Re: [PATCH] arm64: dts: ti: k3-am64-main: Add SYSFW reserved ranges in OCRAM

+Aswath

On 6/12/21 12:46 AM, Nishanth Menon wrote:

On 19:36-20210609, Vignesh Raghavendra wrote:

quoted

Last 256K of OCRAM (256K@0x701c0000) is reserved for SYSFW usage. Hence
add an entry in DT so that its not used for generic pool memory
allocation.

Are you really sure?? I know that I had set a budget for 16K in sysfw
when I did the memory split up for sysfw of which 16k is actually used.

Not sure where this 256K bucket started off from.. am I missing
something here?

Per: http://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am64x/firewalls.html

24	dmsc	0x44060000	0x4407BFFF	dmsc,rwcd	 	 // alias for 0x701E0000
24	dmsc	0x701FC000	0x701FFFFF	sproxy_private,rwcd	 	 
24	dmsc	0x4407C000	0x4407FFFF	sproxy_private,rwcd	 	 
24	dmsc	0x701C0000	0x701DFFFF	everyone,rwcd	 	 

So it looks like only 128K@0x701E0000 is firewalled off. 
Will update the patch.

This makes me wonder why ATF is being moved to 0x701a0000-0x701c0000
leaving a hole at 0x701C0000-0x701DFFFF? 

quoted

Without this certain drivers using SRAM as generic shared memory pool
may end up being allocated memory from this range and will lead to boot
time crash when the reserved range is accessed (due to firewall
violation).

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 arch/arm64/boot/dts/ti/k3-am64-main.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/ti/k3-am64-main.dtsi b/arch/arm64/boot/dts/ti/k3-am64-main.dtsi
index f1c42ef05e52..77b88e536534 100644
--- a/arch/arm64/boot/dts/ti/k3-am64-main.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am64-main.dtsi

@@ -16,6 +16,10 @@ oc_sram: sram@70000000 {
 		atf-sram@0 {
 			reg = <0x0 0x1a000>;
 		};
+
+		dmsc-sram@1c0000 {
+			reg = <0x1c0000 0x40000>;

quoted

+		};
 	};
 
 	gic500: interrupt-controller@1800000 {
-- 
2.31.1