diff options
Diffstat (limited to 'drivers/acpi')
-rw-r--r-- | drivers/acpi/glue.c | 99 |
1 files changed, 82 insertions, 17 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index 17e15d1..408f6b2 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -79,34 +79,99 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev) return ret; } -static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used, - void *addr_p, void **ret_p) +static acpi_status acpi_dev_present(acpi_handle handle, u32 lvl_not_used, + void *not_used, void **ret_p) { - unsigned long long addr, sta; - acpi_status status; + struct acpi_device *adev = NULL; - status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr); - if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) { + acpi_bus_get_device(handle, &adev); + if (adev) { *ret_p = handle; - status = acpi_bus_get_status_handle(handle, &sta); - if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_ENABLED)) - return AE_CTRL_TERMINATE; + return AE_CTRL_TERMINATE; } return AE_OK; } -acpi_handle acpi_get_child(acpi_handle parent, u64 address) +static bool acpi_extra_checks_passed(acpi_handle handle, bool is_bridge) { - void *ret = NULL; + unsigned long long sta; + acpi_status status; + + status = acpi_bus_get_status_handle(handle, &sta); + if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) + return false; + + if (is_bridge) { + void *test = NULL; + + /* Check if this object has at least one child device. */ + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_dev_present, NULL, NULL, &test); + return !!test; + } + return true; +} + +struct find_child_context { + u64 addr; + bool is_bridge; + acpi_handle ret; + bool ret_checked; +}; + +static acpi_status do_find_child(acpi_handle handle, u32 lvl_not_used, + void *data, void **not_used) +{ + struct find_child_context *context = data; + unsigned long long addr; + acpi_status status; - if (!parent) - return NULL; + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr); + if (ACPI_FAILURE(status) || addr != context->addr) + return AE_OK; - acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL, - do_acpi_find_child, &address, &ret); - return (acpi_handle)ret; + if (!context->ret) { + /* This is the first matching object. Save its handle. */ + context->ret = handle; + return AE_OK; + } + /* + * There is more than one matching object with the same _ADR value. + * That really is unexpected, so we are kind of beyond the scope of the + * spec here. We have to choose which one to return, though. + * + * First, check if the previously found object is good enough and return + * its handle if so. Second, check the same for the object that we've + * just found. + */ + if (!context->ret_checked) { + if (acpi_extra_checks_passed(context->ret, context->is_bridge)) + return AE_CTRL_TERMINATE; + else + context->ret_checked = true; + } + if (acpi_extra_checks_passed(handle, context->is_bridge)) { + context->ret = handle; + return AE_CTRL_TERMINATE; + } + return AE_OK; +} + +acpi_handle acpi_find_child(acpi_handle parent, u64 addr, bool is_bridge) +{ + if (parent) { + struct find_child_context context = { + .addr = addr, + .is_bridge = is_bridge, + }; + + acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, do_find_child, + NULL, &context, NULL); + return context.ret; + } + return NULL; } -EXPORT_SYMBOL(acpi_get_child); +EXPORT_SYMBOL_GPL(acpi_find_child); int acpi_bind_one(struct device *dev, acpi_handle handle) { |