Hi Devarsh, On 20:39-20240613, Devarsh Thakkar wrote: > Reserve 576MiB of CMA as global CMA pool starting after initial 1GiB of > DDR. > > AM62ax has different multimedia components such as Camera, Display, H.264 > VPU and JPEG Encoder which use CMA for buffer allocations. > > The 12x 720x480 realtime VPU decode use-case requires 544MiB of CMA, > additional 32MiB is kept as buffer in case some other peripheral also > require it while VPU is running. > > The reason to choose latter 1GiB is to not overlap with existing memory map > which is utilizing initial 1GiB for remoteproc firmwares as shared here > [1]. > > Also some drivers such as JPEG require 32bit addressing so not allocating > from higher DDR address. > > Link: https://lore.kernel.org/all/20240605124859.3034-5-hnagalla@xxxxxx [1] > Signed-off-by: Devarsh Thakkar <devarsht@xxxxxx> I have validated that this patch works with VPU. Tested-by: Brandon Brnich <b-brnich@xxxxxx> Best, Brandon > --- > arch/arm64/boot/dts/ti/k3-am62a7-sk.dts | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts b/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts > index e026f65738b3..67faf46d7a35 100644 > --- a/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts > +++ b/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts > @@ -40,6 +40,15 @@ reserved-memory { > #size-cells = <2>; > ranges; > > + /* global cma region */ > + linux,cma { > + compatible = "shared-dma-pool"; > + reusable; > + size = <0x00 0x24000000>; > + alloc-ranges = <0x00 0xc0000000 0x00 0x24000000>; > + linux,cma-default; > + }; > + > secure_tfa_ddr: tfa@9e780000 { > reg = <0x00 0x9e780000 0x00 0x80000>; > alignment = <0x1000>; > -- > 2.39.1 >
