1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2004, 2006 MIPS Technologies, Inc. All rights reserved.
4 * Author: Maciej W. Rozycki <macro@mips.com>
5 * Copyright (C) 2018 Maciej W. Rozycki
6 */
7
8 #include <linux/dma-mapping.h>
9 #include <linux/pci.h>
10
11 /*
12 * Set the BCM1250, etc. PCI host bridge's TRDY timeout
13 * to the finite max.
14 */
quirk_sb1250_pci(struct pci_dev * dev)15 static void quirk_sb1250_pci(struct pci_dev *dev)
16 {
17 pci_write_config_byte(dev, 0x40, 0xff);
18 }
19 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIBYTE, PCI_DEVICE_ID_BCM1250_PCI,
20 quirk_sb1250_pci);
21
22 /*
23 * The BCM1250, etc. PCI host bridge does not support DAC on its 32-bit
24 * bus, so we set the bus's DMA limit accordingly. However the HT link
25 * down the artificial PCI-HT bridge supports 40-bit addressing and the
26 * SP1011 HT-PCI bridge downstream supports both DAC and a 64-bit bus
27 * width, so we record the PCI-HT bridge's secondary and subordinate bus
28 * numbers and do not set the limit for devices present in the inclusive
29 * range of those.
30 */
31 struct sb1250_bus_dma_limit_exclude {
32 bool set;
33 unsigned char start;
34 unsigned char end;
35 };
36
sb1250_bus_dma_limit(struct pci_dev * dev,void * data)37 static int sb1250_bus_dma_limit(struct pci_dev *dev, void *data)
38 {
39 struct sb1250_bus_dma_limit_exclude *exclude = data;
40 bool exclude_this;
41 bool ht_bridge;
42
43 exclude_this = exclude->set && (dev->bus->number >= exclude->start &&
44 dev->bus->number <= exclude->end);
45 ht_bridge = !exclude->set && (dev->vendor == PCI_VENDOR_ID_SIBYTE &&
46 dev->device == PCI_DEVICE_ID_BCM1250_HT);
47
48 if (exclude_this) {
49 dev_dbg(&dev->dev, "not disabling DAC for device");
50 } else if (ht_bridge) {
51 exclude->start = dev->subordinate->number;
52 exclude->end = pci_bus_max_busnr(dev->subordinate);
53 exclude->set = true;
54 dev_dbg(&dev->dev, "not disabling DAC for [bus %02x-%02x]",
55 exclude->start, exclude->end);
56 } else {
57 dev_dbg(&dev->dev, "disabling DAC for device");
58 dev->dev.bus_dma_limit = DMA_BIT_MASK(32);
59 }
60
61 return 0;
62 }
63
quirk_sb1250_pci_dac(struct pci_dev * dev)64 static void quirk_sb1250_pci_dac(struct pci_dev *dev)
65 {
66 struct sb1250_bus_dma_limit_exclude exclude = { .set = false };
67
68 pci_walk_bus(dev->bus, sb1250_bus_dma_limit, &exclude);
69 }
70 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_SIBYTE, PCI_DEVICE_ID_BCM1250_PCI,
71 quirk_sb1250_pci_dac);
72
73 /*
74 * The BCM1250, etc. PCI/HT bridge reports as a host bridge.
75 */
quirk_sb1250_ht(struct pci_dev * dev)76 static void quirk_sb1250_ht(struct pci_dev *dev)
77 {
78 dev->class = PCI_CLASS_BRIDGE_PCI_NORMAL;
79 }
80 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIBYTE, PCI_DEVICE_ID_BCM1250_HT,
81 quirk_sb1250_ht);
82
83 /*
84 * Set the SP1011 HT/PCI bridge's TRDY timeout to the finite max.
85 */
quirk_sp1011(struct pci_dev * dev)86 static void quirk_sp1011(struct pci_dev *dev)
87 {
88 pci_write_config_byte(dev, 0x64, 0xff);
89 }
90 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIPACKETS, PCI_DEVICE_ID_SP1011,
91 quirk_sp1011);
92