dm: Add dm_remove_devices_active() for ordered device removal
This replaces dm_remove_devices_flags() calls in all boot
implementations to ensure non vital devices are consistently removed
first. All boot implementation except arch/arm/lib/bootm.c currently
just call dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL). This can result
in crashes when dependencies between devices exists. The driver model's
design document describes DM_FLAG_VITAL as "indicates that the device is
'vital' to the operation of other devices". Device removal at boot
should follow this.
Instead of adding dm_remove_devices_flags() with (DM_REMOVE_ACTIVE_ALL |
DM_REMOVE_NON_VITAL) everywhere add dm_remove_devices_active() which
does this.
Fixes a NULL pointer deref in the apple dart IOMMU driver during EFI
boot. The xhci-pci (driver which depends on the IOMMU to work) removes
its mapping on removal. This explodes when the IOMMU device was removed
first.
dm_remove_devices_flags() is kept since it is used for testing of
device_remove() calls in dm.
Signed-off-by: Janne Grunau <j@jannau.net>
diff --git a/include/dm/root.h b/include/dm/root.h
index b2f30a8..5651b86 100644
--- a/include/dm/root.h
+++ b/include/dm/root.h
@@ -167,8 +167,18 @@
* Return: 0 if OK, -ve on error
*/
int dm_remove_devices_flags(uint flags);
+
+/**
+ * dm_remove_devices_active - Call remove function of all active drivers heeding
+ * device dependencies as far as know, i.e. removing
+ * devices marked with DM_FLAG_VITAL last.
+ *
+ * All active devices will be removed
+ */
+void dm_remove_devices_active(void);
#else
static inline int dm_remove_devices_flags(uint flags) { return 0; }
+static inline void dm_remove_devices_active(void) { }
#endif
/**