Re: [Qemu-devel] [PATCH 50/74] pc: acpi: move FDC0 device from DSDT to SSDT

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

On Thu, Dec 10, 2015 at 12:41:44AM +0100, Igor Mammedov wrote:
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/i386/acpi-build.c      | 38 ++++++++++++++++++++++++++++++++------
>  hw/i386/acpi-dsdt-isa.dsl | 18 ------------------
>  2 files changed, 32 insertions(+), 24 deletions(-)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index e5ec6af..2f0f2e1 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1173,17 +1173,34 @@ static void build_hpet_aml(Aml *table)
>  
>  static Aml *
>  build_eisa_device_aml(const char *name, const char *hid, Aml *crs,
> -                      bool have_sta)
> +                      bool have_sta, const char *present_field)

At this point, the number of arguments is getting ridiculous.
I think you should give it up, and write a function
per device type, even if there's a minor code duplication
as a result.

As a bonus, we will get reasonably readable function
names, e.g.  build_floppy_controller()

>  {
>      Aml *dev;
>      Aml *method;
> -    Aml *a_device_present = aml_int(0x0f);
>  
>      dev = aml_device("%s", name);
>      aml_append(dev, aml_name_decl("_HID", aml_eisaid(hid)));
>      if (have_sta) {
> +        Aml *if_ctx;
> +        Aml *else_ctx;
> +        Aml *a_zero = aml_int(0);
> +        Aml *a_is_present = aml_local(0);
> +        Aml *a_device_present = aml_int(0x0f);
> +        Aml *a_device_not_present = aml_int(0x00);
> +

What does a_ prefix mean here?

>          method = aml_method("_STA", 0, AML_NOTSERIALIZED);
> -        aml_append(method, aml_return(a_device_present));
> +        if (!present_field) {
> +            aml_append(method, aml_return(a_device_present));
> +        } else {
> +            aml_append(method,
> +                aml_store(aml_name("%s", present_field), a_is_present));
> +            if_ctx = aml_if(aml_equal(a_is_present, a_zero));
> +            aml_append(if_ctx, aml_return(a_device_not_present));
> +            aml_append(method, if_ctx);
> +            else_ctx = aml_else();
> +            aml_append(else_ctx, aml_return(a_device_present));
> +            aml_append(method, else_ctx);
> +        }
>          aml_append(dev, method);
>      }
>      aml_append(dev, aml_name_decl("_CRS", crs));
> @@ -1201,19 +1218,28 @@ static void build_isa_devices_aml(Aml *table)
>      aml_append(crs, aml_irq_no_flags(8));
>      aml_append(crs, aml_io(AML_DECODE16, 0x0072, 0x0072, 0x02, 0x06));
>      aml_append(scope, build_eisa_device_aml(
> -        "RTC", "PNP0B00", crs, false));
> +        "RTC", "PNP0B00", crs, false, NULL));
>  
>      crs = aml_resource_template();
>      aml_append(crs, aml_io(AML_DECODE16, 0x0060, 0x0060, 0x01, 0x01));
>      aml_append(crs, aml_io(AML_DECODE16, 0x0064, 0x0064, 0x01, 0x01));
>      aml_append(crs, aml_irq_no_flags(1));
>      aml_append(scope, build_eisa_device_aml(
> -        "KBD", "PNP0303", crs, true));
> +        "KBD", "PNP0303", crs, true, NULL));
>  
>      crs = aml_resource_template();
>      aml_append(crs, aml_irq_no_flags(12));
>      aml_append(scope, build_eisa_device_aml(
> -        "MOU", "PNP0F13", crs, true));
> +        "MOU", "PNP0F13", crs, true, NULL));
> +
> +    crs = aml_resource_template();
> +    aml_append(crs, aml_io(AML_DECODE16, 0x03F2, 0x03F2, 0x00, 0x04));
> +    aml_append(crs, aml_io(AML_DECODE16, 0x03F7, 0x03F7, 0x00, 0x01));
> +    aml_append(crs, aml_irq_no_flags(6));
> +    aml_append(crs,
> +        aml_dma(AML_COMPATIBILITY, AML_NOTBUSMASTER, AML_TRANSFER8, 2));
> +    aml_append(scope, build_eisa_device_aml(
> +        "FDC0", "PNP0700", crs, true, "FDEN"));
>  
>      aml_append(table, scope);
>  }
> diff --git a/hw/i386/acpi-dsdt-isa.dsl b/hw/i386/acpi-dsdt-isa.dsl
> index 8936271..64dd4ac 100644
> --- a/hw/i386/acpi-dsdt-isa.dsl
> +++ b/hw/i386/acpi-dsdt-isa.dsl
> @@ -16,24 +16,6 @@
>  /* Common legacy ISA style devices. */
>  Scope(\_SB.PCI0.ISA) {
>  
> -    Device(FDC0) {
> -        Name(_HID, EisaId("PNP0700"))
> -        Method(_STA, 0, NotSerialized) {
> -            Store(FDEN, Local0)
> -            If (LEqual(Local0, 0)) {
> -                Return (0x00)
> -            } Else {
> -                Return (0x0F)
> -            }
> -        }

All these guys have in common is the _STA method.
So write a function generating one, and be done with it.


> -        Name(_CRS, ResourceTemplate() {
> -            IO(Decode16, 0x03F2, 0x03F2, 0x00, 0x04)
> -            IO(Decode16, 0x03F7, 0x03F7, 0x00, 0x01)
> -            IRQNoFlags() { 6 }
> -            DMA(Compatibility, NotBusMaster, Transfer8) { 2 }
> -        })
> -    }
> -
>      Device(LPT) {
>          Name(_HID, EisaId("PNP0400"))
>          Method(_STA, 0, NotSerialized) {
> -- 
> 1.8.3.1
>