[PATCH AUTOSEL 5.5 107/121] ARM: shmobile: Enable ARM_GLOBAL_TIMER on Cortex-A9 MPCore SoCs

Sasha Levin
2020-04-11T23:09:25Z

From: Geert Uytterhoeven <geert+renesas@glider.be>

[ Upstream commit 408324a3c5383716939eea8096a0f999a0665f7e ]

SH-Mobile AG5 and R-Car H1 SoCs are based on the Cortex-A9 MPCore, which
includes a global timer.

Enable the ARM global timer on these SoCs, which will be used for:
- the scheduler clock, improving scheduler accuracy from 10 ms to 3 or
4 ns,
- delay loops, allowing removal of calls to shmobile_init_delay() from
the corresponding machine vectors.

Note that when using an old DTB lacking the global timer, the kernel
will still work. However, loops-per-jiffies will no longer be preset,
and the delay loop will need to be calibrated during boot.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191211135222.26770-5-geert+renesas@glider.be
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/mach-shmobile/setup-r8a7779.c | 1 -
arch/arm/mach-shmobile/setup-sh73a0.c | 1 -
drivers/soc/renesas/Kconfig | 2 ++
3 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-shmobile/setup-r8a7779.c b/arch/arm/mach-shmobile/setup-r8a7779.c
index b13ec9088ce53..86406e3f9b22e 100644
--- a/arch/arm/mach-shmobile/setup-r8a7779.c
+++ b/arch/arm/mach-shmobile/setup-r8a7779.c
@@ -72,7 +72,6 @@ static const char *const r8a7779_compat_dt[] __initconst = {
DT_MACHINE_START(R8A7779_DT, "Generic R8A7779 (Flattened Device Tree)")
.smp = smp_ops(r8a7779_smp_ops),
.map_io = r8a7779_map_io,
- .init_early = shmobile_init_delay,
.init_irq = r8a7779_init_irq_dt,
.init_late = shmobile_init_late,
.dt_compat = r8a7779_compat_dt,
diff --git a/arch/arm/mach-shmobile/setup-sh73a0.c b/arch/arm/mach-shmobile/setup-sh73a0.c
index cc08aa7522447..eb4a62fa42895 100644
--- a/arch/arm/mach-shmobile/setup-sh73a0.c
+++ b/arch/arm/mach-shmobile/setup-sh73a0.c
@@ -56,7 +56,6 @@ static const char *const sh73a0_boards_compat_dt[] __initconst = {
DT_MACHINE_START(SH73A0_DT, "Generic SH73A0 (Flattened Device Tree)")
.smp = smp_ops(sh73a0_smp_ops),
.map_io = sh73a0_map_io,
- .init_early = shmobile_init_delay,
.init_machine = sh73a0_generic_init,
.init_late = shmobile_init_late,
.dt_compat = sh73a0_boards_compat_dt,
diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
index f93492b72c04e..60072242fa6e1 100644
--- a/drivers/soc/renesas/Kconfig
+++ b/drivers/soc/renesas/Kconfig
@@ -116,6 +116,7 @@ config ARCH_R8A7779
bool "R-Car H1 (R8A77790)"
select ARCH_RCAR_GEN1
select ARM_ERRATA_754322
+ select ARM_GLOBAL_TIMER
select HAVE_ARM_SCU if SMP
select HAVE_ARM_TWD if SMP
select SYSC_R8A7779
@@ -163,6 +164,7 @@ config ARCH_SH73A0
bool "SH-Mobile AG5 (R8A73A00)"
select ARCH_RMOBILE
select ARM_ERRATA_754322
+ select ARM_GLOBAL_TIMER
select HAVE_ARM_SCU if SMP
select HAVE_ARM_TWD if SMP
select RENESAS_INTC_IRQPIN
--
2.20.1