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 int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
  60 {
  61         int returnval = -1;
  62         unsigned long buid, addr;
  63         int ret;
  64
  65         if (!pdn)
  66                 return PCIBIOS_DEVICE_NOT_FOUND;
  67         if (!config_access_valid(pdn, where))
  68                 return PCIBIOS_BAD_REGISTER_NUMBER;
  69
  70         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
  71         buid = pdn->phb->buid;
  72         if (buid) {
  73                 ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
  74                                 addr, BUID_HI(buid), BUID_LO(buid), size);
  75         } else {
  76                 ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
  77         }
  78         *val = returnval;
  79
  80         if (ret)
  81                 return PCIBIOS_DEVICE_NOT_FOUND;
  82
  83         if (returnval == EEH_IO_ERROR_VALUE(size) &&
  84             eeh_dn_check_failure (pdn->node, NULL))
  85                 return PCIBIOS_DEVICE_NOT_FOUND;
  86
  87         return PCIBIOS_SUCCESSFUL;
  88 }
  89
  90 static int rtas_pci_read_config(struct pci_bus *bus,
  91                                 unsigned int devfn,
  92                                 int where, int size, u32 *val)
  93 {
  94         struct device_node *busdn, *dn;
  95
  96         if (bus->self)
  97                 busdn = pci_device_to_OF_node(bus->self);
  98         else
  99                 busdn = bus->sysdata;   /* must be a phb */
 100
 101         /* Search only direct children of the bus */
 102         for (dn = busdn->child; dn; dn = dn->sibling) {
 103                 struct pci_dn *pdn = PCI_DN(dn);
 104                 if (pdn && pdn->devfn == devfn
 105                     && of_device_is_available(dn))
 106                         return rtas_read_config(pdn, where, size, val);
 107         }
 108
 109         return PCIBIOS_DEVICE_NOT_FOUND;
 110 }
 111
 112 int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 113 {
 114         unsigned long buid, addr;
 115         int ret;
 116
 117         if (!pdn)
 118                 return PCIBIOS_DEVICE_NOT_FOUND;
 119         if (!config_access_valid(pdn, where))
 120                 return PCIBIOS_BAD_REGISTER_NUMBER;
 121
 122         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
 123         buid = pdn->phb->buid;
 124         if (buid) {
 125                 ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
 126                         BUID_HI(buid), BUID_LO(buid), size, (ulong) val);
 127         } else {
 128                 ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
 129         }
 130
 131         if (ret)
 132                 return PCIBIOS_DEVICE_NOT_FOUND;
 133
 134         return PCIBIOS_SUCCESSFUL;
 135 }
 136
 137 static int rtas_pci_write_config(struct pci_bus *bus,
 138                                  unsigned int devfn,
 139                                  int where, int size, u32 val)
 140 {
 141         struct device_node *busdn, *dn;
 142
 143         if (bus->self)
 144                 busdn = pci_device_to_OF_node(bus->self);
 145         else
 146                 busdn = bus->sysdata;   /* must be a phb */
 147
 148         /* Search only direct children of the bus */
 149         for (dn = busdn->child; dn; dn = dn->sibling) {
 150                 struct pci_dn *pdn = PCI_DN(dn);
 151                 if (pdn && pdn->devfn == devfn
 152                     && of_device_is_available(dn))
 153                         return rtas_write_config(pdn, where, size, val);
 154         }
 155         return PCIBIOS_DEVICE_NOT_FOUND;
 156 }
 157
 158 static struct pci_ops rtas_pci_ops = {
 159         .read = rtas_pci_read_config,
 160         .write = rtas_pci_write_config,
 161 };
 162
 163 static int is_python(struct device_node *dev)
 164 {
 165         const char *model = of_get_property(dev, "model", NULL);
 166
 167         if (model && strstr(model, "Python"))
 168                 return 1;
 169
 170         return 0;
 171 }
 172
 173 static void python_countermeasures(struct device_node *dev)
 174 {
 175         struct resource registers;
 176         void __iomem *chip_regs;
 177         volatile u32 val;
 178
 179         if (of_address_to_resource(dev, 0, &registers)) {
 180                 printk(KERN_ERR "Can't get address for Python workarounds !\n");
 181                 return;
 182         }
 183
 184         /* Python's register file is 1 MB in size. */
 185         chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000);
 186
 187         /*
 188          * Firmware doesn't always clear this bit which is critical
 189          * for good performance - Anton
 190          */
 191
 192 #define PRG_CL_RESET_VALID 0x00010000
 193
 194         val = in_be32(chip_regs + 0xf6030);
 195         if (val & PRG_CL_RESET_VALID) {
 196                 printk(KERN_INFO "Python workaround: ");
 197                 val &= ~PRG_CL_RESET_VALID;
 198                 out_be32(chip_regs + 0xf6030, val);
 199                 /*
 200                  * We must read it back for changes to
 201                  * take effect
 202                  */
 203                 val = in_be32(chip_regs + 0xf6030);
 204                 printk("reg0: %x\n", val);
 205         }
 206
 207         iounmap(chip_regs);
 208 }
 209
 210 void __init init_pci_config_tokens (void)
 211 {
 212         read_pci_config = rtas_token("read-pci-config");
 213         write_pci_config = rtas_token("write-pci-config");
 214         ibm_read_pci_config = rtas_token("ibm,read-pci-config");
 215         ibm_write_pci_config = rtas_token("ibm,write-pci-config");
 216 }
 217
 218 unsigned long __devinit get_phb_buid (struct device_node *phb)
 219 {
 220         struct resource r;
 221
 222         if (ibm_read_pci_config == -1)
 223                 return 0;
 224         if (of_address_to_resource(phb, 0, &r))
 225                 return 0;
 226         return r.start;
 227 }
 228
 229 static int phb_set_bus_ranges(struct device_node *dev,
 230                               struct pci_controller *phb)
 231 {
 232         const int *bus_range;
 233         unsigned int len;
 234
 235         bus_range = of_get_property(dev, "bus-range", &len);
 236         if (bus_range == NULL || len < 2 * sizeof(int)) {
 237                 return 1;
 238         }
 239
 240         phb->first_busno =  bus_range[0];
 241         phb->last_busno  =  bus_range[1];
 242
 243         return 0;
 244 }
 245
 246 int __devinit rtas_setup_phb(struct pci_controller *phb)
 247 {
 248         struct device_node *dev = phb->dn;
 249
 250         if (is_python(dev))
 251                 python_countermeasures(dev);
 252
 253         if (phb_set_bus_ranges(dev, phb))
 254                 return 1;
 255
 256         phb->ops = &rtas_pci_ops;
 257         phb->buid = get_phb_buid(dev);
 258
 259         return 0;
 260 }
 261
 262 void __init find_and_init_phbs(void)
 263 {
 264         struct device_node *node;
 265         struct pci_controller *phb;
 266         struct device_node *root = of_find_node_by_path("/");
 267
 268         for_each_child_of_node(root, node) {
 269                 if (node->type == NULL || (strcmp(node->type, "pci") != 0 &&
 270                                            strcmp(node->type, "pciex") != 0))
 271                         continue;
 272
 273                 phb = pcibios_alloc_controller(node);
 274                 if (!phb)
 275                         continue;
 276                 rtas_setup_phb(phb);
 277                 pci_process_bridge_OF_ranges(phb, node, 0);
 278                 isa_bridge_find_early(phb);
 279         }
 280
 281         of_node_put(root);
 282         pci_devs_phb_init();
 283
 284         /*
 285          * pci_probe_only and pci_assign_all_buses can be set via properties
 286          * in chosen.
 287          */
 288         if (of_chosen) {
 289                 const int *prop;
 290
 291                 prop = of_get_property(of_chosen,
 292                                 "linux,pci-probe-only", NULL);
 293                 if (prop)
 294                         pci_probe_only = *prop;
 295
 296 #ifdef CONFIG_PPC32 /* Will be made generic soon */
 297                 prop = of_get_property(of_chosen,
 298                                 "linux,pci-assign-all-buses", NULL);
 299                 if (prop && *prop)
 300                         ppc_pci_flags |= PPC_PCI_REASSIGN_ALL_BUS;
 301 #endif /* CONFIG_PPC32 */
 302         }
 303 }