[Qemu-devel] Re: [PATCH 04/10] pci_bridge: introduce pci bridge layer.

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jun 17, 2010 at 03:15:46PM +0900, Isaku Yamahata wrote:
> introduce pci bridge layer.
> export pci_bridge_write_config() for generic use.
> support device reset and bus reset of bridge control.
> convert apb bridge and dec p2p bridge to use new pci bridge layer.
> save/restore is supported as a side effect.
> 
> This might be a bit over engineering, but this is also preparation
> for pci express root/upstream/downstream port.
> 
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

Well, preparations are easier to judge with patches that use them.

> ---
>  hw/apb_pci.c    |   38 +++++++++-----
>  hw/dec_pci.c    |   28 +++++++---
>  hw/pci_bridge.c |  146 +++++++++++++++++++++++++++++++++++++------------------
>  hw/pci_bridge.h |   35 ++++++++++++-
>  qemu-common.h   |    1 +
>  5 files changed, 177 insertions(+), 71 deletions(-)
> 
> diff --git a/hw/apb_pci.c b/hw/apb_pci.c
> index c11d9b5..cb9051b 100644
> --- a/hw/apb_pci.c
> +++ b/hw/apb_pci.c
> @@ -31,6 +31,7 @@
>  #include "pci_host.h"
>  #include "pci_bridge.h"
>  #include "rwhandler.h"
> +#include "pci_bridge.h"
>  #include "apb_pci.h"
>  #include "sysemu.h"
>  
> @@ -294,9 +295,12 @@ static void pci_apb_set_irq(void *opaque, int irq_num, int level)
>      }
>  }
>  
> -static void apb_pci_bridge_init(PCIBus *b)
> +static int apb_pci_bridge_init(PCIBridge *br)
>  {
> -    PCIDevice *dev = pci_bridge_get_device(b);
> +    PCIDevice *dev = &br->dev;
> +
> +    pci_config_set_vendor_id(dev->config, PCI_VENDOR_ID_SUN);
> +    pci_config_set_device_id(dev->config, PCI_DEVICE_ID_SUN_SIMBA);
>  
>      /*
>       * command register:
> @@ -316,6 +320,8 @@ static void apb_pci_bridge_init(PCIBus *b)
>      pci_set_byte(dev->config + PCI_HEADER_TYPE,
>                   pci_get_byte(dev->config + PCI_HEADER_TYPE) |
>                   PCI_HEADER_TYPE_MULTI_FUNCTION);
> +
> +    return 0;
>  }
>  
>  PCIBus *pci_apb_init(target_phys_addr_t special_base,
> @@ -326,6 +332,7 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
>      SysBusDevice *s;
>      APBState *d;
>      unsigned int i;
> +    PCIBridge *br;
>  
>      /* Ultrasparc PBM main bus */
>      dev = qdev_create(NULL, "pbm");
> @@ -351,17 +358,13 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
>      pci_create_simple(d->bus, 0, "pbm");
>  
>      /* APB secondary busses */
> -    *bus2 = pci_bridge_init(d->bus, PCI_DEVFN(1, 0),
> -                            PCI_VENDOR_ID_SUN, PCI_DEVICE_ID_SUN_SIMBA,
> -                            pci_apb_map_irq,
> -                            "Advanced PCI Bus secondary bridge 1");
> -    apb_pci_bridge_init(*bus2);
> -
> -    *bus3 = pci_bridge_init(d->bus, PCI_DEVFN(1, 1),
> -                            PCI_VENDOR_ID_SUN, PCI_DEVICE_ID_SUN_SIMBA,
> -                            pci_apb_map_irq,
> -                            "Advanced PCI Bus secondary bridge 2");
> -    apb_pci_bridge_init(*bus3);
> +    br = pci_bridge_create_simple(d->bus, PCI_DEVFN(1, 0), "pbm-bridge",
> +                                  "Advanced PCI Bus secondary bridge 1");
> +    *bus2 = pci_bridge_get_sec_bus(br);
> +
> +    br = pci_bridge_create_simple(d->bus, PCI_DEVFN(1, 1), "pbm-bridge",
> +                                  "Advanced PCI Bus secondary bridge 2");
> +    *bus3 = pci_bridge_get_sec_bus(br);
>  
>      return d->bus;
>  }
> @@ -446,10 +449,19 @@ static SysBusDeviceInfo pbm_host_info = {
>      .qdev.reset = pci_pbm_reset,
>      .init = pci_pbm_init_device,
>  };
> +
> +static PCIBridgeInfo pbm_pci_bridge_info = {
> +    .pci.qdev.name = "pbm-bridge",
> +    .pci.qdev.vmsd = &vmstate_pci_device,
> +    .init = apb_pci_bridge_init,
> +    .map_irq = pci_apb_map_irq,
> +};
> +
>  static void pbm_register_devices(void)
>  {
>      sysbus_register_withprop(&pbm_host_info);
>      pci_qdev_register(&pbm_pci_host_info);
> +    pci_bridge_qdev_register(&pbm_pci_bridge_info);
>  }
>  
>  device_init(pbm_register_devices)
> diff --git a/hw/dec_pci.c b/hw/dec_pci.c
> index b2759dd..45b5c28 100644
> --- a/hw/dec_pci.c
> +++ b/hw/dec_pci.c
> @@ -49,18 +49,27 @@ static int dec_map_irq(PCIDevice *pci_dev, int irq_num)
>      return irq_num;
>  }
>  
> -PCIBus *pci_dec_21154_init(PCIBus *parent_bus, int devfn)
> +static int dec_21154_initfn(PCIBridge *br)
>  {
> -    DeviceState *dev;
> -    PCIBus *ret;
> +    pci_config_set_vendor_id(br->dev.config, PCI_VENDOR_ID_DEC);
> +    pci_config_set_device_id(br->dev.config, PCI_DEVICE_ID_DEC_21154);
> +    return 0;
> +}
>  
> -    dev = qdev_create(NULL, "dec-21154");
> -    qdev_init_nofail(dev);
> -    ret = pci_bridge_init(parent_bus, devfn,
> -                          PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21154,
> -                          dec_map_irq, "DEC 21154 PCI-PCI bridge");
> +static PCIBridgeInfo dec_21154_pci_bridge_info = {
> +    .pci.qdev.name = "dec-21154-p2p-bridge",
> +    .pci.qdev.desc = "DEC 21154 PCI-PCI bridge",
> +    .pci.qdev.vmsd = &vmstate_pci_device,
> +    .init = dec_21154_initfn,
> +    .map_irq = dec_map_irq,
> +};
>  
> -    return ret;
> +PCIBus *pci_dec_21154_init(PCIBus *parent_bus, int devfn)
> +{
> +    PCIBridge *br;
> +    br = pci_bridge_create_simple(parent_bus, devfn, "dec-21154-p2p-bridge",
> +                                  "DEC 21154 PCI-PCI bridge");
> +    return pci_bridge_get_sec_bus(br);
>  }
>  
>  static int pci_dec_21154_init_device(SysBusDevice *dev)
> @@ -99,6 +108,7 @@ static void dec_register_devices(void)
>      sysbus_register_dev("dec-21154", sizeof(DECState),
>                          pci_dec_21154_init_device);
>      pci_qdev_register(&dec_21154_pci_host_info);
> +    pci_bridge_qdev_register(&dec_21154_pci_bridge_info);
>  }
>  
>  device_init(dec_register_devices)

Please document the APIs. For example, what is
pci_bridge_create_simple and how does it differ
from pci_bridge_create?

> diff --git a/hw/pci_bridge.c b/hw/pci_bridge.c
> index bf746f1..43c21d4 100644
> --- a/hw/pci_bridge.c
> +++ b/hw/pci_bridge.c
> @@ -29,16 +29,10 @@
>  
>  #include "pci_bridge.h"
>  
> -typedef struct {
> -    PCIDevice dev;
> -    PCIBus *bus;
> -    uint32_t vid;
> -    uint32_t did;
> -} PCIBridge;
> -
> -static void pci_bridge_write_config(PCIDevice *d,
> -                                    uint32_t address, uint32_t val, int len)
> +void pci_bridge_write_config(PCIDevice *d,
> +                             uint32_t address, uint32_t val, int len)
>  {
> +    uint16_t bridge_control = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
>      pci_default_write_config(d, address, val, len);
>  
>      if (/* io base/limit */
> @@ -49,64 +43,122 @@ static void pci_bridge_write_config(PCIDevice *d,
>          ranges_overlap(address, len, PCI_MEMORY_BASE, 20)) {
>          pci_bridge_update_mappings(d->bus);
>      }
> +
> +    if (ranges_overlap(address, len, PCI_BRIDGE_CONTROL, 2)) {
> +        uint16_t new = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
> +        if (!(bridge_control & PCI_BRIDGE_CTL_BUS_RESET) &&
> +            (new & PCI_BRIDGE_CTL_BUS_RESET)) {
> +            /* 0 -> 1 */
> +            PCIBridge *br = DO_UPCAST(PCIBridge, dev, d);
> +            pci_bus_reset(br->bus);
> +        }
> +    }
>  }
>  
> -static int pci_bridge_initfn(PCIDevice *dev)
> +void pci_bridge_reset_reg(PCIDevice *dev)
>  {
> -    PCIBridge *s = DO_UPCAST(PCIBridge, dev, dev);
> +    uint8_t *conf = dev->config;
> +
> +    conf[PCI_PRIMARY_BUS] = 0;
> +    conf[PCI_SECONDARY_BUS] = 0;
> +    conf[PCI_SUBORDINATE_BUS] = 0;
> +    conf[PCI_SEC_LATENCY_TIMER] = 0;
>  
> -    pci_config_set_vendor_id(s->dev.config, s->vid);
> -    pci_config_set_device_id(s->dev.config, s->did);
> +    conf[PCI_IO_BASE] = 0;
> +    conf[PCI_IO_LIMIT] = 0;
> +    pci_set_word(conf + PCI_MEMORY_BASE, 0);
> +    pci_set_word(conf + PCI_MEMORY_LIMIT, 0);
> +    pci_set_word(conf + PCI_PREF_MEMORY_BASE, 0);
> +    pci_set_word(conf + PCI_PREF_MEMORY_LIMIT, 0);
> +    pci_set_word(conf + PCI_PREF_BASE_UPPER32, 0);
> +    pci_set_word(conf + PCI_PREF_LIMIT_UPPER32, 0);
> +
> +    pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
> +}
> +
> +void pci_bridge_reset(DeviceState *qdev)
> +{
> +    PCIDevice *dev = DO_UPCAST(PCIDevice, qdev, qdev);
> +    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
> +
> +    pci_bus_reset(br->bus);
> +    pci_bridge_reset_reg(dev);
> +    pci_device_reset_default(dev);
> +}
> +
> +static int pci_bridge_initfn(PCIDevice *dev)
> +{
> +    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
> +    PCIDeviceInfo *pci_info = DO_UPCAST(PCIDeviceInfo, qdev, dev->qdev.info);
> +    PCIBridgeInfo *info = DO_UPCAST(PCIBridgeInfo, pci, pci_info);
> +    int rc = 0;
>  
>      pci_set_word(dev->config + PCI_STATUS,
>                   PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
>      pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
> -    dev->config[PCI_HEADER_TYPE] = PCI_HEADER_TYPE_BRIDGE;
>      pci_set_word(dev->config + PCI_SEC_STATUS,
>                   PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
> -    return 0;
> +
> +    br->bus = pci_register_secondary_bus(dev->bus, dev,
> +                                         info->map_irq, br->bus_name);
> +    if (!br->bus) {
> +        return -1;
> +    }
> +    if (info->init) {
> +        rc = info->init(br);
> +    }
> +    return rc;
>  }
>  
> -static int pci_bridge_exitfn(PCIDevice *pci_dev)
> +static int pci_bridge_exitfn(PCIDevice *dev)
>  {
> -    PCIBridge *s = DO_UPCAST(PCIBridge, dev, pci_dev);
> -    pci_unregister_secondary_bus(s->bus);
> +    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
> +    PCIDeviceInfo *pci_info = DO_UPCAST(PCIDeviceInfo, qdev, dev->qdev.info);
> +    PCIBridgeInfo *info = DO_UPCAST(PCIBridgeInfo, pci, pci_info);
> +
> +    if (info->exit) {
> +        int rc = info->exit(br);
> +        if (rc){
> +            return rc;
> +        }
> +    }
> +    pci_unregister_secondary_bus(br->bus);
>      return 0;
>  }
>  
> -PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint16_t vid, uint16_t did,
> -                        pci_map_irq_fn map_irq, const char *name)
> +void pci_bridge_qdev_register(PCIBridgeInfo *info)
>  {
> -    PCIDevice *dev;
> -    PCIBridge *s;
> -
> -    dev = pci_create(bus, devfn, "pci-bridge");
> -    qdev_prop_set_uint32(&dev->qdev, "vendorid", vid);
> -    qdev_prop_set_uint32(&dev->qdev, "deviceid", did);
> -    qdev_init_nofail(&dev->qdev);
> -
> -    s = DO_UPCAST(PCIBridge, dev, dev);
> -    s->bus = pci_register_secondary_bus(bus, &s->dev, map_irq, name);
> -    return s->bus;
> +    if (!info->pci.qdev.size) {
> +        info->pci.qdev.size = sizeof(PCIBridge);
> +    }
> +    info->pci.init = pci_bridge_initfn;
> +    info->pci.exit = pci_bridge_exitfn;
> +    info->pci.header_type = PCI_HEADER_TYPE_BRIDGE;
> +    if (!info->pci.config_write) {
> +        info->pci.config_write = pci_bridge_write_config;
> +    }
> +    if (!info->pci.qdev.reset) {
> +        info->pci.qdev.reset = pci_bridge_reset;
> +    }
> +    pci_qdev_register(&info->pci);
>  }
>  
> -static PCIDeviceInfo bridge_info = {
> -    .qdev.name    = "pci-bridge",
> -    .qdev.size    = sizeof(PCIBridge),
> -    .init         = pci_bridge_initfn,
> -    .exit         = pci_bridge_exitfn,
> -    .config_write = pci_bridge_write_config,
> -    .header_type  = PCI_HEADER_TYPE_BRIDGE,
> -    .qdev.props   = (Property[]) {
> -        DEFINE_PROP_HEX32("vendorid", PCIBridge, vid, 0),
> -        DEFINE_PROP_HEX32("deviceid", PCIBridge, did, 0),
> -        DEFINE_PROP_END_OF_LIST(),
> -    }
> -};
> +PCIBridge *pci_bridge_create(PCIBus *bus, int devfn, const char *name)
> +{
> +    PCIDevice *dev = pci_create(bus, devfn, name);
> +    return DO_UPCAST(PCIBridge, dev, dev);
> +}
>  
> -static void pci_register_devices(void)
> +void pci_bridge_set_bus_name(PCIBridge *br, const char *bus_name)
>  {
> -    pci_qdev_register(&bridge_info);
> +    br->bus_name = bus_name;
>  }
>  
> -device_init(pci_register_devices)
> +PCIBridge *pci_bridge_create_simple(PCIBus *bus, int devfn,
> +                                    const char *name, const char *bus_name)
> +{
> +    PCIBridge *br = pci_bridge_create(bus, devfn, name);
> +    pci_bridge_set_bus_name(br, bus_name);
> +    qdev_init_nofail(&br->dev.qdev);
> +    return br;
> +}
> diff --git a/hw/pci_bridge.h b/hw/pci_bridge.h
> index 1d46abf..2747e7f 100644
> --- a/hw/pci_bridge.h
> +++ b/hw/pci_bridge.h
> @@ -23,8 +23,39 @@
>  
>  #include "pci.h"
>  
> -PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint16_t vid, uint16_t did,
> -                        pci_map_irq_fn map_irq, const char *name);
> +struct PCIBridge {
> +    PCIDevice dev;
> +
> +    /* private member */
> +    PCIBus *bus;
> +    const char *bus_name;
> +};
> +
> +static inline PCIBus *pci_bridge_get_sec_bus(PCIBridge *br)
> +{
> +    return br->bus;
> +}
> +
> +void pci_bridge_write_config(PCIDevice *d,
> +                             uint32_t address, uint32_t val, int len);
> +void pci_bridge_reset_reg(PCIDevice *dev);
> +void pci_bridge_reset(DeviceState *qdev);
> +
> +typedef int (*pci_bridge_qdev_initfn)(PCIBridge *br);
> +typedef int (*pci_bridge_qdev_exitfn)(PCIBridge *br);
> +typedef struct

struct PCIBridgeInfo, so we can later forward declare if we need to.

> +{
> +    PCIDeviceInfo pci;
> +    pci_bridge_qdev_initfn init;
> +    pci_bridge_qdev_exitfn exit;
> +    pci_map_irq_fn map_irq;
> +} PCIBridgeInfo;
> +
> +void pci_bridge_qdev_register(PCIBridgeInfo *info);
> +PCIBridge *pci_bridge_create(PCIBus *bus, int devfn, const char *name);
> +void pci_bridge_set_bus_name(PCIBridge *br, const char *bus_name);
> +PCIBridge *pci_bridge_create_simple(PCIBus *bus, int devfn,
> +                                    const char *name, const char *bus_name);
>  
>  #endif  /* QEMU_PCI_BRIDGE_H */
>  /*
> diff --git a/qemu-common.h b/qemu-common.h
> index d133f35..8257311 100644
> --- a/qemu-common.h
> +++ b/qemu-common.h
> @@ -221,6 +221,7 @@ typedef struct PCIHostState PCIHostState;
>  typedef struct PCIExpressHost PCIExpressHost;
>  typedef struct PCIBus PCIBus;
>  typedef struct PCIDevice PCIDevice;
> +typedef struct PCIBridge PCIBridge;
>  typedef struct SerialState SerialState;
>  typedef struct IRQState *qemu_irq;
>  typedef struct PCMCIACardState PCMCIACardState;
> -- 
> 1.6.6.1