Re: [Bugfix v4] x86/PCI/ACPI: Fix regression caused by commit 63f1789ec716

[Rafael J. Wysocki]

On Tuesday, April 07, 2015 12:30:18 PM Jiang Liu wrote:
> Before commit 593669c2ac0f("Use common ACPI resource interfaces to
> simplify implementation"), arch/x86/pci/acpi.c applies following
> rules when parsing ACPI resources for PCI host bridge:
> 1) Ignore IO port resources defined by acpi_resource_io and
>    acpi_resource_fixed_io, which should be used to define resource
>    for PCI device instead of PCI bridge.
> 2) Accept IOMEM resource defined by acpi_resource_memory24,
>    acpi_resource_memory32 and acpi_resource_fixed_memory32.
>    These IOMEM resources are accepted to workaround some BIOS issue,
>    though they should be ignored. For example, PC Engines APU.1C
>    platform defines PCI host bridge IOMEM resources as:
>                 Memory32Fixed (ReadOnly,
>                     0x000A0000,         // Address Base
>                     0x00020000,         // Address Length
>                     )
>                 Memory32Fixed (ReadOnly,
>                     0x00000000,         // Address Base
>                     0x00000000,         // Address Length
>                     _Y00)
> 3) Accept all IO port and IOMEM resources defined by
>    acpi_resource_address{16,32,64,extended64}, no matter it's marked as
>    ACPI_CONSUMER or ACPI_PRODUCER.
> 
> Commit 593669c2ac0f("Use common ACPI resource interfaces to
> simplify implementation") accept all IO port and IOMEM resources
> defined by acpi_resource_io, acpi_resource_fixed_io,
> acpi_resource_memory24, acpi_resource_memory32,
> acpi_resource_fixed_memory32 and
> acpi_resource_address{16,32,64,extended64}, which causes IO port
> resources consumed by host bridge itself are listed in to host bridge
> resource list.
> 
> Then commit 63f1789ec716("Ignore resources consumed by host bridge
> itself") ignores resources consumed by host bridge itself by checking
> IORESOURCE_WINDOW flag, which accidently removed the workaround in 2)
> above for BIOS bug .
> 
> It's really costed us much time to figure out this whole picture.
> So we refine interface acpi_dev_filter_resource_type as below,
> which should be easier for maintence:
> 1) Caller specifies IORESOURCE_WINDOW flag to explicitly query resource
>    for bridge(PRODUCER), otherwise it's querying resource for
>    device(CONSUMER).
> 2) Ignore IO port resources defined by acpi_resource_io and
>    acpi_resource_fixed_io if IORESOURCE_WINDOW is specified.
> 3) Accpet IOMEM resource defined by acpi_resource_memory24,
>    acpi_resource_memory32 and acpi_resource_fixed_memory32 if both
>    IORESOURCE_WINDOW and IORESOURCE_MEM_8AND16BIT are specified to work
>    around BIOS issues.
> 4) Accept IO port and IOMEM defined by acpi_resource_addressxx if
>    a) IORESOURCE_WINDOW is specified and ACPI_PRODUCER is true
>    b) IORESOURCE_WINDOW is not specified and ACPI_PRODUCER is false
> 
> Currently acpi_dev_filter_resource_type() is only used by ACPI pci
> host bridge and IOAPIC driver, so it shouldn't affect other drivers.
> 
> Another possible fix is to only ignore IO resource consumed by host
> bridge and keep IOMEM resource consumed by host bridge, please refer to:
> http://www.spinics.net/lists/linux-pci/msg39706.html
> 
> Sample ACPI table are archived at:
> https://bugzilla.kernel.org/show_bug.cgi?id=94221
> 
> V3->V4:
> 1) Improve comments
> 2) Use flag IORESOURCE_MEM_8AND16BIT to work around BIOS issue

OK, so how does that address the comments in the previous thread?

It would *really* help if you responded there instead of starting a new
thread by sending a new patch version.  This makes it really difficult to
follow the entire discussion, which is part of why we keep forgetting things.

> Fixes: 63f1789ec716("Ignore resources consumed by host bridge itself")
> Reported-and-Tested-by: Bernhard Thaler <bernhard.thaler@xxxxxxxx>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
> ---
>  arch/x86/pci/acpi.c     |    8 +++++---
>  drivers/acpi/resource.c |   52 +++++++++++++++++++++++++++++++++++++++++------
>  2 files changed, 51 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index e4695985f9de..150774be0f3f 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -332,12 +332,15 @@ static void probe_pci_root_info(struct pci_root_info *info,
>  {
>  	int ret;
>  	struct resource_entry *entry, *tmp;
> +	unsigned long res_flags;
>  
>  	sprintf(info->name, "PCI Bus %04x:%02x", domain, busnum);
>  	info->bridge = device;
> +	res_flags = IORESOURCE_IO | IORESOURCE_MEM |
> +		    IORESOURCE_WINDOW | IORESOURCE_MEM_8AND16BIT;
>  	ret = acpi_dev_get_resources(device, list,
>  				     acpi_dev_filter_resource_type_cb,
> -				     (void *)(IORESOURCE_IO | IORESOURCE_MEM));
> +				     (void *)res_flags);
>  	if (ret < 0)
>  		dev_warn(&device->dev,
>  			 "failed to parse _CRS method, error code %d\n", ret);
> @@ -346,8 +349,7 @@ static void probe_pci_root_info(struct pci_root_info *info,
>  			"no IO and memory resources present in _CRS\n");
>  	else
>  		resource_list_for_each_entry_safe(entry, tmp, list) {
> -			if ((entry->res->flags & IORESOURCE_WINDOW) == 0 ||
> -			    (entry->res->flags & IORESOURCE_DISABLED))
> +			if (entry->res->flags & IORESOURCE_DISABLED)
>  				resource_list_destroy_entry(entry);
>  			else
>  				entry->res->name = info->name;
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 5589a6e2a023..0187e0e11bb8 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -567,6 +567,12 @@ int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
>  }
>  EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
>  
> +static bool acpi_dev_match_producer_consumer(unsigned long types, int producer)
> +{
> +	return ((types & IORESOURCE_WINDOW) && producer == ACPI_PRODUCER) ||
> +		((types & IORESOURCE_WINDOW) == 0 && producer == ACPI_CONSUMER);
> +}
> +
>  /**
>   * acpi_dev_filter_resource_type - Filter ACPI resource according to resource
>   *				   types
> @@ -574,7 +580,19 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
>   * @types: Valid resource types of IORESOURCE_XXX
>   *
>   * This is a hepler function to support acpi_dev_get_resources(), which filters
> - * ACPI resource objects according to resource types.
> + * ACPI resource objects according to resource types and flags as below:
> + * 1) If flag IORESOURCE_WINDOW is not specified, it's querying resources
> + *    consumed by device. That is to return:
> + * 	a) ACPI resources without producer_consumer flag
> + *	b) ACPI resources with producer_consumer flag setting to CONSUMER.

OK, so what if the resource is not of an "extended" type, say DWORD address space,
but has a non-empty Resource Source field pointing to the device itself?

Shouldn't we treat that device as a "producer" too?

> + * 2) If flag IORESOURCE_WINDOW is specified, it's querying resources provided
> + *    by device. That is to return:
> + *	a) ACPI resources with producer_consumer flag setting to PRODUCER.
> + * 3) But there's an exception. Some platforms, such as PC Engines APU.1C,
> + *    report PCI host bridge resource provision by Memory32Fixed().
> + *    Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=94221
> + *    So a special flag IORESOURCE_MEM_8AND16BIT is used to work around this
> + *    BIOS issue.

This is a legitimate thing for the BIOS to do if my reading of the spec is
correct, as the "producer" thing really is supposed to mean "this resource
comes from the device itself".

>   */
>  int acpi_dev_filter_resource_type(struct acpi_resource *ares,
>  				  unsigned long types)
> @@ -585,27 +603,49 @@ int acpi_dev_filter_resource_type(struct acpi_resource *ares,
>  	case ACPI_RESOURCE_TYPE_MEMORY24:
>  	case ACPI_RESOURCE_TYPE_MEMORY32:
>  	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
> -		type = IORESOURCE_MEM;
> +		/*
> +		 * These types of resource descriptor should be used to
> +		 * describe resource consumption instead of resource provision.
> +		 * But some platforms, such as PC Engines APU.1C, report
> +		 * resource provision by Memory32Fixed(). Please refer to:
> +		 * https://bugzilla.kernel.org/show_bug.cgi?id=94221
> +		 * So a special rule to work around BIOS issues.
> +		 */
> +		if ((types & (IORESOURCE_WINDOW | IORESOURCE_MEM_8AND16BIT)) ==
> +		    (IORESOURCE_WINDOW | IORESOURCE_MEM_8AND16BIT) ||
> +		    acpi_dev_match_producer_consumer(types, ACPI_CONSUMER))
> +			type = IORESOURCE_MEM;
>  		break;
>  	case ACPI_RESOURCE_TYPE_IO:
>  	case ACPI_RESOURCE_TYPE_FIXED_IO:
> -		type = IORESOURCE_IO;
> +		if (acpi_dev_match_producer_consumer(types, ACPI_CONSUMER))
> +			type = IORESOURCE_IO;
>  		break;
>  	case ACPI_RESOURCE_TYPE_IRQ:
> +		if (acpi_dev_match_producer_consumer(types, ACPI_CONSUMER))
> +			type = IORESOURCE_IRQ;
> +		break;
>  	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
> -		type = IORESOURCE_IRQ;
> +		if (acpi_dev_match_producer_consumer(types,
> +				ares->data.extended_irq.producer_consumer))
> +			type = IORESOURCE_IRQ;
>  		break;
>  	case ACPI_RESOURCE_TYPE_DMA:
>  	case ACPI_RESOURCE_TYPE_FIXED_DMA:
> -		type = IORESOURCE_DMA;
> +		if (acpi_dev_match_producer_consumer(types, ACPI_CONSUMER))
> +			type = IORESOURCE_DMA;
>  		break;
>  	case ACPI_RESOURCE_TYPE_GENERIC_REGISTER:
> -		type = IORESOURCE_REG;
> +		if (acpi_dev_match_producer_consumer(types, ACPI_CONSUMER))
> +			type = IORESOURCE_REG;
>  		break;
>  	case ACPI_RESOURCE_TYPE_ADDRESS16:
>  	case ACPI_RESOURCE_TYPE_ADDRESS32:
>  	case ACPI_RESOURCE_TYPE_ADDRESS64:
>  	case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
> +		if (!acpi_dev_match_producer_consumer(types,
> +				ares->data.address.producer_consumer))
> +			break;
>  		if (ares->data.address.resource_type == ACPI_MEMORY_RANGE)
>  			type = IORESOURCE_MEM;
>  		else if (ares->data.address.resource_type == ACPI_IO_RANGE)
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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