1/* pci-frv.c: low-level PCI access routines 2 * 3 * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * - Derived from the i386 equivalent stuff 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13#include <linux/types.h> 14#include <linux/kernel.h> 15#include <linux/pci.h> 16#include <linux/init.h> 17#include <linux/ioport.h> 18#include <linux/errno.h> 19 20#include "pci-frv.h" 21 22/* 23 * We need to avoid collisions with `mirrored' VGA ports 24 * and other strange ISA hardware, so we always want the 25 * addresses to be allocated in the 0x000-0x0ff region 26 * modulo 0x400. 27 * 28 * Why? Because some silly external IO cards only decode 29 * the low 10 bits of the IO address. The 0x00-0xff region 30 * is reserved for motherboard devices that decode all 16 31 * bits, so it's ok to allocate at, say, 0x2800-0x28ff, 32 * but we want to try to avoid allocating at 0x2900-0x2bff 33 * which might have be mirrored at 0x0100-0x03ff.. 34 */ 35resource_size_t 36pcibios_align_resource(void *data, const struct resource *res, 37 resource_size_t size, resource_size_t align) 38{ 39 resource_size_t start = res->start; 40 41 if ((res->flags & IORESOURCE_IO) && (start & 0x300)) 42 start = (start + 0x3ff) & ~0x3ff; 43 44 return start; 45} 46 47 48 49static void __init pcibios_allocate_bus_resources(struct list_head *bus_list) 50{ 51 struct list_head *ln; 52 struct pci_bus *bus; 53 struct pci_dev *dev; 54 int idx; 55 struct resource *r; 56 57 /* Depth-First Search on bus tree */ 58 for (ln=bus_list->next; ln != bus_list; ln=ln->next) { 59 bus = pci_bus_b(ln); 60 if ((dev = bus->self)) { 61 for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) { 62 r = &dev->resource[idx]; 63 if (!r->start) 64 continue; 65 pci_claim_resource(dev, idx); 66 } 67 } 68 pcibios_allocate_bus_resources(&bus->children); 69 } 70} 71 72static void __init pcibios_allocate_resources(int pass) 73{ 74 struct pci_dev *dev = NULL; 75 int idx, disabled; 76 u16 command; 77 struct resource *r; 78 79 for_each_pci_dev(dev) { 80 pci_read_config_word(dev, PCI_COMMAND, &command); 81 for(idx = 0; idx < 6; idx++) { 82 r = &dev->resource[idx]; 83 if (r->parent) /* Already allocated */ 84 continue; 85 if (!r->start) /* Address not assigned at all */ 86 continue; 87 if (r->flags & IORESOURCE_IO) 88 disabled = !(command & PCI_COMMAND_IO); 89 else 90 disabled = !(command & PCI_COMMAND_MEMORY); 91 if (pass == disabled) { 92 DBG("PCI: Resource %08lx-%08lx (f=%lx, d=%d, p=%d)\n", 93 r->start, r->end, r->flags, disabled, pass); 94 if (pci_claim_resource(dev, idx) < 0) { 95 /* We'll assign a new address later */ 96 r->end -= r->start; 97 r->start = 0; 98 } 99 } 100 } 101 if (!pass) { 102 r = &dev->resource[PCI_ROM_RESOURCE]; 103 if (r->flags & IORESOURCE_ROM_ENABLE) { 104 /* Turn the ROM off, leave the resource region, but keep it unregistered. */ 105 u32 reg; 106 DBG("PCI: Switching off ROM of %s\n", pci_name(dev)); 107 r->flags &= ~IORESOURCE_ROM_ENABLE; 108 pci_read_config_dword(dev, dev->rom_base_reg, ®); 109 pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE); 110 } 111 } 112 } 113} 114 115static void __init pcibios_assign_resources(void) 116{ 117 struct pci_dev *dev = NULL; 118 int idx; 119 struct resource *r; 120 121 for_each_pci_dev(dev) { 122 int class = dev->class >> 8; 123 124 /* Don't touch classless devices and host bridges */ 125 if (!class || class == PCI_CLASS_BRIDGE_HOST) 126 continue; 127 128 for(idx=0; idx<6; idx++) { 129 r = &dev->resource[idx]; 130 131 /* 132 * Don't touch IDE controllers and I/O ports of video cards! 133 */ 134 if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) || 135 (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO))) 136 continue; 137 138 /* 139 * We shall assign a new address to this resource, either because 140 * the BIOS forgot to do so or because we have decided the old 141 * address was unusable for some reason. 142 */ 143 if (!r->start && r->end) 144 pci_assign_resource(dev, idx); 145 } 146 147 if (pci_probe & PCI_ASSIGN_ROMS) { 148 r = &dev->resource[PCI_ROM_RESOURCE]; 149 r->end -= r->start; 150 r->start = 0; 151 if (r->end) 152 pci_assign_resource(dev, PCI_ROM_RESOURCE); 153 } 154 } 155} 156 157void __init pcibios_resource_survey(void) 158{ 159 DBG("PCI: Allocating resources\n"); 160 pcibios_allocate_bus_resources(&pci_root_buses); 161 pcibios_allocate_resources(0); 162 pcibios_allocate_resources(1); 163 pcibios_assign_resources(); 164} 165 166/* 167 * If we set up a device for bus mastering, we need to check the latency 168 * timer as certain crappy BIOSes forget to set it properly. 169 */ 170unsigned int pcibios_max_latency = 255; 171 172void pcibios_set_master(struct pci_dev *dev) 173{ 174 u8 lat; 175 pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); 176 if (lat < 16) 177 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; 178 else if (lat > pcibios_max_latency) 179 lat = pcibios_max_latency; 180 else 181 return; 182 printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n", pci_name(dev), lat); 183 pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); 184} 185