xref: /kernel/linux/linux-5.10/drivers/ide/rz1000.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  Copyright (C) 1995-1998  Linus Torvalds & author (see below)
4 */
5
6/*
7 *  Principal Author:  mlord@pobox.com (Mark Lord)
8 *
9 *  See linux/MAINTAINERS for address of current maintainer.
10 *
11 *  This file provides support for disabling the buggy read-ahead
12 *  mode of the RZ1000 IDE chipset, commonly used on Intel motherboards.
13 *
14 *  Dunno if this fixes both ports, or only the primary port (?).
15 */
16
17#include <linux/types.h>
18#include <linux/module.h>
19#include <linux/kernel.h>
20#include <linux/pci.h>
21#include <linux/ide.h>
22#include <linux/init.h>
23
24#define DRV_NAME "rz1000"
25
26static int rz1000_disable_readahead(struct pci_dev *dev)
27{
28	u16 reg;
29
30	if (!pci_read_config_word (dev, 0x40, &reg) &&
31	    !pci_write_config_word(dev, 0x40, reg & 0xdfff)) {
32		printk(KERN_INFO "%s: disabled chipset read-ahead "
33			"(buggy RZ1000/RZ1001)\n", pci_name(dev));
34		return 0;
35	} else {
36		printk(KERN_INFO "%s: serialized, disabled unmasking "
37			"(buggy RZ1000/RZ1001)\n", pci_name(dev));
38		return 1;
39	}
40}
41
42static const struct ide_port_info rz1000_chipset = {
43	.name		= DRV_NAME,
44	.host_flags	= IDE_HFLAG_NO_DMA,
45};
46
47static int rz1000_init_one(struct pci_dev *dev, const struct pci_device_id *id)
48{
49	struct ide_port_info d = rz1000_chipset;
50	int rc;
51
52	rc = pci_enable_device(dev);
53	if (rc)
54		return rc;
55
56	if (rz1000_disable_readahead(dev)) {
57		d.host_flags |= IDE_HFLAG_SERIALIZE;
58		d.host_flags |= IDE_HFLAG_NO_UNMASK_IRQS;
59	}
60
61	return ide_pci_init_one(dev, &d, NULL);
62}
63
64static void rz1000_remove(struct pci_dev *dev)
65{
66	ide_pci_remove(dev);
67	pci_disable_device(dev);
68}
69
70static const struct pci_device_id rz1000_pci_tbl[] = {
71	{ PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1000), 0 },
72	{ PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1001), 0 },
73	{ 0, },
74};
75MODULE_DEVICE_TABLE(pci, rz1000_pci_tbl);
76
77static struct pci_driver rz1000_pci_driver = {
78	.name		= "RZ1000_IDE",
79	.id_table	= rz1000_pci_tbl,
80	.probe		= rz1000_init_one,
81	.remove		= rz1000_remove,
82};
83
84static int __init rz1000_ide_init(void)
85{
86	return ide_pci_register_driver(&rz1000_pci_driver);
87}
88
89static void __exit rz1000_ide_exit(void)
90{
91	pci_unregister_driver(&rz1000_pci_driver);
92}
93
94module_init(rz1000_ide_init);
95module_exit(rz1000_ide_exit);
96
97MODULE_AUTHOR("Andre Hedrick");
98MODULE_DESCRIPTION("PCI driver module for RZ1000 IDE");
99MODULE_LICENSE("GPL");
100
101