Re: [PATCH v2 1/2] acpi: ged: Add macro for acpi sleep control register

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 11 Sep 2024 11:09:21 +0800
Bibo Mao <maobibo@loongson.cn> wrote:

> Macro definition is added for acpi sleep control register, so that
> ged emulation driver can use this, also it can be used in FDT table if
> ged is exposed with FDT table.
> 
> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
> ---
>  hw/acpi/generic_event_device.c         | 6 +++---
>  hw/i386/acpi-microvm.c                 | 2 +-
>  hw/loongarch/acpi-build.c              | 2 +-
>  include/hw/acpi/generic_event_device.h | 9 +++++++--
>  4 files changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> index 15b4c3ebbf..94992e6119 100644
> --- a/hw/acpi/generic_event_device.c
> +++ b/hw/acpi/generic_event_device.c
> @@ -201,9 +201,9 @@ static void ged_regs_write(void *opaque, hwaddr addr, uint64_t data,
>  
>      switch (addr) {
>      case ACPI_GED_REG_SLEEP_CTL:
> -        slp_typ = (data >> 2) & 0x07;
> -        slp_en  = (data >> 5) & 0x01;
> -        if (slp_en && slp_typ == 5) {
> +        slp_typ = (data & ACPI_GED_SLP_TYPx_MASK) >> ACPI_GED_SLP_TYPx_POS;
this makes a bit more complex expression once macros are expanded,
but doesn't really helps to clarity.

If I have to touch/share this code, I'd replace magic numbers above
with corresponding simple numeric macro but keep the same expressions.

> +        slp_en  = !!(data & ACPI_GED_SLP_EN);
> +        if (slp_en && slp_typ == ACPI_GED_SLP_TYPx_S5) {
>              qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
>          }
>          return;
> diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c
> index 279da6b4aa..1e424076d2 100644
> --- a/hw/i386/acpi-microvm.c
> +++ b/hw/i386/acpi-microvm.c
> @@ -131,7 +131,7 @@ build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
>      /* ACPI 5.0: Table 7-209 System State Package */
>      scope = aml_scope("\\");
>      pkg = aml_package(4);
> -    aml_append(pkg, aml_int(ACPI_GED_SLP_TYP_S5));
> +    aml_append(pkg, aml_int(ACPI_GED_SLP_TYPx_S5));

what's the point of renaming this?

>      aml_append(pkg, aml_int(0)); /* ignored */
>      aml_append(pkg, aml_int(0)); /* reserved */
>      aml_append(pkg, aml_int(0)); /* reserved */
> diff --git a/hw/loongarch/acpi-build.c b/hw/loongarch/acpi-build.c
> index 2638f87434..974519a347 100644
> --- a/hw/loongarch/acpi-build.c
> +++ b/hw/loongarch/acpi-build.c
> @@ -418,7 +418,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, MachineState *machine)
>      /* System State Package */
>      scope = aml_scope("\\");
>      pkg = aml_package(4);
> -    aml_append(pkg, aml_int(ACPI_GED_SLP_TYP_S5));
> +    aml_append(pkg, aml_int(ACPI_GED_SLP_TYPx_S5));
>      aml_append(pkg, aml_int(0)); /* ignored */
>      aml_append(pkg, aml_int(0)); /* reserved */
>      aml_append(pkg, aml_int(0)); /* reserved */
> diff --git a/include/hw/acpi/generic_event_device.h b/include/hw/acpi/generic_event_device.h
> index 40af3550b5..41741e94ea 100644
> --- a/include/hw/acpi/generic_event_device.h
> +++ b/include/hw/acpi/generic_event_device.h
> @@ -81,8 +81,13 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
>  /* ACPI_GED_REG_RESET value for reset*/
>  #define ACPI_GED_RESET_VALUE       0x42
>  
> -/* ACPI_GED_REG_SLEEP_CTL.SLP_TYP value for S5 (aka poweroff) */
> -#define ACPI_GED_SLP_TYP_S5        0x05
> +/* [ACPI 5.0+ FADT] Sleep Control Register */
> +/* 3-bit field defines the type of hardware sleep state */
> +#define ACPI_GED_SLP_TYPx_POS      0x2
> +#define ACPI_GED_SLP_TYPx_MASK     (0x07 << ACPI_GED_SLP_TYPx_POS)
> +#define ACPI_GED_SLP_TYPx_S5       0x05  /* System \_S5 State (Soft Off) */
> +/* Write-only, Set this bit causes system to enter SLP_TYPx sleeping state */
> +#define ACPI_GED_SLP_EN            0x20
>  
>  #define GED_DEVICE      "GED"
>  #define AML_GED_EVT_REG "EREG"