Subject: [PATCH 2/2] ACPI: Ignore Consumer/Producer for QWord/DWord/Word Address Space

From: [email-masked] (Lorenzo Pieralisi)
Date: Wed, 30 Nov 2016 12:04:25 +0000

On Tue, Nov 29, 2016 at 12:43:34PM -0600, Bjorn Helgaas wrote:
> Per ACPI spec r6.0, sec 6.4.3.5.1, 2, 3, Bit [0] of General Flags (the
> Consumer/Producer bit) should be ignored for QWord/DWord/Word Address Space
> descriptors.  The Consumer/Producer bit is defined only for the Extended
> Address Space descriptor.
> 
> Ignore Consumer/Producer except for Extended Address Space descriptors.
> 
> Note that for QWord/DWord/Word descriptors, we previously applied the
> translation offset (_TRA) only when the Consumer/Producer bit was set.

"..Consumer/Producer bit was clear" ? If that bit was set:

struct acpi_resource_address->producer_consumer == ACPI_CONSUMER

and we are not applying the _TRA offset in that case, right ?

Thanks,
Lorenzo

> This patch changes that: for those descriptors, we ignore Consumer/Producer
> and always apply the translation offset.
> 
> Signed-off-by: Bjorn Helgaas <[email-masked]>
> ---
>  drivers/acpi/resource.c |   16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 2732d39e..b45cd8f 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -261,11 +261,16 @@ bool acpi_dev_resource_address_space(struct acpi_resource *ares,
>  	 * primary side. Non-bridge devices must list 0 for all Address
>  	 * Translation offset bits.
>  	 */
> -	if (addr->producer_consumer == ACPI_PRODUCER)
> +	if (ares->type == ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64) {
> +		if (addr->producer_consumer == ACPI_PRODUCER)
> +			offset = attr->translation_offset;
> +		else if (attr->translation_offset)
> +			pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
> +				 attr->translation_offset);
> +	} else {
>  		offset = attr->translation_offset;
> -	else if (attr->translation_offset)
> -		pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
> -			 attr->translation_offset);
> +	}
> +
>  	start = attr->minimum + offset;
>  	end = attr->maximum + offset;
>  
> @@ -294,7 +299,8 @@ bool acpi_dev_resource_address_space(struct acpi_resource *ares,
>  		return false;
>  	}
>  
> -	if (addr->producer_consumer == ACPI_PRODUCER)
> +	if (ares->type == ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64 &&
> +	    addr->producer_consumer == ACPI_PRODUCER)
>  		res->flags |= IORESOURCE_WINDOW;
>  
>  	if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
> 
> --
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