Re: [Qemu-devel] [PATCH][SPARC] LEON3: Add emulation of AMBA plug&play

[Andreas Färber]

Hi,

Am 08.10.2014 um 16:19 schrieb Fabien Chouteau:
> From: Jiri Gaisler <address@hidden>
> 
> AMBA plug&play is used by kernels to probe available devices (Timers,
> UART, etc...). This is a static declaration of devices implemented in
> QEMU. In the future, a more advanced version could compute those
> information directly from the device tree.

Interesting. There's quite some magic numbers in the read functions; I
wonder if you could read them via QOM if you actually give the devices a
canonical path or search by type? You may want to peek at ACPI code.

> 
> Signed-off-by: Fabien Chouteau <address@hidden>
> ---
>  hw/sparc/Makefile.objs   |    1 +
>  hw/sparc/grlib_ambapnp.c |  206 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  hw/sparc/leon3.c         |    6 ++
>  include/hw/sparc/grlib.h |   36 ++++++++
>  4 files changed, 249 insertions(+)
>  create mode 100644 hw/sparc/grlib_ambapnp.c
> 
> diff --git a/hw/sparc/Makefile.objs b/hw/sparc/Makefile.objs
> index c987b5b..e763701 100644
> --- a/hw/sparc/Makefile.objs
> +++ b/hw/sparc/Makefile.objs
> @@ -1 +1,2 @@
>  obj-y += sun4m.o leon3.o
> +obj-$(CONFIG_GRLIB) += grlib_ambapnp.o
> diff --git a/hw/sparc/grlib_ambapnp.c b/hw/sparc/grlib_ambapnp.c
> new file mode 100644
> index 0000000..dfadd5c
> --- /dev/null
> +++ b/hw/sparc/grlib_ambapnp.c
> @@ -0,0 +1,206 @@
> +/*
> + * QEMU GRLIB AMBA Plug&Play Emulator
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "hw/sysbus.h"
> +
> +#define APBPNP_REG_SIZE 4096     /* Size of memory mapped registers */
> +
> +#define TYPE_GRLIB_APB_PNP "grlib,apbpnp"

If you move the two TYPE_* constants to grlib.h, you can reuse them.

> +#define GRLIB_APB_PNP(obj) \
> +    OBJECT_CHECK(APBPNP, (obj), TYPE_GRLIB_APB_PNP)
> +
> +typedef struct APBPNP {
> +    SysBusDevice parent_obj;
> +    MemoryRegion iomem;
> +} APBPNP;
> +
> +static uint64_t grlib_apbpnp_read(void *opaque, hwaddr addr,
> +                                   unsigned size)

Indentation is off by one for all read/write functions.

> +{
> +    uint64_t read_data;
> +    addr &= 0xfff;
> +
> +    /* Unit registers */
> +    switch (addr & 0xffc) {
> +    case 0x00:
> +        read_data = 0x0400f000; /* Memory controller */
> +        break;
> +    case 0x04:
> +        read_data = 0x0000fff1;
> +        break;
> +    case 0x08:
> +        read_data = 0x0100c023; /* APBUART */
> +        break;
> +    case 0x0C:
> +        read_data = 0x0010fff1;
> +        break;
> +    case 0x10:
> +        read_data = 0x0100d040; /* IRQMP */
> +        break;
> +    case 0x14:
> +        read_data = 0x0020fff1;
> +        break;
> +    case 0x18:
> +        read_data = 0x01011006; /* GPTIMER */
> +        break;
> +    case 0x1C:
> +        read_data = 0x0030fff1;
> +        break;
> +
> +    default:
> +        read_data = 0;
> +    }
> +    if (size == 1) {
> +        read_data >>= (24 - (addr & 3) * 8);
> +        read_data &= 0x0ff;
> +    }
> +    return read_data;
> +}
> +
> +static void grlib_apbpnp_write(void *opaque, hwaddr addr,
> +                                uint64_t value, unsigned size)
> +{
> +}
> +
> +static const MemoryRegionOps grlib_apbpnp_ops = {
> +    .write      = grlib_apbpnp_write,
> +    .read       = grlib_apbpnp_read,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static int grlib_apbpnp_init(SysBusDevice *dev)
> +{
> +    APBPNP *pnp = GRLIB_APB_PNP(dev);
> +
> +    memory_region_init_io(&pnp->iomem, OBJECT(pnp), &grlib_apbpnp_ops, pnp,
> +                          "apbpnp", APBPNP_REG_SIZE);
> +
> +    sysbus_init_mmio(dev, &pnp->iomem);

APBPNP_REG_SIZE seems constant, so you could move both lines into an
instance_init function.

> +
> +    return 0;
> +}
> +
> +static void grlib_apbpnp_class_init(ObjectClass *klass, void *data)

s/klass/oc/g

> +{
> +    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

sdc?

> +
> +    k->init = grlib_apbpnp_init;
> +}
> +
> +static const TypeInfo grlib_apbpnp_info = {
> +    .name          = TYPE_GRLIB_APB_PNP,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(APBPNP),
> +    .class_init    = grlib_apbpnp_class_init,
> +};
> +
> +static void grlib_apbpnp_register_types(void)
> +{
> +    type_register_static(&grlib_apbpnp_info);
> +}
> +
> +type_init(grlib_apbpnp_register_types)

Please either split into two .c files here, ...

> +
> +
> +/* AHB PNP */
> +
> +#define AHBPNP_REG_SIZE (4096 - 8)  /* Size of memory mapped registers */
> +
> +#define TYPE_GRLIB_AHB_PNP "grlib,ahbpnp"
> +#define GRLIB_AHB_PNP(obj) \
> +    OBJECT_CHECK(AHBPNP, (obj), TYPE_GRLIB_AHB_PNP)
> +
> +typedef struct AHBPNP {
> +    SysBusDevice parent_obj;
> +    MemoryRegion iomem;
> +} AHBPNP;
> +
> +static uint64_t grlib_ahbpnp_read(void *opaque, hwaddr addr,
> +                                   unsigned size)
> +{
> +    addr &= 0xffc;
> +
> +    /* Unit registers */
> +    switch (addr) {
> +    case 0:
> +        return 0x01003000;      /* LEON3 */
> +    case 0x800:
> +        return 0x0400f000;      /* Memory controller  */
> +    case 0x810:
> +        return 0x0003e002;
> +    case 0x814:
> +        return 0x2000e002;
> +    case 0x818:
> +        return 0x4003c002;
> +    case 0x820:
> +        return 0x01006000;      /* APB bridge @ 0x80000000 */
> +    case 0x830:
> +        return 0x8000fff2;
> +
> +    default:
> +        return 0;
> +    }
> +}
> +
> +static void grlib_ahbpnp_write(void *opaque, hwaddr addr,
> +                                uint64_t value, unsigned size)
> +{
> +}
> +
> +static const MemoryRegionOps grlib_ahbpnp_ops = {
> +    .write      = grlib_ahbpnp_write,
> +    .read       = grlib_ahbpnp_read,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static int grlib_ahbpnp_init(SysBusDevice *dev)

"dev" is an unlucky naming in case DeviceState is ever needed.
sbd? busdev?

> +{
> +    AHBPNP *pnp = GRLIB_AHB_PNP(dev);
> +
> +    memory_region_init_io(&pnp->iomem, OBJECT(pnp), &grlib_ahbpnp_ops, pnp,
> +                          "ahbpnp", AHBPNP_REG_SIZE);
> +
> +    sysbus_init_mmio(dev, &pnp->iomem);

Ditto for possibly moving to instance_init.

> +
> +    return 0;
> +}
> +
> +static void grlib_ahbpnp_class_init(ObjectClass *klass, void *data)
> +{
> +    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
> +
> +    k->init = grlib_ahbpnp_init;
> +}
> +
> +static const TypeInfo grlib_ahbpnp_info = {
> +    .name          = TYPE_GRLIB_AHB_PNP,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(AHBPNP),
> +    .class_init    = grlib_ahbpnp_class_init,
> +};
> +
> +static void grlib_ahbpnp_register_types(void)
> +{
> +    type_register_static(&grlib_ahbpnp_info);
> +}
> +
> +type_init(grlib_ahbpnp_register_types)

... or if unavoidable use just one type_init and registration function.

> diff --git a/hw/sparc/leon3.c b/hw/sparc/leon3.c
> index 751392e..40de78f 100644
> --- a/hw/sparc/leon3.c
> +++ b/hw/sparc/leon3.c
> @@ -207,6 +207,12 @@ static void leon3_generic_hw_init(MachineState *machine)
>          }
>      }
>  
> +    /* Allocate AHB PNP */
> +    grlib_ahbpnp_create(0xFFFFF000);
> +
> +    /* Allocate APB PNP */
> +    grlib_apbpnp_create(0x800FF000);
> +
>      /* Allocate timers */
>      grlib_gptimer_create(0x80000300, 2, CPU_CLK, cpu_irqs, 6);
>  
> diff --git a/include/hw/sparc/grlib.h b/include/hw/sparc/grlib.h
> index 470ce72..a004427 100644
> --- a/include/hw/sparc/grlib.h
> +++ b/include/hw/sparc/grlib.h
> @@ -123,4 +123,40 @@ DeviceState *grlib_apbuart_create(hwaddr  base,
>      return dev;
>  }
>  
> +/* APB PNP */
> +
> +static inline
> +DeviceState *grlib_apbpnp_create(hwaddr  base)
> +{
> +    DeviceState *dev;
> +
> +    dev = qdev_create(NULL, "grlib,apbpnp");
> +
> +    if (qdev_init(dev)) {
> +        return NULL;
> +    }
> +
> +    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, base);
> +
> +    return dev;
> +}
> +
> +/* AHB PNP */
> +
> +static inline
> +DeviceState *grlib_ahbpnp_create(hwaddr  base)
> +{
> +    DeviceState *dev;
> +
> +    dev = qdev_create(NULL, "grlib,ahbpnp");
> +
> +    if (qdev_init(dev)) {
> +        return NULL;
> +    }
> +
> +    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, base);
> +
> +    return dev;
> +}
> +
>  #endif /* ! _GRLIB_H_ */

Are these functions really needed? Can't you just inline them?
Also note that the return value is never actually checked.

Regards,
Andreas

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