android_kernel_xiaomi_sm8350/drivers/ide/ide-pnp.c
Bartlomiej Zolnierkiewicz 93de00fd1c ide: remove broken/dangerous HDIO_[UNREGISTER,SCAN]_HWIF ioctls (take 3)
hdparm explicitely marks HDIO_[UNREGISTER,SCAN]_HWIF ioctls as DANGEROUS
and given the number of bugs we can assume that there are no real users:

* DMA has no chance of working because DMA resources are released by
  ide_unregister() and they are never allocated again.

* Since ide_init_hwif_ports() is used for ->io_ports[] setup the ioctls
  don't work for almost all hosts with "non-standard" (== non ISA-like)
  layout of IDE taskfile registers (there is a lot of such host drivers).

* ide_port_init_devices() is not called when probing IDE devices so:
  - drive->autotune is never set and IDE host/devices are not programmed
    for the correct PIO/DMA transfer modes (=> possible data corruption)
  - host specific I/O 32-bit and IRQ unmasking settings are not applied
    (=> possible data corruption)
  - host specific ->port_init_devs method is not called (=> no luck with
    ht6560b, qd65xx and opti621 host drivers)

* ->rw_disk method is not preserved (=> no HPT3xxN chipsets support).

* ->serialized flag is not preserved (=> possible data corruption when
   using icside, aec62xx (ATP850UF chipset), cmd640, cs5530, hpt366
   (HPT3xxN chipsets), rz1000, sc1200, dtc2278 and ht6560b host drivers).

* ->ack_intr method is not preserved (=> needed by ide-cris, buddha,
  gayle and macide host drivers).

* ->sata_scr[] and sata_misc[] is cleared by ide_unregister() and it
  isn't initialized again (SiI3112 support needs them).

* To issue an ioctl() there need to be at least one IDE device present
  in the system.

* ->cable_detect method is not preserved + it is not called when probing
  IDE devices so cable detection is broken (however since DMA support is
  also broken it doesn't really matter ;-).

* Some objects which may have already been freed in ide_unregister()
  are restored by ide_hwif_restore() (i.e. ->hwgroup).

* ide_register_hw() may unregister unrelated IDE ports if free ide_hwifs[]
  slot cannot be found.

* When IDE host drivers are modular unregistered port may be re-used by
  different host driver that owned it first causing subtle bugs.

Since we now have a proper warm-plug support remove these ioctls,
then remove no longer needed:
- ide_register_hw() and ide_hwif_restore() functions
- 'init_default' and 'restore' arguments of ide_unregister()
- zeroeing of hwif->{dma,extra}_* fields in ide_unregister()

As an added bonus IDE core code size shrinks by ~3kB (x86-32).

v2:
* fix ide_unregister() arguments in cleanup_module() (Andrew Morton).

v3:
* fix ide_unregister() arguments in palm_bk3710.c.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2008-04-18 00:46:24 +02:00

91 lines
2.2 KiB
C

/*
* This file provides autodetection for ISA PnP IDE interfaces.
* It was tested with "ESS ES1868 Plug and Play AudioDrive" IDE interface.
*
* Copyright (C) 2000 Andrey Panin <pazke@donpac.ru>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* You should have received a copy of the GNU General Public License
* (for example /usr/src/linux/COPYING); if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/init.h>
#include <linux/pnp.h>
#include <linux/ide.h>
/* Add your devices here :)) */
static struct pnp_device_id idepnp_devices[] = {
/* Generic ESDI/IDE/ATA compatible hard disk controller */
{.id = "PNP0600", .driver_data = 0},
{.id = ""}
};
static int idepnp_probe(struct pnp_dev * dev, const struct pnp_device_id *dev_id)
{
hw_regs_t hw;
ide_hwif_t *hwif;
if (!(pnp_port_valid(dev, 0) && pnp_port_valid(dev, 1) && pnp_irq_valid(dev, 0)))
return -1;
memset(&hw, 0, sizeof(hw));
ide_std_init_ports(&hw, pnp_port_start(dev, 0),
pnp_port_start(dev, 1));
hw.irq = pnp_irq(dev, 0);
hwif = ide_find_port(hw.io_ports[IDE_DATA_OFFSET]);
if (hwif) {
u8 index = hwif->index;
u8 idx[4] = { index, 0xff, 0xff, 0xff };
ide_init_port_data(hwif, index);
ide_init_port_hw(hwif, &hw);
printk(KERN_INFO "ide%d: generic PnP IDE interface\n", index);
pnp_set_drvdata(dev,hwif);
ide_device_add(idx, NULL);
return 0;
}
return -1;
}
static void idepnp_remove(struct pnp_dev * dev)
{
ide_hwif_t *hwif = pnp_get_drvdata(dev);
if (hwif)
ide_unregister(hwif->index);
else
printk(KERN_ERR "idepnp: Unable to remove device, please report.\n");
}
static struct pnp_driver idepnp_driver = {
.name = "ide",
.id_table = idepnp_devices,
.probe = idepnp_probe,
.remove = idepnp_remove,
};
static int __init pnpide_init(void)
{
return pnp_register_driver(&idepnp_driver);
}
static void __exit pnpide_exit(void)
{
pnp_unregister_driver(&idepnp_driver);
}
module_init(pnpide_init);
module_exit(pnpide_exit);
MODULE_LICENSE("GPL");