Re: [Qemu-devel] [PATCH 1/8] spapr: Clean up device node name generation for PCI devices

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

On Thu, May 23, 2019 at 03:29:11PM +1000, David Gibson wrote:
> spapr_populate_pci_child_dt() adds a 'name' property to the device tree
> node for PCI devices.  This is never necessary for a flattened device tree,
> it is implicit in the name added when the node is constructed.  In fact
> anything we do add to a 'name' property will be overwritten with something
> derived from the structural name in the guest firmware (but in fact it is
> exactly the same bytes).
> 
> So, remove that.  In addition, pci_get_node_name() is very simple, so fold
> it into its (also simple) sole caller spapr_create_pci_child_dt().
> 
> While we're there rename pci_find_device_name() to the shorter and more
> accurate dt_name_from_class().
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

The threading is broken here btw.

I was CC'd but it's mostly PPC stuff.
I like how pci_XX functions that are not in pci.c are
going away :)

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


> ---
>  hw/ppc/spapr_pci.c | 43 +++++++++++++++++--------------------------
>  1 file changed, 17 insertions(+), 26 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 97961b0128..b2db46ef1d 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1173,8 +1173,8 @@ static const PCIClass pci_classes[] = {
>      { "data-processing-controller", spc_subclass },
>  };
>  
> -static const char *pci_find_device_name(uint8_t class, uint8_t subclass,
> -                                        uint8_t iface)
> +static const char *dt_name_from_class(uint8_t class, uint8_t subclass,
> +                                      uint8_t iface)
>  {
>      const PCIClass *pclass;
>      const PCISubClass *psubclass;
> @@ -1216,23 +1216,6 @@ static const char *pci_find_device_name(uint8_t class, uint8_t subclass,
>      return name;
>  }
>  
> -static gchar *pci_get_node_name(PCIDevice *dev)
> -{
> -    int slot = PCI_SLOT(dev->devfn);
> -    int func = PCI_FUNC(dev->devfn);
> -    uint32_t ccode = pci_default_read_config(dev, PCI_CLASS_PROG, 3);
> -    const char *name;
> -
> -    name = pci_find_device_name((ccode >> 16) & 0xff, (ccode >> 8) & 0xff,
> -                                ccode & 0xff);
> -
> -    if (func != 0) {
> -        return g_strdup_printf("%s@%x,%x", name, slot, func);
> -    } else {
> -        return g_strdup_printf("%s@%x", name, slot);
> -    }
> -}
> -
>  static uint32_t spapr_phb_get_pci_drc_index(SpaprPhbState *phb,
>                                              PCIDevice *pdev);
>  
> @@ -1300,11 +1283,6 @@ static void spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int offset,
>          _FDT(fdt_setprop(fdt, offset, "udf-supported", NULL, 0));
>      }
>  
> -    _FDT(fdt_setprop_string(fdt, offset, "name",
> -                            pci_find_device_name((ccode >> 16) & 0xff,
> -                                                 (ccode >> 8) & 0xff,
> -                                                 ccode & 0xff)));
> -
>      buf = spapr_phb_get_loc_code(sphb, dev);
>      _FDT(fdt_setprop_string(fdt, offset, "ibm,loc-code", buf));
>      g_free(buf);
> @@ -1348,10 +1326,23 @@ static int spapr_create_pci_child_dt(SpaprPhbState *phb, PCIDevice *dev,
>                                       void *fdt, int node_offset)
>  {
>      int offset;
> -    gchar *nodename;
> +    const gchar *basename;
> +    char *nodename;
> +    int slot = PCI_SLOT(dev->devfn);
> +    int func = PCI_FUNC(dev->devfn);
> +    uint32_t ccode = pci_default_read_config(dev, PCI_CLASS_PROG, 3);
> +
> +    basename = dt_name_from_class((ccode >> 16) & 0xff, (ccode >> 8) & 0xff,
> +                                  ccode & 0xff);
> +
> +    if (func != 0) {
> +        nodename = g_strdup_printf("%s@%x,%x", basename, slot, func);
> +    } else {
> +        nodename = g_strdup_printf("%s@%x", basename, slot);
> +    }
>  
> -    nodename = pci_get_node_name(dev);
>      _FDT(offset = fdt_add_subnode(fdt, node_offset, nodename));
> +
>      g_free(nodename);
>  
>      spapr_populate_pci_child_dt(dev, fdt, offset, phb);
> -- 
> 2.21.0