Archipelago » qemu

/*

 * pcie_host.c

 * utility functions for pci express host bridge.

 *

 * Copyright (c) 2009 Isaku Yamahata <yamahata at valinux co jp>

 *                    VA Linux Systems Japan K.K.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include "hw.h"

#include "pci.h"

#include "pcie_host.h"

#include "exec-memory.h"

/*

 * PCI express mmcfig address

 * bit 20 - 28: bus number

 * bit 15 - 19: device number

 * bit 12 - 14: function number

 * bit  0 - 11: offset in configuration space of a given device

 */

#define PCIE_MMCFG_SIZE_MAX             (1ULL << 28)

#define PCIE_MMCFG_SIZE_MIN             (1ULL << 20)

#define PCIE_MMCFG_BUS_BIT              20

#define PCIE_MMCFG_BUS_MASK             0x1ff

#define PCIE_MMCFG_DEVFN_BIT            12

#define PCIE_MMCFG_DEVFN_MASK           0xff

#define PCIE_MMCFG_CONFOFFSET_MASK      0xfff

#define PCIE_MMCFG_BUS(addr)            (((addr) >> PCIE_MMCFG_BUS_BIT) & \

                                         PCIE_MMCFG_BUS_MASK)

#define PCIE_MMCFG_DEVFN(addr)          (((addr) >> PCIE_MMCFG_DEVFN_BIT) & \

                                         PCIE_MMCFG_DEVFN_MASK)

#define PCIE_MMCFG_CONFOFFSET(addr)     ((addr) & PCIE_MMCFG_CONFOFFSET_MASK)

/* a helper function to get a PCIDevice for a given mmconfig address */

static inline PCIDevice *pcie_dev_find_by_mmcfg_addr(PCIBus *s,

                                                     uint32_t mmcfg_addr)

{

    return pci_find_device(s, PCIE_MMCFG_BUS(mmcfg_addr),

                           PCIE_MMCFG_DEVFN(mmcfg_addr));

}

static void pcie_mmcfg_data_write(void *opaque, target_phys_addr_t mmcfg_addr,

                                  uint64_t val, unsigned len)

{

    PCIExpressHost *e = opaque;

    PCIBus *s = e->pci.bus;

    PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);

    uint32_t addr;

    uint32_t limit;

    if (!pci_dev) {

        return;

    }

    addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);

    limit = pci_config_size(pci_dev);

    if (limit <= addr) {

        /* conventional pci device can be behind pcie-to-pci bridge.

           256 <= addr < 4K has no effects. */

        return;

    }

    pci_host_config_write_common(pci_dev, addr, limit, val, len);

}

static uint64_t pcie_mmcfg_data_read(void *opaque,

                                     target_phys_addr_t mmcfg_addr,

                                     unsigned len)

{

    PCIExpressHost *e = opaque;

    PCIBus *s = e->pci.bus;

    PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);

    uint32_t addr;

    uint32_t limit;

    if (!pci_dev) {

        return ~0x0;

    }

    addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);

    limit = pci_config_size(pci_dev);

    if (limit <= addr) {

        /* conventional pci device can be behind pcie-to-pci bridge.

           256 <= addr < 4K has no effects. */

        return ~0x0;

    }

    return pci_host_config_read_common(pci_dev, addr, limit, len);

}

static const MemoryRegionOps pcie_mmcfg_ops = {

    .read = pcie_mmcfg_data_read,

    .write = pcie_mmcfg_data_write,

    .endianness = DEVICE_NATIVE_ENDIAN,

};

/* pcie_host::base_addr == PCIE_BASE_ADDR_UNMAPPED when it isn't mapped. */

#define PCIE_BASE_ADDR_UNMAPPED  ((target_phys_addr_t)-1ULL)

int pcie_host_init(PCIExpressHost *e, uint32_t size)

{

    assert(!(size & (size - 1)));       /* power of 2 */

    assert(size >= PCIE_MMCFG_SIZE_MIN);

    assert(size <= PCIE_MMCFG_SIZE_MAX);

    e->base_addr = PCIE_BASE_ADDR_UNMAPPED;

    e->size = size;

    memory_region_init_io(&e->mmio, &pcie_mmcfg_ops, e, "pcie-mmcfg", e->size);

    return 0;

}

void pcie_host_mmcfg_unmap(PCIExpressHost *e)

{

    if (e->base_addr != PCIE_BASE_ADDR_UNMAPPED) {

        memory_region_del_subregion(get_system_memory(), &e->mmio);

        e->base_addr = PCIE_BASE_ADDR_UNMAPPED;

    }

}

void pcie_host_mmcfg_map(PCIExpressHost *e, target_phys_addr_t addr)

{

    e->base_addr = addr;

    memory_region_add_subregion(get_system_memory(), e->base_addr, &e->mmio);

}

void pcie_host_mmcfg_update(PCIExpressHost *e,

                            int enable,

                            target_phys_addr_t addr)

{

    pcie_host_mmcfg_unmap(e);

    if (enable) {

        pcie_host_mmcfg_map(e, addr);

    }

}