Thomas Huth <th...@redhat.com> writes:
> On Wed, 3 Jun 2015 16:55:56 +0530
> Nikunj A Dadhania <nik...@linux.vnet.ibm.com> wrote:
>
>> Each hardware instance has a platform unique location code. The OF
>> device tree that describes a part of a hardware entity must include
>> the “ibm,loc-code” property with a value that represents the location
>> code for that hardware entity.
>>
>> Populate ibm,loc-code.
>>
>> 1) PCI passthru devices need to identify with its own ibm,loc-code
>> available on the host. In failure cases use:
>> vfio_<name>:<phb-index>:<bus>:<slot>.<fn>
>>
>> 2) Emulated devices encode as following:
>> qemu_<name>:<phb-index>:<bus>:<slot>.<fn>
>>
>> Signed-off-by: Nikunj A Dadhania <nik...@linux.vnet.ibm.com>
>> ---
>> hw/ppc/spapr_pci.c | 78
>> +++++++++++++++++++++++++++++++++++++++++++++++-------
>> 1 file changed, 68 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
>> index 4226468..986bb21 100644
>> --- a/hw/ppc/spapr_pci.c
>> +++ b/hw/ppc/spapr_pci.c
>> @@ -746,6 +746,60 @@ static AddressSpace *spapr_pci_dma_iommu(PCIBus *bus,
>> void *opaque, int devfn)
>> return &phb->iommu_as;
>> }
>>
>> +static char *spapr_phb_vfio_get_loc_code(sPAPRPHBState *sphb, PCIDevice
>> *pdev)
>> +{
>> + char *path = NULL, *buf = NULL, *host = NULL;
>> +
>> + /* Get the PCI VFIO host id */
>> + host = object_property_get_str(OBJECT(pdev), "host", NULL);
>> + if (!host) {
>> + goto err_out;
>> + }
>> +
>> + /* Construct the path of the file that will give us the DT location */
>> + path = g_strdup_printf("/sys/bus/pci/devices/%s/devspec", host);
>> + g_free(host);
>> + if (!path || !g_file_get_contents(path, &buf, NULL, NULL)) {
>> + goto err_out;
>> + }
>> + g_free(path);
>> +
>> + /* Construct and read from host device tree the loc-code */
>> + path = g_strdup_printf("/proc/device-tree%s/ibm,loc-code", buf);
>> + g_free(buf);
>> + if (!path || !g_file_get_contents(path, &buf, NULL, NULL)) {
>> + goto err_out;
>> + }
>> + return buf;
>
> I'd maybe change the above 4 lines into:
>
> if (path && g_file_get_contents(path, &buf, NULL, NULL)) {
> return buf;
> }
>
> so that you can get rid of one goto here.
Wouldnt make much of a difference though !
>> +err_out:
>> + g_free(path);
>> + return NULL;
>> +}
>> +
>> +static char *spapr_phb_get_loc_code(sPAPRPHBState *sphb, PCIDevice *pdev)
>> +{
>> + char *buf;
>> + const char *devtype = "qemu";
>> + uint32_t busnr =
>> pci_bus_num(PCI_BUS(qdev_get_parent_bus(DEVICE(pdev))));
>> +
>> + if (object_dynamic_cast(OBJECT(pdev), "vfio-pci")) {
>> + buf = spapr_phb_vfio_get_loc_code(sphb, pdev);
>> + if (buf) {
>> + return buf;
>> + }
>> + devtype = "vfio";
>> + }
>> + /*
>> + * For emulated devices and VFIO-failure case, make up
>> + * the loc-code.
>> + */
>> + buf = g_strdup_printf("%s_%s:%04x:%02x:%02x.%x",
>> + devtype, pdev->name, sphb->index, busnr,
>> + PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
>> + return buf;
>> +}
>> +
>> /* Macros to operate with address in OF binding to PCI */
>> #define b_x(x, p, l) (((x) & ((1<<(l))-1)) << (p))
>> #define b_n(x) b_x((x), 31, 1) /* 0 if relocatable */
>> @@ -884,11 +938,12 @@ static void populate_resource_props(PCIDevice *d,
>> ResourceProps *rp)
>>
>> static int spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int
>> offset,
>> int phb_index, int drc_index,
>> - const char *drc_name)
>> + sPAPRPHBState *sphb)
>> {
>> ResourceProps rp;
>> bool is_bridge = false;
>> int pci_status;
>> + char *buf = NULL;
>
> Is the "= NULL" required here? If not, please remove, newer version
> of gcc tend to complain otherwise.
>
>> if (pci_default_read_config(dev, PCI_HEADER_TYPE, 1) ==
>> PCI_HEADER_TYPE_BRIDGE) {
>> @@ -949,10 +1004,15 @@ 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"));
>> - if (drc_name) {
>> - _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name,
>> - strlen(drc_name)));
>> + buf = spapr_phb_get_loc_code(sphb, dev);
>> + if (!buf) {
>> + error_report("Failed setting the ibm,loc-code");
>> + return -1;
>> }
>> +
>> + _FDT(fdt_setprop_string(fdt, offset, "ibm,loc-code", buf));
>
> I wonder whether this will cause some Coverity warnings later ...
Not sure about that.
> the _FDT macro can return immediately (ugh, return in a macro ... IMHO
> a bad idea...). buf is not freed in that case, and that might trigger a
> warning...
You are right buf may not get freed in case of FDT error. In this case
let me open code this macro here with proper error handling:
err = fdt_setprop_string(fdt, offset, "ibm,loc-code", buf);
g_free(buf);
if (err < 0) {
return err;
}
Regards
Nikunj
