diff mbox series

[4/9] arm64: dts: qcom: msm8916: Reserve firmware memory dynamically

Message ID 20230911-msm8916-rmem-v1-4-b7089ec3e3a1@gerhold.net
State Accepted
Commit 0ed3d82862e8451cc2b14ddb1b064e72ba3e5a60
Headers show
Series arm64: dts: qcom: msm8916/39: Reserve firmware memory dynamically | expand

Commit Message

Stephan Gerhold Sept. 11, 2023, 5:41 p.m. UTC
Most of the reserved firmware memory on MSM8916 can be relocated when
respecting the required alignment. To avoid having to precompute the
reserved memory regions in every board DT, describe the actual
requirements (size, alignment, alloc-ranges) using the dynamic reserved
memory allocation.

This approach has several advantages:

 1. We can define "templates" for the reserved memory regions in
    msm8916.dtsi and keep only device-specific details in the board DT.
    This is useful for the "mpss" region size for example, which varies
    from device to device. It is no longer necessary to redefine all
    firmware regions to shift their addresses.

 2. When some of the functionality (e.g. WCNSS, Modem, Venus) is not
    enabled or needed for a device, the reserved memory can stay
    disabled, freeing up the unused reservation for Linux.

 3. Devices with special requirements for one of the firmware regions
    are handled automatically. For example, msm8916-longcheer-l8150
    has non-relocatable "wcnss" firmware that must be loaded exactly
    at address 0x8b600000. When this is defined as a static region,
    the other dynamic allocations automatically adjust to a different
    place with suitable alignment.

All in all this approach significantly reduces the boilerplate necessary
to define the different firmware regions, and makes it easier to enable
functionality on the different devices.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
---
 .../boot/dts/qcom/msm8916-longcheer-l8150.dts      |  9 +++++++--
 arch/arm64/boot/dts/qcom/msm8916-ufi.dtsi          | 11 ++++-------
 arch/arm64/boot/dts/qcom/msm8916.dtsi              | 22 ++++++++++++++++++----
 3 files changed, 29 insertions(+), 13 deletions(-)

Comments

Konrad Dybcio Sept. 13, 2023, 9:06 a.m. UTC | #1
On 11.09.2023 19:41, Stephan Gerhold wrote:
> Most of the reserved firmware memory on MSM8916 can be relocated when
> respecting the required alignment. To avoid having to precompute the
> reserved memory regions in every board DT, describe the actual
> requirements (size, alignment, alloc-ranges) using the dynamic reserved
> memory allocation.
> 
> This approach has several advantages:
> 
>  1. We can define "templates" for the reserved memory regions in
>     msm8916.dtsi and keep only device-specific details in the board DT.
>     This is useful for the "mpss" region size for example, which varies
>     from device to device. It is no longer necessary to redefine all
>     firmware regions to shift their addresses.
> 
>  2. When some of the functionality (e.g. WCNSS, Modem, Venus) is not
>     enabled or needed for a device, the reserved memory can stay
>     disabled, freeing up the unused reservation for Linux.
> 
>  3. Devices with special requirements for one of the firmware regions
>     are handled automatically. For example, msm8916-longcheer-l8150
>     has non-relocatable "wcnss" firmware that must be loaded exactly
>     at address 0x8b600000. When this is defined as a static region,
>     the other dynamic allocations automatically adjust to a different
>     place with suitable alignment.
> 
> All in all this approach significantly reduces the boilerplate necessary
> to define the different firmware regions, and makes it easier to enable
> functionality on the different devices.
> 
> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> ---
[...]

>  
>  		mpss_mem: mpss@86800000 {
> +			/*
> +			 * The memory region for the mpss firmware is generally
> +			 * relocatable and could be allocated dynamically.
> +			 * However, many firmware versions tend to fail when
> +			 * loaded to some special addresses, so it is hard to
> +			 * define reliable alloc-ranges.
> +			 *
> +			 * alignment = <0x0 0x400000>;
> +			 * alloc-ranges = <0x0 0x86800000 0x0 0x8000000>;
> +			 */
Do we know of any devices that this would actually work on?

Konrad
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/msm8916-longcheer-l8150.dts b/arch/arm64/boot/dts/qcom/msm8916-longcheer-l8150.dts
index a0bb8de54fb6..503155aefa55 100644
--- a/arch/arm64/boot/dts/qcom/msm8916-longcheer-l8150.dts
+++ b/arch/arm64/boot/dts/qcom/msm8916-longcheer-l8150.dts
@@ -23,9 +23,14 @@  chosen {
 		stdout-path = "serial0";
 	};
 
+	/*
+	 * For some reason, the signed wcnss firmware is not relocatable.
+	 * It must be loaded at 0x8b600000. All other firmware is relocatable,
+	 * so place wcnss at the fixed address and then all other firmware
+	 * regions will be automatically allocated at a fitting place.
+	 */
 	reserved-memory {
-		/* wcnss.mdt is not relocatable, so it must be loaded at 0x8b600000 */
-		/delete-node/ wcnss@89300000;
+		/delete-node/ wcnss;
 
 		wcnss_mem: wcnss@8b600000 {
 			reg = <0x0 0x8b600000 0x0 0x600000>;
diff --git a/arch/arm64/boot/dts/qcom/msm8916-ufi.dtsi b/arch/arm64/boot/dts/qcom/msm8916-ufi.dtsi
index 69f268db4df9..1d92c2e57216 100644
--- a/arch/arm64/boot/dts/qcom/msm8916-ufi.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916-ufi.dtsi
@@ -17,13 +17,6 @@  chosen {
 		stdout-path = "serial0";
 	};
 
-	reserved-memory {
-		mpss_mem: mpss@86800000 {
-			reg = <0x0 0x86800000 0x0 0x5500000>;
-			no-map;
-		};
-	};
-
 	gpio-keys {
 		compatible = "gpio-keys";
 
@@ -91,6 +84,10 @@  &mpss {
 	status = "okay";
 };
 
+&mpss_mem {
+	reg = <0x0 0x86800000 0x0 0x5500000>;
+};
+
 &pm8916_usbin {
 	status = "okay";
 };
diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
index 0257cbbb4971..c237f3e48c86 100644
--- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
@@ -74,17 +74,31 @@  rfsa@867e0000 {
 		};
 
 		mpss_mem: mpss@86800000 {
+			/*
+			 * The memory region for the mpss firmware is generally
+			 * relocatable and could be allocated dynamically.
+			 * However, many firmware versions tend to fail when
+			 * loaded to some special addresses, so it is hard to
+			 * define reliable alloc-ranges.
+			 *
+			 * alignment = <0x0 0x400000>;
+			 * alloc-ranges = <0x0 0x86800000 0x0 0x8000000>;
+			 */
 			reg = <0x0 0x86800000 0x0 0x2b00000>;
 			no-map;
 		};
 
-		wcnss_mem: wcnss@89300000 {
-			reg = <0x0 0x89300000 0x0 0x600000>;
+		wcnss_mem: wcnss {
+			size = <0x0 0x600000>;
+			alignment = <0x0 0x100000>;
+			alloc-ranges = <0x0 0x86800000 0x0 0x8000000>;
 			no-map;
 		};
 
-		venus_mem: venus@89900000 {
-			reg = <0x0 0x89900000 0x0 0x600000>;
+		venus_mem: venus {
+			size = <0x0 0x600000>;
+			alignment = <0x0 0x100000>;
+			alloc-ranges = <0x0 0x86800000 0x0 0x8000000>;
 			no-map;
 		};