Re: [Qemu-ppc] [PATCH 2/8] spapr: Clean up device tree construction for PCI devices

[David Gibson]

On Fri, May 24, 2019 at 05:34:10PM +0200, Greg Kurz wrote:
65;5603;1c> On Thu, 23 May 2019 15:29:12 +1000
> David Gibson <address@hidden> wrote:
> 
> > spapr_create_pci_child_dt() is a trivial wrapper around
> > spapr_populate_pci_child_dt(), but is the latter's only caller.  So fold
> > them together into spapr_dt_pci_device(), which closer matches our modern
> > naming convention.
> > 
> > While there, make a number of cleanups to the function itself.  This is
> > mostly using more temporary locals to avoid awkwardly long lines, and in
> > some cases avoiding double reads of PCI config space variables.
> > 
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> >  hw/ppc/spapr_pci.c | 119 +++++++++++++++++++++------------------------
> >  1 file changed, 55 insertions(+), 64 deletions(-)
> > 
> > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > index b2db46ef1d..4075b433fd 100644
> > --- a/hw/ppc/spapr_pci.c
> > +++ b/hw/ppc/spapr_pci.c
> > @@ -1219,57 +1219,75 @@ static const char *dt_name_from_class(uint8_t 
> > class, uint8_t subclass,
> >  static uint32_t spapr_phb_get_pci_drc_index(SpaprPhbState *phb,
> >                                              PCIDevice *pdev);
> >  
> > -static void spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int 
> > offset,
> > -                                       SpaprPhbState *sphb)
> > +/* create OF node for pci device and required OF DT properties */
> > +static int spapr_dt_pci_device(SpaprPhbState *sphb, PCIDevice *dev,
> > +                               void *fdt, int parent_offset)
> >  {
> > +    int offset;
> > +    const gchar *basename;
> > +    char *nodename;
> 
> Being curious... what's the rationale for using gchar or char, if
> any ?

There isn't one really.  I've changed this to gchar for consistency.

> 
> > +    int slot = PCI_SLOT(dev->devfn);
> > +    int func = PCI_FUNC(dev->devfn);
> >      ResourceProps rp;
> > -    bool is_bridge = false;
> > -    int pci_status;
> > -    char *buf = NULL;
> >      uint32_t drc_index = spapr_phb_get_pci_drc_index(sphb, dev);
> > +    uint32_t header_type = pci_default_read_config(dev, PCI_HEADER_TYPE, 
> > 1);
> > +    bool is_bridge = (header_type == PCI_HEADER_TYPE_BRIDGE);
> > +    uint32_t vendor_id = pci_default_read_config(dev, PCI_VENDOR_ID, 2);
> > +    uint32_t device_id = pci_default_read_config(dev, PCI_DEVICE_ID, 2);
> > +    uint32_t revision_id = pci_default_read_config(dev, PCI_REVISION_ID, 
> > 1);
> >      uint32_t ccode = pci_default_read_config(dev, PCI_CLASS_PROG, 3);
> > -    uint32_t max_msi, max_msix;
> > +    uint32_t irq_pin = pci_default_read_config(dev, PCI_INTERRUPT_PIN, 1);
> > +    uint32_t subsystem_id = pci_default_read_config(dev, PCI_SUBSYSTEM_ID, 
> > 2);
> > +    uint32_t subsystem_vendor_id =
> > +        pci_default_read_config(dev, PCI_SUBSYSTEM_VENDOR_ID, 2);
> > +    uint32_t cache_line_size =
> > +        pci_default_read_config(dev, PCI_CACHE_LINE_SIZE, 1);
> > +    uint32_t pci_status = pci_default_read_config(dev, PCI_STATUS, 2);
> > +    gchar *loc_code;
> > +    
> 
> trailing space ^^

Fixed.
> 
> Apart from that, LGTM.
> 
> Reviewed-by: Greg Kurz <address@hidden>
> 
> > +    basename = dt_name_from_class((ccode >> 16) & 0xff, (ccode >> 8) & 
> > 0xff,
> > +                                  ccode & 0xff);
> >  
> > -    if (pci_default_read_config(dev, PCI_HEADER_TYPE, 1) ==
> > -        PCI_HEADER_TYPE_BRIDGE) {
> > -        is_bridge = true;
> > +    if (func != 0) {
> > +        nodename = g_strdup_printf("address@hidden,%x", basename, slot, 
> > func);
> > +    } else {
> > +        nodename = g_strdup_printf("address@hidden", basename, slot);
> >      }
> >  
> > +    _FDT(offset = fdt_add_subnode(fdt, parent_offset, nodename));
> > +
> > +    g_free(nodename);
> > +
> >      /* in accordance with PAPR+ v2.7 13.6.3, Table 181 */
> > -    _FDT(fdt_setprop_cell(fdt, offset, "vendor-id",
> > -                          pci_default_read_config(dev, PCI_VENDOR_ID, 2)));
> > -    _FDT(fdt_setprop_cell(fdt, offset, "device-id",
> > -                          pci_default_read_config(dev, PCI_DEVICE_ID, 2)));
> > -    _FDT(fdt_setprop_cell(fdt, offset, "revision-id",
> > -                          pci_default_read_config(dev, PCI_REVISION_ID, 
> > 1)));
> > +    _FDT(fdt_setprop_cell(fdt, offset, "vendor-id", vendor_id));
> > +    _FDT(fdt_setprop_cell(fdt, offset, "device-id", device_id));
> > +    _FDT(fdt_setprop_cell(fdt, offset, "revision-id", revision_id));
> > +
> >      _FDT(fdt_setprop_cell(fdt, offset, "class-code", ccode));
> > -    if (pci_default_read_config(dev, PCI_INTERRUPT_PIN, 1)) {
> > -        _FDT(fdt_setprop_cell(fdt, offset, "interrupts",
> > -                 pci_default_read_config(dev, PCI_INTERRUPT_PIN, 1)));
> > +    if (irq_pin) {
> > +        _FDT(fdt_setprop_cell(fdt, offset, "interrupts", irq_pin));
> >      }
> >  
> >      if (!is_bridge) {
> > -        _FDT(fdt_setprop_cell(fdt, offset, "min-grant",
> > -            pci_default_read_config(dev, PCI_MIN_GNT, 1)));
> > -        _FDT(fdt_setprop_cell(fdt, offset, "max-latency",
> > -            pci_default_read_config(dev, PCI_MAX_LAT, 1)));
> > +        uint32_t min_grant = pci_default_read_config(dev, PCI_MIN_GNT, 1);
> > +        uint32_t max_latency = pci_default_read_config(dev, PCI_MAX_LAT, 
> > 1);
> > +        _FDT(fdt_setprop_cell(fdt, offset, "min-grant", min_grant));
> > +        _FDT(fdt_setprop_cell(fdt, offset, "max-latency", max_latency));
> >      }
> >  
> > -    if (pci_default_read_config(dev, PCI_SUBSYSTEM_ID, 2)) {
> > -        _FDT(fdt_setprop_cell(fdt, offset, "subsystem-id",
> > -                 pci_default_read_config(dev, PCI_SUBSYSTEM_ID, 2)));
> > +    if (subsystem_id) {
> > +        _FDT(fdt_setprop_cell(fdt, offset, "subsystem-id", subsystem_id));
> >      }
> >  
> > -    if (pci_default_read_config(dev, PCI_SUBSYSTEM_VENDOR_ID, 2)) {
> > +    if (subsystem_vendor_id) {
> >          _FDT(fdt_setprop_cell(fdt, offset, "subsystem-vendor-id",
> > -                 pci_default_read_config(dev, PCI_SUBSYSTEM_VENDOR_ID, 
> > 2)));
> > +                              subsystem_vendor_id));
> >      }
> >  
> > -    _FDT(fdt_setprop_cell(fdt, offset, "cache-line-size",
> > -        pci_default_read_config(dev, PCI_CACHE_LINE_SIZE, 1)));
> > +    _FDT(fdt_setprop_cell(fdt, offset, "cache-line-size", 
> > cache_line_size));
> > +
> >  
> >      /* the following fdt cells are masked off the pci status register */
> > -    pci_status = pci_default_read_config(dev, PCI_STATUS, 2);
> >      _FDT(fdt_setprop_cell(fdt, offset, "devsel-speed",
> >                            PCI_STATUS_DEVSEL_MASK & pci_status));
> >  
> > @@ -1283,9 +1301,9 @@ static void spapr_populate_pci_child_dt(PCIDevice 
> > *dev, void *fdt, int offset,
> >          _FDT(fdt_setprop(fdt, offset, "udf-supported", NULL, 0));
> >      }
> >  
> > -    buf = spapr_phb_get_loc_code(sphb, dev);
> > -    _FDT(fdt_setprop_string(fdt, offset, "ibm,loc-code", buf));
> > -    g_free(buf);
> > +    loc_code = spapr_phb_get_loc_code(sphb, dev);
> > +    _FDT(fdt_setprop_string(fdt, offset, "ibm,loc-code", loc_code));
> > +    g_free(loc_code);
> >  
> >      if (drc_index) {
> >          _FDT(fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index));
> > @@ -1297,13 +1315,13 @@ static void spapr_populate_pci_child_dt(PCIDevice 
> > *dev, void *fdt, int offset,
> >                            RESOURCE_CELLS_SIZE));
> >  
> >      if (msi_present(dev)) {
> > -        max_msi = msi_nr_vectors_allocated(dev);
> > +        uint32_t max_msi = msi_nr_vectors_allocated(dev);
> >          if (max_msi) {
> >              _FDT(fdt_setprop_cell(fdt, offset, "ibm,req#msi", max_msi));
> >          }
> >      }
> >      if (msix_present(dev)) {
> > -        max_msix = dev->msix_entries_nr;
> > +        uint32_t max_msix = dev->msix_entries_nr;
> >          if (max_msix) {
> >              _FDT(fdt_setprop_cell(fdt, offset, "ibm,req#msi-x", max_msix));
> >          }
> > @@ -1319,33 +1337,6 @@ static void spapr_populate_pci_child_dt(PCIDevice 
> > *dev, void *fdt, int offset,
> >      }
> >  
> >      spapr_phb_nvgpu_populate_pcidev_dt(dev, fdt, offset, sphb);
> > -}
> > -
> > -/* create OF node for pci device and required OF DT properties */
> > -static int spapr_create_pci_child_dt(SpaprPhbState *phb, PCIDevice *dev,
> > -                                     void *fdt, int node_offset)
> > -{
> > -    int offset;
> > -    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("address@hidden,%x", basename, slot, 
> > func);
> > -    } else {
> > -        nodename = g_strdup_printf("address@hidden", basename, slot);
> > -    }
> > -
> > -    _FDT(offset = fdt_add_subnode(fdt, node_offset, nodename));
> > -
> > -    g_free(nodename);
> > -
> > -    spapr_populate_pci_child_dt(dev, fdt, offset, phb);
> >  
> >      return offset;
> >  }
> > @@ -1393,7 +1384,7 @@ int spapr_pci_dt_populate(SpaprDrc *drc, 
> > SpaprMachineState *spapr,
> >      SpaprPhbState *sphb = SPAPR_PCI_HOST_BRIDGE(plug_handler);
> >      PCIDevice *pdev = PCI_DEVICE(drc->dev);
> >  
> > -    *fdt_start_offset = spapr_create_pci_child_dt(sphb, pdev, fdt, 0);
> > +    *fdt_start_offset = spapr_dt_pci_device(sphb, pdev, fdt, 0);
> >      return 0;
> >  }
> >  
> > @@ -2086,7 +2077,7 @@ static void spapr_populate_pci_devices_dt(PCIBus 
> > *bus, PCIDevice *pdev,
> >      int offset;
> >      SpaprFdt s_fdt;
> >  
> > -    offset = spapr_create_pci_child_dt(p->sphb, pdev, p->fdt, p->node_off);
> > +    offset = spapr_dt_pci_device(p->sphb, pdev, p->fdt, p->node_off);
> >      if (!offset) {
> >          error_report("Failed to create pci child device tree node");
> >          return;
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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