[PATCH rtems-lwip] rtemslwip/xil_shims: Perform flush with invalidate

Kinsey Moore kinsey.moore at oarcorp.com
Thu Mar 30 21:13:27 UTC 2023


Xilinx wrote their A53 HAL with the assumption that the CPU did not
support cache invalidation without a flush, so the flush and
invalidation functions were combined and all range invalidations are
promoted to flush/invalidate. The implementation written for lwIP was
written to the original intent of the function and thus was not flushing
in some cases when it needed to. This resolves that issue which prevents
DMA transmit errors in some cases.
---
 rtemslwip/zynqmp/xil_shims.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/rtemslwip/zynqmp/xil_shims.c b/rtemslwip/zynqmp/xil_shims.c
index 2eda0c5..1b1b3cf 100644
--- a/rtemslwip/zynqmp/xil_shims.c
+++ b/rtemslwip/zynqmp/xil_shims.c
@@ -102,7 +102,12 @@ void XScuGic_DisableIntr ( u32 DistBaseAddress, u32 Int_Id )
   rtems_interrupt_vector_disable( Int_Id );
 }
 
+/*
+ * The Xilinx code was written such that it assumed there was no invalidate-only
+ * functionality on A53 cores. This function must flush and invalidate because
+ * of how they mapped things.
+ */
 void Xil_DCacheInvalidateRange( INTPTR adr, INTPTR len )
 {
-  rtems_cache_invalidate_multiple_data_lines( (const void *) adr, len );
+  rtems_cache_flush_multiple_data_lines( (const void *) adr, len );
 }
-- 
2.30.2



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