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/isa-bridge.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 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, pgprot_val(pgprot_noncached(__pgprot(0)))); 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, pgprot_val(pgprot_noncached(__pgprot(0)))); 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 %pOF\n", np); 168 } 169 170 /** 171 * isa_bridge_find_early - Find and map the ISA IO space early before 172 * main PCI discovery. This is optionally called by 173 * the arch code when adding PCI PHBs to get early 174 * access to ISA IO ports 175 */ 176 void __init isa_bridge_init_non_pci(struct device_node *np) 177 { 178 const __be32 *ranges, *pbasep = NULL; 179 int rlen, i, rs; 180 u32 na, ns, pna; 181 u64 cbase, pbase, size = 0; 182 183 /* If we already have an ISA bridge, bail off */ 184 if (isa_bridge_devnode != NULL) 185 return; 186 187 pna = of_n_addr_cells(np); 188 if (of_property_read_u32(np, "#address-cells", &na) || 189 of_property_read_u32(np, "#size-cells", &ns)) { 190 pr_warn("ISA: Non-PCI bridge %pOF is missing address format\n", 191 np); 192 return; 193 } 194 195 /* Check it's a supported address format */ 196 if (na != 2 || ns != 1) { 197 pr_warn("ISA: Non-PCI bridge %pOF has unsupported address format\n", 198 np); 199 return; 200 } 201 rs = na + ns + pna; 202 203 /* Grab the ranges property */ 204 ranges = of_get_property(np, "ranges", &rlen); 205 if (ranges == NULL || rlen < rs) { 206 pr_warn("ISA: Non-PCI bridge %pOF has absent or invalid ranges\n", 207 np); 208 return; 209 } 210 211 /* Parse it. We are only looking for IO space */ 212 for (i = 0; (i + rs - 1) < rlen; i += rs) { 213 if (be32_to_cpup(ranges + i) != 1) 214 continue; 215 cbase = be32_to_cpup(ranges + i + 1); 216 size = of_read_number(ranges + i + na + pna, ns); 217 pbasep = ranges + i + na; 218 break; 219 } 220 221 /* Got something ? */ 222 if (!size || !pbasep) { 223 pr_warn("ISA: Non-PCI bridge %pOF has no usable IO range\n", 224 np); 225 return; 226 } 227 228 /* Align size and make sure it's cropped to 64K */ 229 size = PAGE_ALIGN(size); 230 if (size > 0x10000) 231 size = 0x10000; 232 233 /* Map pbase */ 234 pbase = of_translate_address(np, pbasep); 235 if (pbase == OF_BAD_ADDR) { 236 pr_warn("ISA: Non-PCI bridge %pOF failed to translate IO base\n", 237 np); 238 return; 239 } 240 241 /* We need page alignment */ 242 if ((cbase & ~PAGE_MASK) || (pbase & ~PAGE_MASK)) { 243 pr_warn("ISA: Non-PCI bridge %pOF has non aligned IO range\n", 244 np); 245 return; 246 } 247 248 /* Got it */ 249 isa_bridge_devnode = np; 250 251 /* Set the global ISA io base to indicate we have an ISA bridge 252 * and map it 253 */ 254 isa_io_base = ISA_IO_BASE; 255 __ioremap_at(pbase, (void *)ISA_IO_BASE, 256 size, pgprot_val(pgprot_noncached(__pgprot(0)))); 257 258 pr_debug("ISA: Non-PCI bridge is %pOF\n", np); 259 } 260 261 /** 262 * isa_bridge_find_late - Find and map the ISA IO space upon discovery of 263 * a new ISA bridge 264 */ 265 static void isa_bridge_find_late(struct pci_dev *pdev, 266 struct device_node *devnode) 267 { 268 struct pci_controller *hose = pci_bus_to_host(pdev->bus); 269 270 /* Store ISA device node and PCI device */ 271 isa_bridge_devnode = of_node_get(devnode); 272 isa_bridge_pcidev = pdev; 273 274 /* Now parse the "ranges" property and setup the ISA mapping */ 275 pci_process_ISA_OF_ranges(devnode, hose->io_base_phys); 276 277 /* Set the global ISA io base to indicate we have an ISA bridge */ 278 isa_io_base = ISA_IO_BASE; 279 280 pr_debug("ISA bridge (late) is %pOF on %s\n", 281 devnode, pci_name(pdev)); 282 } 283 284 /** 285 * isa_bridge_remove - Remove/unmap an ISA bridge 286 */ 287 static void isa_bridge_remove(void) 288 { 289 pr_debug("ISA bridge removed !\n"); 290 291 /* Clear the global ISA io base to indicate that we have no more 292 * ISA bridge. Note that drivers don't quite handle that, though 293 * we should probably do something about it. But do we ever really 294 * have ISA bridges being removed on machines using legacy devices ? 295 */ 296 isa_io_base = ISA_IO_BASE; 297 298 /* Clear references to the bridge */ 299 of_node_put(isa_bridge_devnode); 300 isa_bridge_devnode = NULL; 301 isa_bridge_pcidev = NULL; 302 303 /* Unmap the ISA area */ 304 __iounmap_at((void *)ISA_IO_BASE, 0x10000); 305 } 306 307 /** 308 * isa_bridge_notify - Get notified of PCI devices addition/removal 309 */ 310 static int isa_bridge_notify(struct notifier_block *nb, unsigned long action, 311 void *data) 312 { 313 struct device *dev = data; 314 struct pci_dev *pdev = to_pci_dev(dev); 315 struct device_node *devnode = pci_device_to_OF_node(pdev); 316 317 switch(action) { 318 case BUS_NOTIFY_ADD_DEVICE: 319 /* Check if we have an early ISA device, without PCI dev */ 320 if (isa_bridge_devnode && isa_bridge_devnode == devnode && 321 !isa_bridge_pcidev) { 322 pr_debug("ISA bridge PCI attached: %s\n", 323 pci_name(pdev)); 324 isa_bridge_pcidev = pdev; 325 } 326 327 /* Check if we have no ISA device, and this happens to be one, 328 * register it as such if it has an OF device 329 */ 330 if (!isa_bridge_devnode && devnode && devnode->type && 331 !strcmp(devnode->type, "isa")) 332 isa_bridge_find_late(pdev, devnode); 333 334 return 0; 335 case BUS_NOTIFY_DEL_DEVICE: 336 /* Check if this our existing ISA device */ 337 if (pdev == isa_bridge_pcidev || 338 (devnode && devnode == isa_bridge_devnode)) 339 isa_bridge_remove(); 340 return 0; 341 } 342 return 0; 343 } 344 345 static struct notifier_block isa_bridge_notifier = { 346 .notifier_call = isa_bridge_notify 347 }; 348 349 /** 350 * isa_bridge_init - register to be notified of ISA bridge addition/removal 351 * 352 */ 353 static int __init isa_bridge_init(void) 354 { 355 bus_register_notifier(&pci_bus_type, &isa_bridge_notifier); 356 return 0; 357 } 358 arch_initcall(isa_bridge_init); 359