Re: [Qemu-devel] [PATCH-for-4.2 v11 03/11] hw/acpi: Add ACPI Generic Event Device Support

[Igor Mammedov]

On Wed, 18 Sep 2019 14:06:25 +0100
Shameer Kolothum <address@hidden> wrote:

> From: Samuel Ortiz <address@hidden>
> 
> The ACPI Generic Event Device (GED) is a hardware-reduced specific
> device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> including the hotplug ones. This patch generates the AML code that
> defines GEDs.
> 
> Platforms need to specify their own GED Event bitmap to describe
> what kind of events they want to support through GED.  Also this
> uses a a single interrupt for the  GED device, relying on IO
> memory region to communicate the type of device affected by the
> interrupt. This way, we can support up to 32 events with a unique
> interrupt.
> 
> This supports only memory hotplug for now.
> 
> Signed-off-by: Samuel Ortiz <address@hidden>
> Signed-off-by: Sebastien Boeuf <address@hidden>
> Signed-off-by: Shameer Kolothum <address@hidden>
> Reviewed-by: Eric Auger <address@hidden>

Reviewed-by: Igor Mammedov <address@hidden>

> ---
> Addressed comments from Igor.
>  - Removed memhp_state.is_enabled condition check and property.
>  - Used instance_init() instead of realize()
> ---
>  hw/acpi/Kconfig                        |   4 +
>  hw/acpi/Makefile.objs                  |   1 +
>  hw/acpi/generic_event_device.c         | 303 +++++++++++++++++++++++++
>  include/hw/acpi/generic_event_device.h | 100 ++++++++
>  4 files changed, 408 insertions(+)
>  create mode 100644 hw/acpi/generic_event_device.c
>  create mode 100644 include/hw/acpi/generic_event_device.h
> 
> diff --git a/hw/acpi/Kconfig b/hw/acpi/Kconfig
> index 7c59cf900b..12e3f1e86e 100644
> --- a/hw/acpi/Kconfig
> +++ b/hw/acpi/Kconfig
> @@ -31,3 +31,7 @@ config ACPI_VMGENID
>      bool
>      default y
>      depends on PC
> +
> +config ACPI_HW_REDUCED
> +    bool
> +    depends on ACPI
> diff --git a/hw/acpi/Makefile.objs b/hw/acpi/Makefile.objs
> index 9bb2101e3b..655a9c1973 100644
> --- a/hw/acpi/Makefile.objs
> +++ b/hw/acpi/Makefile.objs
> @@ -6,6 +6,7 @@ common-obj-$(CONFIG_ACPI_MEMORY_HOTPLUG) += memory_hotplug.o
>  common-obj-$(CONFIG_ACPI_CPU_HOTPLUG) += cpu.o
>  common-obj-$(CONFIG_ACPI_NVDIMM) += nvdimm.o
>  common-obj-$(CONFIG_ACPI_VMGENID) += vmgenid.o
> +common-obj-$(CONFIG_ACPI_HW_REDUCED) += generic_event_device.o
>  common-obj-$(call lnot,$(CONFIG_ACPI_X86)) += acpi-stub.o
>  
>  common-obj-y += acpi_interface.o
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> new file mode 100644
> index 0000000000..b94500b08d
> --- /dev/null
> +++ b/hw/acpi/generic_event_device.c
> @@ -0,0 +1,303 @@
> +/*
> + *
> + * Copyright (c) 2018 Intel Corporation
> + * Copyright (c) 2019 Huawei Technologies R & D (UK) Ltd
> + * Written by Samuel Ortiz, Shameer Kolothum
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2 or later, as published by the Free Software Foundation.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "exec/address-spaces.h"
> +#include "hw/acpi/acpi.h"
> +#include "hw/acpi/generic_event_device.h"
> +#include "hw/irq.h"
> +#include "hw/mem/pc-dimm.h"
> +#include "hw/qdev-properties.h"
> +#include "migration/vmstate.h"
> +#include "qemu/error-report.h"
> +
> +static const uint32_t ged_supported_events[] = {
> +    ACPI_GED_MEM_HOTPLUG_EVT,
> +};
> +
> +/*
> + * The ACPI Generic Event Device (GED) is a hardware-reduced specific
> + * device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> + * including the hotplug ones. Platforms need to specify their own
> + * GED Event bitmap to describe what kind of events they want to support
> + * through GED. This routine uses a single interrupt for the GED device,
> + * relying on IO memory region to communicate the type of device
> + * affected by the interrupt. This way, we can support up to 32 events
> + * with a unique interrupt.
> + */
> +void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev,
> +                   uint32_t ged_irq, AmlRegionSpace rs, hwaddr ged_base)
> +{
> +    AcpiGedState *s = ACPI_GED(hotplug_dev);
> +    Aml *crs = aml_resource_template();
> +    Aml *evt, *field;
> +    Aml *dev = aml_device("%s", name);
> +    Aml *evt_sel = aml_local(0);
> +    Aml *esel = aml_name(AML_GED_EVT_SEL);
> +
> +    /* _CRS interrupt */
> +    aml_append(crs, aml_interrupt(AML_CONSUMER, AML_EDGE, AML_ACTIVE_HIGH,
> +                                  AML_EXCLUSIVE, &ged_irq, 1));
> +
> +    aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0013")));
> +    aml_append(dev, aml_name_decl("_UID", aml_string(GED_DEVICE)));
> +    aml_append(dev, aml_name_decl("_CRS", crs));
> +
> +    /* Append IO region */
> +    aml_append(dev, aml_operation_region(AML_GED_EVT_REG, rs,
> +               aml_int(ged_base + ACPI_GED_EVT_SEL_OFFSET),
> +               ACPI_GED_EVT_SEL_LEN));
> +    field = aml_field(AML_GED_EVT_REG, AML_DWORD_ACC, AML_NOLOCK,
> +                      AML_WRITE_AS_ZEROS);
> +    aml_append(field, aml_named_field(AML_GED_EVT_SEL,
> +                                      ACPI_GED_EVT_SEL_LEN * BITS_PER_BYTE));
> +    aml_append(dev, field);
> +
> +    /*
> +     * For each GED event we:
> +     * - Add a conditional block for each event, inside a loop.
> +     * - Call a method for each supported GED event type.
> +     *
> +     * The resulting ASL code looks like:
> +     *
> +     * Local0 = ESEL
> +     * If ((Local0 & One) == One)
> +     * {
> +     *     MethodEvent0()
> +     * }
> +     *
> +     * If ((Local0 & 0x2) == 0x2)
> +     * {
> +     *     MethodEvent1()
> +     * }
> +     * ...
> +     */
> +    evt = aml_method("_EVT", 1, AML_SERIALIZED);
> +    {
> +        Aml *if_ctx;
> +        uint32_t i;
> +        uint32_t ged_events = ctpop32(s->ged_event_bitmap);
> +
> +        /* Local0 = ESEL */
> +        aml_append(evt, aml_store(esel, evt_sel));
> +
> +        for (i = 0; i < ARRAY_SIZE(ged_supported_events) && ged_events; i++) 
> {
> +            uint32_t event = s->ged_event_bitmap & ged_supported_events[i];
> +
> +            if (!event) {
> +                continue;
> +            }
> +
> +            if_ctx = aml_if(aml_equal(aml_and(evt_sel, aml_int(event), NULL),
> +                                      aml_int(event)));
> +            switch (event) {
> +            case ACPI_GED_MEM_HOTPLUG_EVT:
> +                aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "."
> +                                             MEMORY_SLOT_SCAN_METHOD));
> +                break;
> +            default:
> +                /*
> +                 * Please make sure all the events in ged_supported_events[]
> +                 * are handled above.
> +                 */
> +                g_assert_not_reached();
> +            }
> +
> +            aml_append(evt, if_ctx);
> +            ged_events--;
> +        }
> +
> +        if (ged_events) {
> +            error_report("Unsupported events specified");
> +            abort();
> +        }
> +    }
> +
> +    /* Append _EVT method */
> +    aml_append(dev, evt);
> +
> +    aml_append(table, dev);
> +}
> +
> +/* Memory read by the GED _EVT AML dynamic method */
> +static uint64_t ged_read(void *opaque, hwaddr addr, unsigned size)
> +{
> +    uint64_t val = 0;
> +    GEDState *ged_st = opaque;
> +
> +    switch (addr) {
> +    case ACPI_GED_EVT_SEL_OFFSET:
> +        /* Read the selector value and reset it */
> +        val = ged_st->sel;
> +        ged_st->sel = 0;
> +        break;
> +    default:
> +        break;
> +    }
> +
> +    return val;
> +}
> +
> +/* Nothing is expected to be written to the GED memory region */
> +static void ged_write(void *opaque, hwaddr addr, uint64_t data,
> +                      unsigned int size)
> +{
> +}
> +
> +static const MemoryRegionOps ged_ops = {
> +    .read = ged_read,
> +    .write = ged_write,
> +    .endianness = DEVICE_LITTLE_ENDIAN,
> +    .valid = {
> +        .min_access_size = 4,
> +        .max_access_size = 4,
> +    },
> +};
> +
> +static void acpi_ged_device_plug_cb(HotplugHandler *hotplug_dev,
> +                                    DeviceState *dev, Error **errp)
> +{
> +    AcpiGedState *s = ACPI_GED(hotplug_dev);
> +
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +            acpi_memory_plug_cb(hotplug_dev, &s->memhp_state, dev, errp);
> +    } else {
> +        error_setg(errp, "virt: device plug request for unsupported device"
> +                   " type: %s", object_get_typename(OBJECT(dev)));
> +    }
> +}
> +
> +static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits ev)
> +{
> +    AcpiGedState *s = ACPI_GED(adev);
> +    GEDState *ged_st = &s->ged_state;
> +    uint32_t sel;
> +
> +    if (ev & ACPI_MEMORY_HOTPLUG_STATUS) {
> +        sel = ACPI_GED_MEM_HOTPLUG_EVT;
> +    } else {
> +        /* Unknown event. Return without generating interrupt. */
> +        warn_report("GED: Unsupported event %d. No irq injected", ev);
> +        return;
> +    }
> +
> +    /*
> +     * Set the GED selector field to communicate the event type.
> +     * This will be read by GED aml code to select the appropriate
> +     * event method.
> +     */
> +    ged_st->sel |= sel;
> +
> +    /* Trigger the event by sending an interrupt to the guest. */
> +    qemu_irq_pulse(s->irq);
> +}
> +
> +static Property acpi_ged_properties[] = {
> +    DEFINE_PROP_UINT32("ged-event", AcpiGedState, ged_event_bitmap, 0),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static const VMStateDescription vmstate_memhp_state = {
> +    .name = "acpi-ged/memhp",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_MEMORY_HOTPLUG(memhp_state, AcpiGedState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static const VMStateDescription vmstate_ged_state = {
> +    .name = "acpi-ged-state",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_UINT32(sel, GEDState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static const VMStateDescription vmstate_acpi_ged = {
> +    .name = "acpi-ged",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_STRUCT(ged_state, AcpiGedState, 1, vmstate_ged_state, 
> GEDState),
> +        VMSTATE_END_OF_LIST(),
> +    },
> +    .subsections = (const VMStateDescription * []) {
> +        &vmstate_memhp_state,
> +        NULL
> +    }
> +};
> +
> +static void acpi_ged_initfn(Object *obj)
> +{
> +    DeviceState *dev = DEVICE(obj);
> +    AcpiGedState *s = ACPI_GED(dev);
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> +    GEDState *ged_st = &s->ged_state;
> +
> +    memory_region_init_io(&ged_st->io, obj, &ged_ops, ged_st,
> +                          TYPE_ACPI_GED, ACPI_GED_EVT_SEL_LEN);
> +    sysbus_init_mmio(sbd, &ged_st->io);
> +
> +    sysbus_init_irq(sbd, &s->irq);
> +
> +    s->memhp_state.is_enabled = true;
> +    /*
> +     * GED handles memory hotplug event and acpi-mem-hotplug
> +     * memory region gets initialized here. Create an exclusive
> +     * container for memory hotplug IO and expose it as GED sysbus
> +     * MMIO so that boards can map it separately.
> +     */
> +     memory_region_init(&s->container_memhp, OBJECT(dev), "memhp container",
> +                        MEMORY_HOTPLUG_IO_LEN);
> +     sysbus_init_mmio(sbd, &s->container_memhp);
> +     acpi_memory_hotplug_init(&s->container_memhp, OBJECT(dev),
> +                              &s->memhp_state, 0);
> +}
> +
> +static void acpi_ged_class_init(ObjectClass *class, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(class);
> +    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(class);
> +    AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_CLASS(class);
> +
> +    dc->desc = "ACPI Generic Event Device";
> +    dc->props = acpi_ged_properties;
> +    dc->vmsd = &vmstate_acpi_ged;
> +
> +    hc->plug = acpi_ged_device_plug_cb;
> +
> +    adevc->send_event = acpi_ged_send_event;
> +}
> +
> +static const TypeInfo acpi_ged_info = {
> +    .name          = TYPE_ACPI_GED,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(AcpiGedState),
> +    .instance_init  = acpi_ged_initfn,
> +    .class_init    = acpi_ged_class_init,
> +    .interfaces = (InterfaceInfo[]) {
> +        { TYPE_HOTPLUG_HANDLER },
> +        { TYPE_ACPI_DEVICE_IF },
> +        { }
> +    }
> +};
> +
> +static void acpi_ged_register_types(void)
> +{
> +    type_register_static(&acpi_ged_info);
> +}
> +
> +type_init(acpi_ged_register_types)
> diff --git a/include/hw/acpi/generic_event_device.h 
> b/include/hw/acpi/generic_event_device.h
> new file mode 100644
> index 0000000000..2049e8d873
> --- /dev/null
> +++ b/include/hw/acpi/generic_event_device.h
> @@ -0,0 +1,100 @@
> +/*
> + *
> + * Copyright (c) 2018 Intel Corporation
> + * Copyright (c) 2019 Huawei Technologies R & D (UK) Ltd
> + * Written by Samuel Ortiz, Shameer Kolothum
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2 or later, as published by the Free Software Foundation.
> + *
> + * The ACPI Generic Event Device (GED) is a hardware-reduced specific
> + * device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> + * including the hotplug ones. Generic Event Device allows platforms
> + * to handle interrupts in ACPI ASL statements. It follows a very
> + * similar approach like the _EVT method from GPIO events. All
> + * interrupts are listed in  _CRS and the handler is written in _EVT
> + * method. Here, we use a single interrupt for the GED device, relying
> + * on IO memory region to communicate the type of device affected by
> + * the interrupt. This way, we can support up to 32 events with a
> + * unique interrupt.
> + *
> + * Here is an example.
> + *
> + * Device (\_SB.GED)
> + * {
> + *     Name (_HID, "ACPI0013")
> + *     Name (_UID, Zero)
> + *     Name (_CRS, ResourceTemplate ()
> + *     {
> + *         Interrupt (ResourceConsumer, Edge, ActiveHigh, Exclusive, ,, )
> + *         {
> + *              0x00000029,
> + *         }
> + *     })
> + *     OperationRegion (EREG, SystemMemory, 0x09080000, 0x04)
> + *     Field (EREG, DWordAcc, NoLock, WriteAsZeros)
> + *     {
> + *         ESEL,   32
> + *     }
> + *
> + *     Method (_EVT, 1, Serialized)  // _EVT: Event
> + *     {
> + *         Local0 = ESEL // ESEL = IO memory region which specifies the
> + *                       // device type.
> + *         If (((Local0 & One) == One))
> + *         {
> + *             MethodEvent1()
> + *         }
> + *         If ((Local0 & 0x2) == 0x2)
> + *         {
> + *             MethodEvent2()
> + *         }
> + *         ...
> + *     }
> + * }
> + *
> + */
> +
> +#ifndef HW_ACPI_GED_H
> +#define HW_ACPI_GED_H
> +
> +#include "hw/sysbus.h"
> +#include "hw/acpi/memory_hotplug.h"
> +
> +#define TYPE_ACPI_GED "acpi-ged"
> +#define ACPI_GED(obj) \
> +    OBJECT_CHECK(AcpiGedState, (obj), TYPE_ACPI_GED)
> +
> +#define ACPI_GED_EVT_SEL_OFFSET    0x0
> +#define ACPI_GED_EVT_SEL_LEN       0x4
> +
> +#define GED_DEVICE      "GED"
> +#define AML_GED_EVT_REG "EREG"
> +#define AML_GED_EVT_SEL "ESEL"
> +
> +/*
> + * Platforms need to specify the GED event bitmap
> + * to describe what kind of events they want to support
> + * through GED.
> + */
> +#define ACPI_GED_MEM_HOTPLUG_EVT   0x1
> +
> +typedef struct GEDState {
> +    MemoryRegion io;
> +    uint32_t     sel;
> +} GEDState;
> +
> +typedef struct AcpiGedState {
> +    SysBusDevice parent_obj;
> +    MemHotplugState memhp_state;
> +    MemoryRegion container_memhp;
> +    GEDState ged_state;
> +    uint32_t ged_event_bitmap;
> +    qemu_irq irq;
> +} AcpiGedState;
> +
> +void build_ged_aml(Aml *table, const char* name, HotplugHandler *hotplug_dev,
> +                   uint32_t ged_irq, AmlRegionSpace rs, hwaddr ged_base);
> +
> +#endif