Re: [Qemu-devel] [PATCH 14/15] acpi: Add hooks for adding things to the SSDT table

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Apr 07, 2015 at 02:51:43PM -0500, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
> 
> This way devices can tie in when then SSDT is built and can add their
> own entries.  This didn't seem to fit anyplace else, primarily because it
> required the Aml type, so I added a new file for it.
> 
> Signed-off-by: Corey Minyard <cminyard@mvista.com>

Hmm, I don't see patch 15/15 so I don't know how this is used.

Presumably devices register using add_device_ssdt_encoder?
Can't they, instead, add their tables to some list at that point?

It also would seem a bit easier to debug to have devices add their own
tables rather than patch SSDT.
Somewhere near the line
    /* Add tables supplied by user (if any) */
would be a good place to stick this.


> ---
>  hw/acpi/Makefile.objs        |  1 +
>  hw/acpi/acpi-hooks.c         | 55 ++++++++++++++++++++++++++++++++++++++++++++
>  hw/i386/acpi-build.c         |  3 +++
>  include/hw/acpi/acpi-hooks.h | 31 +++++++++++++++++++++++++
>  4 files changed, 90 insertions(+)
>  create mode 100644 hw/acpi/acpi-hooks.c
>  create mode 100644 include/hw/acpi/acpi-hooks.h
> 
> diff --git a/hw/acpi/Makefile.objs b/hw/acpi/Makefile.objs
> index b9fefa7..f60b12a 100644
> --- a/hw/acpi/Makefile.objs
> +++ b/hw/acpi/Makefile.objs
> @@ -3,3 +3,4 @@ common-obj-$(CONFIG_ACPI) += memory_hotplug.o
>  common-obj-$(CONFIG_ACPI) += acpi_interface.o
>  common-obj-$(CONFIG_ACPI) += bios-linker-loader.o
>  common-obj-$(CONFIG_ACPI) += aml-build.o
> +common-obj-$(CONFIG_ACPI) += acpi-hooks.o
> diff --git a/hw/acpi/acpi-hooks.c b/hw/acpi/acpi-hooks.c
> new file mode 100644
> index 0000000..c499208
> --- /dev/null
> +++ b/hw/acpi/acpi-hooks.c
> @@ -0,0 +1,55 @@
> +/*
> + * ACPI hooks for inserting table entries from devices into the SSDT table.
> + *
> + * Copyright (c) 2015 Corey Minyard, MontaVista Software, LLC
> + *
> + * 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/acpi/acpi-hooks.h>
> +#include <qemu/queue.h>
> +
> +struct ssdt_device_encoder {
> +    void (*encode)(Aml *ssdt, void *opaque);
> +    void *opaque;
> +    QSLIST_ENTRY(ssdt_device_encoder) next;
> +};
> +
> +static QSLIST_HEAD(ssdt_device_encoders, ssdt_device_encoder)
> +     ssdt_device_encoders = QSLIST_HEAD_INITIALIZER(&ssdt_device_encoders);
> +
> +void
> +add_device_ssdt_encoder(void (*encode)(Aml *ssdt, void *opaque), void *opaque)
> +{
> +    struct ssdt_device_encoder *e = g_new0(struct ssdt_device_encoder, 1);
> +
> +    e->encode = encode;
> +    e->opaque = opaque;
> +    QSLIST_INSERT_HEAD(&ssdt_device_encoders, e, next);
> +}
> +
> +void
> +call_device_ssdt_encoders(Aml *ssdt)
> +{
> +    struct ssdt_device_encoder *e;
> +
> +    QSLIST_FOREACH(e, &ssdt_device_encoders, next) {
> +        e->encode(ssdt, e->opaque);
> +    }
> +}
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index e761005..3a4b1ce 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -35,6 +35,7 @@
>  #include "hw/timer/hpet.h"
>  #include "hw/i386/acpi-defs.h"
>  #include "hw/acpi/acpi.h"
> +#include "hw/acpi/acpi-hooks.h"
>  #include "hw/nvram/fw_cfg.h"
>  #include "hw/acpi/bios-linker-loader.h"
>  #include "hw/loader.h"
> @@ -1008,6 +1009,8 @@ build_ssdt(GArray *table_data, GArray *linker,
>          aml_append(ssdt, sb_scope);
>      }
>  
> +    call_device_ssdt_encoders(ssdt);
> +
>      /* copy AML table into ACPI tables blob and patch header there */
>      g_array_append_vals(table_data, ssdt->buf->data, ssdt->buf->len);
>      build_header(linker, table_data,
> diff --git a/include/hw/acpi/acpi-hooks.h b/include/hw/acpi/acpi-hooks.h
> new file mode 100644
> index 0000000..ae66925
> --- /dev/null
> +++ b/include/hw/acpi/acpi-hooks.h
> @@ -0,0 +1,31 @@
> +/*
> + * Hooks for dynamically construct ACPI tables in devices
> + *
> + * Copyright (C) 2015  Corey Minyard <cminyard@mvista.com>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License version 2 as published by the Free Software Foundation.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>
> + *
> + * Contributions after 2012-01-13 are licensed under the terms of the
> + * GNU GPL, version 2 or (at your option) any later version.
> + */
> +
> +#ifndef QEMU_HW_ACPI_HOOKS_H
> +#define QEMU_HW_ACPI_HOOKS_H
> +
> +#include <hw/acpi/aml-build.h>
> +
> +void add_device_ssdt_encoder(void (*encode)(Aml *ssdt, void *opaque),
> +                             void *opaque);
> +void call_device_ssdt_encoders(Aml *ssdt);
> +
> +#endif /* QEMU_HW_ACPI_HOOKS_H */
> -- 
> 1.8.3.1
>