Without software reset the secondary CPU does not power up and
exynos_boot_secondary() ends with pen_release equal to 1. This can be
observed in dmesg:
CPU1: failed to come online
Brought up 1 CPUs
SMP: Total of 1 processors activated.
CPU: All CPU(s) started in SVC mode.
When booting the secondary CPU on Exynos3250 execute also software
reset for core 1.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
---
arch/arm/mach-exynos/platsmp.c | 22 ++++++++++++++++++++++
arch/arm/mach-exynos/regs-pmu.h | 3 +++
2 files changed, 25 insertions(+)
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 8b88eb2f077b..64ec5ca18f60 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -76,6 +76,25 @@ static inline void __iomem *cpu_boot_reg(int cpu)
}
/*
+ * Set wake up by local power mode and execute software reset for given core.
+ *
+ * Currently this is needed only when booting secondary CPU on Exynos3250.
+ */
+static inline void exynos_core_restart(u32 core_id)
+{
+ if (of_machine_is_compatible("samsung,exynos3250")) {
+ u32 val;
+
+ val = __raw_readl(S5P_ARM_CORE_STATUS(core_id));
+ val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
+ __raw_writel(val, S5P_ARM_CORE_STATUS(core_id));
+
+ pr_info("CPU%u: Software reset\n", core_id);
+ __raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
+ }
+}
+
+/*
* Write pen_release in a way that is guaranteed to be visible to all
* observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
@@ -155,6 +174,9 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
return -ETIMEDOUT;
}
}
+
+ exynos_core_restart(core_id);
+
/*
* Send the secondary CPU a soft interrupt, thereby causing
* the boot monitor to read the system wide flags register,
diff --git a/arch/arm/mach-exynos/regs-pmu.h b/arch/arm/mach-exynos/regs-pmu.h
index d94bbc85d7e0..3ecbb4fe227b 100644
--- a/arch/arm/mach-exynos/regs-pmu.h
+++ b/arch/arm/mach-exynos/regs-pmu.h
@@ -26,6 +26,8 @@
#define S5P_USE_STANDBY_WFI0 (1 << 16)
#define S5P_USE_STANDBY_WFE0 (1 << 24)
+#define EXYNOS_CORE_PO_RESET(n) ((1 << 4) << n)
+
#define EXYNOS_SWRESET S5P_PMUREG(0x0400)
#define EXYNOS5440_SWRESET S5P_PMUREG(0x00C4)
@@ -117,6 +119,7 @@
#define S5P_PAD_RET_EBIB_OPTION S5P_PMUREG(0x31A8)
#define S5P_CORE_LOCAL_PWR_EN 0x3
+#define S5P_CORE_WAKEUP_FROM_LOCAL_CFG (0x3 << 8)
#define S5P_INT_LOCAL_PWR_EN 0x7
#define S5P_CHECK_SLEEP 0x00000BAD
--
1.9.1
--
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