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;