[Qemu-devel] Re: [PATCH V5 09/29] pci: clean up of pci_default_read_config.

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

On Fri, Oct 09, 2009 at 03:28:42PM +0900, Isaku Yamahata wrote:
> This patch cleans up pci_default_read_config() removing
> ugly length and range check.
> 
> Suggesed by "Michael S. Tsirkin" <mst@redhat.com>
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/pci.c |   26 +++++---------------------
>  1 files changed, 5 insertions(+), 21 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 634899a..755ebad 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -558,27 +558,11 @@ static void pci_update_mappings(PCIDevice *d)
>  uint32_t pci_default_read_config(PCIDevice *d,
>                                   uint32_t address, int len)
>  {
> -    uint32_t val;
> -
> -    switch(len) {
> -    default:
> -    case 4:
> -	if (address <= 0xfc) {
> -            val = pci_get_long(d->config + address);
> -	    break;
> -	}
> -	/* fall through */
> -    case 2:
> -        if (address <= 0xfe) {
> -            val = pci_get_word(d->config + address);
> -	    break;
> -	}
> -	/* fall through */
> -    case 1:
> -        val = pci_get_byte(d->config + address);
> -        break;
> -    }
> -    return val;
> +    uint32_t val = 0;
> +    assert(len == 1 || len == 2 || len == 4);
> +    len = MIN(len, PCI_CONFIG_SPACE_SIZE - address);
> +    memcpy(&val, d->config + address, len);
> +    return le32_to_cpu(val);
>  }
>  
>  void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
> -- 
> 1.6.0.2