arm: mvebu: Add support for coherency fabric in mach-mvebu

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 <yehuday@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
new file mode 100644
index 00000000000..596ee66a9cc
--- /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;
+}