linux/arch/powerpc/kernel/rtas_pci.c
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   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
  30#include <asm/io.h>
  31#include <asm/pgtable.h>
  32#include <asm/irq.h>
  33#include <asm/prom.h>
  34#include <asm/machdep.h>
  35#include <asm/pci-bridge.h>
  36#include <asm/iommu.h>
  37#include <asm/rtas.h>
  38#include <asm/mpic.h>
  39#include <asm/ppc-pci.h>
  40#include <asm/eeh.h>
  41
  42/* RTAS tokens */
  43static int read_pci_config;
  44static int write_pci_config;
  45static int ibm_read_pci_config;
  46static int ibm_write_pci_config;
  47
  48static 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
  58int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
  59{
  60        int returnval = -1;
  61        unsigned long buid, addr;
  62        int ret;
  63
  64        if (!pdn)
  65                return PCIBIOS_DEVICE_NOT_FOUND;
  66        if (!config_access_valid(pdn, where))
  67                return PCIBIOS_BAD_REGISTER_NUMBER;
  68#ifdef CONFIG_EEH
  69        if (pdn->edev && pdn->edev->pe &&
  70            (pdn->edev->pe->state & EEH_PE_CFG_BLOCKED))
  71                return PCIBIOS_SET_FAILED;
  72#endif
  73
  74        addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
  75        buid = pdn->phb->buid;
  76        if (buid) {
  77                ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
  78                                addr, BUID_HI(buid), BUID_LO(buid), size);
  79        } else {
  80                ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
  81        }
  82        *val = returnval;
  83
  84        if (ret)
  85                return PCIBIOS_DEVICE_NOT_FOUND;
  86
  87        return PCIBIOS_SUCCESSFUL;
  88}
  89
  90static 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        struct pci_dn *pdn;
  96        bool found = false;
  97        int ret;
  98
  99        /* Search only direct children of the bus */
 100        *val = 0xFFFFFFFF;
 101        busdn = pci_bus_to_OF_node(bus);
 102        for (dn = busdn->child; dn; dn = dn->sibling) {
 103                pdn = PCI_DN(dn);
 104                if (pdn && pdn->devfn == devfn
 105                    && of_device_is_available(dn)) {
 106                        found = true;
 107                        break;
 108                }
 109        }
 110
 111        if (!found)
 112                return PCIBIOS_DEVICE_NOT_FOUND;
 113
 114        ret = rtas_read_config(pdn, where, size, val);
 115        if (*val == EEH_IO_ERROR_VALUE(size) &&
 116            eeh_dev_check_failure(pdn_to_eeh_dev(pdn)))
 117                return PCIBIOS_DEVICE_NOT_FOUND;
 118
 119        return ret;
 120}
 121
 122int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 123{
 124        unsigned long buid, addr;
 125        int ret;
 126
 127        if (!pdn)
 128                return PCIBIOS_DEVICE_NOT_FOUND;
 129        if (!config_access_valid(pdn, where))
 130                return PCIBIOS_BAD_REGISTER_NUMBER;
 131#ifdef CONFIG_EEH
 132        if (pdn->edev && pdn->edev->pe &&
 133            (pdn->edev->pe->state & EEH_PE_CFG_BLOCKED))
 134                return PCIBIOS_SET_FAILED;
 135#endif
 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
 152static 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        struct pci_dn *pdn;
 158        bool found = false;
 159
 160        /* Search only direct children of the bus */
 161        busdn = pci_bus_to_OF_node(bus);
 162        for (dn = busdn->child; dn; dn = dn->sibling) {
 163                pdn = PCI_DN(dn);
 164                if (pdn && pdn->devfn == devfn
 165                    && of_device_is_available(dn)) {
 166                        found = true;
 167                        break;
 168                }
 169        }
 170
 171        if (!found)
 172                return PCIBIOS_DEVICE_NOT_FOUND;
 173
 174        return rtas_write_config(pdn, where, size, val);
 175}
 176
 177static struct pci_ops rtas_pci_ops = {
 178        .read = rtas_pci_read_config,
 179        .write = rtas_pci_write_config,
 180};
 181
 182static int is_python(struct device_node *dev)
 183{
 184        const char *model = of_get_property(dev, "model", NULL);
 185
 186        if (model && strstr(model, "Python"))
 187                return 1;
 188
 189        return 0;
 190}
 191
 192static void python_countermeasures(struct device_node *dev)
 193{
 194        struct resource registers;
 195        void __iomem *chip_regs;
 196        volatile u32 val;
 197
 198        if (of_address_to_resource(dev, 0, &registers)) {
 199                printk(KERN_ERR "Can't get address for Python workarounds !\n");
 200                return;
 201        }
 202
 203        /* Python's register file is 1 MB in size. */
 204        chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000);
 205
 206        /*
 207         * Firmware doesn't always clear this bit which is critical
 208         * for good performance - Anton
 209         */
 210
 211#define PRG_CL_RESET_VALID 0x00010000
 212
 213        val = in_be32(chip_regs + 0xf6030);
 214        if (val & PRG_CL_RESET_VALID) {
 215                printk(KERN_INFO "Python workaround: ");
 216                val &= ~PRG_CL_RESET_VALID;
 217                out_be32(chip_regs + 0xf6030, val);
 218                /*
 219                 * We must read it back for changes to
 220                 * take effect
 221                 */
 222                val = in_be32(chip_regs + 0xf6030);
 223                printk("reg0: %x\n", val);
 224        }
 225
 226        iounmap(chip_regs);
 227}
 228
 229void __init init_pci_config_tokens(void)
 230{
 231        read_pci_config = rtas_token("read-pci-config");
 232        write_pci_config = rtas_token("write-pci-config");
 233        ibm_read_pci_config = rtas_token("ibm,read-pci-config");
 234        ibm_write_pci_config = rtas_token("ibm,write-pci-config");
 235}
 236
 237unsigned long get_phb_buid(struct device_node *phb)
 238{
 239        struct resource r;
 240
 241        if (ibm_read_pci_config == -1)
 242                return 0;
 243        if (of_address_to_resource(phb, 0, &r))
 244                return 0;
 245        return r.start;
 246}
 247
 248static int phb_set_bus_ranges(struct device_node *dev,
 249                              struct pci_controller *phb)
 250{
 251        const __be32 *bus_range;
 252        unsigned int len;
 253
 254        bus_range = of_get_property(dev, "bus-range", &len);
 255        if (bus_range == NULL || len < 2 * sizeof(int)) {
 256                return 1;
 257        }
 258
 259        phb->first_busno = be32_to_cpu(bus_range[0]);
 260        phb->last_busno  = be32_to_cpu(bus_range[1]);
 261
 262        return 0;
 263}
 264
 265int rtas_setup_phb(struct pci_controller *phb)
 266{
 267        struct device_node *dev = phb->dn;
 268
 269        if (is_python(dev))
 270                python_countermeasures(dev);
 271
 272        if (phb_set_bus_ranges(dev, phb))
 273                return 1;
 274
 275        phb->ops = &rtas_pci_ops;
 276        phb->buid = get_phb_buid(dev);
 277
 278        return 0;
 279}
 280