[PATCH v3 3/3] ARM: dts: broadcom: Use CFE CPU bring-up on the XG6846B

The XG6846B boots through CFE, which parks CPU1 in a holding pen and does
not provide PSCI. Starting Linux from CFE does not install a PSCI
implementation either. The working PSCI interface in newer GenXOS
firmware belongs to a different boot stack.

Disable the inherited PSCI node on this board so Linux does not issue
SMCs to an interface that is absent. Set the CPUs' enable-method to
brcm,bca-smp to select the BCMBCA CFE SMP operations. Describe the CFE
mailbox in CPU1's cpu-release-addr property. Keep both CPU nodes enabled
and leave the SoC's PSCI defaults available to other boards.

Also remove no-map from the secondary-boot reservation. Its overlap
with ARM's initial page tables otherwise causes the reservation to be
rejected, leaving CFE's holding pen unprotected.

Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts b/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts
index a3616fb7b3a8..45d4df523110 100644
--- a/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts
+++ b/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts

@@ -34,7 +34,7 @@ reserved-memory {
 		ranges;
 
 		secondary-boot@0 {
-			no-map;
+			/* Includes the kernel's initial page tables. */
 			reg = <0x00000000 0x00008000>;
 		};
 		pmc3-firmware@8000 {

@@ -56,6 +56,20 @@ button-restart {
 	};
 };
 
+/* CFE parks CPU1 in its holding pen and does not provide PSCI. */
+&{/psci} {
+	status = "disabled";
+};
+
+&CA7_0 {
+	enable-method = "brcm,bca-smp";
+};
+
+&CA7_1 {
+	enable-method = "brcm,bca-smp";
+	cpu-release-addr = <0xff800568>;
+};
+
 &gpio0 {
 	status = "okay";
 };

-- 
2.56.0