[PATCH AUTOSEL 5.8 20/72] ARM: exynos: MCPM: Restore big.LITTLE cpuidle support

Sasha Levin
2020-08-08T23:51:08Z

From: Marek Szyprowski <m.szyprowski@samsung.com>

[ Upstream commit ea9dd8f61c8a890843f68e8dc0062ce78365aab8 ]

Call exynos_cpu_power_up(cpunr) unconditionally. This is needed by the
big.LITTLE cpuidle driver and has no side-effects on other code paths.

The additional soft-reset call during little core power up has been added
to properly boot all cores on the Exynos5422-based boards with secure
firmware (like Odroid XU3/XU4 family). This however broke big.LITTLE
CPUidle driver, which worked only on boards without secure firmware (like
Peach-Pit/Pi Chromebooks). Apply the workaround only when board is
running under secure firmware.

Fixes: 833b5794e330 ("ARM: EXYNOS: reset Little cores when cpu is up")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/mach-exynos/mcpm-exynos.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
index 9a681b421ae11..cd861c57d5adf 100644
--- a/arch/arm/mach-exynos/mcpm-exynos.c
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -26,6 +26,7 @@
#define EXYNOS5420_USE_L2_COMMON_UP_STATE BIT(30)

static void __iomem *ns_sram_base_addr __ro_after_init;
+static bool secure_firmware __ro_after_init;

/*
* The common v7_exit_coherency_flush API could not be used because of the
@@ -58,15 +59,16 @@ static void __iomem *ns_sram_base_addr __ro_after_init;
static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
{
unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
+ bool state;

pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
cluster >= EXYNOS5420_NR_CLUSTERS)
return -EINVAL;

- if (!exynos_cpu_power_state(cpunr)) {
- exynos_cpu_power_up(cpunr);
-
+ state = exynos_cpu_power_state(cpunr);
+ exynos_cpu_power_up(cpunr);
+ if (!state && secure_firmware) {
/*
* This assumes the cluster number of the big cores(Cortex A15)
* is 0 and the Little cores(Cortex A7) is 1.
@@ -258,6 +260,8 @@ static int __init exynos_mcpm_init(void)
return -ENOMEM;
}

+ secure_firmware = exynos_secure_firmware_available();
+
/*
* To increase the stability of KFC reset we need to program
* the PMU SPARE3 register
--
2.25.1