+/* Check of resource interference between native drivers and ACPI
+ * OperationRegions (SystemIO and System Memory only).
+ * IO ports and memory declared in ACPI might be used by the ACPI subsystem
+ * in arbitrary AML code and can interfere with legacy drivers.
+ * acpi_enforce_resources= can be set to:
+ *
+ * - strict (default) (2)
+ * -> further driver trying to access the resources will not load
+ * - lax (1)
+ * -> further driver trying to access the resources will load, but you
+ * get a system message that something might go wrong...
+ *
+ * - no (0)
+ * -> ACPI Operation Region resources will not be registered
+ *
+ */
+#define ENFORCE_RESOURCES_STRICT 2
+#define ENFORCE_RESOURCES_LAX 1
+#define ENFORCE_RESOURCES_NO 0
+
+static unsigned int acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;
+
+static int __init acpi_enforce_resources_setup(char *str)
+{
+ if (str == NULL || *str == '\0')
+ return 0;
+
+ if (!strcmp("strict", str))
+ acpi_enforce_resources = ENFORCE_RESOURCES_STRICT;
+ else if (!strcmp("lax", str))
+ acpi_enforce_resources = ENFORCE_RESOURCES_LAX;
+ else if (!strcmp("no", str))
+ acpi_enforce_resources = ENFORCE_RESOURCES_NO;
+
+ return 1;
+}
+
+__setup("acpi_enforce_resources=", acpi_enforce_resources_setup);
+
+/* Check for resource conflicts between ACPI OperationRegions and native
+ * drivers */
+int acpi_check_resource_conflict(struct resource *res)
+{
+ struct acpi_res_list *res_list_elem;
+ int ioport;
+ int clash = 0;
+
+ if (acpi_enforce_resources == ENFORCE_RESOURCES_NO)
+ return 0;
+ if (!(res->flags & IORESOURCE_IO) && !(res->flags & IORESOURCE_MEM))
+ return 0;
+
+ ioport = res->flags & IORESOURCE_IO;
+
+ spin_lock(&acpi_res_lock);
+ list_for_each_entry(res_list_elem, &resource_list_head,
+ resource_list) {
+ if (ioport && (res_list_elem->resource_type
+ != ACPI_ADR_SPACE_SYSTEM_IO))
+ continue;
+ if (!ioport && (res_list_elem->resource_type
+ != ACPI_ADR_SPACE_SYSTEM_MEMORY))
+ continue;
+
+ if (res->end < res_list_elem->start
+ || res_list_elem->end < res->start)
+ continue;
+ clash = 1;
+ break;
+ }
+ spin_unlock(&acpi_res_lock);
+
+ if (clash) {
+ if (acpi_enforce_resources != ENFORCE_RESOURCES_NO) {
+ printk("%sACPI: %s resource %s [0x%llx-0x%llx]"
+ " conflicts with ACPI region %s"
+ " [0x%llx-0x%llx]\n",
+ acpi_enforce_resources == ENFORCE_RESOURCES_LAX
+ ? KERN_WARNING : KERN_ERR,
+ ioport ? "I/O" : "Memory", res->name,
+ (long long) res->start, (long long) res->end,
+ res_list_elem->name,
+ (long long) res_list_elem->start,
+ (long long) res_list_elem->end);
+ if (acpi_enforce_resources == ENFORCE_RESOURCES_LAX)
+ printk(KERN_NOTICE "ACPI: This conflict may"
+ " cause random problems and system"
+ " instability\n");
+ printk(KERN_INFO "ACPI: If an ACPI driver is available"
+ " for this device, you should use it instead of"
+ " the native driver\n");
+ }
+ if (acpi_enforce_resources == ENFORCE_RESOURCES_STRICT)
+ return -EBUSY;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(acpi_check_resource_conflict);
+
+int acpi_check_region(resource_size_t start, resource_size_t n,
+ const char *name)
+{
+ struct resource res = {
+ .start = start,
+ .end = start + n - 1,
+ .name = name,
+ .flags = IORESOURCE_IO,
+ };
+
+ return acpi_check_resource_conflict(&res);
+}
+EXPORT_SYMBOL(acpi_check_region);
+
+int acpi_check_mem_region(resource_size_t start, resource_size_t n,
+ const char *name)
+{
+ struct resource res = {
+ .start = start,
+ .end = start + n - 1,
+ .name = name,
+ .flags = IORESOURCE_MEM,
+ };
+
+ return acpi_check_resource_conflict(&res);
+
+}
+EXPORT_SYMBOL(acpi_check_mem_region);
+