linux/arch/powerpc/sysdev/indirect_pci.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Support for indirect PCI bridges.
   4 *
   5 * Copyright (C) 1998 Gabriel Paubert.
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/pci.h>
  10#include <linux/delay.h>
  11#include <linux/string.h>
  12#include <linux/init.h>
  13
  14#include <asm/io.h>
  15#include <asm/prom.h>
  16#include <asm/pci-bridge.h>
  17#include <asm/machdep.h>
  18
  19int __indirect_read_config(struct pci_controller *hose,
  20                           unsigned char bus_number, unsigned int devfn,
  21                           int offset, int len, u32 *val)
  22{
  23        volatile void __iomem *cfg_data;
  24        u8 cfg_type = 0;
  25        u32 bus_no, reg;
  26
  27        if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
  28                if (bus_number != hose->first_busno)
  29                        return PCIBIOS_DEVICE_NOT_FOUND;
  30                if (devfn != 0)
  31                        return PCIBIOS_DEVICE_NOT_FOUND;
  32        }
  33
  34        if (ppc_md.pci_exclude_device)
  35                if (ppc_md.pci_exclude_device(hose, bus_number, devfn))
  36                        return PCIBIOS_DEVICE_NOT_FOUND;
  37
  38        if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
  39                if (bus_number != hose->first_busno)
  40                        cfg_type = 1;
  41
  42        bus_no = (bus_number == hose->first_busno) ?
  43                        hose->self_busno : bus_number;
  44
  45        if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
  46                reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
  47        else
  48                reg = offset & 0xfc;
  49
  50        if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
  51                out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
  52                         (devfn << 8) | reg | cfg_type));
  53        else
  54                out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
  55                         (devfn << 8) | reg | cfg_type));
  56
  57        /*
  58         * Note: the caller has already checked that offset is
  59         * suitably aligned and that len is 1, 2 or 4.
  60         */
  61        cfg_data = hose->cfg_data + (offset & 3);
  62        switch (len) {
  63        case 1:
  64                *val = in_8(cfg_data);
  65                break;
  66        case 2:
  67                *val = in_le16(cfg_data);
  68                break;
  69        default:
  70                *val = in_le32(cfg_data);
  71                break;
  72        }
  73        return PCIBIOS_SUCCESSFUL;
  74}
  75
  76int indirect_read_config(struct pci_bus *bus, unsigned int devfn,
  77                         int offset, int len, u32 *val)
  78{
  79        struct pci_controller *hose = pci_bus_to_host(bus);
  80
  81        return __indirect_read_config(hose, bus->number, devfn, offset, len,
  82                                      val);
  83}
  84
  85int indirect_write_config(struct pci_bus *bus, unsigned int devfn,
  86                          int offset, int len, u32 val)
  87{
  88        struct pci_controller *hose = pci_bus_to_host(bus);
  89        volatile void __iomem *cfg_data;
  90        u8 cfg_type = 0;
  91        u32 bus_no, reg;
  92
  93        if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
  94                if (bus->number != hose->first_busno)
  95                        return PCIBIOS_DEVICE_NOT_FOUND;
  96                if (devfn != 0)
  97                        return PCIBIOS_DEVICE_NOT_FOUND;
  98        }
  99
 100        if (ppc_md.pci_exclude_device)
 101                if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
 102                        return PCIBIOS_DEVICE_NOT_FOUND;
 103
 104        if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
 105                if (bus->number != hose->first_busno)
 106                        cfg_type = 1;
 107
 108        bus_no = (bus->number == hose->first_busno) ?
 109                        hose->self_busno : bus->number;
 110
 111        if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
 112                reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
 113        else
 114                reg = offset & 0xfc;
 115
 116        if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
 117                out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
 118                         (devfn << 8) | reg | cfg_type));
 119        else
 120                out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
 121                         (devfn << 8) | reg | cfg_type));
 122
 123        /* suppress setting of PCI_PRIMARY_BUS */
 124        if (hose->indirect_type & PPC_INDIRECT_TYPE_SURPRESS_PRIMARY_BUS)
 125                if ((offset == PCI_PRIMARY_BUS) &&
 126                        (bus->number == hose->first_busno))
 127                val &= 0xffffff00;
 128
 129        /* Workaround for PCI_28 Errata in 440EPx/GRx */
 130        if ((hose->indirect_type & PPC_INDIRECT_TYPE_BROKEN_MRM) &&
 131                        offset == PCI_CACHE_LINE_SIZE) {
 132                val = 0;
 133        }
 134
 135        /*
 136         * Note: the caller has already checked that offset is
 137         * suitably aligned and that len is 1, 2 or 4.
 138         */
 139        cfg_data = hose->cfg_data + (offset & 3);
 140        switch (len) {
 141        case 1:
 142                out_8(cfg_data, val);
 143                break;
 144        case 2:
 145                out_le16(cfg_data, val);
 146                break;
 147        default:
 148                out_le32(cfg_data, val);
 149                break;
 150        }
 151        return PCIBIOS_SUCCESSFUL;
 152}
 153
 154static struct pci_ops indirect_pci_ops =
 155{
 156        .read = indirect_read_config,
 157        .write = indirect_write_config,
 158};
 159
 160void setup_indirect_pci(struct pci_controller *hose, resource_size_t cfg_addr,
 161                        resource_size_t cfg_data, u32 flags)
 162{
 163        resource_size_t base = cfg_addr & PAGE_MASK;
 164        void __iomem *mbase;
 165
 166        mbase = ioremap(base, PAGE_SIZE);
 167        hose->cfg_addr = mbase + (cfg_addr & ~PAGE_MASK);
 168        if ((cfg_data & PAGE_MASK) != base)
 169                mbase = ioremap(cfg_data & PAGE_MASK, PAGE_SIZE);
 170        hose->cfg_data = mbase + (cfg_data & ~PAGE_MASK);
 171        hose->ops = &indirect_pci_ops;
 172        hose->indirect_type = flags;
 173}
 174