[PATCH] arm64: dts: exynos: Specify reserved secure memory explicitly

[PATCH] arm64: dts: exynos: Specify reserved secure memory explicitly

[Sam Protsenko]

Instead of carving out the secure area in 'memory' node, let's describe
it in 'reserved-memory'. That makes it easier to understand both RAM
regions and particular secure world memory region. Originally the device
tree was created in a way to make sure it was well aligned with the way
LittleKernel bootloader modified it. But later it was found the
LittleKernel works fine with properly described reserved regions, so
it's possible now to define those in a cleaner way.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 arch/arm64/boot/dts/exynos/exynos850-e850-96.dts | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts b/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts
index f074df8982b3..7d70a32e75b2 100644
--- a/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts
+++ b/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts
@@ -45,17 +45,9 @@ usb_dr_connector: endpoint {
 		};
 	};
 
-	/*
-	 * RAM: 4 GiB (eMCP):
-	 *   - 2 GiB at 0x80000000
-	 *   - 2 GiB at 0x880000000
-	 *
-	 * 0xbab00000..0xbfffffff: secure memory (85 MiB).
-	 */
 	memory@80000000 {
 		device_type = "memory";
-		reg = <0x0 0x80000000 0x3ab00000>,
-		      <0x0 0xc0000000 0x40000000>,
+		reg = <0x0 0x80000000 0x80000000>,
 		      <0x8 0x80000000 0x80000000>;
 	};
 
@@ -146,6 +138,11 @@ reserved-memory {
 		#size-cells = <1>;
 		ranges;
 
+		secure_mem: memory@bab00000 {
+			reg = <0x0 0xbab00000 0x5500000>;
+			no-map;
+		};
+
 		ramoops@f0000000 {
 			compatible = "ramoops";
 			reg = <0x0 0xf0000000 0x200000>;
-- 
2.39.5

Re: [PATCH] arm64: dts: exynos: Specify reserved secure memory explicitly

[Krzysztof Kozlowski]

On Tue, 10 Dec 2024 21:30:27 -0600, Sam Protsenko wrote:
> Instead of carving out the secure area in 'memory' node, let's describe
> it in 'reserved-memory'. That makes it easier to understand both RAM
> regions and particular secure world memory region. Originally the device
> tree was created in a way to make sure it was well aligned with the way
> LittleKernel bootloader modified it. But later it was found the
> LittleKernel works fine with properly described reserved regions, so
> it's possible now to define those in a cleaner way.
> 
> [...]

Applied, thanks!

[1/1] arm64: dts: exynos: Specify reserved secure memory explicitly
      https://git.kernel.org/krzk/linux/c/11fd6c9b047c30c72dcea3f79c0acb7deb69c822

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>