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authorCatalin Marinas <catalin.marinas@arm.com>2014-04-25 15:31:45 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2014-05-03 22:20:34 +0100
commit6ecba8eb51b7d23fda66388a5420be7d8688b186 (patch)
tree930af6e7dfff301c121e59f91171ab884c9ceb75
parentc7a4a7658d689f664050c45493d79adf053f226e (diff)
arm64: Use bus notifiers to set per-device coherent DMA ops
Recently, the default DMA ops have been changed to non-coherent for alignment with 32-bit ARM platforms (and DT files). This patch adds bus notifiers to be able to set the coherent DMA ops (with no cache maintenance) for devices explicitly marked as coherent via the "dma-coherent" DT property. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/kernel/setup.c2
-rw-r--r--arch/arm64/mm/dma-mapping.c33
2 files changed, 33 insertions, 2 deletions
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 93e7df8968f..7ec784653b2 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -396,7 +396,7 @@ static int __init arm64_device_init(void)
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
return 0;
}
-arch_initcall(arm64_device_init);
+arch_initcall_sync(arm64_device_init);
static DEFINE_PER_CPU(struct cpu, cpu_data);
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 1f65963a9c0..c851eb44dc5 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -22,8 +22,11 @@
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
#include <linux/vmalloc.h>
#include <linux/swiotlb.h>
+#include <linux/amba/bus.h>
#include <asm/cacheflush.h>
@@ -305,17 +308,45 @@ struct dma_map_ops coherent_swiotlb_dma_ops = {
};
EXPORT_SYMBOL(coherent_swiotlb_dma_ops);
+static int dma_bus_notifier(struct notifier_block *nb,
+ unsigned long event, void *_dev)
+{
+ struct device *dev = _dev;
+
+ if (event != BUS_NOTIFY_ADD_DEVICE)
+ return NOTIFY_DONE;
+
+ if (of_property_read_bool(dev->of_node, "dma-coherent"))
+ set_dma_ops(dev, &coherent_swiotlb_dma_ops);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block platform_bus_nb = {
+ .notifier_call = dma_bus_notifier,
+};
+
+static struct notifier_block amba_bus_nb = {
+ .notifier_call = dma_bus_notifier,
+};
+
extern int swiotlb_late_init_with_default_size(size_t default_size);
static int __init swiotlb_late_init(void)
{
size_t swiotlb_size = min(SZ_64M, MAX_ORDER_NR_PAGES << PAGE_SHIFT);
+ /*
+ * These must be registered before of_platform_populate().
+ */
+ bus_register_notifier(&platform_bus_type, &platform_bus_nb);
+ bus_register_notifier(&amba_bustype, &amba_bus_nb);
+
dma_ops = &noncoherent_swiotlb_dma_ops;
return swiotlb_late_init_with_default_size(swiotlb_size);
}
-subsys_initcall(swiotlb_late_init);
+arch_initcall(swiotlb_late_init);
#define PREALLOC_DMA_DEBUG_ENTRIES 4096