Merge tag 'devicetree-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:

 - Unit test for overlays with GPIO hogs

 - Improve dma-ranges parsing to handle dma-ranges with multiple entries

 - Update dtc to upstream version v1.6.0-2-g87a656ae5ff9

 - Improve overlay error reporting

 - Device link support for power-domains and hwlocks bindings

 - Add vendor prefixes for Beacon, Topwise, ENE, Dell, SG Micro, Elida,
   PocketBook, Xiaomi, Linutronix, OzzMaker, Waveshare Electronics, and
   ITE Tech

 - Add deprecated Marvell vendor prefix 'mrvl'

 - A bunch of binding conversions to DT schema continues. Of note, the
   common serial and USB connector bindings are converted.

 - Add more Arm CPU compatibles

 - Drop Mark Rutland as DT maintainer :(

* tag 'devicetree-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (106 commits)
  MAINTAINERS: drop an old reference to stm32 pwm timers doc
  MAINTAINERS: dt: update etnaviv file reference
  dt-bindings: usb: dwc2: fix bindings for amlogic, meson-gxbb-usb
  dt-bindings: uniphier-system-bus: fix warning in the example
  dt-bindings: display: meson-vpu: fix indentation of reg-names' "items"
  dt-bindings: iio: Fix adi, ltc2983 uint64-matrix schema constraints
  dt-bindings: power: Fix example for power-domain
  dt-bindings: arm: Add some constraints for PSCI nodes
  of: some unittest overlays not untracked
  of: gpio unittest kfree() wrong object
  dt-bindings: phy: convert phy-rockchip-inno-usb2 bindings to yaml
  dt-bindings: serial: sh-sci: Convert to json-schema
  dt-bindings: serial: Document serialN aliases
  dt-bindings: thermal: tsens: Set 'additionalProperties: false'
  dt-bindings: thermal: tsens: Fix nvmem-cell-names schema
  dt-bindings: vendor-prefixes: Add Beacon vendor prefix
  dt-bindings: vendor-prefixes: Add Topwise
  of: of_private.h: Replace zero-length array with flexible-array member
  docs: dt: fix a broken reference to input.yaml
  docs: dt: fix references to ap806-system-controller.txt
  ...

1 files changed, 122 insertions, 0 deletions

diff --git a/scripts/dtc/libfdt/libfdt_internal.h b/scripts/dtc/libfdt/libfdt_internal.h
index 058c7358d441..d4e0bd49c037 100644
--- a/scripts/dtc/libfdt/libfdt_internal.h
+++ b/scripts/dtc/libfdt/libfdt_internal.h
@@ -48,4 +48,126 @@ static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n)
 
 #define FDT_SW_MAGIC		(~FDT_MAGIC)
 
+/**********************************************************************/
+/* Checking controls                                                  */
+/**********************************************************************/
+
+#ifndef FDT_ASSUME_MASK
+#define FDT_ASSUME_MASK 0
+#endif
+
+/*
+ * Defines assumptions which can be enabled. Each of these can be enabled
+ * individually. For maximum safety, don't enable any assumptions!
+ *
+ * For minimal code size and no safety, use ASSUME_PERFECT at your own risk.
+ * You should have another method of validating the device tree, such as a
+ * signature or hash check before using libfdt.
+ *
+ * For situations where security is not a concern it may be safe to enable
+ * ASSUME_SANE.
+ */
+enum {
+	/*
+	 * This does essentially no checks. Only the latest device-tree
+	 * version is correctly handled. Inconsistencies or errors in the device
+	 * tree may cause undefined behaviour or crashes. Invalid parameters
+	 * passed to libfdt may do the same.
+	 *
+	 * If an error occurs when modifying the tree it may leave the tree in
+	 * an intermediate (but valid) state. As an example, adding a property
+	 * where there is insufficient space may result in the property name
+	 * being added to the string table even though the property itself is
+	 * not added to the struct section.
+	 *
+	 * Only use this if you have a fully validated device tree with
+	 * the latest supported version and wish to minimise code size.
+	 */
+	ASSUME_PERFECT		= 0xff,
+
+	/*
+	 * This assumes that the device tree is sane. i.e. header metadata
+	 * and basic hierarchy are correct.
+	 *
+	 * With this assumption enabled, normal device trees produced by libfdt
+	 * and the compiler should be handled safely. Malicious device trees and
+	 * complete garbage may cause libfdt to behave badly or crash. Truncated
+	 * device trees (e.g. those only partially loaded) can also cause
+	 * problems.
+	 *
+	 * Note: Only checks that relate exclusively to the device tree itself
+	 * (not the parameters passed to libfdt) are disabled by this
+	 * assumption. This includes checking headers, tags and the like.
+	 */
+	ASSUME_VALID_DTB	= 1 << 0,
+
+	/*
+	 * This builds on ASSUME_VALID_DTB and further assumes that libfdt
+	 * functions are called with valid parameters, i.e. not trigger
+	 * FDT_ERR_BADOFFSET or offsets that are out of bounds. It disables any
+	 * extensive checking of parameters and the device tree, making various
+	 * assumptions about correctness.
+	 *
+	 * It doesn't make sense to enable this assumption unless
+	 * ASSUME_VALID_DTB is also enabled.
+	 */
+	ASSUME_VALID_INPUT	= 1 << 1,
+
+	/*
+	 * This disables checks for device-tree version and removes all code
+	 * which handles older versions.
+	 *
+	 * Only enable this if you know you have a device tree with the latest
+	 * version.
+	 */
+	ASSUME_LATEST		= 1 << 2,
+
+	/*
+	 * This assumes that it is OK for a failed addition to the device tree,
+	 * due to lack of space or some other problem, to skip any rollback
+	 * steps (such as dropping the property name from the string table).
+	 * This is safe to enable in most circumstances, even though it may
+	 * leave the tree in a sub-optimal state.
+	 */
+	ASSUME_NO_ROLLBACK	= 1 << 3,
+
+	/*
+	 * This assumes that the device tree components appear in a 'convenient'
+	 * order, i.e. the memory reservation block first, then the structure
+	 * block and finally the string block.
+	 *
+	 * This order is not specified by the device-tree specification,
+	 * but is expected by libfdt. The device-tree compiler always created
+	 * device trees with this order.
+	 *
+	 * This assumption disables a check in fdt_open_into() and removes the
+	 * ability to fix the problem there. This is safe if you know that the
+	 * device tree is correctly ordered. See fdt_blocks_misordered_().
+	 */
+	ASSUME_LIBFDT_ORDER	= 1 << 4,
+
+	/*
+	 * This assumes that libfdt itself does not have any internal bugs. It
+	 * drops certain checks that should never be needed unless libfdt has an
+	 * undiscovered bug.
+	 *
+	 * This can generally be considered safe to enable.
+	 */
+	ASSUME_LIBFDT_FLAWLESS	= 1 << 5,
+};
+
+/**
+ * can_assume_() - check if a particular assumption is enabled
+ *
+ * @mask: Mask to check (ASSUME_...)
+ * @return true if that assumption is enabled, else false
+ */
+static inline bool can_assume_(int mask)
+{
+	return FDT_ASSUME_MASK & mask;
+}
+
+/** helper macros for checking assumptions */
+#define can_assume(_assume)	can_assume_(ASSUME_ ## _assume)
+
 #endif /* LIBFDT_INTERNAL_H */