Re: [Qemu-ppc] [PATCH v7 3/6] spapr_pci: enumerate and add PCI device tree

[David Gibson]

On Thu, Jun 11, 2015 at 04:32:26PM +0530, Nikunj A Dadhania wrote:
> All the PCI enumeration and device node creation was off-loaded to
> SLOF. With PCI hotplug support, code needed to be added to add device
> node. This creates multiple copy of the code one in SLOF and other in
> hotplug code. To unify this, the patch adds the pci device node
> creation in Qemu. For backward compatibility, a flag
> "qemu,phb-enumerated" is added to the phb, suggesting to SLOF to not
> do device node creation.
> 
> Signed-off-by: Nikunj A Dadhania <address@hidden>
> [ Squashed Michael's drc_index changes ]
> Signed-off-by: Michael Roth <address@hidden>
> Signed-off-by: Nikunj A Dadhania <address@hidden>
> ---
>  hw/ppc/spapr_pci.c | 167 
> +++++++++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 142 insertions(+), 25 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 33254b3..6ef7f44 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -23,6 +23,7 @@
>   * THE SOFTWARE.
>   */
>  #include "hw/hw.h"
> +#include "hw/sysbus.h"
>  #include "hw/pci/pci.h"
>  #include "hw/pci/msi.h"
>  #include "hw/pci/msix.h"
> @@ -35,6 +36,7 @@
>  #include "qemu/error-report.h"
>  #include "qapi/qmp/qerror.h"
>  
> +#include "hw/pci/pci_bridge.h"
>  #include "hw/pci/pci_bus.h"
>  #include "hw/ppc/spapr_drc.h"
>  #include "sysemu/device_tree.h"
> @@ -946,8 +948,13 @@ static int spapr_populate_pci_child_dt(PCIDevice *dev, 
> void *fdt, int offset,
>       * processed by OF beforehand
>       */
>      _FDT(fdt_setprop_string(fdt, offset, "name", "pci"));
> -    _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name, 
> strlen(drc_name)));
> -    _FDT(fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index));
> +    if (drc_name) {
> +        _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name,
> +                         strlen(drc_name)));
> +    }
> +    if (drc_index) {
> +        _FDT(fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index));
> +    }
>  
>      _FDT(fdt_setprop_cell(fdt, offset, "#address-cells",
>                            RESOURCE_CELLS_ADDRESS));
> @@ -964,30 +971,38 @@ static int spapr_populate_pci_child_dt(PCIDevice *dev, 
> void *fdt, int offset,
>      return 0;
>  }
>  
> +typedef struct sPAPRFDT {
> +    void *fdt;
> +    int node_off;
> +    sPAPRPHBState *sphb;
> +} sPAPRFDT;

I don't really like this structure - it seems a very ad-hoc collection
of things.  Even though it means there will be a lot of parameters to
the function, I'd prefer passing them separately to
spapr_create_pci_child_dt() rather than using this structure.

> +static uint32_t spapr_phb_get_pci_drc_index(sPAPRPHBState *phb,
> +                                            PCIDevice *pdev);
> +
>  /* create OF node for pci device and required OF DT properties */
> -static void *spapr_create_pci_child_dt(sPAPRPHBState *phb, PCIDevice *dev,
> -                                       int drc_index, const char *drc_name,
> -                                       int *dt_offset)
> +static int spapr_create_pci_child_dt(PCIDevice *dev, sPAPRFDT *p,
> +                                     const char *drc_name)
>  {
> -    void *fdt;
> -    int offset, ret, fdt_size;
> +    int offset, ret;
>      int slot = PCI_SLOT(dev->devfn);
>      int func = PCI_FUNC(dev->devfn);
>      char nodename[512];
> +    uint32_t drc_index = spapr_phb_get_pci_drc_index(p->sphb, dev);
>  
> -    fdt = create_device_tree(&fdt_size);
>      if (func != 0) {
>          sprintf(nodename, "address@hidden,%d", slot, func);
>      } else {
>          sprintf(nodename, "address@hidden", slot);
>      }
> -    offset = fdt_add_subnode(fdt, 0, nodename);
> -    ret = spapr_populate_pci_child_dt(dev, fdt, offset, phb->index, 
> drc_index,
> -                                      drc_name);
> +    offset = fdt_add_subnode(p->fdt, p->node_off, nodename);
> +    ret = spapr_populate_pci_child_dt(dev, p->fdt, offset, p->sphb->index,
> +                                      drc_index, drc_name);
>      g_assert(!ret);
> -
> -    *dt_offset = offset;
> -    return fdt;
> +    if (ret) {
> +        return 0;
> +    }
> +    return offset;
>  }
>  
>  static void spapr_phb_add_pci_device(sPAPRDRConnector *drc,
> @@ -997,24 +1012,26 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector 
> *drc,
>  {
>      sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
>      DeviceState *dev = DEVICE(pdev);
> -    int drc_index = drck->get_index(drc);
>      const char *drc_name = drck->get_name(drc);
> -    void *fdt = NULL;
> -    int fdt_start_offset = 0;
> +    int fdt_start_offset = 0, fdt_size;
> +    sPAPRFDT s_fdt = {NULL, 0, NULL};
>  
> -    /* boot-time devices get their device tree node created by SLOF, but for
> -     * hotplugged devices we need QEMU to generate it so the guest can fetch
> -     * it via RTAS
> -     */
>      if (dev->hotplugged) {
> -        fdt = spapr_create_pci_child_dt(phb, pdev, drc_index, drc_name,
> -                                        &fdt_start_offset);
> +        s_fdt.fdt = create_device_tree(&fdt_size);
> +        s_fdt.sphb = phb;
> +        s_fdt.node_off = 0;
> +        fdt_start_offset = spapr_create_pci_child_dt(pdev, &s_fdt, drc_name);
> +        if (!fdt_start_offset) {
> +            error_setg(errp, "Failed to create pci child device tree node");
> +            goto out;
> +        }
>      }
>  
>      drck->attach(drc, DEVICE(pdev),
> -                 fdt, fdt_start_offset, !dev->hotplugged, errp);
> +                 s_fdt.fdt, fdt_start_offset, !dev->hotplugged, errp);
> +out:
>      if (*errp) {
> -        g_free(fdt);
> +        g_free(s_fdt.fdt);
>      }
>  }
>  
> @@ -1054,6 +1071,20 @@ static sPAPRDRConnector 
> *spapr_phb_get_pci_drc(sPAPRPHBState *phb,
>                                      pdev->devfn);
>  }
>  
> +static uint32_t spapr_phb_get_pci_drc_index(sPAPRPHBState *phb,
> +                                            PCIDevice *pdev)
> +{
> +    sPAPRDRConnector *drc = spapr_phb_get_pci_drc(phb, pdev);
> +    sPAPRDRConnectorClass *drck;
> +
> +    if (!drc) {
> +        return 0;
> +    }
> +
> +    drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +    return drck->get_index(drc);
> +}
> +
>  static void spapr_phb_hot_plug_child(HotplugHandler *plug_handler,
>                                       DeviceState *plugged_dev, Error **errp)
>  {
> @@ -1484,6 +1515,78 @@ PCIHostState *spapr_create_phb(sPAPRMachineState 
> *spapr, int index)
>      return PCI_HOST_BRIDGE(dev);
>  }
>  
> +static void spapr_populate_pci_devices_dt(PCIBus *bus, PCIDevice *pdev,
> +                                          void *opaque)
> +{
> +    PCIBus *sec_bus;
> +    sPAPRFDT *p = opaque;
> +    int offset;
> +    sPAPRFDT s_fdt;
> +
> +    offset = spapr_create_pci_child_dt(pdev, p, NULL);
> +    if (!offset) {
> +        error_report("Failed to create pci child device tree node");
> +        return;
> +    }
> +
> +    if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) !=
> +         PCI_HEADER_TYPE_BRIDGE)) {
> +        return;
> +    }
> +
> +    sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
> +    if (!sec_bus) {
> +        return;
> +    }
> +
> +    s_fdt.fdt = p->fdt;
> +    s_fdt.node_off = offset;
> +    s_fdt.sphb = p->sphb;
> +    pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
> +                        spapr_populate_pci_devices_dt,
> +                        &s_fdt);
> +}
> +
> +static void spapr_phb_pci_enumerate_bridge(PCIBus *bus, PCIDevice *pdev,
> +                                           void *opaque)
> +{
> +    unsigned int *bus_no = opaque;
> +    unsigned int primary = *bus_no;
> +    unsigned int subordinate = 0xff;
> +    PCIBus *sec_bus = NULL;
> +
> +    if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) !=
> +         PCI_HEADER_TYPE_BRIDGE)) {
> +        return;
> +    }
> +
> +    (*bus_no)++;
> +    pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1);
> +    pci_default_write_config(pdev, PCI_SECONDARY_BUS, *bus_no, 1);
> +    pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, *bus_no, 1);
> +
> +    sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
> +    if (!sec_bus) {
> +        return;
> +    }
> +
> +    pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, subordinate, 1);
> +    pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
> +                        spapr_phb_pci_enumerate_bridge, bus_no);
> +    pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, *bus_no, 1);
> +}
> +
> +static void spapr_phb_pci_enumerate(sPAPRPHBState *phb)
> +{
> +    PCIBus *bus = PCI_HOST_BRIDGE(phb)->bus;
> +    unsigned int bus_no = 0;
> +
> +    pci_for_each_device(bus, pci_bus_num(bus),
> +                        spapr_phb_pci_enumerate_bridge,
> +                        &bus_no);
> +
> +}
> +
>  int spapr_populate_pci_dt(sPAPRPHBState *phb,
>                            uint32_t xics_phandle,
>                            void *fdt)
> @@ -1523,6 +1626,8 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
>          cpu_to_be32(b_ddddd(-1)|b_fff(0)), 0x0, 0x0, cpu_to_be32(-1)};
>      uint32_t interrupt_map[PCI_SLOT_MAX * PCI_NUM_PINS][7];
>      sPAPRTCETable *tcet;
> +    PCIBus *bus = PCI_HOST_BRIDGE(phb)->bus;
> +    sPAPRFDT s_fdt;
>  
>      /* Start populating the FDT */
>      sprintf(nodename, "address@hidden" PRIx64, phb->buid);
> @@ -1572,6 +1677,18 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
>                   tcet->liobn, tcet->bus_offset,
>                   tcet->nb_table << tcet->page_shift);
>  
> +    /* Walk the bridges and program the bus numbers*/
> +    spapr_phb_pci_enumerate(phb);
> +    _FDT(fdt_setprop_cell(fdt, bus_off, "qemu,phb-enumerated", 0x1));
> +
> +    /* Populate tree nodes with PCI devices attached */
> +    s_fdt.fdt = fdt;
> +    s_fdt.node_off = bus_off;
> +    s_fdt.sphb = phb;
> +    pci_for_each_device(bus, pci_bus_num(bus),
> +                        spapr_populate_pci_devices_dt,
> +                        &s_fdt);
> +
>      ret = spapr_drc_populate_dt(fdt, bus_off, OBJECT(phb),
>                                  SPAPR_DR_CONNECTOR_TYPE_PCI);
>      if (ret) {

-- 
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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