1 /* 2 * Routines for tracking a legacy ISA bridge 3 * 4 * Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. 5 * 6 * Some bits and pieces moved over from pci_64.c 7 * 8 * Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #define DEBUG 17 18 #include <linux/kernel.h> 19 #include <linux/pci.h> 20 #include <linux/string.h> 21 #include <linux/export.h> 22 #include <linux/init.h> 23 #include <linux/mm.h> 24 #include <linux/notifier.h> 25 26 #include <asm/processor.h> 27 #include <asm/io.h> 28 #include <asm/prom.h> 29 #include <asm/pci-bridge.h> 30 #include <asm/machdep.h> 31 #include <asm/ppc-pci.h> 32 #include <asm/firmware.h> 33 34 unsigned long isa_io_base; /* NULL if no ISA bus */ 35 EXPORT_SYMBOL(isa_io_base); 36 37 /* Cached ISA bridge dev. */ 38 static struct device_node *isa_bridge_devnode; 39 struct pci_dev *isa_bridge_pcidev; 40 EXPORT_SYMBOL_GPL(isa_bridge_pcidev); 41 42 #define ISA_SPACE_MASK 0x1 43 #define ISA_SPACE_IO 0x1 44 45 static void __devinit pci_process_ISA_OF_ranges(struct device_node *isa_node, 46 unsigned long phb_io_base_phys) 47 { 48 /* We should get some saner parsing here and remove these structs */ 49 struct pci_address { 50 u32 a_hi; 51 u32 a_mid; 52 u32 a_lo; 53 }; 54 55 struct isa_address { 56 u32 a_hi; 57 u32 a_lo; 58 }; 59 60 struct isa_range { 61 struct isa_address isa_addr; 62 struct pci_address pci_addr; 63 unsigned int size; 64 }; 65 66 const struct isa_range *range; 67 unsigned long pci_addr; 68 unsigned int isa_addr; 69 unsigned int size; 70 int rlen = 0; 71 72 range = of_get_property(isa_node, "ranges", &rlen); 73 if (range == NULL || (rlen < sizeof(struct isa_range))) 74 goto inval_range; 75 76 /* From "ISA Binding to 1275" 77 * The ranges property is laid out as an array of elements, 78 * each of which comprises: 79 * cells 0 - 1: an ISA address 80 * cells 2 - 4: a PCI address 81 * (size depending on dev->n_addr_cells) 82 * cell 5: the size of the range 83 */ 84 if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO) { 85 range++; 86 rlen -= sizeof(struct isa_range); 87 if (rlen < sizeof(struct isa_range)) 88 goto inval_range; 89 } 90 if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO) 91 goto inval_range; 92 93 isa_addr = range->isa_addr.a_lo; 94 pci_addr = (unsigned long) range->pci_addr.a_mid << 32 | 95 range->pci_addr.a_lo; 96 97 /* Assume these are both zero. Note: We could fix that and 98 * do a proper parsing instead ... oh well, that will do for 99 * now as nobody uses fancy mappings for ISA bridges 100 */ 101 if ((pci_addr != 0) || (isa_addr != 0)) { 102 printk(KERN_ERR "unexpected isa to pci mapping: %s\n", 103 __func__); 104 return; 105 } 106 107 /* Align size and make sure it's cropped to 64K */ 108 size = PAGE_ALIGN(range->size); 109 if (size > 0x10000) 110 size = 0x10000; 111 112 __ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE, 113 size, _PAGE_NO_CACHE|_PAGE_GUARDED); 114 return; 115 116 inval_range: 117 printk(KERN_ERR "no ISA IO ranges or unexpected isa range, " 118 "mapping 64k\n"); 119 __ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE, 120 0x10000, _PAGE_NO_CACHE|_PAGE_GUARDED); 121 } 122 123 124 /** 125 * isa_bridge_find_early - Find and map the ISA IO space early before 126 * main PCI discovery. This is optionally called by 127 * the arch code when adding PCI PHBs to get early 128 * access to ISA IO ports 129 */ 130 void __init isa_bridge_find_early(struct pci_controller *hose) 131 { 132 struct device_node *np, *parent = NULL, *tmp; 133 134 /* If we already have an ISA bridge, bail off */ 135 if (isa_bridge_devnode != NULL) 136 return; 137 138 /* For each "isa" node in the system. Note : we do a search by 139 * type and not by name. It might be better to do by name but that's 140 * what the code used to do and I don't want to break too much at 141 * once. We can look into changing that separately 142 */ 143 for_each_node_by_type(np, "isa") { 144 /* Look for our hose being a parent */ 145 for (parent = of_get_parent(np); parent;) { 146 if (parent == hose->dn) { 147 of_node_put(parent); 148 break; 149 } 150 tmp = parent; 151 parent = of_get_parent(parent); 152 of_node_put(tmp); 153 } 154 if (parent != NULL) 155 break; 156 } 157 if (np == NULL) 158 return; 159 isa_bridge_devnode = np; 160 161 /* Now parse the "ranges" property and setup the ISA mapping */ 162 pci_process_ISA_OF_ranges(np, hose->io_base_phys); 163 164 /* Set the global ISA io base to indicate we have an ISA bridge */ 165 isa_io_base = ISA_IO_BASE; 166 167 pr_debug("ISA bridge (early) is %s\n", np->full_name); 168 } 169 170 /** 171 * isa_bridge_find_late - Find and map the ISA IO space upon discovery of 172 * a new ISA bridge 173 */ 174 static void __devinit isa_bridge_find_late(struct pci_dev *pdev, 175 struct device_node *devnode) 176 { 177 struct pci_controller *hose = pci_bus_to_host(pdev->bus); 178 179 /* Store ISA device node and PCI device */ 180 isa_bridge_devnode = of_node_get(devnode); 181 isa_bridge_pcidev = pdev; 182 183 /* Now parse the "ranges" property and setup the ISA mapping */ 184 pci_process_ISA_OF_ranges(devnode, hose->io_base_phys); 185 186 /* Set the global ISA io base to indicate we have an ISA bridge */ 187 isa_io_base = ISA_IO_BASE; 188 189 pr_debug("ISA bridge (late) is %s on %s\n", 190 devnode->full_name, pci_name(pdev)); 191 } 192 193 /** 194 * isa_bridge_remove - Remove/unmap an ISA bridge 195 */ 196 static void isa_bridge_remove(void) 197 { 198 pr_debug("ISA bridge removed !\n"); 199 200 /* Clear the global ISA io base to indicate that we have no more 201 * ISA bridge. Note that drivers don't quite handle that, though 202 * we should probably do something about it. But do we ever really 203 * have ISA bridges being removed on machines using legacy devices ? 204 */ 205 isa_io_base = ISA_IO_BASE; 206 207 /* Clear references to the bridge */ 208 of_node_put(isa_bridge_devnode); 209 isa_bridge_devnode = NULL; 210 isa_bridge_pcidev = NULL; 211 212 /* Unmap the ISA area */ 213 __iounmap_at((void *)ISA_IO_BASE, 0x10000); 214 } 215 216 /** 217 * isa_bridge_notify - Get notified of PCI devices addition/removal 218 */ 219 static int __devinit isa_bridge_notify(struct notifier_block *nb, 220 unsigned long action, void *data) 221 { 222 struct device *dev = data; 223 struct pci_dev *pdev = to_pci_dev(dev); 224 struct device_node *devnode = pci_device_to_OF_node(pdev); 225 226 switch(action) { 227 case BUS_NOTIFY_ADD_DEVICE: 228 /* Check if we have an early ISA device, without PCI dev */ 229 if (isa_bridge_devnode && isa_bridge_devnode == devnode && 230 !isa_bridge_pcidev) { 231 pr_debug("ISA bridge PCI attached: %s\n", 232 pci_name(pdev)); 233 isa_bridge_pcidev = pdev; 234 } 235 236 /* Check if we have no ISA device, and this happens to be one, 237 * register it as such if it has an OF device 238 */ 239 if (!isa_bridge_devnode && devnode && devnode->type && 240 !strcmp(devnode->type, "isa")) 241 isa_bridge_find_late(pdev, devnode); 242 243 return 0; 244 case BUS_NOTIFY_DEL_DEVICE: 245 /* Check if this our existing ISA device */ 246 if (pdev == isa_bridge_pcidev || 247 (devnode && devnode == isa_bridge_devnode)) 248 isa_bridge_remove(); 249 return 0; 250 } 251 return 0; 252 } 253 254 static struct notifier_block isa_bridge_notifier = { 255 .notifier_call = isa_bridge_notify 256 }; 257 258 /** 259 * isa_bridge_init - register to be notified of ISA bridge addition/removal 260 * 261 */ 262 static int __init isa_bridge_init(void) 263 { 264 if (firmware_has_feature(FW_FEATURE_ISERIES)) 265 return 0; 266 bus_register_notifier(&pci_bus_type, &isa_bridge_notifier); 267 return 0; 268 } 269 arch_initcall(isa_bridge_init); 270