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authorJiang Liu <jiang.liu@linux.intel.com>2015-04-30 12:41:28 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-04-30 22:17:34 +0200
commit2c62e8492ed7358bbe7da51666c7e0f6da9474ee (patch)
tree2365277b20cc65a81df81fc6ad56187662d44f81
parentb787f68c36d49bb1d9236f403813641efa74a031 (diff)
downloadlinux-stericsson-2c62e8492ed7358bbe7da51666c7e0f6da9474ee.tar.gz
x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus
An IO port or MMIO resource assigned to a PCI host bridge may be consumed by the host bridge itself or available to its child bus/devices. The ACPI specification defines a bit (Producer/Consumer) to tell whether the resource is consumed by the host bridge itself, but firmware hasn't used that bit consistently, so we can't rely on it. Before commit 593669c2ac0f ("x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation"), arch/x86/pci/acpi.c ignored all IO port resources defined by acpi_resource_io and acpi_resource_fixed_io to filter out IO ports consumed by the host bridge itself. Commit 593669c2ac0f ("x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation") started accepting all IO port and MMIO resources, which caused a regression that IO port resources consumed by the host bridge itself became available to its child devices. Then commit 63f1789ec716 ("x86/PCI/ACPI: Ignore resources consumed by host bridge itself") ignored resources consumed by the host bridge itself by checking the IORESOURCE_WINDOW flag, which accidently removed MMIO resources defined by acpi_resource_memory24, acpi_resource_memory32 and acpi_resource_fixed_memory32. On x86 and IA64 platforms, all IO port and MMIO resources are assumed to be available to child bus/devices except one special case: IO port [0xCF8-0xCFF] is consumed by the host bridge itself to access PCI configuration space. So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF]. This solution will also ease the way to consolidate ACPI PCI host bridge common code from x86, ia64 and ARM64. Related ACPI table are archived at: https://bugzilla.kernel.org/show_bug.cgi?id=94221 Related discussions at: http://patchwork.ozlabs.org/patch/461633/ https://lkml.org/lkml/2015/3/29/304 Fixes: 63f1789ec716 (Ignore resources consumed by host bridge itself) Reported-by: Bernhard Thaler <bernhard.thaler@wvnet.at> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: 4.0+ <stable@vger.kernel.org> # 4.0+ Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--arch/x86/pci/acpi.c24
-rw-r--r--drivers/acpi/resource.c2
2 files changed, 23 insertions, 3 deletions
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index e4695985f9de..d93963340c3c 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -325,6 +325,26 @@ static void release_pci_root_info(struct pci_host_bridge *bridge)
kfree(info);
}
+/*
+ * An IO port or MMIO resource assigned to a PCI host bridge may be
+ * consumed by the host bridge itself or available to its child
+ * bus/devices. The ACPI specification defines a bit (Producer/Consumer)
+ * to tell whether the resource is consumed by the host bridge itself,
+ * but firmware hasn't used that bit consistently, so we can't rely on it.
+ *
+ * On x86 and IA64 platforms, all IO port and MMIO resources are assumed
+ * to be available to child bus/devices except one special case:
+ * IO port [0xCF8-0xCFF] is consumed by the host bridge itself
+ * to access PCI configuration space.
+ *
+ * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
+ */
+static bool resource_is_pcicfg_ioport(struct resource *res)
+{
+ return (res->flags & IORESOURCE_IO) &&
+ res->start == 0xCF8 && res->end == 0xCFF;
+}
+
static void probe_pci_root_info(struct pci_root_info *info,
struct acpi_device *device,
int busnum, int domain,
@@ -346,8 +366,8 @@ 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_is_pcicfg_ioport(entry->res))
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..8244f013f210 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -573,7 +573,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
* @ares: Input ACPI resource object.
* @types: Valid resource types of IORESOURCE_XXX
*
- * This is a hepler function to support acpi_dev_get_resources(), which filters
+ * This is a helper function to support acpi_dev_get_resources(), which filters
* ACPI resource objects according to resource types.
*/
int acpi_dev_filter_resource_type(struct acpi_resource *ares,