Re: [Qemu-devel] [PATCH 02/12] spapr_pci: populate DRC dt entries for PHBs

[Michael Roth]

Quoting Alexey Kardashevskiy (2014-08-26 03:32:58)
> On 08/19/2014 10:21 AM, Michael Roth wrote:
> > Reserve 32 entries of type PCI in each PHB's initial FDT. This
> > advertises to guests that each PHB is DR-capable device with
> > physical hotpluggable slots. This is necessary for allowing
> > hotplugging of devices to it later via bus rescan or guest rpaphp
> > hotplug module.
> > 
> > Each entry is assigned a name of "Slot <<bus_idx>*32 +1>",
> > advertised as a hotpluggable PCI slot, and assigned to power domain
> > -1 to indicate to the guest that power management is handled by the
> > hardware.
> > 
> > This models a DR-capable PCI expansion device attached to a host/lpar
> > via a single PHB with 32 physical hotpluggable slots (as opposed to a
> > virtual bridge device with external management console). Hotplug will
> > be handled by the guest via bus rescan or the rpaphp hotplug module.
> > 
> > Signed-off-by: Michael Roth <address@hidden>
> > ---
> >  hw/ppc/spapr.c              |   3 +-
> >  hw/ppc/spapr_pci.c          | 102 
> > ++++++++++++++++++++++++++++++++++++++++++++
> >  include/hw/pci-host/spapr.h |   1 +
> >  3 files changed, 105 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index d5e46c3..90b25b3 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -890,7 +890,8 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
> >      QLIST_FOREACH(phb, &spapr->phbs, list) {
> >          drc_entry = spapr_phb_to_drc_entry(phb->buid);
> >          g_assert(drc_entry);
> > -        ret = spapr_populate_pci_dt(phb, PHANDLE_XICP, fdt);
> > +        ret = spapr_populate_pci_dt(phb, PHANDLE_XICP, 
> > drc_entry->drc_index,
> > +                                    fdt);
> >      }
> >  
> >      if (ret < 0) {
> > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > index e85134f..924d488 100644
> > --- a/hw/ppc/spapr_pci.c
> > +++ b/hw/ppc/spapr_pci.c
> > @@ -851,8 +851,104 @@ static int spapr_phb_children_dt(Object *child, void 
> > *opaque)
> >      return 1;
> >  }
> >  
> > +static void spapr_create_drc_phb_dt_entries(void *fdt, int bus_off, int 
> > phb_index)
> > +{
> > +    char char_buf[1024];
> > +    uint32_t int_buf[SPAPR_DRC_PHB_SLOT_MAX + 1];
> > +    uint32_t *entries;
> > +    int i, ret, offset;
> > +
> > +    /* ibm,drc-indexes */
> > +    memset(int_buf, 0 , sizeof(int_buf));
> > +    int_buf[0] = SPAPR_DRC_PHB_SLOT_MAX;
> > +
> > +    for (i = 1; i <= SPAPR_DRC_PHB_SLOT_MAX; i++) {
> > +        int_buf[i] = SPAPR_DRC_DEV_ID_BASE + (phb_index << 8) + ((i - 1) 
> > << 3);
> > +    }
> > +
> > +    ret = fdt_setprop(fdt, bus_off, "ibm,drc-indexes", int_buf,
> > +                      sizeof(int_buf));
> > +    if (ret) {
> > +        fprintf(stderr, "error adding 'ibm,drc-indexes' field for PHB 
> > FDT");
> > +    }
> > +
> > +    /* ibm,drc-power-domains */
> > +    memset(int_buf, 0, sizeof(int_buf));
> > +    int_buf[0] = SPAPR_DRC_PHB_SLOT_MAX;
> > +
> > +    for (i = 1; i <= SPAPR_DRC_PHB_SLOT_MAX; i++) {
> > +        int_buf[i] = 0xffffffff;
> > +    }
> > +
> > +    ret = fdt_setprop(fdt, bus_off, "ibm,drc-power-domains", int_buf,
> > +                      sizeof(int_buf));
> > +    if (ret) {
> > +        fprintf(stderr,
> > +                "error adding 'ibm,drc-power-domains' field for PHB FDT");
> 
> As before - return here and below.
> 
> > +    }
> > +
> > +    /* ibm,drc-names */
> > +    memset(char_buf, 0, sizeof(char_buf));
> > +    entries = (uint32_t *)&char_buf[0];
> > +    *entries = SPAPR_DRC_PHB_SLOT_MAX;
> > +    offset = sizeof(*entries);
> > +
> > +    for (i = 1; i <= SPAPR_DRC_PHB_SLOT_MAX; i++) {
> > +        offset += sprintf(char_buf + offset, "Slot %d",
> > +                          (phb_index * SPAPR_DRC_PHB_SLOT_MAX) + i - 1);
> 
> Mmmm. From 1 to <=MAX and (i-1) inside the loop when it could be
> traditional  0 to <MAX and (i) as it is done below :)
> 
> 
> > +        char_buf[offset++] = '\0';
> 
> 
> sprintf() puts zero there itself, no? And as we are here, should not it be
> snprintf()?

You mean something like this?

    snprintf(char_buf + offset, sizeof(char_buf) - offset, "Slot %d", ...)

I'm not sure what happens if sizeof(char_buf) - offset goes negative though, so
maybe:

    for (i = 0; i < SPAPR_DRC_PHB_SLOT_MAX && offset < sizeof(char_buf); i++) {
        if (offset >= sizeof(char_buf)) {
            fprintf(stderr,
                    "error generating 'ibm,drc-names' field for PHB FDT");
            return;
        }
        offset += snprintf(char_buf + offset, sizeof(char_buf) - offset,
                           "Slot %d", (phb_index * SPAPR_DRC_PHB_SLOT_MAX) + i);
        offset++;
    }

> 
> 
> > +    }

> 
> 
> > +    }
> > +
> > +    ret = fdt_setprop(fdt, bus_off, "ibm,drc-names", char_buf, offset);
> > +    if (ret) {
> > +        fprintf(stderr, "error adding 'ibm,drc-names' field for PHB FDT");
> > +    }
> > +
> > +    /* ibm,drc-types */
> > +    memset(char_buf, 0, sizeof(char_buf));
> > +    entries = (uint32_t *)&char_buf[0];
> > +    *entries = SPAPR_DRC_PHB_SLOT_MAX;
> > +    offset = sizeof(*entries);
> > +
> > +    for (i = 0; i < SPAPR_DRC_PHB_SLOT_MAX; i++) {
> > +        offset += sprintf(char_buf + offset, "28");
> > +        char_buf[offset++] = '\0';
> > +    }
> > +
> > +    ret = fdt_setprop(fdt, bus_off, "ibm,drc-types", char_buf, offset);
> > +    if (ret) {
> > +        fprintf(stderr, "error adding 'ibm,drc-types' field for PHB FDT");
> > +    }
> > +
> > +    /* we want the initial indicator state to be 0 - "empty", when we
> > +     * hot-plug an adaptor in the slot, we need to set the indicator
> > +     * to 1 - "present."
> > +     */
> > +
> > +    /* ibm,indicator-9003 */
> > +    memset(int_buf, 0, sizeof(int_buf));
> > +    int_buf[0] = SPAPR_DRC_PHB_SLOT_MAX;
> > +
> > +    ret = fdt_setprop(fdt, bus_off, "ibm,indicator-9003", int_buf,
> > +                      sizeof(int_buf));
> > +    if (ret) {
> > +        fprintf(stderr, "error adding 'ibm,indicator-9003' field for PHB 
> > FDT");
> > +    }
> > +
> > +    /* ibm,sensor-9003 */
> > +    memset(int_buf, 0, sizeof(int_buf));
> > +    int_buf[0] = SPAPR_DRC_PHB_SLOT_MAX;
> > +
> > +    ret = fdt_setprop(fdt, bus_off, "ibm,sensor-9003", int_buf,
> > +                      sizeof(int_buf));
> > +    if (ret) {
> > +        fprintf(stderr, "error adding 'ibm,sensor-9003' field for PHB 
> > FDT");
> > +    }
> > +}
> > +
> >  int spapr_populate_pci_dt(sPAPRPHBState *phb,
> >                            uint32_t xics_phandle,
> > +                          uint32_t drc_index,
> >                            void *fdt)
> >  {
> >      int bus_off, i, j;
> > @@ -934,6 +1030,12 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
> >      object_child_foreach(OBJECT(phb), spapr_phb_children_dt,
> >                           &((sPAPRTCEDT){ .fdt = fdt, .node_off = bus_off 
> > }));
> >  
> > +    spapr_create_drc_phb_dt_entries(fdt, bus_off, phb->index);
> > +    if (drc_index) {
> > +        _FDT(fdt_setprop(fdt, bus_off, "ibm,my-drc-index", &drc_index,
> > +                         sizeof(drc_index)));
> > +    }
> > +
> >      return 0;
> >  }
> >  
> > diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
> > index 32f0aa7..8f0a42f 100644
> > --- a/include/hw/pci-host/spapr.h
> > +++ b/include/hw/pci-host/spapr.h
> > @@ -116,6 +116,7 @@ PCIHostState *spapr_create_phb(sPAPREnvironment *spapr, 
> > int index);
> >  
> >  int spapr_populate_pci_dt(sPAPRPHBState *phb,
> >                            uint32_t xics_phandle,
> > +                          uint32_t drc_index,
> >                            void *fdt);
> >  
> >  void spapr_pci_msi_init(sPAPREnvironment *spapr, hwaddr addr);
> > 
> 
> 
> -- 
> Alexey