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 */ 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 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 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 */ 76 static void quirk_sb1250_ht(struct pci_dev *dev) 77 { 78 dev->class = PCI_CLASS_BRIDGE_PCI << 8; 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 */ 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