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_dev_check_failure(of_node_to_eeh_dev(pdn->node)))
  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         busdn = pci_bus_to_OF_node(bus);
  97
  98         /* Search only direct children of the bus */
  99         for (dn = busdn->child; dn; dn = dn->sibling) {
 100                 struct pci_dn *pdn = PCI_DN(dn);
 101                 if (pdn && pdn->devfn == devfn
 102                     && of_device_is_available(dn))
 103                         return rtas_read_config(pdn, where, size, val);
 104         }
 105
 106         return PCIBIOS_DEVICE_NOT_FOUND;
 107 }
 108
 109 int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 110 {
 111         unsigned long buid, addr;
 112         int ret;
 113
 114         if (!pdn)
 115                 return PCIBIOS_DEVICE_NOT_FOUND;
 116         if (!config_access_valid(pdn, where))
 117                 return PCIBIOS_BAD_REGISTER_NUMBER;
 118
 119         addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
 120         buid = pdn->phb->buid;
 121         if (buid) {
 122                 ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
 123                         BUID_HI(buid), BUID_LO(buid), size, (ulong) val);
 124         } else {
 125                 ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
 126         }
 127
 128         if (ret)
 129                 return PCIBIOS_DEVICE_NOT_FOUND;
 130
 131         return PCIBIOS_SUCCESSFUL;
 132 }
 133
 134 static int rtas_pci_write_config(struct pci_bus *bus,
 135                                  unsigned int devfn,
 136                                  int where, int size, u32 val)
 137 {
 138         struct device_node *busdn, *dn;
 139
 140         busdn = pci_bus_to_OF_node(bus);
 141
 142         /* Search only direct children of the bus */
 143         for (dn = busdn->child; dn; dn = dn->sibling) {
 144                 struct pci_dn *pdn = PCI_DN(dn);
 145                 if (pdn && pdn->devfn == devfn
 146                     && of_device_is_available(dn))
 147                         return rtas_write_config(pdn, where, size, val);
 148         }
 149         return PCIBIOS_DEVICE_NOT_FOUND;
 150 }
 151
 152 static struct pci_ops rtas_pci_ops = {
 153         .read = rtas_pci_read_config,
 154         .write = rtas_pci_write_config,
 155 };
 156
 157 static int is_python(struct device_node *dev)
 158 {
 159         const char *model = of_get_property(dev, "model", NULL);
 160
 161         if (model && strstr(model, "Python"))
 162                 return 1;
 163
 164         return 0;
 165 }
 166
 167 static void python_countermeasures(struct device_node *dev)
 168 {
 169         struct resource registers;
 170         void __iomem *chip_regs;
 171         volatile u32 val;
 172
 173         if (of_address_to_resource(dev, 0, &registers)) {
 174                 printk(KERN_ERR "Can't get address for Python workarounds !\n");
 175                 return;
 176         }
 177
 178         /* Python's register file is 1 MB in size. */
 179         chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000);
 180
 181         /*
 182          * Firmware doesn't always clear this bit which is critical
 183          * for good performance - Anton
 184          */
 185
 186 #define PRG_CL_RESET_VALID 0x00010000
 187
 188         val = in_be32(chip_regs + 0xf6030);
 189         if (val & PRG_CL_RESET_VALID) {
 190                 printk(KERN_INFO "Python workaround: ");
 191                 val &= ~PRG_CL_RESET_VALID;
 192                 out_be32(chip_regs + 0xf6030, val);
 193                 /*
 194                  * We must read it back for changes to
 195                  * take effect
 196                  */
 197                 val = in_be32(chip_regs + 0xf6030);
 198                 printk("reg0: %x\n", val);
 199         }
 200
 201         iounmap(chip_regs);
 202 }
 203
 204 void __init init_pci_config_tokens(void)
 205 {
 206         read_pci_config = rtas_token("read-pci-config");
 207         write_pci_config = rtas_token("write-pci-config");
 208         ibm_read_pci_config = rtas_token("ibm,read-pci-config");
 209         ibm_write_pci_config = rtas_token("ibm,write-pci-config");
 210 }
 211
 212 unsigned long get_phb_buid(struct device_node *phb)
 213 {
 214         struct resource r;
 215
 216         if (ibm_read_pci_config == -1)
 217                 return 0;
 218         if (of_address_to_resource(phb, 0, &r))
 219                 return 0;
 220         return r.start;
 221 }
 222
 223 static int phb_set_bus_ranges(struct device_node *dev,
 224                               struct pci_controller *phb)
 225 {
 226         const __be32 *bus_range;
 227         unsigned int len;
 228
 229         bus_range = of_get_property(dev, "bus-range", &len);
 230         if (bus_range == NULL || len < 2 * sizeof(int)) {
 231                 return 1;
 232         }
 233
 234         phb->first_busno = be32_to_cpu(bus_range[0]);
 235         phb->last_busno  = be32_to_cpu(bus_range[1]);
 236
 237         return 0;
 238 }
 239
 240 int rtas_setup_phb(struct pci_controller *phb)
 241 {
 242         struct device_node *dev = phb->dn;
 243
 244         if (is_python(dev))
 245                 python_countermeasures(dev);
 246
 247         if (phb_set_bus_ranges(dev, phb))
 248                 return 1;
 249
 250         phb->ops = &rtas_pci_ops;
 251         phb->buid = get_phb_buid(dev);
 252
 253         return 0;
 254 }
 255
 256 void __init find_and_init_phbs(void)
 257 {
 258         struct device_node *node;
 259         struct pci_controller *phb;
 260         struct device_node *root = of_find_node_by_path("/");
 261
 262         for_each_child_of_node(root, node) {
 263                 if (node->type == NULL || (strcmp(node->type, "pci") != 0 &&
 264                                            strcmp(node->type, "pciex") != 0))
 265                         continue;
 266
 267                 phb = pcibios_alloc_controller(node);
 268                 if (!phb)
 269                         continue;
 270                 rtas_setup_phb(phb);
 271                 pci_process_bridge_OF_ranges(phb, node, 0);
 272                 isa_bridge_find_early(phb);
 273         }
 274
 275         of_node_put(root);
 276         pci_devs_phb_init();
 277
 278         /*
 279          * PCI_PROBE_ONLY and PCI_REASSIGN_ALL_BUS can be set via properties
 280          * in chosen.
 281          */
 282         if (of_chosen) {
 283                 const int *prop;
 284
 285                 prop = of_get_property(of_chosen,
 286                                 "linux,pci-probe-only", NULL);
 287                 if (prop) {
 288                         if (*prop)
 289                                 pci_add_flags(PCI_PROBE_ONLY);
 290                         else
 291                                 pci_clear_flags(PCI_PROBE_ONLY);
 292                 }
 293
 294 #ifdef CONFIG_PPC32 /* Will be made generic soon */
 295                 prop = of_get_property(of_chosen,
 296                                 "linux,pci-assign-all-buses", NULL);
 297                 if (prop && *prop)
 298                         pci_add_flags(PCI_REASSIGN_ALL_BUS);
 299 #endif /* CONFIG_PPC32 */
 300         }
 301 }