Re: [Qemu-devel] [RFC PATCH v2 18/21] ppc/xive: add device tree support

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Sep 11, 2017 at 07:12:32PM +0200, Cédric Le Goater wrote:
> Like for XICS, the XIVE interface for the guest is described in the
> device tree under the "interrupt-controller" node. A couple of new
> properties are specific to XIVE :
> 
>  - "reg"
> 
>    contains the base address and size of the thread interrupt
>    managnement areas (TIMA), also called rings, for the User level and
>    for the Guest OS level. Only the Guest OS level is taken into
>    account today.
> 
>  - "ibm,xive-eq-sizes"
> 
>    the size of the event queues. One cell per size supported, contains
>    log2 of size, in ascending order.
> 
>  - "ibm,xive-lisn-ranges"
> 
>    the interrupt numbers ranges assigned to the guest. These are
>    allocated using a simple bitmap.
> 
> and also under the root node :
> 
>  - "ibm,plat-res-int-priorities"
> 
>    contains a list of priorities that the hypervisor has reserved for
>    its own use. Simulate ranges as defined by the PowerVM Hypervisor.
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>  hw/intc/spapr_xive_hcall.c  | 54 +++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/ppc/spapr_xive.h |  1 +
>  2 files changed, 55 insertions(+)
> 
> diff --git a/hw/intc/spapr_xive_hcall.c b/hw/intc/spapr_xive_hcall.c
> index 4c77b65683de..7b19ea6373dd 100644
> --- a/hw/intc/spapr_xive_hcall.c
> +++ b/hw/intc/spapr_xive_hcall.c
> @@ -874,3 +874,57 @@ void spapr_xive_hcall_init(sPAPRMachineState *spapr)
>      spapr_register_hypercall(H_INT_SYNC, h_int_sync);
>      spapr_register_hypercall(H_INT_RESET, h_int_reset);
>  }
> +
> +void spapr_xive_populate(sPAPRXive *xive, void *fdt, uint32_t phandle)
> +{
> +    int node;
> +    uint64_t timas[2 * 2];
> +    uint32_t lisn_ranges[] = {
> +        cpu_to_be32(xive->nr_irqs - xive->nr_targets + xive->ics->offset),
> +        cpu_to_be32(xive->nr_targets),
> +    };
> +    uint32_t eq_sizes[] = {
> +        cpu_to_be32(12), /* 4K */
> +        cpu_to_be32(16), /* 64K */
> +        cpu_to_be32(21), /* 2M */
> +        cpu_to_be32(24), /* 16M */
> +    };
> +
> +    /* Use some ranges to exercise the Linux driver, which should
> +     * result in Linux choosing priority 6. This is not strictly
> +     * necessary
> +     */
> +    uint32_t reserved_priorities[] = {
> +        cpu_to_be32(1),  /* start */
> +        cpu_to_be32(2),  /* count */
> +        cpu_to_be32(7),  /* start */
> +        cpu_to_be32(0xf8),  /* count */
> +    };
> +    int i;
> +
> +    /* Thread Interrupt Management Areas : User and OS */
> +    for (i = 0; i < 2; i++) {
> +        timas[i * 2] = cpu_to_be64(xive->tm_base + i * (1 << xive->tm_shift));
> +        timas[i * 2 + 1] = cpu_to_be64(1 << xive->tm_shift);
> +    }
> +
> +    _FDT(node = fdt_add_subnode(fdt, 0, "interrupt-controller"));
> +
> +    _FDT(fdt_setprop_string(fdt, node, "name", "interrupt-controller"));

Shouldn't need this - SLOF will figure it out from the node name above.

> +    _FDT(fdt_setprop_string(fdt, node, "device_type", "power-ivpe"));
> +    _FDT(fdt_setprop(fdt, node, "reg", timas, sizeof(timas)));
> +
> +    _FDT(fdt_setprop_string(fdt, node, "compatible", "ibm,power-ivpe"));
> +    _FDT(fdt_setprop(fdt, node, "ibm,xive-eq-sizes", eq_sizes,
> +                     sizeof(eq_sizes)));
> +    _FDT(fdt_setprop(fdt, node, "ibm,xive-lisn-ranges", lisn_ranges,
> +                     sizeof(lisn_ranges)));

I note this doesn't have the interrupt-controller or #interrupt-cells
properties.  So what acts as the interrupt parent for all the devices
in the tree with XIVE?

> +    /* For SLOF */
> +    _FDT(fdt_setprop_cell(fdt, node, "linux,phandle", phandle));
> +    _FDT(fdt_setprop_cell(fdt, node, "phandle", phandle));
> +
> +    /* top properties */
> +    _FDT(fdt_setprop(fdt, 0, "ibm,plat-res-int-priorities",
> +                     reserved_priorities, sizeof(reserved_priorities)));
> +}
> diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
> index ae5ff89533c0..0a156f2d8591 100644
> --- a/include/hw/ppc/spapr_xive.h
> +++ b/include/hw/ppc/spapr_xive.h
> @@ -69,5 +69,6 @@ struct sPAPRXive {
>  typedef struct sPAPRMachineState sPAPRMachineState;
>  
>  void spapr_xive_hcall_init(sPAPRMachineState *spapr);
> +void spapr_xive_populate(sPAPRXive *xive, void *fdt, uint32_t phandle);
>  
>  #endif /* PPC_SPAPR_XIVE_H */

-- 
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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