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

From: Thomas Gleixner
Date: Thu Dec 11 2014 - 14:48:34 EST


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@xxxxxxxxxxxxx>
---
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)) {


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