hw/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 "hw.h"
  23 #include "pci.h"
  24 #include "pcie_host.h"
  25 #include "exec-memory.h"
  26
  27 /*
  28  * PCI express mmcfig address
  29  * bit 20 - 28: bus number
  30  * bit 15 - 19: device number
  31  * bit 12 - 14: function number
  32  * bit  0 - 11: offset in configuration space of a given device
  33  */
  34 #define PCIE_MMCFG_SIZE_MAX             (1ULL << 28)
  35 #define PCIE_MMCFG_SIZE_MIN             (1ULL << 20)
  36 #define PCIE_MMCFG_BUS_BIT              20
  37 #define PCIE_MMCFG_BUS_MASK             0x1ff
  38 #define PCIE_MMCFG_DEVFN_BIT            12
  39 #define PCIE_MMCFG_DEVFN_MASK           0xff
  40 #define PCIE_MMCFG_CONFOFFSET_MASK      0xfff
  41 #define PCIE_MMCFG_BUS(addr)            (((addr) >> PCIE_MMCFG_BUS_BIT) & \
  42                                          PCIE_MMCFG_BUS_MASK)
  43 #define PCIE_MMCFG_DEVFN(addr)          (((addr) >> PCIE_MMCFG_DEVFN_BIT) & \
  44                                          PCIE_MMCFG_DEVFN_MASK)
  45 #define PCIE_MMCFG_CONFOFFSET(addr)     ((addr) & PCIE_MMCFG_CONFOFFSET_MASK)
  46
  47
  48 /* a helper function to get a PCIDevice for a given mmconfig address */
  49 static inline PCIDevice *pcie_dev_find_by_mmcfg_addr(PCIBus *s,
  50                                                      uint32_t mmcfg_addr)
  51 {
  52     return pci_find_device(s, PCIE_MMCFG_BUS(mmcfg_addr),
  53                            PCIE_MMCFG_DEVFN(mmcfg_addr));
  54 }
  55
  56 static void pcie_mmcfg_data_write(void *opaque, target_phys_addr_t mmcfg_addr,
  57                                   uint64_t val, unsigned len)
  58 {
  59     PCIExpressHost *e = opaque;
  60     PCIBus *s = e->pci.bus;
  61     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
  62     uint32_t addr;
  63     uint32_t limit;
  64
  65     if (!pci_dev) {
  66         return;
  67     }
  68     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
  69     limit = pci_config_size(pci_dev);
  70     if (limit <= addr) {
  71         /* conventional pci device can be behind pcie-to-pci bridge.
  72            256 <= addr < 4K has no effects. */
  73         return;
  74     }
  75     pci_host_config_write_common(pci_dev, addr, limit, val, len);
  76 }
  77
  78 static uint64_t pcie_mmcfg_data_read(void *opaque,
  79                                      target_phys_addr_t mmcfg_addr,
  80                                      unsigned len)
  81 {
  82     PCIExpressHost *e = opaque;
  83     PCIBus *s = e->pci.bus;
  84     PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
  85     uint32_t addr;
  86     uint32_t limit;
  87
  88     if (!pci_dev) {
  89         return ~0x0;
  90     }
  91     addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
  92     limit = pci_config_size(pci_dev);
  93     if (limit <= addr) {
  94         /* conventional pci device can be behind pcie-to-pci bridge.
  95            256 <= addr < 4K has no effects. */
  96         return ~0x0;
  97     }
  98     return pci_host_config_read_common(pci_dev, addr, limit, len);
  99 }
 100
 101 static const MemoryRegionOps pcie_mmcfg_ops = {
 102     .read = pcie_mmcfg_data_read,
 103     .write = pcie_mmcfg_data_write,
 104     .endianness = DEVICE_NATIVE_ENDIAN,
 105 };
 106
 107 /* pcie_host::base_addr == PCIE_BASE_ADDR_UNMAPPED when it isn't mapped. */
 108 #define PCIE_BASE_ADDR_UNMAPPED  ((target_phys_addr_t)-1ULL)
 109
 110 int pcie_host_init(PCIExpressHost *e, uint32_t size)
 111 {
 112     assert(!(size & (size - 1)));       /* power of 2 */
 113     assert(size >= PCIE_MMCFG_SIZE_MIN);
 114     assert(size <= PCIE_MMCFG_SIZE_MAX);
 115     e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
 116     e->size = size;
 117     memory_region_init_io(&e->mmio, &pcie_mmcfg_ops, e, "pcie-mmcfg", e->size);
 118
 119     return 0;
 120 }
 121
 122 void pcie_host_mmcfg_unmap(PCIExpressHost *e)
 123 {
 124     if (e->base_addr != PCIE_BASE_ADDR_UNMAPPED) {
 125         memory_region_del_subregion(get_system_memory(), &e->mmio);
 126         e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
 127     }
 128 }
 129
 130 void pcie_host_mmcfg_map(PCIExpressHost *e, target_phys_addr_t addr)
 131 {
 132     e->base_addr = addr;
 133     memory_region_add_subregion(get_system_memory(), e->base_addr, &e->mmio);
 134 }
 135
 136 void pcie_host_mmcfg_update(PCIExpressHost *e,
 137                             int enable,
 138                             target_phys_addr_t addr)
 139 {
 140     pcie_host_mmcfg_unmap(e);
 141     if (enable) {
 142         pcie_host_mmcfg_map(e, addr);
 143     }
 144 }