arch/powerpc/kernel/rtas_pci.c

   1 /*
   2  * Copyright (C) 2001 Dave Engebretsen, IBM Corporation
   3  * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
   4  *
   5  * RTAS specific routines for PCI.
   6  *
   7  * Based on code from pci.c, chrp_pci.c and pSeries_pci.c
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/threads.h>
  26 #include <linux/pci.h>
  27 #include <linux/string.h>
  28 #include <linux/init.h>
  29 #include <linux/bootmem.h>
  30
  31 #include <asm/io.h>
  32 #include <asm/pgtable.h>
  33 #include <asm/irq.h>
  34 #include <asm/prom.h>
  35 #include <asm/machdep.h>
  36 #include <asm/pci-bridge.h>
  37 #include <asm/iommu.h>
  38 #include <asm/rtas.h>
  39 #include <asm/mpic.h>
  40 #include <asm/ppc-pci.h>
  41
  42 /* RTAS tokens */
  43 static int read_pci_config;
  44 static int write_pci_config;
  45 static int ibm_read_pci_config;
  46 static int ibm_write_pci_config;
  47
  48 static inline int config_access_valid(struct pci_dn *dn, int where)
  49 {
  50         if (where < 256)
  51                 return 1;
  52         if (where < 4096 && dn->pci_ext_config_space)
  53                 return 1;
  54
  55         return 0;
  56 }
  57
  58 static int of_device_available(struct device_node * dn)
  59 {
  60         const char *status;
  61
  62         status = get_property(dn, "status", NULL);
  63
  64         if (!status)
  65                 return 1;
  66
  67         if (!strcmp(status, "okay"))
  68                 return 1;
  69
  70         return 0;
  71 }
  72
  73 int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
  74 {
  75         int returnval = -1;
  76         unsigned long buid, addr;
  77         int ret;
  78
  79         if (!pdn)
  80                 return PCIBIOS_DEVICE_NOT_FOUND;
  81         if (!config_access_valid(pdn, where))
  82                 return PCIBIOS_BAD_REGISTER_NUMBER;
  83
  84         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
  85         buid = pdn->phb->buid;
  86         if (buid) {
  87                 ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
  88                                 addr, BUID_HI(buid), BUID_LO(buid), size);
  89         } else {
  90                 ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
  91         }
  92         *val = returnval;
  93
  94         if (ret)
  95                 return PCIBIOS_DEVICE_NOT_FOUND;
  96
  97         if (returnval == EEH_IO_ERROR_VALUE(size) &&
  98             eeh_dn_check_failure (pdn->node, NULL))
  99                 return PCIBIOS_DEVICE_NOT_FOUND;
 100
 101         return PCIBIOS_SUCCESSFUL;
 102 }
 103
 104 static int rtas_pci_read_config(struct pci_bus *bus,
 105                                 unsigned int devfn,
 106                                 int where, int size, u32 *val)
 107 {
 108         struct device_node *busdn, *dn;
 109
 110         if (bus->self)
 111                 busdn = pci_device_to_OF_node(bus->self);
 112         else
 113                 busdn = bus->sysdata;   /* must be a phb */
 114
 115         /* Search only direct children of the bus */
 116         for (dn = busdn->child; dn; dn = dn->sibling) {
 117                 struct pci_dn *pdn = PCI_DN(dn);
 118                 if (pdn && pdn->devfn == devfn
 119                     && of_device_available(dn))
 120                         return rtas_read_config(pdn, where, size, val);
 121         }
 122
 123         return PCIBIOS_DEVICE_NOT_FOUND;
 124 }
 125
 126 int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 127 {
 128         unsigned long buid, addr;
 129         int ret;
 130
 131         if (!pdn)
 132                 return PCIBIOS_DEVICE_NOT_FOUND;
 133         if (!config_access_valid(pdn, where))
 134                 return PCIBIOS_BAD_REGISTER_NUMBER;
 135
 136         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
 137         buid = pdn->phb->buid;
 138         if (buid) {
 139                 ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
 140                         BUID_HI(buid), BUID_LO(buid), size, (ulong) val);
 141         } else {
 142                 ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
 143         }
 144
 145         if (ret)
 146                 return PCIBIOS_DEVICE_NOT_FOUND;
 147
 148         return PCIBIOS_SUCCESSFUL;
 149 }
 150
 151 static int rtas_pci_write_config(struct pci_bus *bus,
 152                                  unsigned int devfn,
 153                                  int where, int size, u32 val)
 154 {
 155         struct device_node *busdn, *dn;
 156
 157         if (bus->self)
 158                 busdn = pci_device_to_OF_node(bus->self);
 159         else
 160                 busdn = bus->sysdata;   /* must be a phb */
 161
 162         /* Search only direct children of the bus */
 163         for (dn = busdn->child; dn; dn = dn->sibling) {
 164                 struct pci_dn *pdn = PCI_DN(dn);
 165                 if (pdn && pdn->devfn == devfn
 166                     && of_device_available(dn))
 167                         return rtas_write_config(pdn, where, size, val);
 168         }
 169         return PCIBIOS_DEVICE_NOT_FOUND;
 170 }
 171
 172 struct pci_ops rtas_pci_ops = {
 173         rtas_pci_read_config,
 174         rtas_pci_write_config
 175 };
 176
 177 int is_python(struct device_node *dev)
 178 {
 179         const char *model = get_property(dev, "model", NULL);
 180
 181         if (model && strstr(model, "Python"))
 182                 return 1;
 183
 184         return 0;
 185 }
 186
 187 static void python_countermeasures(struct device_node *dev)
 188 {
 189         struct resource registers;
 190         void __iomem *chip_regs;
 191         volatile u32 val;
 192
 193         if (of_address_to_resource(dev, 0, &registers)) {
 194                 printk(KERN_ERR "Can't get address for Python workarounds !\n");
 195                 return;
 196         }
 197
 198         /* Python's register file is 1 MB in size. */
 199         chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000);
 200
 201         /*
 202          * Firmware doesn't always clear this bit which is critical
 203          * for good performance - Anton
 204          */
 205
 206 #define PRG_CL_RESET_VALID 0x00010000
 207
 208         val = in_be32(chip_regs + 0xf6030);
 209         if (val & PRG_CL_RESET_VALID) {
 210                 printk(KERN_INFO "Python workaround: ");
 211                 val &= ~PRG_CL_RESET_VALID;
 212                 out_be32(chip_regs + 0xf6030, val);
 213                 /*
 214                  * We must read it back for changes to
 215                  * take effect
 216                  */
 217                 val = in_be32(chip_regs + 0xf6030);
 218                 printk("reg0: %x\n", val);
 219         }
 220
 221         iounmap(chip_regs);
 222 }
 223
 224 void __init init_pci_config_tokens (void)
 225 {
 226         read_pci_config = rtas_token("read-pci-config");
 227         write_pci_config = rtas_token("write-pci-config");
 228         ibm_read_pci_config = rtas_token("ibm,read-pci-config");
 229         ibm_write_pci_config = rtas_token("ibm,write-pci-config");
 230 }
 231
 232 unsigned long __devinit get_phb_buid (struct device_node *phb)
 233 {
 234         int addr_cells;
 235         const unsigned int *buid_vals;
 236         unsigned int len;
 237         unsigned long buid;
 238
 239         if (ibm_read_pci_config == -1) return 0;
 240
 241         /* PHB's will always be children of the root node,
 242          * or so it is promised by the current firmware. */
 243         if (phb->parent == NULL)
 244                 return 0;
 245         if (phb->parent->parent)
 246                 return 0;
 247
 248         buid_vals = get_property(phb, "reg", &len);
 249         if (buid_vals == NULL)
 250                 return 0;
 251
 252         addr_cells = prom_n_addr_cells(phb);
 253         if (addr_cells == 1) {
 254                 buid = (unsigned long) buid_vals[0];
 255         } else {
 256                 buid = (((unsigned long)buid_vals[0]) << 32UL) |
 257                         (((unsigned long)buid_vals[1]) & 0xffffffff);
 258         }
 259         return buid;
 260 }
 261
 262 static int phb_set_bus_ranges(struct device_node *dev,
 263                               struct pci_controller *phb)
 264 {
 265         const int *bus_range;
 266         unsigned int len;
 267
 268         bus_range = get_property(dev, "bus-range", &len);
 269         if (bus_range == NULL || len < 2 * sizeof(int)) {
 270                 return 1;
 271         }
 272
 273         phb->first_busno =  bus_range[0];
 274         phb->last_busno  =  bus_range[1];
 275
 276         return 0;
 277 }
 278
 279 int __devinit setup_phb(struct device_node *dev, struct pci_controller *phb)
 280 {
 281         if (is_python(dev))
 282                 python_countermeasures(dev);
 283
 284         if (phb_set_bus_ranges(dev, phb))
 285                 return 1;
 286
 287         phb->ops = &rtas_pci_ops;
 288         phb->buid = get_phb_buid(dev);
 289
 290         return 0;
 291 }
 292
 293 unsigned long __init find_and_init_phbs(void)
 294 {
 295         struct device_node *node;
 296         struct pci_controller *phb;
 297         unsigned int index;
 298         struct device_node *root = of_find_node_by_path("/");
 299
 300         index = 0;
 301         for (node = of_get_next_child(root, NULL);
 302              node != NULL;
 303              node = of_get_next_child(root, node)) {
 304
 305                 if (node->type == NULL || (strcmp(node->type, "pci") != 0 &&
 306                                            strcmp(node->type, "pciex") != 0))
 307                         continue;
 308
 309                 phb = pcibios_alloc_controller(node);
 310                 if (!phb)
 311                         continue;
 312                 setup_phb(node, phb);
 313                 pci_process_bridge_OF_ranges(phb, node, 0);
 314                 pci_setup_phb_io(phb, index == 0);
 315                 index++;
 316         }
 317
 318         of_node_put(root);
 319         pci_devs_phb_init();
 320
 321         /*
 322          * pci_probe_only and pci_assign_all_buses can be set via properties
 323          * in chosen.
 324          */
 325         if (of_chosen) {
 326                 const int *prop;
 327
 328                 prop = get_property(of_chosen,
 329                                 "linux,pci-probe-only", NULL);
 330                 if (prop)
 331                         pci_probe_only = *prop;
 332
 333                 prop = get_property(of_chosen,
 334                                 "linux,pci-assign-all-buses", NULL);
 335                 if (prop)
 336                         pci_assign_all_buses = *prop;
 337         }
 338
 339         return 0;
 340 }
 341
 342 /* RPA-specific bits for removing PHBs */
 343 int pcibios_remove_root_bus(struct pci_controller *phb)
 344 {
 345         struct pci_bus *b = phb->bus;
 346         struct resource *res;
 347         int rc, i;
 348
 349         res = b->resource[0];
 350         if (!res->flags) {
 351                 printk(KERN_ERR "%s: no IO resource for PHB %s\n", __FUNCTION__,
 352                                 b->name);
 353                 return 1;
 354         }
 355
 356         rc = unmap_bus_range(b);
 357         if (rc) {
 358                 printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
 359                         __FUNCTION__, b->name);
 360                 return 1;
 361         }
 362
 363         if (release_resource(res)) {
 364                 printk(KERN_ERR "%s: failed to release IO on bus %s\n",
 365                                 __FUNCTION__, b->name);
 366                 return 1;
 367         }
 368
 369         for (i = 1; i < 3; ++i) {
 370                 res = b->resource[i];
 371                 if (!res->flags && i == 0) {
 372                         printk(KERN_ERR "%s: no MEM resource for PHB %s\n",
 373                                 __FUNCTION__, b->name);
 374                         return 1;
 375                 }
 376                 if (res->flags && release_resource(res)) {
 377                         printk(KERN_ERR
 378                                "%s: failed to release IO %d on bus %s\n",
 379                                 __FUNCTION__, i, b->name);
 380                         return 1;
 381                 }
 382         }
 383
 384         list_del(&phb->list_node);
 385         pcibios_free_controller(phb);
 386
 387         return 0;
 388 }
 389 EXPORT_SYMBOL(pcibios_remove_root_bus);