Re: [Qemu-devel] [PATCH v10 6/7] hw/arm/sysbus-fdt: enable vfio-calxeda-xgmac dynamic instantiation

[Eric Auger <eric.auger@linaro.org>]

Alex,
On 02/17/2015 12:36 PM, Alex Bennée wrote:
> 
> Eric Auger <eric.auger@linaro.org> writes:
> 
>> vfio-calxeda-xgmac now can be instantiated using the -device option.
>> The node creation function generates a very basic dt node composed
>> of the compat, reg and interrupts properties
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>
>> ---
>> v8 -> v9:
>> - properly free resources in case of errors in
>>   add_calxeda_midway_xgmac_fdt_node
>>
>> v7 -> v8:
>> - move the add_fdt_node_functions array declaration between the device
>>   specific code and the generic code to avoid forward declarations of
>>   decice specific functions
>> - rename add_basic_vfio_fdt_node into
>>   add_calxeda_midway_xgmac_fdt_node
>>
>> v6 -> v7:
>> - compat string re-formatting removed since compat string is not exposed
>>   anymore as a user option
>> - VFIO IRQ kick-off removed from sysbus-fdt and moved to VFIO platform
>>   device
>> ---
>>  hw/arm/sysbus-fdt.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 83 insertions(+)
>>
>> diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
>> index 3038b94..d4f97f5 100644
>> --- a/hw/arm/sysbus-fdt.c
>> +++ b/hw/arm/sysbus-fdt.c
>> @@ -26,6 +26,8 @@
>>  #include "sysemu/device_tree.h"
>>  #include "hw/platform-bus.h"
>>  #include "sysemu/sysemu.h"
>> +#include "hw/vfio/vfio-platform.h"
>> +#include "hw/vfio/vfio-calxeda-xgmac.h"
>>  
>>  /*
>>   * internal struct that contains the information to create dynamic
>> @@ -53,11 +55,92 @@ typedef struct NodeCreationPair {
>>      int (*add_fdt_node_fn)(SysBusDevice *sbdev, void *opaque);
>>  } NodeCreationPair;
>>  
>> +/* Device Specific Code */
>> +
>> +/**
>> + * add_calxeda_midway_xgmac_fdt_node
>> + *
>> + * Generates a very simple node with following properties:
>> + * compatible string, regs, interrupts
>> + */
>> +static int add_calxeda_midway_xgmac_fdt_node(SysBusDevice *sbdev, void *opaque)
>> +{
>> +    PlatformBusFDTData *data = opaque;
>> +    PlatformBusDevice *pbus = data->pbus;
>> +    void *fdt = data->fdt;
>> +    const char *parent_node = data->pbus_node_name;
>> +    int compat_str_len;
>> +    char *nodename;
>> +    int i, ret = -1;
>> +    uint32_t *irq_attr;
>> +    uint64_t *reg_attr;
>> +    uint64_t mmio_base;
>> +    uint64_t irq_number;
>> +    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
>> +    VFIODevice *vbasedev = &vdev->vbasedev;
>> +    Object *obj = OBJECT(sbdev);
>> +
>> +    mmio_base = object_property_get_int(obj, "mmio[0]", NULL);
>> +
>> +    nodename = g_strdup_printf("%s/%s@%" PRIx64, parent_node,
>> +                               vbasedev->name,
>> +                               mmio_base);
>> +
>> +    qemu_fdt_add_subnode(fdt, nodename);
>> +
>> +    compat_str_len = strlen(vdev->compat) + 1;
>> +    qemu_fdt_setprop(fdt, nodename, "compatible",
>> +                          vdev->compat, compat_str_len);
>> +
>> +    reg_attr = g_new(uint64_t, vbasedev->num_regions*4);
>> +
>> +    for (i = 0; i < vbasedev->num_regions; i++) {
>> +        mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
>> +        reg_attr[4*i] = 1;
>> +        reg_attr[4*i+1] = mmio_base;
>> +        reg_attr[4*i+2] = 1;
>> +        reg_attr[4*i+3] = memory_region_size(&vdev->regions[i]->mem);
>> +    }
>> +
>> +    ret = qemu_fdt_setprop_sized_cells_from_array(fdt, nodename, "reg",
>> +                     vbasedev->num_regions*2, reg_attr);
> 
> Could we use qemu_fdt_setprop_sized_cells() like everyone else to hide
> the uglyness of the _from_array?

Due to the fact I need to handle 'num_regions' regions, I need to setup
the array programmatically. I could use qemu_fdt_setprop instead since
the cell size always is 1 but I currently do not see how I could easily
take benefit from qemu_fdt_setprop_sized_cells.
> 
>> +    if (ret) {
>> +        error_report("could not set reg property of node %s", nodename);
>> +        goto fail_reg;
>> +    }
>> +
>> +    irq_attr = g_new(uint32_t, vbasedev->num_irqs*3);
>> +
>> +    for (i = 0; i < vbasedev->num_irqs; i++) {
>> +        irq_number = platform_bus_get_irqn(pbus, sbdev , i)
>> +                         + data->irq_start;
>> +        irq_attr[3*i] = cpu_to_be32(0);
>> +        irq_attr[3*i+1] = cpu_to_be32(irq_number);
>> +        irq_attr[3*i+2] = cpu_to_be32(0x4);
>> +    }
>> +
>> +   ret = qemu_fdt_setprop(fdt, nodename, "interrupts",
>> +                     irq_attr,
>> vbasedev->num_irqs*3*sizeof(uint32_t));
> 
> Ditto.
Here also I need to handle num_irqs. But maybe I misunderstand your
comment here.

Best Regards

Eric
> 
>> +    if (ret) {
>> +        error_report("could not set interrupts property of node %s",
>> +                     nodename);
>> +    }
>> +
>> +    g_free(irq_attr);
>> +fail_reg:
>> +    g_free(reg_attr);
>> +    g_free(nodename);
>> +    return ret;
>> +}
>> +
>>  /* list of supported dynamic sysbus devices */
>>  static const NodeCreationPair add_fdt_node_functions[] = {
>> +    {TYPE_VFIO_CALXEDA_XGMAC, add_calxeda_midway_xgmac_fdt_node},
>>      {"", NULL}, /* last element */
>>  };
>>  
>> +/* Generic Code */
>> +
>>  /**
>>   * add_fdt_node - add the device tree node of a dynamic sysbus device
>>   *
>