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 #include <asm/eeh.h>
  42
  43 /* RTAS tokens */
  44 static int read_pci_config;
  45 static int write_pci_config;
  46 static int ibm_read_pci_config;
  47 static int ibm_write_pci_config;
  48
  49 static inline int config_access_valid(struct pci_dn *dn, int where)
  50 {
  51         if (where < 256)
  52                 return 1;
  53         if (where < 4096 && dn->pci_ext_config_space)
  54                 return 1;
  55
  56         return 0;
  57 }
  58
  59 static int of_device_available(struct device_node * dn)
  60 {
  61         const char *status;
  62
  63         status = of_get_property(dn, "status", NULL);
  64
  65         if (!status)
  66                 return 1;
  67
  68         if (!strcmp(status, "okay"))
  69                 return 1;
  70
  71         return 0;
  72 }
  73
  74 int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
  75 {
  76         int returnval = -1;
  77         unsigned long buid, addr;
  78         int ret;
  79
  80         if (!pdn)
  81                 return PCIBIOS_DEVICE_NOT_FOUND;
  82         if (!config_access_valid(pdn, where))
  83                 return PCIBIOS_BAD_REGISTER_NUMBER;
  84
  85         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
  86         buid = pdn->phb->buid;
  87         if (buid) {
  88                 ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
  89                                 addr, BUID_HI(buid), BUID_LO(buid), size);
  90         } else {
  91                 ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
  92         }
  93         *val = returnval;
  94
  95         if (ret)
  96                 return PCIBIOS_DEVICE_NOT_FOUND;
  97
  98         if (returnval == EEH_IO_ERROR_VALUE(size) &&
  99             eeh_dn_check_failure (pdn->node, NULL))
 100                 return PCIBIOS_DEVICE_NOT_FOUND;
 101
 102         return PCIBIOS_SUCCESSFUL;
 103 }
 104
 105 static int rtas_pci_read_config(struct pci_bus *bus,
 106                                 unsigned int devfn,
 107                                 int where, int size, u32 *val)
 108 {
 109         struct device_node *busdn, *dn;
 110
 111         if (bus->self)
 112                 busdn = pci_device_to_OF_node(bus->self);
 113         else
 114                 busdn = bus->sysdata;   /* must be a phb */
 115
 116         /* Search only direct children of the bus */
 117         for (dn = busdn->child; dn; dn = dn->sibling) {
 118                 struct pci_dn *pdn = PCI_DN(dn);
 119                 if (pdn && pdn->devfn == devfn
 120                     && of_device_available(dn))
 121                         return rtas_read_config(pdn, where, size, val);
 122         }
 123
 124         return PCIBIOS_DEVICE_NOT_FOUND;
 125 }
 126
 127 int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 128 {
 129         unsigned long buid, addr;
 130         int ret;
 131
 132         if (!pdn)
 133                 return PCIBIOS_DEVICE_NOT_FOUND;
 134         if (!config_access_valid(pdn, where))
 135                 return PCIBIOS_BAD_REGISTER_NUMBER;
 136
 137         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
 138         buid = pdn->phb->buid;
 139         if (buid) {
 140                 ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
 141                         BUID_HI(buid), BUID_LO(buid), size, (ulong) val);
 142         } else {
 143                 ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
 144         }
 145
 146         if (ret)
 147                 return PCIBIOS_DEVICE_NOT_FOUND;
 148
 149         return PCIBIOS_SUCCESSFUL;
 150 }
 151
 152 static int rtas_pci_write_config(struct pci_bus *bus,
 153                                  unsigned int devfn,
 154                                  int where, int size, u32 val)
 155 {
 156         struct device_node *busdn, *dn;
 157
 158         if (bus->self)
 159                 busdn = pci_device_to_OF_node(bus->self);
 160         else
 161                 busdn = bus->sysdata;   /* must be a phb */
 162
 163         /* Search only direct children of the bus */
 164         for (dn = busdn->child; dn; dn = dn->sibling) {
 165                 struct pci_dn *pdn = PCI_DN(dn);
 166                 if (pdn && pdn->devfn == devfn
 167                     && of_device_available(dn))
 168                         return rtas_write_config(pdn, where, size, val);
 169         }
 170         return PCIBIOS_DEVICE_NOT_FOUND;
 171 }
 172
 173 struct pci_ops rtas_pci_ops = {
 174         rtas_pci_read_config,
 175         rtas_pci_write_config
 176 };
 177
 178 int is_python(struct device_node *dev)
 179 {
 180         const char *model = of_get_property(dev, "model", NULL);
 181
 182         if (model && strstr(model, "Python"))
 183                 return 1;
 184
 185         return 0;
 186 }
 187
 188 static void python_countermeasures(struct device_node *dev)
 189 {
 190         struct resource registers;
 191         void __iomem *chip_regs;
 192         volatile u32 val;
 193
 194         if (of_address_to_resource(dev, 0, &registers)) {
 195                 printk(KERN_ERR "Can't get address for Python workarounds !\n");
 196                 return;
 197         }
 198
 199         /* Python's register file is 1 MB in size. */
 200         chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000);
 201
 202         /*
 203          * Firmware doesn't always clear this bit which is critical
 204          * for good performance - Anton
 205          */
 206
 207 #define PRG_CL_RESET_VALID 0x00010000
 208
 209         val = in_be32(chip_regs + 0xf6030);
 210         if (val & PRG_CL_RESET_VALID) {
 211                 printk(KERN_INFO "Python workaround: ");
 212                 val &= ~PRG_CL_RESET_VALID;
 213                 out_be32(chip_regs + 0xf6030, val);
 214                 /*
 215                  * We must read it back for changes to
 216                  * take effect
 217                  */
 218                 val = in_be32(chip_regs + 0xf6030);
 219                 printk("reg0: %x\n", val);
 220         }
 221
 222         iounmap(chip_regs);
 223 }
 224
 225 void __init init_pci_config_tokens (void)
 226 {
 227         read_pci_config = rtas_token("read-pci-config");
 228         write_pci_config = rtas_token("write-pci-config");
 229         ibm_read_pci_config = rtas_token("ibm,read-pci-config");
 230         ibm_write_pci_config = rtas_token("ibm,write-pci-config");
 231 }
 232
 233 unsigned long __devinit get_phb_buid (struct device_node *phb)
 234 {
 235         struct resource r;
 236
 237         if (ibm_read_pci_config == -1)
 238                 return 0;
 239         if (of_address_to_resource(phb, 0, &r))
 240                 return 0;
 241         return r.start;
 242 }
 243
 244 static int phb_set_bus_ranges(struct device_node *dev,
 245                               struct pci_controller *phb)
 246 {
 247         const int *bus_range;
 248         unsigned int len;
 249
 250         bus_range = of_get_property(dev, "bus-range", &len);
 251         if (bus_range == NULL || len < 2 * sizeof(int)) {
 252                 return 1;
 253         }
 254
 255         phb->first_busno =  bus_range[0];
 256         phb->last_busno  =  bus_range[1];
 257
 258         return 0;
 259 }
 260
 261 int __devinit rtas_setup_phb(struct pci_controller *phb)
 262 {
 263         struct device_node *dev = phb->arch_data;
 264
 265         if (is_python(dev))
 266                 python_countermeasures(dev);
 267
 268         if (phb_set_bus_ranges(dev, phb))
 269                 return 1;
 270
 271         phb->ops = &rtas_pci_ops;
 272         phb->buid = get_phb_buid(dev);
 273
 274         return 0;
 275 }
 276
 277 void __init find_and_init_phbs(void)
 278 {
 279         struct device_node *node;
 280         struct pci_controller *phb;
 281         unsigned int index;
 282         struct device_node *root = of_find_node_by_path("/");
 283
 284         index = 0;
 285         for (node = of_get_next_child(root, NULL);
 286              node != NULL;
 287              node = of_get_next_child(root, node)) {
 288
 289                 if (node->type == NULL || (strcmp(node->type, "pci") != 0 &&
 290                                            strcmp(node->type, "pciex") != 0))
 291                         continue;
 292
 293                 phb = pcibios_alloc_controller(node);
 294                 if (!phb)
 295                         continue;
 296                 rtas_setup_phb(phb);
 297                 pci_process_bridge_OF_ranges(phb, node, 0);
 298                 pci_setup_phb_io(phb, index == 0);
 299                 index++;
 300         }
 301
 302         of_node_put(root);
 303         pci_devs_phb_init();
 304
 305         /*
 306          * pci_probe_only and pci_assign_all_buses can be set via properties
 307          * in chosen.
 308          */
 309         if (of_chosen) {
 310                 const int *prop;
 311
 312                 prop = of_get_property(of_chosen,
 313                                 "linux,pci-probe-only", NULL);
 314                 if (prop)
 315                         pci_probe_only = *prop;
 316
 317                 prop = of_get_property(of_chosen,
 318                                 "linux,pci-assign-all-buses", NULL);
 319                 if (prop)
 320                         pci_assign_all_buses = *prop;
 321         }
 322 }
 323
 324 /* RPA-specific bits for removing PHBs */
 325 int pcibios_remove_root_bus(struct pci_controller *phb)
 326 {
 327         struct pci_bus *b = phb->bus;
 328         struct resource *res;
 329         int rc, i;
 330
 331         res = b->resource[0];
 332         if (!res->flags) {
 333                 printk(KERN_ERR "%s: no IO resource for PHB %s\n", __FUNCTION__,
 334                                 b->name);
 335                 return 1;
 336         }
 337
 338         rc = unmap_bus_range(b);
 339         if (rc) {
 340                 printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
 341                         __FUNCTION__, b->name);
 342                 return 1;
 343         }
 344
 345         if (release_resource(res)) {
 346                 printk(KERN_ERR "%s: failed to release IO on bus %s\n",
 347                                 __FUNCTION__, b->name);
 348                 return 1;
 349         }
 350
 351         for (i = 1; i < 3; ++i) {
 352                 res = b->resource[i];
 353                 if (!res->flags && i == 0) {
 354                         printk(KERN_ERR "%s: no MEM resource for PHB %s\n",
 355                                 __FUNCTION__, b->name);
 356                         return 1;
 357                 }
 358                 if (res->flags && release_resource(res)) {
 359                         printk(KERN_ERR
 360                                "%s: failed to release IO %d on bus %s\n",
 361                                 __FUNCTION__, i, b->name);
 362                         return 1;
 363                 }
 364         }
 365
 366         pcibios_free_controller(phb);
 367
 368         return 0;
 369 }
 370 EXPORT_SYMBOL(pcibios_remove_root_bus);