On Tue, 5 May 2015 14:23:54 +0530
Nikunj A Dadhania <nik...@linux.vnet.ibm.com> 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 <nik...@linux.vnet.ibm.com>
> ---
> hw/ppc/spapr_pci.c | 108
> ++++++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 103 insertions(+), 5 deletions(-)
>
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 8b02a3e..103284a 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"
> @@ -945,7 +947,10 @@ 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)));
> + if (drc_name) {
> + _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));
>
> _FDT(fdt_setprop_cell(fdt, offset, "#address-cells",
> @@ -1001,10 +1006,6 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector
> *drc,
> void *fdt = NULL;
> int fdt_start_offset = 0;
>
> - /* 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);
> @@ -1482,6 +1483,89 @@ PCIHostState *spapr_create_phb(sPAPREnvironment
> *spapr, int index)
> return PCI_HOST_BRIDGE(dev);
> }
>
> +typedef struct sPAPRFDT {
> + void *fdt;
> + int node_off;
> + uint32_t index;
> +} sPAPRFDT;
> +
> +static void spapr_populate_pci_devices_dt(PCIBus *bus, PCIDevice *pdev,
> + void *opaque)
> +{
> + PCIBus *sec_bus;
> + sPAPRFDT *p = opaque;
> + int ret, offset;
> + int slot = PCI_SLOT(pdev->devfn);
> + int func = PCI_FUNC(pdev->devfn);
> + char nodename[512];
That's quite a big array ....
> + sPAPRFDT s_fdt;
> +
> + if (func) {
> + sprintf(nodename, "pci@%d,%d", slot, func);
> + } else {
> + sprintf(nodename, "pci@%d", slot);
> + }
... just for holding such a small string. Could you maybe use
a smaller array size for nodename (especially since you call this
function recursively)?
> + offset = fdt_add_subnode(p->fdt, p->node_off, nodename);
> + ret = spapr_populate_pci_child_dt(pdev, p->fdt, offset, p->index, 0,
> NULL);
The above code sequence looks pretty much similar to
spapr_create_pci_child_dt() ... maybe it's worth the effort to merge
the common code of both functions into a separate helper function
to avoid the duplication? ... not sure if this is worth the effort,
it's just a suggestion.
> + g_assert(!ret);
You know that assert statements can simply be disabled by a
preprocessor switch - and in that case there is no more error handling
here at all and the code continues silently with a partial initialized
node! So it's maybe better to do a proper error handling here instead?
> + 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.index = p->index;
> + 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 short *bus_no = (unsigned short *) opaque;
opaque is a void pointer, so I think you don't need the typecast here.
> + unsigned short primary = *bus_no;
> + unsigned short secondary;
> + unsigned short subordinate = 0xff;
Is there a special reason for using unsigned short variables here?
"unsigned int" would sound much more natural to me.
> + if ((pci_default_read_config(pdev, PCI_HEADER_TYPE, 1) ==
> + PCI_HEADER_TYPE_BRIDGE)) {
> + PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
> + secondary = *bus_no + 1;
> + pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1);
> + pci_default_write_config(pdev, PCI_SECONDARY_BUS, secondary, 1);
> + pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, secondary, 1);
> + *bus_no = *bus_no + 1;
> + if (sec_bus) {
> + pci_default_write_config(pdev, PCI_PRIMARY_BUS, primary, 1);
> + pci_default_write_config(pdev, PCI_SECONDARY_BUS, secondary, 1);
> + pci_default_write_config(pdev, PCI_SUBORDINATE_BUS, subordinate,
> 1);
You write all value here again ... I think you could either drop the
write to the PRIMARY and SECONDARY BUS registers, or you could use a
proper if-else instead.
> + 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 short bus_no = 0;
Again, why "short" ?
> + 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)
> @@ -1521,6 +1605,8 @@ 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, "pci@%" PRIx64, phb->buid);
> @@ -1570,6 +1656,18 @@ 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.index = phb->index;
> + 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) {
Thomas
