nilfs2: remove pointless NULL check of bpop_commit_alloc_ptr function

[linux-2.6/mini2440.git] / drivers / ide / ide.c

/*
 *  Copyright (C) 1994-1998         Linus Torvalds & authors (see below)
 *  Copyright (C) 2003-2005, 2007   Bartlomiej Zolnierkiewicz
 */

/*
 *  Mostly written by Mark Lord  <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 *  See linux/MAINTAINERS for address of current maintainer.
 *
 * This is the multiple IDE interface driver, as evolved from hd.c.
 * It supports up to MAX_HWIFS IDE interfaces, on one or more IRQs
 *   (usually 14 & 15).
 * There can be up to two drives per interface, as per the ATA-2 spec.
 *
 * ...
 *
 *  From hd.c:
 *  |
 *  | It traverses the request-list, using interrupts to jump between functions.
 *  | As nearly all functions can be called within interrupts, we may not sleep.
 *  | Special care is recommended.  Have Fun!
 *  |
 *  | modified by Drew Eckhardt to check nr of hd's from the CMOS.
 *  |
 *  | Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
 *  | in the early extended-partition checks and added DM partitions.
 *  |
 *  | Early work on error handling by Mika Liljeberg (liljeber@cs.Helsinki.FI).
 *  |
 *  | IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
 *  | and general streamlining by Mark Lord (mlord@pobox.com).
 *
 *  October, 1994 -- Complete line-by-line overhaul for linux 1.1.x, by:
 *
 *      Mark Lord       (mlord@pobox.com)               (IDE Perf.Pkg)
 *      Delman Lee      (delman@ieee.org)               ("Mr. atdisk2")
 *      Scott Snyder    (snyder@fnald0.fnal.gov)        (ATAPI IDE cd-rom)
 *
 *  This was a rewrite of just about everything from hd.c, though some original
 *  code is still sprinkled about.  Think of it as a major evolution, with
 *  inspiration from lots of linux users, esp.  hamish@zot.apana.org.au
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/hdreg.h>
#include <linux/completion.h>
#include <linux/device.h>

struct class *ide_port_class;

/**
 * ide_device_get       -       get an additional reference to a ide_drive_t
 * @drive:      device to get a reference to
 *
 * Gets a reference to the ide_drive_t and increments the use count of the
 * underlying LLDD module.
 */
int ide_device_get(ide_drive_t *drive)
{
        struct device *host_dev;
        struct module *module;

        if (!get_device(&drive->gendev))
                return -ENXIO;

        host_dev = drive->hwif->host->dev[0];
        module = host_dev ? host_dev->driver->owner : NULL;

        if (module && !try_module_get(module)) {
                put_device(&drive->gendev);
                return -ENXIO;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(ide_device_get);

/**
 * ide_device_put       -       release a reference to a ide_drive_t
 * @drive:      device to release a reference on
 *
 * Release a reference to the ide_drive_t and decrements the use count of
 * the underlying LLDD module.
 */
void ide_device_put(ide_drive_t *drive)
{
#ifdef CONFIG_MODULE_UNLOAD
        struct device *host_dev = drive->hwif->host->dev[0];
        struct module *module = host_dev ? host_dev->driver->owner : NULL;

        if (module)
                module_put(module);
#endif
        put_device(&drive->gendev);
}
EXPORT_SYMBOL_GPL(ide_device_put);

static int ide_bus_match(struct device *dev, struct device_driver *drv)
{
        return 1;
}

static int ide_uevent(struct device *dev, struct kobj_uevent_env *env)
{
        ide_drive_t *drive = to_ide_device(dev);

        add_uevent_var(env, "MEDIA=%s", ide_media_string(drive));
        add_uevent_var(env, "DRIVENAME=%s", drive->name);
        add_uevent_var(env, "MODALIAS=ide:m-%s", ide_media_string(drive));
        return 0;
}

static int generic_ide_probe(struct device *dev)
{
        ide_drive_t *drive = to_ide_device(dev);
        struct ide_driver *drv = to_ide_driver(dev->driver);

        return drv->probe ? drv->probe(drive) : -ENODEV;
}

static int generic_ide_remove(struct device *dev)
{
        ide_drive_t *drive = to_ide_device(dev);
        struct ide_driver *drv = to_ide_driver(dev->driver);

        if (drv->remove)
                drv->remove(drive);

        return 0;
}

static void generic_ide_shutdown(struct device *dev)
{
        ide_drive_t *drive = to_ide_device(dev);
        struct ide_driver *drv = to_ide_driver(dev->driver);

        if (dev->driver && drv->shutdown)
                drv->shutdown(drive);
}

struct bus_type ide_bus_type = {
        .name           = "ide",
        .match          = ide_bus_match,
        .uevent         = ide_uevent,
        .probe          = generic_ide_probe,
        .remove         = generic_ide_remove,
        .shutdown       = generic_ide_shutdown,
        .dev_attrs      = ide_dev_attrs,
        .suspend        = generic_ide_suspend,
        .resume         = generic_ide_resume,
};

EXPORT_SYMBOL_GPL(ide_bus_type);

int ide_vlb_clk;
EXPORT_SYMBOL_GPL(ide_vlb_clk);

module_param_named(vlb_clock, ide_vlb_clk, int, 0);
MODULE_PARM_DESC(vlb_clock, "VLB clock frequency (in MHz)");

int ide_pci_clk;
EXPORT_SYMBOL_GPL(ide_pci_clk);

module_param_named(pci_clock, ide_pci_clk, int, 0);
MODULE_PARM_DESC(pci_clock, "PCI bus clock frequency (in MHz)");

static int ide_set_dev_param_mask(const char *s, struct kernel_param *kp)
{
        int a, b, i, j = 1;
        unsigned int *dev_param_mask = (unsigned int *)kp->arg;

        /* controller . device (0 or 1) [ : 1 (set) | 0 (clear) ] */
        if (sscanf(s, "%d.%d:%d", &a, &b, &j) != 3 &&
            sscanf(s, "%d.%d", &a, &b) != 2)
                return -EINVAL;

        i = a * MAX_DRIVES + b;

        if (i >= MAX_HWIFS * MAX_DRIVES || j < 0 || j > 1)
                return -EINVAL;

        if (j)
                *dev_param_mask |= (1 << i);
        else
                *dev_param_mask &= ~(1 << i);

        return 0;
}

static unsigned int ide_nodma;

module_param_call(nodma, ide_set_dev_param_mask, NULL, &ide_nodma, 0);
MODULE_PARM_DESC(nodma, "disallow DMA for a device");

static unsigned int ide_noflush;

module_param_call(noflush, ide_set_dev_param_mask, NULL, &ide_noflush, 0);
MODULE_PARM_DESC(noflush, "disable flush requests for a device");

static unsigned int ide_noprobe;

module_param_call(noprobe, ide_set_dev_param_mask, NULL, &ide_noprobe, 0);
MODULE_PARM_DESC(noprobe, "skip probing for a device");

static unsigned int ide_nowerr;

module_param_call(nowerr, ide_set_dev_param_mask, NULL, &ide_nowerr, 0);
MODULE_PARM_DESC(nowerr, "ignore the ATA_DF bit for a device");

static unsigned int ide_cdroms;

module_param_call(cdrom, ide_set_dev_param_mask, NULL, &ide_cdroms, 0);
MODULE_PARM_DESC(cdrom, "force device as a CD-ROM");

struct chs_geom {
        unsigned int    cyl;
        u8              head;
        u8              sect;
};

static unsigned int ide_disks;
static struct chs_geom ide_disks_chs[MAX_HWIFS * MAX_DRIVES];

static int ide_set_disk_chs(const char *str, struct kernel_param *kp)
{
        int a, b, c = 0, h = 0, s = 0, i, j = 1;

        /* controller . device (0 or 1) : Cylinders , Heads , Sectors */
        /* controller . device (0 or 1) : 1 (use CHS) | 0 (ignore CHS) */
        if (sscanf(str, "%d.%d:%d,%d,%d", &a, &b, &c, &h, &s) != 5 &&
            sscanf(str, "%d.%d:%d", &a, &b, &j) != 3)
                return -EINVAL;

        i = a * MAX_DRIVES + b;

        if (i >= MAX_HWIFS * MAX_DRIVES || j < 0 || j > 1)
                return -EINVAL;

        if (c > INT_MAX || h > 255 || s > 255)
                return -EINVAL;

        if (j)
                ide_disks |= (1 << i);
        else
                ide_disks &= ~(1 << i);

        ide_disks_chs[i].cyl  = c;
        ide_disks_chs[i].head = h;
        ide_disks_chs[i].sect = s;

        return 0;
}

module_param_call(chs, ide_set_disk_chs, NULL, NULL, 0);
MODULE_PARM_DESC(chs, "force device as a disk (using CHS)");

static void ide_dev_apply_params(ide_drive_t *drive, u8 unit)
{
        int i = drive->hwif->index * MAX_DRIVES + unit;

        if (ide_nodma & (1 << i)) {
                printk(KERN_INFO "ide: disallowing DMA for %s\n", drive->name);
                drive->dev_flags |= IDE_DFLAG_NODMA;
        }
        if (ide_noflush & (1 << i)) {
                printk(KERN_INFO "ide: disabling flush requests for %s\n",
                                 drive->name);
                drive->dev_flags |= IDE_DFLAG_NOFLUSH;
        }
        if (ide_noprobe & (1 << i)) {
                printk(KERN_INFO "ide: skipping probe for %s\n", drive->name);
                drive->dev_flags |= IDE_DFLAG_NOPROBE;
        }
        if (ide_nowerr & (1 << i)) {
                printk(KERN_INFO "ide: ignoring the ATA_DF bit for %s\n",
                                 drive->name);
                drive->bad_wstat = BAD_R_STAT;
        }
        if (ide_cdroms & (1 << i)) {
                printk(KERN_INFO "ide: forcing %s as a CD-ROM\n", drive->name);
                drive->dev_flags |= IDE_DFLAG_PRESENT;
                drive->media = ide_cdrom;
                /* an ATAPI device ignores DRDY */
                drive->ready_stat = 0;
        }
        if (ide_disks & (1 << i)) {
                drive->cyl  = drive->bios_cyl  = ide_disks_chs[i].cyl;
                drive->head = drive->bios_head = ide_disks_chs[i].head;
                drive->sect = drive->bios_sect = ide_disks_chs[i].sect;

                printk(KERN_INFO "ide: forcing %s as a disk (%d/%d/%d)\n",
                                 drive->name,
                                 drive->cyl, drive->head, drive->sect);

                drive->dev_flags |= IDE_DFLAG_FORCED_GEOM | IDE_DFLAG_PRESENT;
                drive->media = ide_disk;
                drive->ready_stat = ATA_DRDY;
        }
}

static unsigned int ide_ignore_cable;

static int ide_set_ignore_cable(const char *s, struct kernel_param *kp)
{
        int i, j = 1;

        /* controller (ignore) */
        /* controller : 1 (ignore) | 0 (use) */
        if (sscanf(s, "%d:%d", &i, &j) != 2 && sscanf(s, "%d", &i) != 1)
                return -EINVAL;

        if (i >= MAX_HWIFS || j < 0 || j > 1)
                return -EINVAL;

        if (j)
                ide_ignore_cable |= (1 << i);
        else
                ide_ignore_cable &= ~(1 << i);

        return 0;
}

module_param_call(ignore_cable, ide_set_ignore_cable, NULL, NULL, 0);
MODULE_PARM_DESC(ignore_cable, "ignore cable detection");

void ide_port_apply_params(ide_hwif_t *hwif)
{
        ide_drive_t *drive;
        int i;

        if (ide_ignore_cable & (1 << hwif->index)) {
                printk(KERN_INFO "ide: ignoring cable detection for %s\n",
                                 hwif->name);
                hwif->cbl = ATA_CBL_PATA40_SHORT;
        }

        ide_port_for_each_dev(i, drive, hwif)
                ide_dev_apply_params(drive, i);
}

/*
 * This is gets invoked once during initialization, to set *everything* up
 */
static int __init ide_init(void)
{
        int ret;

        printk(KERN_INFO "Uniform Multi-Platform E-IDE driver\n");

        ret = bus_register(&ide_bus_type);
        if (ret < 0) {
                printk(KERN_WARNING "IDE: bus_register error: %d\n", ret);
                return ret;
        }

        ide_port_class = class_create(THIS_MODULE, "ide_port");
        if (IS_ERR(ide_port_class)) {
                ret = PTR_ERR(ide_port_class);
                goto out_port_class;
        }

        ide_acpi_init();

        proc_ide_create();

        return 0;

out_port_class:
        bus_unregister(&ide_bus_type);

        return ret;
}

static void __exit ide_exit(void)
{
        proc_ide_destroy();

        class_destroy(ide_port_class);

        bus_unregister(&ide_bus_type);
}

module_init(ide_init);
module_exit(ide_exit);

MODULE_LICENSE("GPL");