			  drive		setting name		read/write access				data type	min	max				mul_factor	div_factor	data pointer			set function
+ */
+	__ide_add_setting(drive,	"io_32bit",		drive->no_io_32bit ? SETTING_READ : SETTING_RW,	TYPE_BYTE,	0,	1 + (SUPPORT_VLB_SYNC << 1),	1,		1,		&drive->io_32bit,		set_io_32bit,	0);
+	__ide_add_setting(drive,	"keepsettings",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->keep_settings,		NULL,		0);
+	__ide_add_setting(drive,	"nice1",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->nice1,			NULL,		0);
+	__ide_add_setting(drive,	"pio_mode",		SETTING_WRITE,					TYPE_BYTE,	0,	255,				1,		1,		NULL,				set_pio_mode,	0);
+	__ide_add_setting(drive,	"unmaskirq",		drive->no_unmask ? SETTING_READ : SETTING_RW,	TYPE_BYTE,	0,	1,				1,		1,		&drive->unmask,			NULL,		0);
+	__ide_add_setting(drive,	"using_dma",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->using_dma,		set_using_dma,	0);
+	__ide_add_setting(drive,	"init_speed",		SETTING_RW,					TYPE_BYTE,	0,	70,				1,		1,		&drive->init_speed,		NULL,		0);
+	__ide_add_setting(drive,	"current_speed",	SETTING_RW,					TYPE_BYTE,	0,	70,				1,		1,		&drive->current_speed,		set_xfer_rate,	0);
+	__ide_add_setting(drive,	"number",		SETTING_RW,					TYPE_BYTE,	0,	3,				1,		1,		&drive->dn,			NULL,		0);
+}
+
 static void proc_ide_settings_warn(void)
 {
 	static int warned = 0;
@@ -399,7 +660,7 @@ static ide_proc_entry_t generic_drive_entries[] = {
 	{ NULL,	0, NULL, NULL }
 };
 
-void ide_add_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p, void *data)
+static void ide_add_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p, void *data)
 {
 	struct proc_dir_entry *ent;
 
@@ -415,7 +676,7 @@ void ide_add_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p, void
 	}
 }
 
-void ide_remove_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p)
+static void ide_remove_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p)
 {
 	if (!dir || !p)
 		return;
@@ -425,6 +686,51 @@ void ide_remove_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p)
 	}
 }
 
+void ide_proc_register_driver(ide_drive_t *drive, ide_driver_t *driver)
+{
+	ide_add_proc_entries(drive->proc, driver->proc, drive);
+}
+
+EXPORT_SYMBOL(ide_proc_register_driver);
+
+/**
+ *	ide_proc_unregister_driver	-	remove driver specific data
+ *	@drive: drive
+ *	@driver: driver
+ *
+ *	Clean up the driver specific /proc files and IDE settings
+ *	for a given drive.
+ *
+ *	Takes ide_setting_sem and ide_lock.
+ *	Caller must hold none of the locks.
+ */
+
+void ide_proc_unregister_driver(ide_drive_t *drive, ide_driver_t *driver)
+{
+	unsigned long flags;
+
+	ide_remove_proc_entries(drive->proc, driver->proc);
+
+	down(&ide_setting_sem);
+	spin_lock_irqsave(&ide_lock, flags);
+	/*
+	 * ide_setting_sem protects the settings list
+	 * ide_lock protects the use of settings
+	 *
+	 * so we need to hold both, ide_settings_sem because we want to
+	 * modify the settings list, and ide_lock because we cannot take
+	 * a setting out that is being used.
+	 *
+	 * OTOH both ide_{read,write}_setting are only ever used under
+	 * ide_setting_sem.
+	 */
+	auto_remove_settings(drive);
+	spin_unlock_irqrestore(&ide_lock, flags);
+	up(&ide_setting_sem);
+}
+
+EXPORT_SYMBOL(ide_proc_unregister_driver);
+
 static void create_proc_ide_drives(ide_hwif_t *hwif)
 {
 	int	d;