[PATCH v2 0/5] ARM: Berlin: SMP support

[PATCH v2 0/5] ARM: Berlin: SMP support

[Antoine Ténart]

This series adds the SMP support for Marvell Berlin BG2 and BG2Q.

This implementation takes advantage of the reset exception register and
the software reset address register to make the CPUs execute the Berlin
secondary startup when being reset. This has the advantage of not using
the pen lock mechanism.

Patch 3 depends on Alex Elder effort to properly document CPU enable
methods: https://patchwork.kernel.org/patch/4138211/

Changes since v1:
	- added a proper enable-method documentation
	- s/reseted/reset/ and s/register/vector/
	- removed unneeded 'select SMP'

Antoine Ténart (5):
  ARM: berlin: add SMP support
  Documentation: bindings: add the Berlin CPU control doc
  Documentation: bindings: add the marvell,berlin-smp CPU enable method
  ARM: dts: berlin: add SMP related nodes and properties for BG2
  ARM: dts: berlin: add SMP related nodes and properties for BG2Q

 .../arm/cpu-enable-method/marvell,berlin-smp       | 41 +++++++++
 .../devicetree/bindings/arm/marvell,berlin.txt     | 16 ++++
 arch/arm/boot/dts/berlin2.dtsi                     | 11 +++
 arch/arm/boot/dts/berlin2q.dtsi                    | 11 +++
 arch/arm/mach-berlin/Kconfig                       |  3 +
 arch/arm/mach-berlin/Makefile                      |  3 +-
 arch/arm/mach-berlin/headsmp.S                     | 30 +++++++
 arch/arm/mach-berlin/platsmp.c                     | 99 ++++++++++++++++++++++
 8 files changed, 213 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/marvell,berlin-smp
 create mode 100644 arch/arm/mach-berlin/headsmp.S
 create mode 100644 arch/arm/mach-berlin/platsmp.c

-- 
1.9.1


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[PATCH v2 1/5] ARM: berlin: add SMP support

[Antoine Ténart]

Adds SMP support for Berlin SoCs. Secondary CPUs are reset, then
execute the instruction we put in the reset exception register, setting
the pc at the address contained in the software reset address register,
which is the physical address of the Berlin secondary startup.

This implementation avoid using the pen lock mechanism.

Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
---
 arch/arm/mach-berlin/Kconfig   |  3 ++
 arch/arm/mach-berlin/Makefile  |  3 +-
 arch/arm/mach-berlin/headsmp.S | 30 +++++++++++++
 arch/arm/mach-berlin/platsmp.c | 99 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 134 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-berlin/headsmp.S
 create mode 100644 arch/arm/mach-berlin/platsmp.c

diff --git a/arch/arm/mach-berlin/Kconfig b/arch/arm/mach-berlin/Kconfig
index d3c5f14dc142..69e94c4e0e28 100644
--- a/arch/arm/mach-berlin/Kconfig
+++ b/arch/arm/mach-berlin/Kconfig
@@ -13,7 +13,9 @@ config MACH_BERLIN_BG2
 	bool "Marvell Armada 1500 (BG2)"
 	select CACHE_L2X0
 	select CPU_PJ4B
+	select HAVE_ARM_SCU if SMP
 	select HAVE_ARM_TWD if SMP
+	select HAVE_SMP
 
 config MACH_BERLIN_BG2CD
 	bool "Marvell Armada 1500-mini (BG2CD)"
@@ -24,6 +26,7 @@ config MACH_BERLIN_BG2Q
 	bool "Marvell Armada 1500 Pro (BG2-Q)"
 	select CACHE_L2X0
 	select CPU_V7
+	select HAVE_ARM_SCU if SMP
 	select HAVE_ARM_TWD if SMP
 	select HAVE_SMP
 
diff --git a/arch/arm/mach-berlin/Makefile b/arch/arm/mach-berlin/Makefile
index ab69fe956f49..c0719ecd1890 100644
--- a/arch/arm/mach-berlin/Makefile
+++ b/arch/arm/mach-berlin/Makefile
@@ -1 +1,2 @@
-obj-y += berlin.o
+obj-y			+= berlin.o
+obj-$(CONFIG_SMP)	+= headsmp.o platsmp.o
diff --git a/arch/arm/mach-berlin/headsmp.S b/arch/arm/mach-berlin/headsmp.S
new file mode 100644
index 000000000000..4a4c56a58ad3
--- /dev/null
+++ b/arch/arm/mach-berlin/headsmp.S
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2014 Marvell Technology Group Ltd.
+ *
+ * Antoine Ténart <antoine.tenart@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+
+ENTRY(berlin_secondary_startup)
+ ARM_BE8(setend be)
+	bl	v7_invalidate_l1
+	b       secondary_startup
+ENDPROC(berlin_secondary_startup)
+
+/*
+ * If the following instruction is set in the reset exception vector, CPUs
+ * will fetch the value of the software reset address vector when being
+ * reset.
+ */
+.global boot_inst
+boot_inst:
+	ldr	pc, [pc, #140]
+
+	.align
diff --git a/arch/arm/mach-berlin/platsmp.c b/arch/arm/mach-berlin/platsmp.c
new file mode 100644
index 000000000000..702e7982015a
--- /dev/null
+++ b/arch/arm/mach-berlin/platsmp.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2014 Marvell Technology Group Ltd.
+ *
+ * Antoine Ténart <antoine.tenart@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#define CPU_RESET		0x00
+
+#define RESET_VECT		0x00
+#define SW_RESET_ADDR		0x94
+
+extern void berlin_secondary_startup(void);
+extern u32 boot_inst;
+
+static void __iomem *cpu_ctrl;
+
+static inline void berlin_perform_reset_cpu(unsigned int cpu)
+{
+	u32 val;
+
+	val = readl(cpu_ctrl + CPU_RESET);
+	val |= BIT(cpu_logical_map(cpu));
+	writel(val, cpu_ctrl + CPU_RESET);
+}
+
+static int berlin_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	if (!cpu_ctrl)
+		return -EFAULT;
+
+	/*
+	 * Reset the CPU, making it to execute the instruction in the reset
+	 * exception vector.
+	 */
+	berlin_perform_reset_cpu(cpu);
+
+	return 0;
+}
+
+static void __init berlin_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *np;
+	void __iomem *scu_base;
+	void __iomem *vectors_base;
+
+	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+	scu_base = of_iomap(np, 0);
+	of_node_put(np);
+	if (!scu_base)
+		return;
+
+	np = of_find_compatible_node(NULL, NULL, "marvell,berlin-cpu-ctrl");
+	cpu_ctrl = of_iomap(np, 0);
+	of_node_put(np);
+	if (!cpu_ctrl)
+		goto unmap_scu;
+
+	vectors_base = ioremap(CONFIG_VECTORS_BASE, SZ_32K);
+	if (!vectors_base)
+		goto unmap_scu;
+
+	scu_enable(scu_base);
+	flush_cache_all();
+
+	/*
+	 * Write the first instruction the CPU will execute after being reset
+	 * in the reset exception vector.
+	 */
+	writel(boot_inst, vectors_base + RESET_VECT);
+
+	/*
+	 * Write the secondary startup address into the SW reset address
+	 * vector. This is used by boot_inst.
+	 */
+	writel(virt_to_phys(berlin_secondary_startup), vectors_base + SW_RESET_ADDR);
+
+	iounmap(vectors_base);
+unmap_scu:
+	iounmap(scu_base);
+}
+
+static struct smp_operations berlin_smp_ops __initdata = {
+	.smp_prepare_cpus	= berlin_smp_prepare_cpus,
+	.smp_boot_secondary	= berlin_boot_secondary,
+};
+CPU_METHOD_OF_DECLARE(berlin_smp, "marvell,berlin-smp", &berlin_smp_ops);
-- 
1.9.1


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[PATCH v2 2/5] Documentation: bindings: add the Berlin CPU control doc

[Antoine Ténart]

Document the CPU control compatible, needed for the SMP support on
Marvell Berlin SoCs.

Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
---
 Documentation/devicetree/bindings/arm/marvell,berlin.txt | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/marvell,berlin.txt b/Documentation/devicetree/bindings/arm/marvell,berlin.txt
index 0677003e1476..7f9b3ccdf25b 100644
--- a/Documentation/devicetree/bindings/arm/marvell,berlin.txt
+++ b/Documentation/devicetree/bindings/arm/marvell,berlin.txt
@@ -23,3 +23,19 @@ SoC and board used. Currently known SoC compatibles are:
 
 	...
 }
+
+* Marvell Berlin CPU control bindings
+
+CPU control register allows various operations on CPUs, like resetting them
+independently.
+
+Required properties:
+- compatible: should be "marvell,berlin-cpu-ctrl"
+- reg: address and length of the register set
+
+Example:
+
+cpu-ctrl@f7dd0000 {
+	compatible = "marvell,berlin-cpu-ctrl";
+	reg = <0xf7dd0000 0x10000>;
+};
-- 
1.9.1


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[PATCH v2 3/5] Documentation: bindings: add the marvell, berlin-smp CPU enable method

[Antoine Ténart]

Document the CPU enable method used by Marvell Berlin SoCs.

Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
---
 .../arm/cpu-enable-method/marvell,berlin-smp       | 41 ++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/cpu-enable-method/marvell,berlin-smp

diff --git a/Documentation/devicetree/bindings/arm/cpu-enable-method/marvell,berlin-smp b/Documentation/devicetree/bindings/arm/cpu-enable-method/marvell,berlin-smp
new file mode 100644
index 000000000000..cd236b727e2a
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/cpu-enable-method/marvell,berlin-smp
@@ -0,0 +1,41 @@
+========================================================
+Secondary CPU enable-method "marvell,berlin-smp" binding
+========================================================
+
+This document describes the "marvell,berlin-smp" method for enabling secondary
+CPUs. To apply to all CPUs, a single "marvell,berlin-smp" enable method should
+be defined in the "cpus" node.
+
+Enable method name:	"marvell,berlin-smp"
+Compatible machines:	"marvell,berlin2" and "marvell,berlin2q"
+Compatible CPUs:	"marvell,pj4b" and "arm,cortex-a9"
+Related properties:	(none)
+
+Note:
+This enable method needs valid nodes compatible with "arm,cortex-a9-scu" and
+"marvell,berlin-cpu-ctrl"[1].
+
+Example:
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		enable-method = "marvell,berlin-smp";
+
+		cpu@0 {
+			compatible = "marvell,pj4b";
+			device_type = "cpu";
+			next-level-cache = <&l2>;
+			reg = <0>;
+		};
+
+		cpu@1 {
+			compatible = "marvell,pj4b";
+			device_type = "cpu";
+			next-level-cache = <&l2>;
+			reg = <1>;
+		};
+	};
+
+--
+[1] arm/marvell,berlin.txt
-- 
1.9.1


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[PATCH v2 4/5] ARM: dts: berlin: add SMP related nodes and properties for BG2

[Antoine Ténart]

Add required nodes and properties into the Berlin BG2 device tree to
take advantage of the newly introduced SMP support. Add the scu and
cpu-ctrl nodes along with the CPUs enable-method property.

Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2.dtsi b/arch/arm/boot/dts/berlin2.dtsi
index 56a1af2f1052..f38ddda8a75e 100644
--- a/arch/arm/boot/dts/berlin2.dtsi
+++ b/arch/arm/boot/dts/berlin2.dtsi
@@ -21,6 +21,7 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "marvell,berlin-smp";
 
 		cpu@0 {
 			compatible = "marvell,pj4b";
@@ -72,6 +73,11 @@
 			cache-level = <2>;
 		};
 
+		scu: snoop-control-unit@ad0000 {
+			compatible = "arm,cortex-a9-scu";
+			reg = <0xad0000 0x58>;
+		};
+
 		gic: interrupt-controller@ad1000 {
 			compatible = "arm,cortex-a9-gic";
 			reg = <0xad1000 0x1000>, <0xad0100 0x0100>;
@@ -86,6 +92,11 @@
 			clocks = <&sysclk>;
 		};
 
+		cpu-ctrl@dd0000 {
+			compatible = "marvell,berlin-cpu-ctrl";
+			reg = <0xdd0000 0x10000>;
+		};
+
 		apb@e80000 {
 			compatible = "simple-bus";
 			#address-cells = <1>;
-- 
1.9.1


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[PATCH v2 5/5] ARM: dts: berlin: add SMP related nodes and properties for BG2Q

[Antoine Ténart]

Add required nodes and properties into the Berlin BG2Q device tree to
take advantage of the newly introduced SMP support. Add the scu and
cpu-ctrl nodes along with the CPUs enable-method property.

Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2q.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
index 07452a7483fa..570f12f7e9c4 100644
--- a/arch/arm/boot/dts/berlin2q.dtsi
+++ b/arch/arm/boot/dts/berlin2q.dtsi
@@ -17,6 +17,7 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "marvell,berlin-smp";
 
 		cpu@0 {
 			compatible = "arm,cortex-a9";
@@ -94,6 +95,11 @@
 			interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
+		scu: snoop-control-unit@ad0000 {
+			compatible = "arm,cortex-a9-scu";
+			reg = <0xad0000 0x58>;
+		};
+
 		gic: interrupt-controller@ad1000 {
 			compatible = "arm,cortex-a9-gic";
 			reg = <0xad1000 0x1000>, <0xad0100 0x100>;
@@ -101,6 +107,11 @@
 			#interrupt-cells = <3>;
 		};
 
+		cpu-ctrl@dd0000 {
+			compatible = "marvell,berlin-cpu-ctrl";
+			reg = <0xdd0000 0x10000>;
+		};
+
 		apb@e80000 {
 			compatible = "simple-bus";
 			#address-cells = <1>;
-- 
1.9.1


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Re: [PATCH v2 1/5] ARM: berlin: add SMP support

[Sebastian Hesselbarth]

On 06/04/2014 06:03 PM, Antoine Ténart wrote:
> Adds SMP support for Berlin SoCs. Secondary CPUs are reset, then
> execute the instruction we put in the reset exception register, setting
> the pc at the address contained in the software reset address register,
> which is the physical address of the Berlin secondary startup.
>
> This implementation avoid using the pen lock mechanism.
>
> Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>

Applied to berlin/soc with Andrew's Reviewed-by.

Thanks!

Re: [PATCH v2 2/5] Documentation: bindings: add the Berlin CPU control doc

[Sebastian Hesselbarth]

On 06/04/2014 06:03 PM, Antoine Ténart wrote:
> Document the CPU control compatible, needed for the SMP support on
> Marvell Berlin SoCs.
>
> Signed-off-by: Antoine Ténart <antoine.tenart-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---

Applied patches 2-5 to berlin/dt.

Thanks!


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