Re: [Qemu-devel] [PATCH v3 1/6] hw/misc/dyn_sysbus_binding: helpers for sysbus device dynamic binding

[Paolo Bonzini <pbonzini@redhat.com>]

Il 09/09/2014 09:54, Eric Auger ha scritto:
> This new module implements routines which help in dynamic device
> binding (mmio regions, irq). They are supposed to be used by machine
> files that support dynamic sysbus instantiation.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> 
> ---
> 
> v1 -> v2:
> - platform_devices renamed into dyn_sysbus_binding

Please use "dynamic" instead of dyn.

> - PlatformParams renamed into DynSysbusParams
> - PlatformBusNotifier renamed into DynSysbusNotifier
> - platform_bus_map_irq, platform_bus_map_mmio, sysbus_device_check,
>   platform_bus_init become static
> - PlatformBusInitData becomes private to the module
> - page_shift becomes a member of DynSysbusParams
> 
> v1: Dynamic sysbus device allocation fully written by Alex Graf.
> Those functions were initially in ppc e500 machine file. Now moved to a
> separate module.
> PPCE500Params is replaced by a generic struct named PlatformParams
> ---
>  hw/misc/Makefile.objs                |   1 +
>  hw/misc/dyn_sysbus_binding.c         | 163 +++++++++++++++++++++++++++++++++++

Please put these in hw/core/sysbus.c and include/hw/sysbus.h, and rename
everything called "Platform" or "platform_" to "Sysbus" or "sysbus_".

> +void platform_bus_init_notify(Notifier *notifier, void *data)
> +{
> +    DynSysbusNotifier *pn = (DynSysbusNotifier *)notifier;
> +    platform_bus_init(&pn->params, pn->address_space_mem, pn->mpic);
> +}

Please provide a wrapper like sysbus_register_dynamic that takes the
params/address_space_mem/mpic as parameter.  platform_bus_init_notify
and DynSysbusNotifier can remain hidden within the .c file.

Also, why not move the address_space_mem and mpic into the parameters
struct?

Paolo

>  include/hw/misc/dyn_sysbus_binding.h |  24 ++++++
>  3 files changed, 188 insertions(+)
>  create mode 100644 hw/misc/dyn_sysbus_binding.c
>  create mode 100644 include/hw/misc/dyn_sysbus_binding.h
> 
> diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
> index 979e532..86f6243 100644
> --- a/hw/misc/Makefile.objs
> +++ b/hw/misc/Makefile.objs
> @@ -41,3 +41,4 @@ obj-$(CONFIG_SLAVIO) += slavio_misc.o
>  obj-$(CONFIG_ZYNQ) += zynq_slcr.o
>  
>  obj-$(CONFIG_PVPANIC) += pvpanic.o
> +obj-y += dyn_sysbus_binding.o
> diff --git a/hw/misc/dyn_sysbus_binding.c b/hw/misc/dyn_sysbus_binding.c
> new file mode 100644
> index 0000000..0f34f0b
> --- /dev/null
> +++ b/hw/misc/dyn_sysbus_binding.c
> @@ -0,0 +1,163 @@
> +#include "hw/misc/dyn_sysbus_binding.h"
> +#include "qemu/error-report.h"
> +
> +typedef struct PlatformBusInitData {
> +    unsigned long *used_irqs;
> +    unsigned long *used_mem;
> +    MemoryRegion *mem;
> +    qemu_irq *irqs;
> +    int device_count;
> +    DynSysbusParams *params;
> +} PlatformBusInitData;
> +
> +
> +static int platform_bus_map_irq(DynSysbusParams *params,
> +                                SysBusDevice *sbdev,
> +                                int n, unsigned long *used_irqs,
> +                                qemu_irq *platform_irqs)
> +{
> +    int max_irqs = params->platform_bus_num_irqs;
> +    char *prop = g_strdup_printf("irq[%d]", n);
> +    int irqn = object_property_get_int(OBJECT(sbdev), prop, NULL);
> +
> +    if (irqn == SYSBUS_DYNAMIC) {
> +        /* Find the first available IRQ */
> +        irqn = find_first_zero_bit(used_irqs, max_irqs);
> +    }
> +
> +    if ((irqn >= max_irqs) || test_and_set_bit(irqn, used_irqs)) {
> +        hw_error("IRQ %d is already allocated or no free IRQ left", irqn);
> +    }
> +
> +    sysbus_connect_irq(sbdev, n, platform_irqs[irqn]);
> +    object_property_set_int(OBJECT(sbdev), irqn, prop, NULL);
> +
> +    g_free(prop);
> +    return 0;
> +}
> +
> +static int platform_bus_map_mmio(DynSysbusParams *params,
> +                                 SysBusDevice *sbdev,
> +                                 int n, unsigned long *used_mem,
> +                                 MemoryRegion *pmem)
> +{
> +    MemoryRegion *device_mem = sbdev->mmio[n].memory;
> +    uint64_t size = memory_region_size(device_mem);
> +    uint64_t page_size = (1 << params->page_shift);
> +    uint64_t page_mask = page_size - 1;
> +    uint64_t size_pages = (size + page_mask) >> params->page_shift;
> +    uint64_t max_size = params->platform_bus_size;
> +    uint64_t max_pages = max_size >> params->page_shift;
> +    char *prop = g_strdup_printf("mmio[%d]", n);
> +    hwaddr addr = object_property_get_int(OBJECT(sbdev), prop, NULL);
> +    int page;
> +    int i;
> +
> +    page = addr >> params->page_shift;
> +    if (addr == SYSBUS_DYNAMIC) {
> +        uint64_t size_pages_align;
> +
> +        /* Align the region to at least its own size granularity */
> +        if (is_power_of_2(size_pages)) {
> +            size_pages_align = size_pages;
> +        } else {
> +            size_pages_align = pow2floor(size_pages) << 1;
> +        }
> +
> +        /* Find the first available region that fits */
> +        page = bitmap_find_next_zero_area(used_mem, max_pages, 0, size_pages,
> +                                          size_pages_align);
> +
> +        addr = (uint64_t)page << params->page_shift;
> +    }
> +
> +    if (page >= max_pages || test_bit(page, used_mem) ||
> +        (find_next_bit(used_mem, max_pages, page) < size_pages)) {
> +        hw_error("Memory [%"PRIx64":%"PRIx64" is already allocated or "
> +                 "no slot left", addr, size);
> +    }
> +
> +    for (i = page; i < (page + size_pages); i++) {
> +        set_bit(i, used_mem);
> +    }
> +
> +    memory_region_add_subregion(pmem, addr, device_mem);
> +    sbdev->mmio[n].addr = addr;
> +    object_property_set_int(OBJECT(sbdev), addr, prop, NULL);
> +
> +    g_free(prop);
> +    return 0;
> +}
> +
> +static int sysbus_device_check(Object *obj, void *opaque)
> +{
> +    PlatformBusInitData *init = opaque;
> +    Object *dev;
> +    SysBusDevice *sbdev;
> +    int i;
> +
> +    dev = object_dynamic_cast(obj, TYPE_SYS_BUS_DEVICE);
> +    sbdev = (SysBusDevice *)dev;
> +
> +    if (!sbdev) {
> +        /* Container, traverse it for children */
> +        return object_child_foreach(obj, sysbus_device_check, opaque);
> +    }
> +
> +    /* Connect sysbus device to virtual platform bus */
> +    for (i = 0; i < sbdev->num_irq; i++) {
> +        if (!sbdev->irqp[i]) {
> +            /* This IRQ is an incoming IRQ, we can't wire those here */
> +            continue;
> +        }
> +        platform_bus_map_irq(init->params, sbdev, i,
> +                             init->used_irqs, init->irqs);
> +    }
> +
> +    for (i = 0; i < sbdev->num_mmio; i++) {
> +        platform_bus_map_mmio(init->params, sbdev, i,
> +                              init->used_mem, init->mem);
> +    }
> +
> +    return 0;
> +}
> +
> +static void platform_bus_init(DynSysbusParams *params,
> +                       MemoryRegion *address_space_mem,
> +                       qemu_irq *mpic)
> +{
> +    uint64_t max_size = params->platform_bus_size;
> +    uint64_t max_pages = max_size >> params->page_shift;
> +    DECLARE_BITMAP(used_irqs, params->platform_bus_num_irqs);
> +    DECLARE_BITMAP(used_mem, max_pages);
> +    MemoryRegion *platform_region = g_new(MemoryRegion, 1);
> +    Object *container;
> +    PlatformBusInitData init = {
> +        .used_irqs = used_irqs,
> +        .used_mem = used_mem,
> +        .mem = platform_region,
> +        .irqs = &mpic[params->platform_bus_first_irq],
> +        .params = params,
> +    };
> +
> +    memory_region_init(platform_region, NULL, "platform devices",
> +                       params->platform_bus_size);
> +
> +    bitmap_clear(used_irqs, 0, params->platform_bus_num_irqs);
> +    bitmap_clear(used_mem, 0, max_pages);
> +
> +    /* Loop through all sysbus devices that were spawened outside the machine */
> +    container = container_get(qdev_get_machine(), "/peripheral");
> +    sysbus_device_check(container, &init);
> +    container = container_get(qdev_get_machine(), "/peripheral-anon");
> +    sysbus_device_check(container, &init);
> +
> +    memory_region_add_subregion(address_space_mem, params->platform_bus_base,
> +                                platform_region);
> +}
> +
> +void platform_bus_init_notify(Notifier *notifier, void *data)
> +{
> +    DynSysbusNotifier *pn = (DynSysbusNotifier *)notifier;
> +    platform_bus_init(&pn->params, pn->address_space_mem, pn->mpic);
> +}
> diff --git a/include/hw/misc/dyn_sysbus_binding.h b/include/hw/misc/dyn_sysbus_binding.h
> new file mode 100644
> index 0000000..961c9c7
> --- /dev/null
> +++ b/include/hw/misc/dyn_sysbus_binding.h
> @@ -0,0 +1,24 @@
> +#ifndef HW_MISC_PLATFORM_DEVICES_H
> +#define HW_MISC_PLATFORM_DEVICES_H
> +
> +#include "qemu-common.h"
> +#include "hw/sysbus.h"
> +
> +typedef struct {
> +    bool has_platform_bus;
> +    hwaddr platform_bus_base;
> +    hwaddr platform_bus_size;
> +    int platform_bus_first_irq;
> +    int platform_bus_num_irqs;
> +    int page_shift;
> +} DynSysbusParams;
> +
> +typedef struct DynSysbusNotifier {
> +    Notifier notifier;
> +    MemoryRegion *address_space_mem;
> +    qemu_irq *mpic;
> +    DynSysbusParams params;
> +} DynSysbusNotifier;
> +
> +void platform_bus_init_notify(Notifier *notifier, void *data);
> +#endif
>