From ce5cb67c664fbc93d1af20b3fbd7a07eda9f6ee6 Mon Sep 17 00:00:00 2001
From: Will Deacon <will@kernel.org>
Date: Mon, 16 Aug 2021 14:26:16 +0100
Subject: of: Move of_dma_set_restricted_buffer() into device.c

Rob observes that:

  | of_dma_set_restricted_buffer() [...] should also be moved to
  | of/device.c. There's no reason for it to be in of/address.c. It has
  | nothing to do with address parsing.

Move it to of/device.c, as he suggests.

Cc: Claire Chang <tientzu@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Suggested-by: Rob Herring <robh+dt@kernel.org>
Link: https://lore.kernel.org/r/CAL_JsqJ7ROWWJX84x2kEex9NQ8G+2=ybRuNOobX+j8bjZzSemQ@mail.gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/of/device.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

(limited to 'drivers/of/device.c')

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2defdca418ec..089c5b4b97fb 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -5,6 +5,7 @@
 #include <linux/of_device.h>
 #include <linux/of_address.h>
 #include <linux/of_iommu.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/dma-direct.h> /* for bus_dma_region */
 #include <linux/dma-map-ops.h>
 #include <linux/init.h>
@@ -52,6 +53,39 @@ int of_device_add(struct platform_device *ofdev)
 	return device_add(&ofdev->dev);
 }
 
+static int
+of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
+{
+	struct device_node *node, *of_node = dev->of_node;
+	int count, i;
+
+	count = of_property_count_elems_of_size(of_node, "memory-region",
+						sizeof(u32));
+	/*
+	 * If dev->of_node doesn't exist or doesn't contain memory-region, try
+	 * the OF node having DMA configuration.
+	 */
+	if (count <= 0) {
+		of_node = np;
+		count = of_property_count_elems_of_size(
+			of_node, "memory-region", sizeof(u32));
+	}
+
+	for (i = 0; i < count; i++) {
+		node = of_parse_phandle(of_node, "memory-region", i);
+		/*
+		 * There might be multiple memory regions, but only one
+		 * restricted-dma-pool region is allowed.
+		 */
+		if (of_device_is_compatible(node, "restricted-dma-pool") &&
+		    of_device_is_available(node))
+			return of_reserved_mem_device_init_by_idx(dev, of_node,
+								  i);
+	}
+
+	return 0;
+}
+
 /**
  * of_dma_configure_id - Setup DMA configuration
  * @dev:	Device to apply DMA configuration
-- 
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