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linux_kernel/drivers/ide/umc8672.c
Kees Cook 3f649ab728 treewide: Remove uninitialized_var() usage 
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 1995-1996 Linus Torvalds & author (see below)
*/
/*
* Principal Author/Maintainer: PODIEN@hml2.atlas.de (Wolfram Podien)
*
* This file provides support for the advanced features
* of the UMC 8672 IDE interface.
*
* Version 0.01 Initial version, hacked out of ide.c,
* and #include'd rather than compiled separately.
* This will get cleaned up in a subsequent release.
*
* Version 0.02 now configs/compiles separate from ide.c -ml
* Version 0.03 enhanced auto-tune, fix display bug
* Version 0.05 replace sti() with restore_flags() -ml
* add detection of possible race condition -ml
*/
/*
* VLB Controller Support from
* Wolfram Podien
* Rohoefe 3
* D28832 Achim
* Germany
*
* To enable UMC8672 support there must a lilo line like
* append="ide0=umc8672"...
* To set the speed according to the abilities of the hardware there must be a
* line like
* #define UMC_DRIVE0 11
* in the beginning of the driver, which sets the speed of drive 0 to 11 (there
* are some lines present). 0 - 11 are allowed speed values. These values are
* the results from the DOS speed test program supplied from UMC. 11 is the
* highest speed (about PIO mode 3)
*/
#define REALLY_SLOW_IO /* some systems can safely undef this */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/blkdev.h>
#include <linux/ide.h>
#include <linux/init.h>
#include <asm/io.h>
#define DRV_NAME "umc8672"
/*
* Default speeds. These can be changed with "auto-tune" and/or hdparm.
*/
#define UMC_DRIVE0 1 /* DOS measured drive speeds */
#define UMC_DRIVE1 1 /* 0 to 11 allowed */
#define UMC_DRIVE2 1 /* 11 = Fastest Speed */
#define UMC_DRIVE3 1 /* In case of crash reduce speed */
static u8 current_speeds[4] = {UMC_DRIVE0, UMC_DRIVE1, UMC_DRIVE2, UMC_DRIVE3};
static const u8 pio_to_umc [5] = {0, 3, 7, 10, 11}; /* rough guesses */
/* 0 1 2 3 4 5 6 7 8 9 10 11 */
static const u8 speedtab [3][12] = {
{0x0f, 0x0b, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x1},
{0x03, 0x02, 0x02, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0x1},
{0xff, 0xcb, 0xc0, 0x58, 0x36, 0x33, 0x23, 0x22, 0x21, 0x11, 0x10, 0x0}
};
static void out_umc(char port, char wert)
{
outb_p(port, 0x108);
outb_p(wert, 0x109);
}
static inline u8 in_umc(char port)
{
outb_p(port, 0x108);
return inb_p(0x109);
}
static void umc_set_speeds(u8 speeds[])
{
int i, tmp;
outb_p(0x5A, 0x108); /* enable umc */
out_umc(0xd7, (speedtab[0][speeds[2]] | (speedtab[0][speeds[3]]<<4)));
out_umc(0xd6, (speedtab[0][speeds[0]] | (speedtab[0][speeds[1]]<<4)));
tmp = 0;
for (i = 3; i >= 0; i--)
tmp = (tmp << 2) | speedtab[1][speeds[i]];
out_umc(0xdc, tmp);
for (i = 0; i < 4; i++) {
out_umc(0xd0 + i, speedtab[2][speeds[i]]);
out_umc(0xd8 + i, speedtab[2][speeds[i]]);
}
outb_p(0xa5, 0x108); /* disable umc */
printk("umc8672: drive speeds [0 to 11]: %d %d %d %d\n",
speeds[0], speeds[1], speeds[2], speeds[3]);
}
static void umc_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
{
ide_hwif_t *mate = hwif->mate;
unsigned long flags;
const u8 pio = drive->pio_mode - XFER_PIO_0;
printk("%s: setting umc8672 to PIO mode%d (speed %d)\n",
drive->name, pio, pio_to_umc[pio]);
if (mate)
spin_lock_irqsave(&mate->lock, flags);
if (mate && mate->handler) {
printk(KERN_ERR "umc8672: other interface is busy: exiting tune_umc()\n");
} else {
current_speeds[drive->name[2] - 'a'] = pio_to_umc[pio];
umc_set_speeds(current_speeds);
}
if (mate)
spin_unlock_irqrestore(&mate->lock, flags);
}
static const struct ide_port_ops umc8672_port_ops = {
.set_pio_mode = umc_set_pio_mode,
};
static const struct ide_port_info umc8672_port_info __initconst = {
.name = DRV_NAME,
.chipset = ide_umc8672,
.port_ops = &umc8672_port_ops,
.host_flags = IDE_HFLAG_NO_DMA,
.pio_mask = ATA_PIO4,
};
static int __init umc8672_probe(void)
{
unsigned long flags;
if (!request_region(0x108, 2, "umc8672")) {
printk(KERN_ERR "umc8672: ports 0x108-0x109 already in use.\n");
return 1;
}
local_irq_save(flags);
outb_p(0x5A, 0x108); /* enable umc */
if (in_umc (0xd5) != 0xa0) {
local_irq_restore(flags);
printk(KERN_ERR "umc8672: not found\n");
release_region(0x108, 2);
return 1;
}
outb_p(0xa5, 0x108); /* disable umc */
umc_set_speeds(current_speeds);
local_irq_restore(flags);
return ide_legacy_device_add(&umc8672_port_info, 0);
}
static bool probe_umc8672;
module_param_named(probe, probe_umc8672, bool, 0);
MODULE_PARM_DESC(probe, "probe for UMC8672 chipset");
static int __init umc8672_init(void)
{
if (probe_umc8672 == 0)
goto out;
if (umc8672_probe() == 0)
return 0;
out:
return -ENODEV;
}
module_init(umc8672_init);
MODULE_AUTHOR("Wolfram Podien");
MODULE_DESCRIPTION("Support for UMC 8672 IDE chipset");
MODULE_LICENSE("GPL");
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