diff mbox series

arm64: gic-v3-its: Clear the Pending talbe before enabling LPIs

Message ID 20210302100536.40376-1-Zhiqiang.Hou@nxp.com
State Superseded
Delegated to: Tom Rini
Headers show
Series arm64: gic-v3-its: Clear the Pending talbe before enabling LPIs | expand

Commit Message

Z.Q. Hou March 2, 2021, 10:05 a.m. UTC 
From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

The GICv3 RM requires "The first 1KB of memory for the LPI Pending tables
must contain only zeros on initial allocation, and this must be visible
to the Redistributors, or else the effect is UNPREDICTABLE".

And as the following statement, we here clear the whole Pending talbes
instead of the first 1KB.
"An LPI Pending table that contains only zeros, including in the first 1KB,
indicates that there are no pending LPIs.
The first 1KB of the LPI Pending table is IMPLEMENTATION DEFINED. However,
if the first 1KB of the LPI Pending table and the rest of the table contain
only zeros, this must indicate that there are no pending LPIs."

And there isn't any pending LPI under U-Boot, so it's unnecessary to
loading the contents of the Pending talbe during the enablement, then set
the GICR_PENDBASER.PTZ flag.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
---
 arch/arm/lib/gic-v3-its.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/arm/lib/gic-v3-its.c b/arch/arm/lib/gic-v3-its.c
index f5a921b3d1..5620e67ce3 100644
--- a/arch/arm/lib/gic-v3-its.c
+++ b/arch/arm/lib/gic-v3-its.c
@@ -3,6 +3,7 @@ 
  * Copyright 2019 Broadcom.
  */
 #include <common.h>
+#include <cpu_func.h>
 #include <dm.h>
 #include <regmap.h>
 #include <syscon.h>
@@ -161,6 +162,8 @@  int gic_lpi_tables_init(void)
 	}
 
 	redist_lpi_base = priv.lpi_base + LPI_PROPBASE_SZ;
+	memset((void *)redist_lpi_base, 0, priv.num_redist * LPI_PENDBASE_SZ);
+	flush_cache(redist_lpi_base, priv.num_redist * LPI_PENDBASE_SZ);
 
 	pend_base = priv.gicr_base + GICR_PENDBASER;
 	for (i = 0; i < priv.num_redist; i++) {
@@ -168,7 +171,8 @@  int gic_lpi_tables_init(void)
 
 		val = ((redist_lpi_base + (i * LPI_PENDBASE_SZ)) |
 			GICR_PENDBASER_INNERSHAREABLE |
-			GICR_PENDBASER_RAWAWB);
+			GICR_PENDBASER_RAWAWB |
+			GICR_PENDBASER_PTZ);
 
 		writeq(val, (uintptr_t)(pend_base + offset));
 		tmp = readq((uintptr_t)(pend_base + offset));