[Qemu-devel] Re: [PATCH v6 02/12] pci/bridge: fix pci_bridge_reset()

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

On Wed, Oct 20, 2010 at 05:18:51PM +0900, Isaku Yamahata wrote:
> The default value of base/limit registers aren't specified in the spec.
> So pci_bridge_reset() shouldn't touch them.
> Instead, introduced two functions to reset those registers in a way
> of typical implementation. zero base/limit registers or disable forwarding.
> They will be used later.
> 
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

The commit message seems to be out of date?

> ---
> Changes v5 -> v6:
> - pci_bridge_disable_base_limit()
> 
> Changes v4 -> v5:
> - drop the lines in pci_bridge_reset()
> - introduced two functions to reset base/limit registers.
> ---
>  hw/pci_bridge.c |   48 ++++++++++++++++++++++++++++++++++++++++++------
>  hw/pci_bridge.h |    1 +
>  2 files changed, 43 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/pci_bridge.c b/hw/pci_bridge.c
> index 638e3b3..7e8488a 100644
> --- a/hw/pci_bridge.c
> +++ b/hw/pci_bridge.c
> @@ -151,6 +151,26 @@ void pci_bridge_write_config(PCIDevice *d,
>      }
>  }
>  
> +void pci_bridge_disable_base_limit(PCIDevice *dev)
> +{
> +    uint8_t *conf = dev->config;
> +
> +    pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
> +                               PCI_IO_RANGE_MASK & 0xff);
> +    pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
> +                                 PCI_IO_RANGE_MASK & 0xff);
> +    pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
> +                               PCI_MEMORY_RANGE_MASK & 0xffff);
> +    pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
> +                                 PCI_MEMORY_RANGE_MASK & 0xffff);
> +    pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
> +                               PCI_PREF_RANGE_MASK & 0xffff);
> +    pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
> +                                 PCI_PREF_RANGE_MASK & 0xffff);
> +    pci_set_word(conf + PCI_PREF_BASE_UPPER32, 0);
> +    pci_set_word(conf + PCI_PREF_LIMIT_UPPER32, 0);
> +}
> +
>  /* reset bridge specific configuration registers */
>  void pci_bridge_reset_reg(PCIDevice *dev)
>  {
> @@ -161,12 +181,28 @@ void pci_bridge_reset_reg(PCIDevice *dev)
>      conf[PCI_SUBORDINATE_BUS] = 0;
>      conf[PCI_SEC_LATENCY_TIMER] = 0;
>  
> -    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);
> +    /*
> +     * the default values for base/limit registers aren't specified
> +     * in the PCI-to-PCI-bridge spec. So we don't thouch them here.
> +     * Each implementation can override it.
> +     * typical implementation does
> +     * zero base/limit registers or
> +     * disable forwarding: pci_bridge_disable_base_limit()
> +     * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
> +     * after this function.
> +     */
> +    pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
> +                                 PCI_IO_RANGE_MASK & 0xff);
> +    pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
> +                                 PCI_IO_RANGE_MASK & 0xff);
> +    pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
> +                                 PCI_MEMORY_RANGE_MASK & 0xffff);
> +    pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
> +                                 PCI_MEMORY_RANGE_MASK & 0xffff);
> +    pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
> +                                 PCI_PREF_RANGE_MASK & 0xffff);
> +    pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
> +                                 PCI_PREF_RANGE_MASK & 0xffff);
>      pci_set_word(conf + PCI_PREF_BASE_UPPER32, 0);
>      pci_set_word(conf + PCI_PREF_LIMIT_UPPER32, 0);
>  
> diff --git a/hw/pci_bridge.h b/hw/pci_bridge.h
> index f6fade0..84411a6 100644
> --- a/hw/pci_bridge.h
> +++ b/hw/pci_bridge.h
> @@ -39,6 +39,7 @@ pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type);
>  
>  void pci_bridge_write_config(PCIDevice *d,
>                               uint32_t address, uint32_t val, int len);
> +void pci_bridge_disable_base_limit(PCIDevice *dev);
>  void pci_bridge_reset_reg(PCIDevice *dev);
>  void pci_bridge_reset(DeviceState *qdev);
>  
> -- 
> 1.7.1.1