1/* ASB2305 PCI resource stuff 2 * 3 * Copyright (C) 2001 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * - Derived from arch/i386/pci-i386.c 6 * - Copyright 1997--2000 Martin Mares <mj@suse.cz> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public Licence 10 * as published by the Free Software Foundation; either version 11 * 2 of the Licence, or (at your option) any later version. 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#include "pci-asb2305.h" 20 21/* 22 * We need to avoid collisions with `mirrored' VGA ports 23 * and other strange ISA hardware, so we always want the 24 * addresses to be allocated in the 0x000-0x0ff region 25 * modulo 0x400. 26 * 27 * Why? Because some silly external IO cards only decode 28 * the low 10 bits of the IO address. The 0x00-0xff region 29 * is reserved for motherboard devices that decode all 16 30 * bits, so it's ok to allocate at, say, 0x2800-0x28ff, 31 * but we want to try to avoid allocating at 0x2900-0x2bff 32 * which might have be mirrored at 0x0100-0x03ff.. 33 */ 34resource_size_t pcibios_align_resource(void *data, const struct resource *res, 35 resource_size_t size, resource_size_t align) 36{ 37 resource_size_t start = res->start; 38 39#if 0 40 struct pci_dev *dev = data; 41 42 printk(KERN_DEBUG 43 "### PCIBIOS_ALIGN_RESOURCE(%s,,{%08lx-%08lx,%08lx},%lx)\n", 44 pci_name(dev), 45 res->start, 46 res->end, 47 res->flags, 48 size 49 ); 50#endif 51 52 if ((res->flags & IORESOURCE_IO) && (start & 0x300)) 53 start = (start + 0x3ff) & ~0x3ff; 54 55 return start; 56} 57 58 59/* 60 * Handle resources of PCI devices. If the world were perfect, we could 61 * just allocate all the resource regions and do nothing more. It isn't. 62 * On the other hand, we cannot just re-allocate all devices, as it would 63 * require us to know lots of host bridge internals. So we attempt to 64 * keep as much of the original configuration as possible, but tweak it 65 * when it's found to be wrong. 66 * 67 * Known BIOS problems we have to work around: 68 * - I/O or memory regions not configured 69 * - regions configured, but not enabled in the command register 70 * - bogus I/O addresses above 64K used 71 * - expansion ROMs left enabled (this may sound harmless, but given 72 * the fact the PCI specs explicitly allow address decoders to be 73 * shared between expansion ROMs and other resource regions, it's 74 * at least dangerous) 75 * 76 * Our solution: 77 * (1) Allocate resources for all buses behind PCI-to-PCI bridges. 78 * This gives us fixed barriers on where we can allocate. 79 * (2) Allocate resources for all enabled devices. If there is 80 * a collision, just mark the resource as unallocated. Also 81 * disable expansion ROMs during this step. 82 * (3) Try to allocate resources for disabled devices. If the 83 * resources were assigned correctly, everything goes well, 84 * if they weren't, they won't disturb allocation of other 85 * resources. 86 * (4) Assign new addresses to resources which were either 87 * not configured at all or misconfigured. If explicitly 88 * requested by the user, configure expansion ROM address 89 * as well. 90 */ 91static void __init pcibios_allocate_bus_resources(struct list_head *bus_list) 92{ 93 struct pci_bus *bus; 94 struct pci_dev *dev; 95 int idx; 96 struct resource *r; 97 98 /* Depth-First Search on bus tree */ 99 list_for_each_entry(bus, bus_list, node) { 100 dev = bus->self; 101 if (dev) { 102 for (idx = PCI_BRIDGE_RESOURCES; 103 idx < PCI_NUM_RESOURCES; 104 idx++) { 105 r = &dev->resource[idx]; 106 if (!r->flags) 107 continue; 108 if (!r->start || 109 pci_claim_resource(dev, idx) < 0) { 110 printk(KERN_ERR "PCI:" 111 " Cannot allocate resource" 112 " region %d of bridge %s\n", 113 idx, pci_name(dev)); 114 /* Something is wrong with the region. 115 * Invalidate the resource to prevent 116 * child resource allocations in this 117 * range. */ 118 r->start = r->end = 0; 119 r->flags = 0; 120 } 121 } 122 } 123 pcibios_allocate_bus_resources(&bus->children); 124 } 125} 126 127static void __init pcibios_allocate_resources(int pass) 128{ 129 struct pci_dev *dev = NULL; 130 int idx, disabled; 131 u16 command; 132 struct resource *r; 133 134 for_each_pci_dev(dev) { 135 pci_read_config_word(dev, PCI_COMMAND, &command); 136 for (idx = 0; idx < 6; idx++) { 137 r = &dev->resource[idx]; 138 if (r->parent) /* Already allocated */ 139 continue; 140 if (!r->start) /* Address not assigned */ 141 continue; 142 if (r->flags & IORESOURCE_IO) 143 disabled = !(command & PCI_COMMAND_IO); 144 else 145 disabled = !(command & PCI_COMMAND_MEMORY); 146 if (pass == disabled) { 147 DBG("PCI[%s]: Resource %08lx-%08lx" 148 " (f=%lx, d=%d, p=%d)\n", 149 pci_name(dev), r->start, r->end, r->flags, 150 disabled, pass); 151 if (pci_claim_resource(dev, idx) < 0) { 152 printk(KERN_ERR "PCI:" 153 " Cannot allocate resource" 154 " region %d of device %s\n", 155 idx, pci_name(dev)); 156 /* We'll assign a new address later */ 157 r->end -= r->start; 158 r->start = 0; 159 } 160 } 161 } 162 if (!pass) { 163 r = &dev->resource[PCI_ROM_RESOURCE]; 164 if (r->flags & IORESOURCE_ROM_ENABLE) { 165 /* Turn the ROM off, leave the resource region, 166 * but keep it unregistered. */ 167 u32 reg; 168 DBG("PCI: Switching off ROM of %s\n", 169 pci_name(dev)); 170 r->flags &= ~IORESOURCE_ROM_ENABLE; 171 pci_read_config_dword( 172 dev, dev->rom_base_reg, ®); 173 pci_write_config_dword( 174 dev, dev->rom_base_reg, 175 reg & ~PCI_ROM_ADDRESS_ENABLE); 176 } 177 } 178 } 179} 180 181static int __init pcibios_assign_resources(void) 182{ 183 struct pci_dev *dev = NULL; 184 struct resource *r; 185 186 if (!(pci_probe & PCI_ASSIGN_ROMS)) { 187 /* Try to use BIOS settings for ROMs, otherwise let 188 pci_assign_unassigned_resources() allocate the new 189 addresses. */ 190 for_each_pci_dev(dev) { 191 r = &dev->resource[PCI_ROM_RESOURCE]; 192 if (!r->flags || !r->start) 193 continue; 194 if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) { 195 r->end -= r->start; 196 r->start = 0; 197 } 198 } 199 } 200 201 pci_assign_unassigned_resources(); 202 203 return 0; 204} 205 206fs_initcall(pcibios_assign_resources); 207 208void __init pcibios_resource_survey(void) 209{ 210 DBG("PCI: Allocating resources\n"); 211 pcibios_allocate_bus_resources(&pci_root_buses); 212 pcibios_allocate_resources(0); 213 pcibios_allocate_resources(1); 214} 215 216int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, 217 enum pci_mmap_state mmap_state, int write_combine) 218{ 219 unsigned long prot; 220 221 /* Leave vm_pgoff as-is, the PCI space address is the physical 222 * address on this platform. 223 */ 224 vma->vm_flags |= VM_LOCKED | VM_IO; 225 226 prot = pgprot_val(vma->vm_page_prot); 227 prot &= ~_PAGE_CACHE; 228 vma->vm_page_prot = __pgprot(prot); 229 230 /* Write-combine setting is ignored */ 231 if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, 232 vma->vm_end - vma->vm_start, 233 vma->vm_page_prot)) 234 return -EAGAIN; 235 236 return 0; 237} 238