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

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

On Tue, May 28, 2019 at 11:23:54PM -0400, Michael S. Tsirkin wrote:
> 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>

and that's for the whole patchset.

> 
> > ---
> >  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