2010-04-20 19:52:45

by Bjorn Helgaas

Subject: [PATCH] x86/PCI: parse additional host bridge window resource types

This adds support for Memory24, Memory32, and Memory32Fixed descriptors in
PCI host bridge _CRS.

I experimentally determined that Windows (2008 R2) accepts these descriptors
and treats them as windows that are forwarded to the PCI bus, e.g., if
it finds any PCI devices with BARs outside the windows, it moves them into
the windows.

I don't know whether any machines actually use these descriptors in PCI
host bridge _CRS methods, but if any exist and they're new enough that we
automatically turn on "pci=use_crs", they will work with Windows but not
with Linux.

Here are the details: https://bugzilla.kernel.org/show_bug.cgi?id=15817

Signed-off-by: Bjorn Helgaas <[email protected]>
---

arch/x86/pci/acpi.c | 43 +++++++++++++++++++++++++++++++++++++------
1 files changed, 37 insertions(+), 6 deletions(-)


diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 334153c..44f83ce 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -66,13 +66,44 @@ resource_to_addr(struct acpi_resource *resource,
struct acpi_resource_address64 *addr)
{
acpi_status status;
-
- status = acpi_resource_to_address64(resource, addr);
- if (ACPI_SUCCESS(status) &&
- (addr->resource_type == ACPI_MEMORY_RANGE ||
- addr->resource_type == ACPI_IO_RANGE) &&
- addr->address_length > 0) {
+ struct acpi_resource_memory24 *memory24;
+ struct acpi_resource_memory32 *memory32;
+ struct acpi_resource_fixed_memory32 *fixed_memory32;
+
+ memset(addr, 0, sizeof(*addr));
+ switch (resource->type) {
+ case ACPI_RESOURCE_TYPE_MEMORY24:
+ memory24 = &resource->data.memory24;
+ addr->resource_type = ACPI_MEMORY_RANGE;
+ addr->minimum = memory24->minimum;
+ addr->address_length = memory24->address_length;
+ addr->maximum = addr->minimum + addr->address_length - 1;
+ return AE_OK;
+ case ACPI_RESOURCE_TYPE_MEMORY32:
+ memory32 = &resource->data.memory32;
+ addr->resource_type = ACPI_MEMORY_RANGE;
+ addr->minimum = memory32->minimum;
+ addr->address_length = memory32->address_length;
+ addr->maximum = addr->minimum + addr->address_length - 1;
return AE_OK;
+ case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
+ fixed_memory32 = &resource->data.fixed_memory32;
+ addr->resource_type = ACPI_MEMORY_RANGE;
+ addr->minimum = fixed_memory32->address;
+ addr->address_length = fixed_memory32->address_length;
+ addr->maximum = addr->minimum + addr->address_length - 1;
+ return AE_OK;
+ case ACPI_RESOURCE_TYPE_ADDRESS16:
+ case ACPI_RESOURCE_TYPE_ADDRESS32:
+ case ACPI_RESOURCE_TYPE_ADDRESS64:
+ status = acpi_resource_to_address64(resource, addr);
+ if (ACPI_SUCCESS(status) &&
+ (addr->resource_type == ACPI_MEMORY_RANGE ||
+ addr->resource_type == ACPI_IO_RANGE) &&
+ addr->address_length > 0) {
+ return AE_OK;
+ }
+ break;
}
return AE_ERROR;
}

2010-04-22 23:17:54

by Jesse Barnes

Subject: Re: [PATCH] x86/PCI: parse additional host bridge window resource types

On Tue, 20 Apr 2010 13:52:41 -0600
Bjorn Helgaas <[email protected]> wrote:

>
> This adds support for Memory24, Memory32, and Memory32Fixed descriptors in
> PCI host bridge _CRS.
>
> I experimentally determined that Windows (2008 R2) accepts these descriptors
> and treats them as windows that are forwarded to the PCI bus, e.g., if
> it finds any PCI devices with BARs outside the windows, it moves them into
> the windows.
>
> I don't know whether any machines actually use these descriptors in PCI
> host bridge _CRS methods, but if any exist and they're new enough that we
> automatically turn on "pci=use_crs", they will work with Windows but not
> with Linux.
>
> Here are the details: https://bugzilla.kernel.org/show_bug.cgi?id=15817
>
> Signed-off-by: Bjorn Helgaas <[email protected]>
> ---

Applied to for-linus, thanks.

--
Jesse Barnes, Intel Open Source Technology Center