[PATCHv3] arm64: gic-v3-its: Clear the Pending table before enabling LPIs

[Priyanka Jain]

>-----Original Message-----
>From: Z.q. Hou <zhiqiang.hou at nxp.com>
>Sent: Friday, March 5, 2021 12:33 PM
>To: u-boot at lists.denx.de
>Cc: sjg at chromium.org; rayagonda.kokatanur at broadcom.com; Priyanka Jain
><priyanka.jain at nxp.com>; Z.q. Hou <zhiqiang.hou at nxp.com>
>Subject: [PATCHv3] arm64: gic-v3-its: Clear the Pending table before enabling
>LPIs
>
>From: Hou Zhiqiang <Zhiqiang.Hou at 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 tables
>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 load the
>contents of the Pending table during the enablement, then set the
>GICR_PENDBASER.PTZ flag.
>
>Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
>---
>V3:
> - Fix a mistake code delete in v2.
>
> arch/arm/lib/gic-v3-its.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
>diff --git a/arch/arm/lib/gic-v3-its.c b/arch/arm/lib/gic-v3-its.c index
>f5a921b3d1..2d3fdb600e 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>
>@@ -108,6 +109,8 @@ int gic_lpi_tables_init(void)
> 	int i;
> 	u64 redist_lpi_base;
> 	u64 pend_base;
>+	ulong pend_tab_total_sz;
>+	void *pend_tab_va;
>
> 	if (gic_v3_its_get_gic_addr(&priv))
> 		return -EINVAL;
>@@ -161,6 +164,12 @@ int gic_lpi_tables_init(void)
> 	}
>
> 	redist_lpi_base = priv.lpi_base + LPI_PROPBASE_SZ;
>+	pend_tab_total_sz = priv.num_redist * LPI_PENDBASE_SZ;
>+	pend_tab_va = map_physmem(redist_lpi_base, pend_tab_total_sz,
>+				  MAP_NOCACHE);
>+	memset(pend_tab_va, 0, pend_tab_total_sz);
>+	flush_cache((ulong)pend_tab_va, pend_tab_total_sz);
>+	unmap_physmem(pend_tab_va, MAP_NOCACHE);
>
> 	pend_base = priv.gicr_base + GICR_PENDBASER;
> 	for (i = 0; i < priv.num_redist; i++) { @@ -168,7 +177,8 @@ 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));
>--
>2.17.1


Reviewed-by: Priyanka Jain <priyanka.jain at nxp.com>

Tom,

Kindly help to merge this patch.
This is required to fix boot issue on many of NXP fsl-qoriq platforms like lx2160ardb.

Thanks
Priyanka