microblaze: Support DMA

Add DMA support for Microblaze. There are some part of this new feature:
1. Basic DMA support
2. Enable DMA debug option
3. Setup notifier

Ad 1. dma-mapping come from powerpc and x86 version and it is based on
generic dma-mapping-common.h

Ad 2. DMA support debug features which is used in generic file.
For more information please look at Documentation/DMA-API.txt

Ad 3. notifier is very important to setup dma_ops. Without this part
for example ll_temac driver failed because there are no setup dma operations.

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 36 insertions, 0 deletions

diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index bb8c4b9..bc325ac 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -23,6 +23,8 @@
 #include <linux/bug.h>
 #include <linux/param.h>
 #include <linux/cache.h>
+#include <linux/of_platform.h>
+#include <linux/dma-mapping.h>
 #include <asm/cacheflush.h>
 #include <asm/entry.h>
 #include <asm/cpuinfo.h>
@@ -188,3 +190,37 @@ static int microblaze_debugfs_init(void)
 }
 arch_initcall(microblaze_debugfs_init);
 #endif
+
+static int dflt_bus_notify(struct notifier_block *nb,
+				unsigned long action, void *data)
+{
+	struct device *dev = data;
+
+	/* We are only intereted in device addition */
+	if (action != BUS_NOTIFY_ADD_DEVICE)
+		return 0;
+
+	set_dma_ops(dev, &dma_direct_ops);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block dflt_plat_bus_notifier = {
+	.notifier_call = dflt_bus_notify,
+	.priority = INT_MAX,
+};
+
+static struct notifier_block dflt_of_bus_notifier = {
+	.notifier_call = dflt_bus_notify,
+	.priority = INT_MAX,
+};
+
+static int __init setup_bus_notifier(void)
+{
+	bus_register_notifier(&platform_bus_type, &dflt_plat_bus_notifier);
+	bus_register_notifier(&of_platform_bus_type, &dflt_of_bus_notifier);
+
+	return 0;
+}
+
+arch_initcall(setup_bus_notifier);