[PATCH] ARM: exynos: move sysram info to exynos.c

This solves a problem with building with CONFIG_SMP=n due to missing
sysram_base_addr (or sysram_ns_base_addr) variables.

The new setup method is more awkward than I'd like for it to be, but
it can't be done in init_early() since ioremap is not yet available,
but it needs to happen before SMP.

Reported-by: Russell King <redacted>
Cc: Kukjin Kim <redacted>
Cc: Tomasz Figa <redacted>
Cc: Daniel Lezcano <redacted>
Signed-off-by: Olof Johansson <redacted>
---

I'm not entirely happy with the solution here, especially the dual
call path. The platsmp.c->exynos.c call isn't ideal either but I'm less
worried about that. Seemed overkill to create a new c file just for this.

I've tested to make sure this still works on arndale, and the build
errors as reported by Russell are definitely gone.

Better ideas welcome.


 arch/arm/mach-exynos/common.h  |    1 +
 arch/arm/mach-exynos/exynos.c  |   29 +++++++++++++++++++++++++++++
 arch/arm/mach-exynos/platsmp.c |   26 ++------------------------
 3 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
index 80b90e3..5a3a1ec 100644
--- a/arch/arm/mach-exynos/common.h
+++ b/arch/arm/mach-exynos/common.h

@@ -118,6 +118,7 @@ extern void __iomem *sysram_ns_base_addr;
 extern void __iomem *sysram_base_addr;
 void exynos_init_io(void);
 void exynos_restart(enum reboot_mode mode, const char *cmd);
+void exynos_sysram_init(void);
 void exynos_cpuidle_init(void);
 void exynos_cpufreq_init(void);
 void exynos_init_late(void);

diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
index bc43e22..9183675 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c

@@ -187,6 +187,28 @@ void __init exynos_cpufreq_init(void)
 	platform_device_register_simple("exynos-cpufreq", -1, NULL, 0);
 }
 
+void __iomem *sysram_base_addr;
+void __iomem *sysram_ns_base_addr;
+
+void __init exynos_sysram_init(void)
+{
+	struct device_node *node;
+
+	for_each_compatible_node(node, NULL, "samsung,exynos4210-sysram") {
+		if (!of_device_is_available(node))
+			continue;
+		sysram_base_addr = of_iomap(node, 0);
+		break;
+	}
+
+	for_each_compatible_node(node, NULL, "samsung,exynos4210-sysram-ns") {
+		if (!of_device_is_available(node))
+			continue;
+		sysram_ns_base_addr = of_iomap(node, 0);
+		break;
+	}
+}
+
 void __init exynos_init_late(void)
 {
 	if (of_machine_is_compatible("samsung,exynos5440"))

@@ -293,6 +315,13 @@ static void __init exynos_dt_machine_init(void)
 		}
 	}
 
+	/*
+	 * This is called from smp_prepare_cpus if we've built for SMP, but
+	 * we still need to set it up for PM and firmware ops if not.
+	 */
+	if (!IS_ENABLED(SMP))
+		exynos_sysram_init();
+
 	exynos_cpuidle_init();
 	exynos_cpufreq_init();
 

diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index ec02422..1c8d31e 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c

@@ -32,28 +32,6 @@
 
 extern void exynos4_secondary_startup(void);
 
-void __iomem *sysram_base_addr;
-void __iomem *sysram_ns_base_addr;
-
-static void __init exynos_smp_prepare_sysram(void)
-{
-	struct device_node *node;
-
-	for_each_compatible_node(node, NULL, "samsung,exynos4210-sysram") {
-		if (!of_device_is_available(node))
-			continue;
-		sysram_base_addr = of_iomap(node, 0);
-		break;
-	}
-
-	for_each_compatible_node(node, NULL, "samsung,exynos4210-sysram-ns") {
-		if (!of_device_is_available(node))
-			continue;
-		sysram_ns_base_addr = of_iomap(node, 0);
-		break;
-	}
-}
-
 static inline void __iomem *cpu_boot_reg_base(void)
 {
 	if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)

@@ -234,11 +212,11 @@ static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
 {
 	int i;
 
+	exynos_sysram_init();
+
 	if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9)
 		scu_enable(scu_base_addr());
 
-	exynos_smp_prepare_sysram();
-
 	/*
 	 * Write the address of secondary startup into the
 	 * system-wide flags register. The boot monitor waits

-- 
1.7.10.4

Hi Olof,

On 03.06.2014 06:47, Olof Johansson wrote:

This solves a problem with building with CONFIG_SMP=n due to missing
sysram_base_addr (or sysram_ns_base_addr) variables.

The new setup method is more awkward than I'd like for it to be, but
it can't be done in init_early() since ioremap is not yet available,
but it needs to happen before SMP.

Reported-by: Russell King <redacted>
Cc: Kukjin Kim <redacted>
Cc: Tomasz Figa <redacted>
Cc: Daniel Lezcano <redacted>
Signed-off-by: Olof Johansson <redacted>
---

I'm not entirely happy with the solution here, especially the dual
call path. The platsmp.c->exynos.c call isn't ideal either but I'm less
worried about that. Seemed overkill to create a new c file just for this.

I've tested to make sure this still works on arndale, and the build
errors as reported by Russell are definitely gone.

In general, I'm okay with this patch, so if nobody is willing to find a
better way feel free to add my Reviewed-by.

Better ideas welcome.

Probably the best idea would be to find a way to always call
exynos_sysram_init() after DT unflattening and before SMP
initialization. Some platforms (e.g. tegra) abuse .init_irq callback for
this, e.g.:

mach-tegra/tegra.c:
	static void __init tegra_dt_init_irq(void)
	{
		tegra_pmc_init_irq();
		tegra_init_irq();
		irqchip_init();
		tegra_legacy_irq_syscore_init();
	}

We could do the same on Exynos if this is considered better.

Best regards,
Tomasz