hw/pci/pcie_host.c

   1 /*
   2  * pcie_host.c
   3  * utility functions for pci express host bridge.
   4  *
   5  * Copyright (c) 2009 Isaku Yamahata <yamahata at valinux co jp>
   6  *                    VA Linux Systems Japan K.K.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "qemu/osdep.h"
  23 #include "hw/hw.h"
  24 #include "hw/pci/pci.h"
  25 #include "hw/pci/pcie_host.h"
  26 #include "exec/address-spaces.h"
  27
  28 /* a helper function to get a PCIDevice for a given mmconfig address */
  29 static inline PCIDevice *pcie_dev_find_by_mmcfg_addr(PCIBus *s,
  30                                                      uint32_t mmcfg_addr)
  31 {
  32     return pci_find_device(s, PCIE_MMCFG_BUS(mmcfg_addr),
  33                            PCIE_MMCFG_DEVFN(mmcfg_addr));
  34 }
  35
  36 static void pcie_mmcfg_data_write(void *opaque, hwaddr mmcfg_addr,
  37                                   uint64_t val, unsigned len)
  38 {
  39     PCIExpressHost *e = opaque;
  40     PCIBus *s = e->pci.bus;
  41     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
  42     uint32_t addr;
  43     uint32_t limit;
  44
  45     if (!pci_dev) {
  46         return;
  47     }
  48     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
  49     limit = pci_config_size(pci_dev);
  50     if (limit <= addr) {
  51         /* conventional pci device can be behind pcie-to-pci bridge.
  52            256 <= addr < 4K has no effects. */
  53         return;
  54     }
  55     pci_host_config_write_common(pci_dev, addr, limit, val, len);
  56 }
  57
  58 static uint64_t pcie_mmcfg_data_read(void *opaque,
  59                                      hwaddr mmcfg_addr,
  60                                      unsigned len)
  61 {
  62     PCIExpressHost *e = opaque;
  63     PCIBus *s = e->pci.bus;
  64     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
  65     uint32_t addr;
  66     uint32_t limit;
  67
  68     if (!pci_dev) {
  69         return ~0x0;
  70     }
  71     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
  72     limit = pci_config_size(pci_dev);
  73     if (limit <= addr) {
  74         /* conventional pci device can be behind pcie-to-pci bridge.
  75            256 <= addr < 4K has no effects. */
  76         return ~0x0;
  77     }
  78     return pci_host_config_read_common(pci_dev, addr, limit, len);
  79 }
  80
  81 static const MemoryRegionOps pcie_mmcfg_ops = {
  82     .read = pcie_mmcfg_data_read,
  83     .write = pcie_mmcfg_data_write,
  84     .endianness = DEVICE_LITTLE_ENDIAN,
  85 };
  86
  87 static void pcie_host_init(Object *obj)
  88 {
  89     PCIExpressHost *e = PCIE_HOST_BRIDGE(obj);
  90
  91     e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
  92     memory_region_init_io(&e->mmio, OBJECT(e), &pcie_mmcfg_ops, e, "pcie-mmcfg-mmio",
  93                           PCIE_MMCFG_SIZE_MAX);
  94 }
  95
  96 void pcie_host_mmcfg_unmap(PCIExpressHost *e)
  97 {
  98     if (e->base_addr != PCIE_BASE_ADDR_UNMAPPED) {
  99         memory_region_del_subregion(get_system_memory(), &e->mmio);
 100         e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
 101     }
 102 }
 103
 104 void pcie_host_mmcfg_init(PCIExpressHost *e, uint32_t size)
 105 {
 106     assert(!(size & (size - 1)));       /* power of 2 */
 107     assert(size >= PCIE_MMCFG_SIZE_MIN);
 108     assert(size <= PCIE_MMCFG_SIZE_MAX);
 109     e->size = size;
 110     memory_region_set_size(&e->mmio, e->size);
 111 }
 112
 113 void pcie_host_mmcfg_map(PCIExpressHost *e, hwaddr addr,
 114                          uint32_t size)
 115 {
 116     pcie_host_mmcfg_init(e, size);
 117     e->base_addr = addr;
 118     memory_region_add_subregion(get_system_memory(), e->base_addr, &e->mmio);
 119 }
 120
 121 void pcie_host_mmcfg_update(PCIExpressHost *e,
 122                             int enable,
 123                             hwaddr addr,
 124                             uint32_t size)
 125 {
 126     memory_region_transaction_begin();
 127     pcie_host_mmcfg_unmap(e);
 128     if (enable) {
 129         pcie_host_mmcfg_map(e, addr, size);
 130     }
 131     memory_region_transaction_commit();
 132 }
 133
 134 static const TypeInfo pcie_host_type_info = {
 135     .name = TYPE_PCIE_HOST_BRIDGE,
 136     .parent = TYPE_PCI_HOST_BRIDGE,
 137     .abstract = true,
 138     .instance_size = sizeof(PCIExpressHost),
 139     .instance_init = pcie_host_init,
 140 };
 141
 142 static void pcie_host_register_types(void)
 143 {
 144     type_register_static(&pcie_host_type_info);
 145 }
 146
 147 type_init(pcie_host_register_types)