Update the interface for child drivers. Add acpi_scan_children, which

allows a bus to re-enumerate its child handles and optionally replace
them with new children, arranged to the bus's liking.  (The current device
space is flat with all devices immediately under acpi0).  Add comments
for each interface.

1 files changed, 77 insertions, 11 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index f9295e2f0c23..e8cd3f4dcd47 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -111,15 +111,16 @@ static char	*acpi_device_id_probe(device_t bus, device_t dev, char **ids);
 static ACPI_STATUS acpi_device_eval_obj(device_t bus, device_t dev,
 		    ACPI_STRING pathname, ACPI_OBJECT_LIST *parameters,
 		    ACPI_BUFFER *ret);
-static ACPI_STATUS acpi_device_walk_ns(device_t bus, device_t dev,
-		    ACPI_OBJECT_TYPE type, UINT32 max_depth,
-		    ACPI_WALK_CALLBACK user_fn, void *context, void **ret);
+static ACPI_STATUS acpi_device_scan_cb(ACPI_HANDLE h, UINT32 level,
+		    void *context, void **retval);
+static ACPI_STATUS acpi_device_scan_children(device_t bus, device_t dev,
+		    int max_depth, acpi_scan_cb_t user_fn, void *arg);
 static int	acpi_isa_pnp_probe(device_t bus, device_t child,
-			struct isa_pnp_id *ids);
+		    struct isa_pnp_id *ids);
 static void	acpi_probe_children(device_t bus);
 static int	acpi_probe_order(ACPI_HANDLE handle, int *order);
 static ACPI_STATUS acpi_probe_child(ACPI_HANDLE handle, UINT32 level,
-			void *context, void **status);
+		    void *context, void **status);
 static BOOLEAN	acpi_MatchHid(ACPI_HANDLE h, const char *hid);
 static void	acpi_shutdown_final(void *arg, int howto);
 static void	acpi_enable_fixed_events(struct acpi_softc *sc);
@@ -169,7 +170,7 @@ static device_method_t acpi_methods[] = {
     /* ACPI bus */
     DEVMETHOD(acpi_id_probe,		acpi_device_id_probe),
     DEVMETHOD(acpi_evaluate_object,	acpi_device_eval_obj),
-    DEVMETHOD(acpi_walk_namespace,	acpi_device_walk_ns),
+    DEVMETHOD(acpi_scan_children,	acpi_device_scan_children),
 
     /* ISA emulation */
     DEVMETHOD(isa_pnp_probe,		acpi_isa_pnp_probe),
@@ -1036,20 +1037,85 @@ acpi_device_eval_obj(device_t bus, device_t dev, ACPI_STRING pathname,
 {
     ACPI_HANDLE h;
 
-    if ((h = acpi_get_handle(dev)) == NULL)
+    if (dev == NULL)
+	h = ACPI_ROOT_OBJECT;
+    else if ((h = acpi_get_handle(dev)) == NULL)
 	return (AE_BAD_PARAMETER);
     return (AcpiEvaluateObject(h, pathname, parameters, ret));
 }
 
+/* Callback arg for our implementation of walking the namespace. */
+struct acpi_device_scan_ctx {
+    acpi_scan_cb_t	user_fn;
+    void		*arg;
+    ACPI_HANDLE		parent;
+};
+
+static ACPI_STATUS
+acpi_device_scan_cb(ACPI_HANDLE h, UINT32 level, void *arg, void **retval)
+{
+    struct acpi_device_scan_ctx *ctx;
+    device_t dev, old_dev;
+    ACPI_STATUS status;
+    ACPI_OBJECT_TYPE type;
+
+    /*
+     * Skip this device if we think we'll have trouble with it or it is
+     * the parent where the scan began.
+     */
+    ctx = (struct acpi_device_scan_ctx *)arg;
+    if (acpi_avoid(h) || h == ctx->parent)
+	return (AE_OK);
+
+    /* If this is not a valid device type (e.g., a method), skip it. */
+    if (ACPI_FAILURE(AcpiGetType(h, &type)))
+	return (AE_OK);
+    if (type != ACPI_TYPE_DEVICE && type != ACPI_TYPE_PROCESSOR &&
+	type != ACPI_TYPE_THERMAL && type != ACPI_TYPE_POWER)
+	return (AE_OK);
+
+    /*
+     * Call the user function with the current device.  If it is unchanged
+     * afterwards, return.  Otherwise, we update the handle to the new dev.
+     */
+    old_dev = acpi_get_device(h);
+    dev = old_dev;
+    status = ctx->user_fn(h, &dev, level, ctx->arg);
+    if (ACPI_FAILURE(status) || old_dev == dev)
+	return (status);
+
+    /* Remove the old child and its connection to the handle. */
+    if (old_dev != NULL) {
+	device_delete_child(device_get_parent(old_dev), old_dev);
+	AcpiDetachData(h, acpi_fake_objhandler);
+    }
+
+    /* Recreate the handle association if the user created a device. */
+    if (dev != NULL)
+	AcpiAttachData(h, acpi_fake_objhandler, dev);
+
+    return (AE_OK);
+}
+
 static ACPI_STATUS
-acpi_device_walk_ns(device_t bus, device_t dev, ACPI_OBJECT_TYPE type,
-    UINT32 max_depth, ACPI_WALK_CALLBACK user_fn, void *context, void **ret)
+acpi_device_scan_children(device_t bus, device_t dev, int max_depth,
+    acpi_scan_cb_t user_fn, void *arg)
 {
     ACPI_HANDLE h;
+    struct acpi_device_scan_ctx ctx;
 
-    if ((h = acpi_get_handle(dev)) == NULL)
+    if (acpi_disabled("children"))
+	return (AE_OK);
+
+    if (dev == NULL)
+	h = ACPI_ROOT_OBJECT;
+    else if ((h = acpi_get_handle(dev)) == NULL)
 	return (AE_BAD_PARAMETER);
-    return (AcpiWalkNamespace(type, h, max_depth, user_fn, context, ret));
+    ctx.user_fn = user_fn;
+    ctx.arg = arg;
+    ctx.parent = h;
+    return (AcpiWalkNamespace(ACPI_TYPE_ANY, h, max_depth,
+	acpi_device_scan_cb, &ctx, NULL));
 }
 
 static int