Re: [PATCH] ACPICA / hwreg: Use acpi_gbl_reduced_hardware to prevent accessing PM registers

[Hanjun Guo <hanjun.guo@linaro.org>]

On 2013-9-19 10:37, Moore, Robert wrote:
> While we are at it, here is the *complete* list of ACPICA interfaces that are 
> meaningless on a hardware-reduced platform. If we are going to dynamically
> disable some of these interfaces, we will need to disable all of them -- for
> completeness. So, this is actually not a trivial change.

Yes, you are right.
Actually, before I send this patch out, I searched all the ACPICA API on
a hardware-reduced platform as you did, I found some of them will finally call
acpi_hw_register_read/write(), so some of the ACPICA API do not need to change.

Some of these APIs are already disabled in linux kernel tree now, such as
acpi_enable():
acpi_status acpi_enable(void)
{
	acpi_status status;
	int retry;

	ACPI_FUNCTION_TRACE(acpi_enable);

	/* ACPI tables must be present */

	if (!acpi_tb_tables_loaded()) {
		return_ACPI_STATUS(AE_NO_ACPI_TABLES);
	}

	/* If the Hardware Reduced flag is set, machine is always in acpi mode */

	if (acpi_gbl_reduced_hardware) {
		return_ACPI_STATUS(AE_OK);
	}
...
}

and some of them need to be disabled as you said.

> 
> I'll let the linux experts chime in on this one.
> Bob
> 
> 
> AcpiInstallSciHandler
> AcpiRemoveSciHandler
> AcpiInstallGlobalEventHandler
> AcpiInstallFixedEventHandler
> AcpiRemoveFixedEventHandler
> AcpiInstallGpeHandler
> AcpiRemoveGpeHandler
> AcpiAcquireGlobalLock
> AcpiReleaseGlobalLock
> AcpiEnable
> AcpiDisable
> AcpiEnableEvent
> AcpiDisableEvent
> AcpiClearEvent
> AcpiGetEventStatus
> AcpiUpdateAllGpes
> AcpiEnableGpe
> AcpiDisableGpe
> AcpiSetGpe
> AcpiSetupGpeForWake
> AcpiSetGpeWakeMask
> AcpiClearGpe
> AcpiGetGpeStatus
> AcpiFinishGpe
> AcpiDisableAllGpes
> AcpiEnableAllRuntimeGpes
> AcpiInstallGpeBlock
> AcpiRemoveGpeBlock
> AcpiGetGpeDevice
> AcpiGetTimerResolution
> AcpiGetTimer
> AcpiGetTimerDuration
> AcpiReadBitRegister
> AcpiWriteBitRegister
> AcpiSetFirmwareWakingVector
> AcpiSetFirmwareWakingVector64
> AcpiEnterSleepStateS4bios