libfdt: add fdt_append_addrrange()

This function will append an address range property using parent node's
"#address-cells" and "#size-cells" properties.

It will be used in implementing kdump with kexec_file_load system call
at linux kernel for arm64 once it is merged into kernel tree.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Message-Id: <20190327061552.17170-2-takahiro.akashi@linaro.org>
[dwg: Correct a SEGV error in the testcase]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 47 insertions, 0 deletions

diff --git a/cpukit/dtc/libfdt/fdt_addresses.c b/cpukit/dtc/libfdt/fdt_addresses.c
index f13a87dfa0..2cc997ea50 100644
--- a/cpukit/dtc/libfdt/fdt_addresses.c
+++ b/cpukit/dtc/libfdt/fdt_addresses.c
@@ -95,3 +95,50 @@ int fdt_size_cells(const void *fdt, int nodeoffset)
 		return 1;
 	return val;
 }
+
+/* This function assumes that [address|size]_cells is 1 or 2 */
+int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
+			     const char *name, uint64_t addr, uint64_t size)
+{
+	int addr_cells, size_cells, ret;
+	uint8_t data[sizeof(fdt64_t) * 2], *prop;
+
+	ret = fdt_address_cells(fdt, parent);
+	if (ret < 0)
+		return ret;
+	addr_cells = ret;
+
+	ret = fdt_size_cells(fdt, parent);
+	if (ret < 0)
+		return ret;
+	size_cells = ret;
+
+	/* check validity of address */
+	prop = data;
+	if (addr_cells == 1) {
+		if ((addr > UINT32_MAX) || ((UINT32_MAX + 1 - addr) < size))
+			return -FDT_ERR_BADVALUE;
+
+		fdt32_st(prop, (uint32_t)addr);
+	} else if (addr_cells == 2) {
+		fdt64_st(prop, addr);
+	} else {
+		return -FDT_ERR_BADNCELLS;
+	}
+
+	/* check validity of size */
+	prop += addr_cells * sizeof(fdt32_t);
+	if (size_cells == 1) {
+		if (size > UINT32_MAX)
+			return -FDT_ERR_BADVALUE;
+
+		fdt32_st(prop, (uint32_t)size);
+	} else if (size_cells == 2) {
+		fdt64_st(prop, size);
+	} else {
+		return -FDT_ERR_BADNCELLS;
+	}
+
+	return fdt_appendprop(fdt, nodeoffset, name, data,
+			      (addr_cells + size_cells) * sizeof(fdt32_t));
+}