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>
Reviewed-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
---
Changes since v2:
1. Rebase on Kukjin's for-next tree from 24th of September
(v3.17-rc3-97-gbcf20e084a4b)
Changes since v1:
1. Removed inline keyword and change if statement to early return as
Tomasz suggested.
2. Added reviewed-by Tomasz Figa.
---
arch/arm/mach-exynos/platsmp.c | 23 +++++++++++++++++++++++
arch/arm/mach-exynos/regs-pmu.h | 2 ++
2 files changed, 25 insertions(+)
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 41ae28d69e6f..8543064dc445 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -121,6 +121,26 @@ 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 void exynos_core_restart(u32 core_id)
+{
+ u32 val;
+
+ if (!of_machine_is_compatible("samsung,exynos3250"))
+ return;
+
+ val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
+ val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
+ pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));
+
+ pr_info("CPU%u: Software reset\n", core_id);
+ pmu_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.
@@ -196,6 +216,9 @@ 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 30c03017aa6a..4ea5e320c6d1 100644
--- a/arch/arm/mach-exynos/regs-pmu.h
+++ b/arch/arm/mach-exynos/regs-pmu.h
@@ -21,6 +21,7 @@
#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_WAKEUP_FROM_LOWPWR (1 << 28)
#define EXYNOS_SWRESET 0x0400
#define EXYNOS5440_SWRESET 0x00C4
@@ -125,6 +126,7 @@
#define S5P_PAD_RET_EBIB_OPTION 0x31A8
#define S5P_CORE_LOCAL_PWR_EN 0x3
+#define S5P_CORE_WAKEUP_FROM_LOCAL_CFG (0x3 << 8)
/* Only for EXYNOS4210 */
#define S5P_CMU_CLKSTOP_LCD1_LOWPWR 0x1154
--
1.9.1
--
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