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Subject[PATCH V3] ARM: mach-shmobile: Don't init CNTVOFF if PSCI is available
Date
From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

If PSCI is available then most likely we are running on PSCI-enabled
U-Boot which, we assume, has already taken care of resetting CNTVOFF
before switching to non-secure mode and we don't need to.

Please note, an extra check to prevent secure_cntvoff_init() from
being called for secondary CPUs in headsmp-apmu.S is not needed,
as SMP code for APMU based system is not executed if PSCI is in use.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
CC: Julien Grall <julien.grall@arm.com>

---
You can find previous discussions here:
[v1] https://lkml.org/lkml/2019/4/17/810
[v2] https://lkml.org/lkml/2019/5/3/338

Changes in v2:
- Clarify patch subject/description
- Don't use CONFIG_ARM_PSCI option, check whether the PSCI is available,
by using psci_smp_available()
- Check whether we are running on top of Xen, by using xen_domain()

Changes in v3:
- Don't check for the presence of Xen
---
arch/arm/mach-shmobile/setup-rcar-gen2.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c
index eea60b2..35dda21 100644
--- a/arch/arm/mach-shmobile/setup-rcar-gen2.c
+++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c
@@ -18,6 +18,7 @@
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <asm/mach/arch.h>
+#include <asm/psci.h>
#include <asm/secure_cntvoff.h>
#include "common.h"
#include "rcar-gen2.h"
@@ -63,7 +64,13 @@ void __init rcar_gen2_timer_init(void)
void __iomem *base;
u32 freq;

- secure_cntvoff_init();
+ /*
+ * If PSCI is available then most likely we are running on PSCI-enabled
+ * U-Boot which, we assume, has already taken care of resetting CNTVOFF
+ * before switching to non-secure mode and we don't need to.
+ */
+ if (!psci_smp_available())
+ secure_cntvoff_init();

if (of_machine_is_compatible("renesas,r8a7745") ||
of_machine_is_compatible("renesas,r8a77470") ||
--
2.7.4
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