Thread (1 message) 1 message, 1 author, 2012-11-21
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[PATCH V6 1/5] arm: mvebu: Add support for coherency fabric in mach-mvebu

From: Gregory CLEMENT <hidden>
Date: 2012-11-21 14:59:26
Also in: linux-devicetree
Subsystem: arm port, arm/marvell kirkwood and armada 370, 375, 38x, 39x, xp, 3700, 7k/8k, cn9130 soc support, open firmware and flattened device tree bindings, the rest · Maintainers: Russell King, Andrew Lunn, Gregory Clement, Sebastian Hesselbarth, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds

Possibly related (same subject, not in this thread)

The Armada 370 and Armada XP SOCs have a coherency fabric unit which
is responsible for ensuring hardware coherency between all CPUs and
between CPUs and I/O masters. This patch provides the basic support
needed for SMP.

Signed-off-by: Yehuda Yitschak <redacted>
Signed-off-by: Gregory CLEMENT <redacted>
---
 .../devicetree/bindings/arm/coherency-fabric.txt   |   16 ++++
 arch/arm/boot/dts/armada-370-xp.dtsi               |    5 ++
 arch/arm/mach-mvebu/Makefile                       |    2 +-
 arch/arm/mach-mvebu/coherency.c                    |   82 ++++++++++++++++++++
 arch/arm/mach-mvebu/coherency.h                    |   24 ++++++
 arch/arm/mach-mvebu/coherency_ll.S                 |   49 ++++++++++++
 arch/arm/mach-mvebu/common.h                       |    1 +
 7 files changed, 178 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/arm/coherency-fabric.txt
 create mode 100644 arch/arm/mach-mvebu/coherency.c
 create mode 100644 arch/arm/mach-mvebu/coherency.h
 create mode 100644 arch/arm/mach-mvebu/coherency_ll.S
diff --git a/Documentation/devicetree/bindings/arm/coherency-fabric.txt b/Documentation/devicetree/bindings/arm/coherency-fabric.txt
new file mode 100644
index 0000000..2bfbf67
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/coherency-fabric.txt
@@ -0,0 +1,16 @@
+Coherency fabric
+----------------
+Available on Marvell SOCs: Armada 370 and Armada XP
+
+Required properties:
+
+- compatible: "marvell,coherency-fabric"
+- reg: Should contain,coherency fabric registers location and length.
+
+Example:
+
+coherency-fabric at d0020200 {
+	compatible = "marvell,coherency-fabric";
+	reg = <0xd0020200 0xb0>;
+};
+
diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi
index 94b4b9e..b0d075b 100644
--- a/arch/arm/boot/dts/armada-370-xp.dtsi
+++ b/arch/arm/boot/dts/armada-370-xp.dtsi
@@ -36,6 +36,11 @@
 	      interrupt-controller;
 	};
 
+	coherency-fabric at d0020200 {
+		compatible = "marvell,coherency-fabric";
+		reg = <0xd0020200 0xb0>;
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index 57f996b..5ce4b42 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -2,4 +2,4 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \
 	-I$(srctree)/arch/arm/plat-orion/include
 
 obj-y += system-controller.o
-obj-$(CONFIG_MACH_ARMADA_370_XP) += armada-370-xp.o irq-armada-370-xp.o addr-map.o
+obj-$(CONFIG_MACH_ARMADA_370_XP) += armada-370-xp.o irq-armada-370-xp.o addr-map.o coherency.o coherency_ll.o
diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
new file mode 100644
index 0000000..596ee66
--- /dev/null
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -0,0 +1,82 @@
+/*
+ * Coherency fabric (Aurora) support for Armada 370 and XP platforms.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Yehuda Yitschak <yehuday@marvell.com>
+ * Gregory Clement <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * The Armada 370 and Armada XP SOCs have a coherency fabric which is
+ * responsible for ensuring hardware coherency between all CPUs and between
+ * CPUs and I/O masters. This file initializes the coherency fabric and
+ * supplies basic routines for configuring and controlling hardware coherency
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/smp.h>
+#include <asm/smp_plat.h>
+#include "armada-370-xp.h"
+
+/*
+ * Some functions in this file are called very early during SMP
+ * initialization. At that time the device tree framework is not yet
+ * ready, and it is not possible to get the register address to
+ * ioremap it. That's why the pointer below is given with an initial
+ * value matching its virtual mapping
+ */
+static void __iomem *coherency_base = ARMADA_370_XP_REGS_VIRT_BASE + 0x20200;
+
+/* Coherency fabric registers */
+#define COHERENCY_FABRIC_CFG_OFFSET		   0x4
+
+static struct of_device_id of_coherency_table[] = {
+	{.compatible = "marvell,coherency-fabric"},
+	{ /* end of list */ },
+};
+
+#ifdef CONFIG_SMP
+int coherency_get_cpu_count(void)
+{
+	int reg, cnt;
+
+	reg = readl(coherency_base + COHERENCY_FABRIC_CFG_OFFSET);
+	cnt = (reg & 0xF) + 1;
+
+	return cnt;
+}
+#endif
+
+/* Function defined in coherency_ll.S */
+int ll_set_cpu_coherent(void __iomem *base_addr, unsigned int hw_cpu_id);
+
+int set_cpu_coherent(unsigned int hw_cpu_id, int smp_group_id)
+{
+	if (!coherency_base) {
+		pr_warn("Can't make CPU %d cache coherent.\n", hw_cpu_id);
+		pr_warn("Coherency fabric is not initialized\n");
+		return 1;
+	}
+
+	return ll_set_cpu_coherent(coherency_base, hw_cpu_id);
+}
+
+int __init coherency_init(void)
+{
+	struct device_node *np;
+
+	np = of_find_matching_node(NULL, of_coherency_table);
+	if (np) {
+		pr_info("Initializing Coherency fabric\n");
+		coherency_base = of_iomap(np, 0);
+	}
+
+	return 0;
+}
diff --git a/arch/arm/mach-mvebu/coherency.h b/arch/arm/mach-mvebu/coherency.h
new file mode 100644
index 0000000..2f42813
--- /dev/null
+++ b/arch/arm/mach-mvebu/coherency.h
@@ -0,0 +1,24 @@
+/*
+ * arch/arm/mach-mvebu/include/mach/coherency.h
+ *
+ *
+ * Coherency fabric (Aurora) support for Armada 370 and XP platforms.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __MACH_370_XP_COHERENCY_H
+#define __MACH_370_XP_COHERENCY_H
+
+#ifdef CONFIG_SMP
+int coherency_get_cpu_count(void);
+#endif
+
+int set_cpu_coherent(int cpu_id, int smp_group_id);
+int coherency_init(void);
+
+#endif	/* __MACH_370_XP_COHERENCY_H */
diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S
new file mode 100644
index 0000000..74272b6
--- /dev/null
+++ b/arch/arm/mach-mvebu/coherency_ll.S
@@ -0,0 +1,49 @@
+/*
+ * Coherency fabric: low level functions
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * This file implements the assembly function to add a CPU to the
+ * coherency fabric. This function is called by each of the secondary
+ * CPUs during their early boot in an SMP kernel, this why this
+ * function have to callable from assembly. It can also be called by a
+ * primary CPU from C code during its boot.
+ */
+
+#include <linux/linkage.h>
+#define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0
+#define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4
+
+	.text
+/*
+ * r0: Coherency fabric base register address
+ * r1: HW CPU id
+ */
+ENTRY(ll_set_cpu_coherent)
+	/* Create bit by cpu index */
+	mov	r3, #(1 << 24)
+	lsl     r1, r3, r1
+
+	/* Add CPU to SMP group - Atomic */
+	add	r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET
+	ldr     r2, [r3]
+	orr     r2, r2, r1
+	str	r2, [r0]
+
+	/* Enable coherency on CPU - Atomic */
+	add	r3, r0, #ARMADA_XP_CFB_CFG_REG_OFFSET
+	ldr     r2, [r3]
+	orr     r2, r2, r1
+	str     r2, [r3]
+
+	dsb
+
+	mov	r0, #0
+	mov	pc, lr
+ENDPROC(ll_set_cpu_coherent)
diff --git a/arch/arm/mach-mvebu/common.h b/arch/arm/mach-mvebu/common.h
index 02f89ea..ba6b62a 100644
--- a/arch/arm/mach-mvebu/common.h
+++ b/arch/arm/mach-mvebu/common.h
@@ -20,4 +20,5 @@ void mvebu_restart(char mode, const char *cmd);
 void armada_370_xp_init_irq(void);
 void armada_370_xp_handle_irq(struct pt_regs *regs);
 
+int armada_370_xp_coherency_init(void);
 #endif
-- 
1.7.9.5
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