[PATCH] fixup! of: request reserved memory regions so other code can't

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
can squash for v2
---
 drivers/of/reserved-mem.c | 65 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 drivers/of/reserved-mem.c

diff --git a/drivers/of/reserved-mem.c b/drivers/of/reserved-mem.c
new file mode 100644
index 000000000000..efa96fe65cd9
--- /dev/null
+++ b/drivers/of/reserved-mem.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2021 Rouven Czerwinski <r.czerwinski@pengutronix.de>, Pengutronix
+
+#define pr_fmt(fmt) "reserved-memory: " fmt
+
+#include <common.h>
+#include <init.h>
+#include <of.h>
+#include <of_address.h>
+
+static void reserve(const char *name, u64 start, u64 end, bool xn)
+{
+	int flags = OF_RESERVE_ENTRY_FLAG_NO_FIXUP;
+
+	if (xn)
+		flags |= OF_RESERVE_ENTRY_FLAG_RUNTIME_FW;
+
+	pr_debug("region %s 0x%08llx-0x%08llx\n", name, start, end);
+
+	of_add_reserve_entry(start, end, flags);
+}
+
+static int reserved_mem_read(void)
+{
+	struct device_node *node, *child;
+	struct resource resource;
+	const __be32 *reg;
+
+	node = of_find_node_by_path("/reserved-memory");
+	if (node) {
+		for_each_available_child_of_node(node, child) {
+			/* skip e.g. linux,cma */
+			if (!of_get_property(child, "reg", NULL))
+				continue;
+
+			of_address_to_resource(child, 0, &resource);
+
+			/*
+			 * Just keep on mapping 1:1, but avoid speculative
+			 * execution into such a region
+			 */
+			reserve(child->name,
+				resource.start, resource.end,
+				of_find_property(child, "no-map", 0));
+		}
+	}
+
+	node = of_find_node_by_path("/memreserve");
+	reg = of_get_property(node, "reg", NULL);
+	if (reg) {
+		u32 na = 2, ns = 2;
+		u64 addr, size;
+
+		of_property_read_u32(node, "#address-cells", &na);
+		of_property_read_u32(node, "#size-cells", &ns);
+
+		addr = of_read_number(reg, na);
+		size = of_read_number(reg + na, ns);
+
+		reserve("/memreserve", addr, addr + size - 1, false);
+	}
+
+	return 0;
+}
+postconsole_initcall(reserved_mem_read);
-- 
2.30.2


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