[PATCH 5/5] xilinx: zynqmp: beckhoff cx8200: setup inner cache broadcasting

Steffen Dirkwinkel lists at steffen.cc
Wed Aug 30 16:03:34 CEST 2023

From: Steffen Dirkwinkel <s.dirkwinkel at beckhoff.com>

We need it for coherent access between pl and ps.

>From xilinx documentation:

Inner Cache Broadcasting

Linux sets up the MMU for cacheable memory to be inner shareable as that supports SMP operation.
As modifying the MMU tables from kernel or userspace is not a straightforwards task, the inner
cache broadcasting feature can be used to allow inner cacheble transactions be broadcasted.
Outside the APU, in the outer domain, the CCI handles coherency across the system.
The brdc_inner bit of the lpd_apu register within the LPD_SLCR module must be written while
the APU is in reset.

The requirement to alter the register while the APU is in reset can be accomplished using the
register initialization feature in the boot image.
.set. 0xFF41A040 = 0x3;

Signed-off-by: Steffen Dirkwinkel <s.dirkwinkel at beckhoff.com>


 board/xilinx/zynqmp/zynqmp-beckhoff-cx8200/regs.init | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 board/xilinx/zynqmp/zynqmp-beckhoff-cx8200/regs.init

diff --git a/board/xilinx/zynqmp/zynqmp-beckhoff-cx8200/regs.init b/board/xilinx/zynqmp/zynqmp-beckhoff-cx8200/regs.init
new file mode 100644
index 0000000000..e7038dd80a
--- /dev/null
+++ b/board/xilinx/zynqmp/zynqmp-beckhoff-cx8200/regs.init
@@ -0,0 +1 @@
+0xFF41A040 0x3
\ No newline at end of file

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