Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
| 35 | void |
| 36 | pcibios_align_resource(void *data, struct resource *res, |
Greg Kroah-Hartman | e31dd6e | 2006-06-12 17:06:02 -0700 | [diff] [blame] | 37 | resource_size_t size, resource_size_t align) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | { |
| 39 | if (res->flags & IORESOURCE_IO) { |
Greg Kroah-Hartman | e31dd6e | 2006-06-12 17:06:02 -0700 | [diff] [blame] | 40 | resource_size_t start = res->start; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
| 42 | if (start & 0x300) { |
| 43 | start = (start + 0x3ff) & ~0x3ff; |
| 44 | res->start = start; |
| 45 | } |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | |
| 50 | /* |
| 51 | * Handle resources of PCI devices. If the world were perfect, we could |
| 52 | * just allocate all the resource regions and do nothing more. It isn't. |
| 53 | * On the other hand, we cannot just re-allocate all devices, as it would |
| 54 | * require us to know lots of host bridge internals. So we attempt to |
| 55 | * keep as much of the original configuration as possible, but tweak it |
| 56 | * when it's found to be wrong. |
| 57 | * |
| 58 | * Known BIOS problems we have to work around: |
| 59 | * - I/O or memory regions not configured |
| 60 | * - regions configured, but not enabled in the command register |
| 61 | * - bogus I/O addresses above 64K used |
| 62 | * - expansion ROMs left enabled (this may sound harmless, but given |
| 63 | * the fact the PCI specs explicitly allow address decoders to be |
| 64 | * shared between expansion ROMs and other resource regions, it's |
| 65 | * at least dangerous) |
| 66 | * |
| 67 | * Our solution: |
| 68 | * (1) Allocate resources for all buses behind PCI-to-PCI bridges. |
| 69 | * This gives us fixed barriers on where we can allocate. |
| 70 | * (2) Allocate resources for all enabled devices. If there is |
| 71 | * a collision, just mark the resource as unallocated. Also |
| 72 | * disable expansion ROMs during this step. |
| 73 | * (3) Try to allocate resources for disabled devices. If the |
| 74 | * resources were assigned correctly, everything goes well, |
| 75 | * if they weren't, they won't disturb allocation of other |
| 76 | * resources. |
| 77 | * (4) Assign new addresses to resources which were either |
| 78 | * not configured at all or misconfigured. If explicitly |
| 79 | * requested by the user, configure expansion ROM address |
| 80 | * as well. |
| 81 | */ |
| 82 | |
| 83 | static void __init pcibios_allocate_bus_resources(struct list_head *bus_list) |
| 84 | { |
| 85 | struct list_head *ln; |
| 86 | struct pci_bus *bus; |
| 87 | struct pci_dev *dev; |
| 88 | int idx; |
Matthew Wilcox | eae91c0 | 2009-06-19 09:36:13 -0400 | [diff] [blame] | 89 | struct resource *r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
| 91 | /* Depth-First Search on bus tree */ |
| 92 | for (ln=bus_list->next; ln != bus_list; ln=ln->next) { |
| 93 | bus = pci_bus_b(ln); |
| 94 | if ((dev = bus->self)) { |
| 95 | for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) { |
| 96 | r = &dev->resource[idx]; |
| 97 | if (!r->start) |
| 98 | continue; |
Matthew Wilcox | eae91c0 | 2009-06-19 09:36:13 -0400 | [diff] [blame] | 99 | if (pci_claim_resource(dev, idx) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | printk(KERN_ERR "PCI: Cannot allocate resource region %d of bridge %s\n", idx, pci_name(dev)); |
| 101 | } |
| 102 | } |
| 103 | pcibios_allocate_bus_resources(&bus->children); |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | static void __init pcibios_allocate_resources(int pass) |
| 108 | { |
| 109 | struct pci_dev *dev = NULL; |
| 110 | int idx, disabled; |
| 111 | u16 command; |
Matthew Wilcox | eae91c0 | 2009-06-19 09:36:13 -0400 | [diff] [blame] | 112 | struct resource *r; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | |
Jiri Slaby | 619daa2 | 2005-11-06 23:39:33 -0800 | [diff] [blame] | 114 | for_each_pci_dev(dev) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | pci_read_config_word(dev, PCI_COMMAND, &command); |
| 116 | for(idx = 0; idx < 6; idx++) { |
| 117 | r = &dev->resource[idx]; |
| 118 | if (r->parent) /* Already allocated */ |
| 119 | continue; |
| 120 | if (!r->start) /* Address not assigned at all */ |
| 121 | continue; |
| 122 | if (r->flags & IORESOURCE_IO) |
| 123 | disabled = !(command & PCI_COMMAND_IO); |
| 124 | else |
| 125 | disabled = !(command & PCI_COMMAND_MEMORY); |
| 126 | if (pass == disabled) { |
| 127 | DBG("PCI: Resource %08lx-%08lx (f=%lx, d=%d, p=%d)\n", |
| 128 | r->start, r->end, r->flags, disabled, pass); |
Matthew Wilcox | eae91c0 | 2009-06-19 09:36:13 -0400 | [diff] [blame] | 129 | if (pci_claim_resource(dev, idx) < 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | printk(KERN_ERR "PCI: Cannot allocate resource region %d of device %s\n", idx, pci_name(dev)); |
| 131 | /* We'll assign a new address later */ |
| 132 | r->end -= r->start; |
| 133 | r->start = 0; |
| 134 | } |
| 135 | } |
| 136 | } |
| 137 | if (!pass) { |
| 138 | r = &dev->resource[PCI_ROM_RESOURCE]; |
| 139 | if (r->flags & IORESOURCE_ROM_ENABLE) { |
| 140 | /* Turn the ROM off, leave the resource region, but keep it unregistered. */ |
| 141 | u32 reg; |
| 142 | DBG("PCI: Switching off ROM of %s\n", pci_name(dev)); |
| 143 | r->flags &= ~IORESOURCE_ROM_ENABLE; |
| 144 | pci_read_config_dword(dev, dev->rom_base_reg, ®); |
| 145 | pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE); |
| 146 | } |
| 147 | } |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | static void __init pcibios_assign_resources(void) |
| 152 | { |
| 153 | struct pci_dev *dev = NULL; |
| 154 | int idx; |
| 155 | struct resource *r; |
| 156 | |
Jiri Slaby | 619daa2 | 2005-11-06 23:39:33 -0800 | [diff] [blame] | 157 | for_each_pci_dev(dev) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | int class = dev->class >> 8; |
| 159 | |
| 160 | /* Don't touch classless devices and host bridges */ |
| 161 | if (!class || class == PCI_CLASS_BRIDGE_HOST) |
| 162 | continue; |
| 163 | |
| 164 | for(idx=0; idx<6; idx++) { |
| 165 | r = &dev->resource[idx]; |
| 166 | |
| 167 | /* |
| 168 | * Don't touch IDE controllers and I/O ports of video cards! |
| 169 | */ |
| 170 | if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) || |
| 171 | (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO))) |
| 172 | continue; |
| 173 | |
| 174 | /* |
| 175 | * We shall assign a new address to this resource, either because |
| 176 | * the BIOS forgot to do so or because we have decided the old |
| 177 | * address was unusable for some reason. |
| 178 | */ |
| 179 | if (!r->start && r->end) |
| 180 | pci_assign_resource(dev, idx); |
| 181 | } |
| 182 | |
| 183 | if (pci_probe & PCI_ASSIGN_ROMS) { |
| 184 | r = &dev->resource[PCI_ROM_RESOURCE]; |
| 185 | r->end -= r->start; |
| 186 | r->start = 0; |
| 187 | if (r->end) |
| 188 | pci_assign_resource(dev, PCI_ROM_RESOURCE); |
| 189 | } |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | void __init pcibios_resource_survey(void) |
| 194 | { |
| 195 | DBG("PCI: Allocating resources\n"); |
| 196 | pcibios_allocate_bus_resources(&pci_root_buses); |
| 197 | pcibios_allocate_resources(0); |
| 198 | pcibios_allocate_resources(1); |
| 199 | pcibios_assign_resources(); |
| 200 | } |
| 201 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | /* |
| 203 | * If we set up a device for bus mastering, we need to check the latency |
| 204 | * timer as certain crappy BIOSes forget to set it properly. |
| 205 | */ |
| 206 | unsigned int pcibios_max_latency = 255; |
| 207 | |
| 208 | void pcibios_set_master(struct pci_dev *dev) |
| 209 | { |
| 210 | u8 lat; |
| 211 | pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); |
| 212 | if (lat < 16) |
| 213 | lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; |
| 214 | else if (lat > pcibios_max_latency) |
| 215 | lat = pcibios_max_latency; |
| 216 | else |
| 217 | return; |
| 218 | printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n", pci_name(dev), lat); |
| 219 | pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); |
| 220 | } |