Merge tag 'sunxi-core-for-4.17' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into next/soc

Pull "Allwinner core changes for 4.17" from Maxime Ripard:

Here is our bunch of changes for mach-sunxi for this release cycle. This is
basically only about bringing the SMP support to the A80, which has a bug
in hardware and cannot use PSCI like the other SoCs we have.

* tag 'sunxi-core-for-4.17' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/sunxi/linux:
  ARM: sunxi: mc-smp: Split out SoC-specific device node lookup sequence
  ARM: sunxi: mc-smp: Use DT enable-method for sun9i A80 SMP
  ARM: sunxi: mc-smp: Fix "lookback" typo
  ARM: sun9i: smp: Support cpu0 hotplug
  dt-bindings: ARM: sunxi: Document A80 SoC secure SRAM usage by SMP hotplug
  ARM: sun9i: smp: Support CPU/cluster power down and hotplugging for cpu1~7
  ARM: sun9i: Support SMP bring-up on A80

2 files changed, 45 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index f4a777039f03..76655d0d67c2 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -198,6 +198,7 @@ described below.
 			    "actions,s500-smp"
 			    "allwinner,sun6i-a31"
 			    "allwinner,sun8i-a23"
+			    "allwinner,sun9i-a80-smp"
 			    "amlogic,meson8-smp"
 			    "amlogic,meson8b-smp"
 			    "arm,realview-smp"
diff --git a/Documentation/devicetree/bindings/arm/sunxi/smp-sram.txt b/Documentation/devicetree/bindings/arm/sunxi/smp-sram.txt
new file mode 100644
index 000000000000..082e6a9382d3
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/sunxi/smp-sram.txt
@@ -0,0 +1,44 @@
+Allwinner SRAM for smp bringup:
+------------------------------------------------
+
+Allwinner's A80 SoC uses part of the secure sram for hotplugging of the
+primary core (cpu0). Once the core gets powered up it checks if a magic
+value is set at a specific location. If it is then the BROM will jump
+to the software entry address, instead of executing a standard boot.
+
+Therefore a reserved section sub-node has to be added to the mmio-sram
+declaration.
+
+Note that this is separate from the Allwinner SRAM controller found in
+../../sram/sunxi-sram.txt. This SRAM is secure only and not mappable to
+any device.
+
+Also there are no "secure-only" properties. The implementation should
+check if this SRAM is usable first.
+
+Required sub-node properties:
+- compatible : depending on the SoC this should be one of:
+		"allwinner,sun9i-a80-smp-sram"
+
+The rest of the properties should follow the generic mmio-sram discription
+found in ../../misc/sram.txt
+
+Example:
+
+	sram_b: sram@20000 {
+		/* 256 KiB secure SRAM at 0x20000 */
+		compatible = "mmio-sram";
+		reg = <0x00020000 0x40000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0 0x00020000 0x40000>;
+
+		smp-sram@1000 {
+			/*
+			 * This is checked by BROM to determine if
+			 * cpu0 should jump to SMP entry vector
+			 */
+			compatible = "allwinner,sun9i-a80-smp-sram";
+			reg = <0x1000 0x8>;
+		};
+	};