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authorCatalin Marinas <catalin.marinas@arm.com>2014-04-25 15:31:45 +0100
committerAlex Shi <alex.shi@linaro.org>2014-05-29 10:48:52 +0800
commit73cc7ba0f2e856ad90ab0ec8700826b9f0df219a (patch)
tree73a66614b974fe78fa493c383db09471a1be9ca2
parent8ad69ebf680c65d2aeecb1c02a94e69ce3469cf8 (diff)
downloadlinux-linaro-stable-v3.14/topic/arm64-cmadma.tar.gz
arm64: Use bus notifiers to set per-device coherent DMA opsv3.14/topic/arm64-cmadma
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> (cherry picked from commit 6ecba8eb51b7d23fda66388a5420be7d8688b186) Signed-off-by: Alex Shi <alex.shi@linaro.org>
-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 c8e9eff..43f690f 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -360,7 +360,7 @@ 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 26d0ac7..9337524 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>
@@ -307,17 +310,45 @@ 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