bhyve: save softc of ACPI devices

[corvink]

Summary

This will be useful for writing device specific ACPI tables or DSDT
methods.

[corvink]

• rebase

[markj]

usr.sbin/bhyve/acpi_device.c

46

The comment above needs to be updated.

147

This can be an assertion.

[corvink]

• update commnent as suggested
• make use of assert
• pass fwcfg_sc as parent to acpi_device_create

[markj]

usr.sbin/bhyve/acpi_device.h

41

But it's not (necessarily) an ACPI device. The type is void * and the one caller passes a device softc.

Is "parent" really the right name? Should it just be an opaque "context" field?

[corvink]

usr.sbin/bhyve/acpi_device.h

41

Renaming this parameter is fine but I don't know which word fits best.

In C++ this would be solved by inheritance. E.g.:

class tpm_device: acpi_device
{ ... };

The tpm_device inherits from acpi_device. So, in C++ the tpm_device is an acpi_device.

My C code uses:

struct tpm_device {
  struct acpi_device *dev,
  ...
};

struct tpm_device tpm_softc;

int
tpm_init() {
  acpi_device_create(&tpm_softc.dev, &tpm_softc, ...);
  ...
}

int
tpm_do_some_stuff(struct acpi_device *dev) {
  sc = acpi_device_get_parent(dev);
  ...
}

[markj]

usr.sbin/bhyve/acpi_device.h

41

I'd call it softc (software context) or dev_ctx then.

[corvink]

• rename parent into softc