[Qemu-devel] Re: [PATCH 14/23] pci: factor out the logic to get pci device from address.

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

On Mon, Oct 05, 2009 at 07:06:54PM +0900, Isaku Yamahata wrote:
> factor out conversion logic from io port address into bus+dev+func
> with bit shift operation and conversion bus+dev+func into pci device.
> They will be used later by pcie support.
> This patch also eliminates the logic duplication.

Please split removing logic duplication into separate patch.
It might be applicable already, while express stuff needs more work IMO.

> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
> ---
>  hw/pci.c |   83 ++++++++++++++++++++++++++++++++++---------------------------
>  1 files changed, 46 insertions(+), 37 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 6ddd256..5f808ff 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -629,44 +629,25 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
>          pci_update_mappings(d);
>  }
>  
> -void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len)
> +static void pci_data_write_common(PCIDevice *pci_dev,
> +                                  uint32_t config_addr, uint32_t val, int len)

So as I said in the previous comment, pci express should just be able to
use pci code directly, instead of reusing this low-level stuff.
All you need to do is range-check address and ignore extended registers.

>  {
> -    PCIBus *s = opaque;
> -    PCIDevice *pci_dev;
> -    int config_addr, bus_num;
> -
> -#if 0
> -    PCI_DPRINTF("pci_data_write: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n",
> -                addr, val, len);
> -#endif
> -    bus_num = (addr >> 16) & 0xff;
> -    s = pci_find_bus(s, bus_num);
> -    if (!s)
> -        return;
> -    pci_dev = s->devices[(addr >> 8) & 0xff];
> +    assert(len == 1 || len == 2 || len == 4);
>      if (!pci_dev)
>          return;
> -    config_addr = addr & 0xff;
> -    PCI_DPRINTF("pci_config_write: %s: "
> -                "addr=%02x val=%08"PRI32x" len=%d\n",
> -                pci_dev->name, config_addr, val, len);
> +
> +    PCI_DPRINTF("%s: %s: addr=%02"PRIx32" val=%08"PRI32x" len=%d\n",
> +                __func__, pci_dev->name, config_addr, val, len);
>      pci_dev->config_write(pci_dev, config_addr, val, len);
>  }
>  
> -uint32_t pci_data_read(void *opaque, uint32_t addr, int len)
> +static uint32_t pci_data_read_common(PCIDevice *pci_dev,
> +                                     uint32_t config_addr, int len)
>  {
> -    PCIBus *s = opaque;
> -    PCIDevice *pci_dev;
> -    int config_addr, bus_num;
>      uint32_t val;
>  
> -    bus_num = (addr >> 16) & 0xff;
> -    s = pci_find_bus(s, bus_num);
> -    if (!s)
> -        goto fail;
> -    pci_dev = s->devices[(addr >> 8) & 0xff];
> +    assert(len == 1 || len == 2 || len == 4);
>      if (!pci_dev) {
> -    fail:
>          switch(len) {
>          case 1:
>              val = 0xff;
> @@ -679,21 +660,49 @@ uint32_t pci_data_read(void *opaque, uint32_t addr, int len)
>              val = 0xffffffff;
>              break;
>          }
> -        goto the_end;
> +    } else {
> +        val = pci_dev->config_read(pci_dev, config_addr, len);
> +        PCI_DPRINTF("%s: %s: addr=%02"PRIx32" val=%08"PRIx32" len=%d\n",
> +                    __func__, pci_dev->name, config_addr, val, len);
>      }
> -    config_addr = addr & 0xff;
> -    val = pci_dev->config_read(pci_dev, config_addr, len);
> -    PCI_DPRINTF("pci_config_read: %s: "
> -                "addr=%02x val=%08"PRIx32" len=%d\n",
> -                pci_dev->name, config_addr, val, len);
> - the_end:
> +
>  #if 0
> -    PCI_DPRINTF("pci_data_read: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n",
> -                addr, val, len);
> +    PCI_DPRINTF("%s: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n",
> +                __func__, addr, val, len);
>  #endif

move to real pci_data_read?

>      return val;
>  }
>  
> +static inline PCIDevice *pci_addr_to_dev(PCIBus *bus, uint32_t addr)
> +{
> +    uint8_t bus_num = (addr >> 16) & 0xff;
> +    uint8_t devfn = (addr >> 8) & 0xff;
> +    return pci_find_device(bus, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
> +}
> +
> +static inline uint32_t pci_addr_to_config(uint32_t addr)
> +{
> +    return addr & 0xff;
> +}
> +
> +void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len)
> +{
> +    PCIBus *s = opaque;
> +#if 0
> +    PCI_DPRINTF("pci_data_write: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n",
> +                addr, val, len);
> +#endif
> +
> +    pci_data_write_common(pci_addr_to_dev(s, addr), pci_addr_to_config(addr),
> +                          val, len);

For pci express, there's extended register number in bits 11:8
so what we should do here IMO is check these bits and
ignore if they are not 0.

> +}
> +
> +uint32_t pci_data_read(void *opaque, uint32_t addr, int len)
> +{
> +    PCIBus *s = opaque;

For pci express, there's extended register number in bits 11:8
so what we should do here IMO is check these bits and
return 0 if not 0.

> +    return pci_data_read_common(pci_addr_to_dev(s, addr),
> +                                pci_addr_to_config(addr), len);
> +}
>  /***********************************************************/
>  /* generic PCI irq support */
>  
> -- 
> 1.6.0.2