[patch 4/4] acpi: ioapic: Respect the resource flags

[Thomas Gleixner <tglx@linutronix.de>]

[-- Attachment #1: acpi-ioapoc-respect-resource-flags.patch --]
[-- Type: text/plain, Size: 2387 bytes --]

The acpi parser can set the DISABLED flag on a resource. In
setup_res() we clear all flags except MEM, so we ignore the DISABLED
flag. Add proper checks and preserve the flags.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/acpi/ioapic.c |   38 +++++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 17 deletions(-)

Index: tip/drivers/acpi/ioapic.c
===================================================================
--- tip.orig/drivers/acpi/ioapic.c
+++ tip/drivers/acpi/ioapic.c
@@ -40,29 +40,33 @@ struct acpi_pci_ioapic {
 static LIST_HEAD(ioapic_list);
 static DEFINE_MUTEX(ioapic_list_lock);
 
+static inline bool is_valid_mem_resource(struct resource *res)
+{
+	return !(res->flags & IORESOURCE_DISABLED) &&
+		(res->flags & IORESOURCE_MEM);
+}
+
 static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
 {
+	struct acpi_resource_address64 addr;
 	struct resource *res = data;
 
 	memset(res, 0, sizeof(*res));
-	if (acpi_dev_resource_memory(acpi_res, res)) {
-		res->flags &= IORESOURCE_MEM;
-		if (res->flags)
-			return AE_OK;
-	} else if (acpi_dev_resource_address_space(acpi_res, res)) {
-		struct acpi_resource_address64 addr;
+	if (acpi_dev_resource_memory(acpi_res, res))
+		return AE_OK;
 
-		res->flags &= IORESOURCE_MEM;
-		if (res->flags &&
-		    ACPI_SUCCESS(acpi_resource_to_address64(acpi_res, &addr)) &&
-		    addr.info.mem.caching != ACPI_PREFETCHABLE_MEMORY) {
-			res->start += addr.translation_offset;
-			res->end += addr.translation_offset;
-			return AE_OK;
-		}
+	if (!acpi_dev_resource_address_space(acpi_res, res) ||
+	    !is_valid_mem_resource(res))
+		return AE_OK;
+	/*
+	 * FIXME: This lacks a proper comment, why the resource
+	 * address needs to be translated.
+	 */
+	if (ACPI_SUCCESS(acpi_resource_to_address64(acpi_res, &addr)) &&
+	    addr.info.mem.caching != ACPI_PREFETCHABLE_MEMORY) {
+		res->start += addr.translation_offset;
+		res->end += addr.translation_offset;
 	}
-	res->flags = 0;
-
 	return AE_OK;
 }
 
@@ -150,7 +154,7 @@ static acpi_status handle_ioapic_add(acp
 
 		res = &ioapic->res;
 		acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, res);
-		if (res->flags == IORESOURCE_UNSET) {
+		if (!is_valid_mem_resource(res)) {
 			acpi_handle_warn(handle, "failed to get resource\n");
 			goto exit_free;
 		} else if (request_resource(&iomem_resource, res)) {