[Bugfix 1/2] x86/PCI/ACPI: Ignore resources consumed by host bridge itself

[Bugfix 1/2] x86/PCI/ACPI: Ignore resources consumed by host bridge itself

[Jiang Liu]

When parsing resources for PCI host bridge, we should ignore resources
consumed by host bridge itself and only report window resources available
to child PCI busses.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 arch/x86/pci/acpi.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 6ac273832f28..e4695985f9de 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -331,7 +331,7 @@ static void probe_pci_root_info(struct pci_root_info *info,
 				struct list_head *list)
 {
 	int ret;
-	struct resource_entry *entry;
+	struct resource_entry *entry, *tmp;
 
 	sprintf(info->name, "PCI Bus %04x:%02x", domain, busnum);
 	info->bridge = device;
@@ -345,8 +345,13 @@ static void probe_pci_root_info(struct pci_root_info *info,
 		dev_dbg(&device->dev,
 			"no IO and memory resources present in _CRS\n");
 	else
-		resource_list_for_each_entry(entry, list)
-			entry->res->name = info->name;
+		resource_list_for_each_entry_safe(entry, tmp, list) {
+			if ((entry->res->flags & IORESOURCE_WINDOW) == 0 ||
+			    (entry->res->flags & IORESOURCE_DISABLED))
+				resource_list_destroy_entry(entry);
+			else
+				entry->res->name = info->name;
+		}
 }
 
 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
-- 
1.7.10.4

[Bugfix 2/2] x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs

[Jiang Liu]

Some BIOSes report incorrect length for ACPI address space descriptors,
so relax the checks to avoid regressions. This issue has appeared several
times as:
3162b6f0c5e1 ("PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
d558b483d5a7 ("x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
f238b414a74a ("PNPACPI: compute Address Space length rather than using _LEN")
48728e077480 ("x86/PCI: compute Address Space length rather than using _LEN")

Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=94221
for more details and example malformed ACPI resource descriptors.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Tested-by: Dave Airlie <airlied@redhat.com>
Tested-by: Prakash Punnoor <prakash@punnoor.de>
---
 drivers/acpi/resource.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index c723668e3e27..5589a6e2a023 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -42,8 +42,10 @@ static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
 	 * CHECKME: len might be required to check versus a minimum
 	 * length as well. 1 for io is fine, but for memory it does
 	 * not make any sense at all.
+	 * Note: some BIOSes report incorrect length for ACPI address space
+	 * descriptor, so remove check of 'reslen == len' to avoid regression.
 	 */
-	if (len && reslen && reslen == len && start <= end)
+	if (len && reslen && start <= end)
 		return true;
 
 	pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
-- 
1.7.10.4

Re: [Bugfix 1/2] x86/PCI/ACPI: Ignore resources consumed by host bridge itself

[Rafael J. Wysocki]

On Wednesday, March 04, 2015 04:47:11 PM Jiang Liu wrote:
> When parsing resources for PCI host bridge, we should ignore resources
> consumed by host bridge itself and only report window resources available
> to child PCI busses.
> 
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>

Queued up for 4.0-rc3, thanks!

> ---
>  arch/x86/pci/acpi.c |   11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index 6ac273832f28..e4695985f9de 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -331,7 +331,7 @@ static void probe_pci_root_info(struct pci_root_info *info,
>  				struct list_head *list)
>  {
>  	int ret;
> -	struct resource_entry *entry;
> +	struct resource_entry *entry, *tmp;
>  
>  	sprintf(info->name, "PCI Bus %04x:%02x", domain, busnum);
>  	info->bridge = device;
> @@ -345,8 +345,13 @@ static void probe_pci_root_info(struct pci_root_info *info,
>  		dev_dbg(&device->dev,
>  			"no IO and memory resources present in _CRS\n");
>  	else
> -		resource_list_for_each_entry(entry, list)
> -			entry->res->name = info->name;
> +		resource_list_for_each_entry_safe(entry, tmp, list) {
> +			if ((entry->res->flags & IORESOURCE_WINDOW) == 0 ||
> +			    (entry->res->flags & IORESOURCE_DISABLED))
> +				resource_list_destroy_entry(entry);
> +			else
> +				entry->res->name = info->name;
> +		}
>  }
>  
>  struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> 

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

Re: [Bugfix 2/2] x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs

[Rafael J. Wysocki]

On Wednesday, March 04, 2015 04:47:12 PM Jiang Liu wrote:
> Some BIOSes report incorrect length for ACPI address space descriptors,
> so relax the checks to avoid regressions. This issue has appeared several
> times as:
> 3162b6f0c5e1 ("PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
> d558b483d5a7 ("x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
> f238b414a74a ("PNPACPI: compute Address Space length rather than using _LEN")
> 48728e077480 ("x86/PCI: compute Address Space length rather than using _LEN")
> 
> Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=94221
> for more details and example malformed ACPI resource descriptors.
> 
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> Tested-by: Dave Airlie <airlied@redhat.com>
> Tested-by: Prakash Punnoor <prakash@punnoor.de>

Queued up for 4.0-rc3, thanks!

Bjorn, please let me know if you have any objections.

> ---
>  drivers/acpi/resource.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index c723668e3e27..5589a6e2a023 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -42,8 +42,10 @@ static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
>  	 * CHECKME: len might be required to check versus a minimum
>  	 * length as well. 1 for io is fine, but for memory it does
>  	 * not make any sense at all.
> +	 * Note: some BIOSes report incorrect length for ACPI address space
> +	 * descriptor, so remove check of 'reslen == len' to avoid regression.
>  	 */
> -	if (len && reslen && reslen == len && start <= end)
> +	if (len && reslen && start <= end)
>  		return true;
>  
>  	pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
> 

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