From: Benjamin Fair <b-fair@xxxxxx>
This patch extends the capability of libfdt to parse the contents of device
trees in a similar manner to fdt_address_cells and fdt_size_cells.
It adds a helper function which reads the address and size of a device from
the reg property and performs basic sanity checks.
It does not perform translation to a physical address using the ranges
properties of parents, but this enhancement may be added as a separate
function in the future.
Signed-off-by: Benjamin Fair <b-fair@xxxxxx>
Reviewed-by: Simon Glass <sjg@xxxxxxxxxxxx>
Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
Signed-off-by: Andrew F. Davis <afd@xxxxxx>
---
libfdt/fdt_addresses.c | 64 +++++++++++++++++++++++++++++++++++++++
libfdt/libfdt.h | 33 ++++++++++++++++++++
libfdt/version.lds | 1 +
tests/.gitignore | 1 +
tests/Makefile.tests | 2 +-
tests/addr_size.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++
tests/addresses.dts | 21 +++++++++++++
tests/run_tests.sh | 1 +
8 files changed, 203 insertions(+), 1 deletion(-)
create mode 100644 tests/addr_size.c
diff --git a/libfdt/fdt_addresses.c b/libfdt/fdt_addresses.c
index eff4dbc..85fd2ee 100644
--- a/libfdt/fdt_addresses.c
+++ b/libfdt/fdt_addresses.c
@@ -94,3 +94,67 @@ int fdt_size_cells(const void *fdt, int nodeoffset)
return val;
}
+
+static int fdt_read_int_(const fdt32_t *cells, unsigned int n, uint64_t *value)
+{
+ int i;
+
+ if (n > 2)
+ return -FDT_ERR_BADNCELLS;
+
+ *value = 0;
+ for (i = 0; i < n; i++) {
+ *value <<= (sizeof(*cells) * 8);
+ *value |= fdt32_to_cpu(cells[i]);
+ }
+
+ return 0;
+}
+
+int fdt_simple_read_reg(const void *fdt, int nodeoffset, int idx,
+ uint64_t *addrp, uint64_t *sizep)
+{
+ int parent;
+ int ac, sc, reg_stride;
+ int res;
+ const fdt32_t *reg;
+
+ reg = fdt_getprop(fdt, nodeoffset, "reg", &res);
+ if (res < 0)
+ return res;
+
+ parent = fdt_parent_offset(fdt, nodeoffset);
+ if (parent == -FDT_ERR_NOTFOUND) /* an node without a parent does
+ * not have _any_ number of cells */
+ return -FDT_ERR_BADNCELLS;
+ if (parent < 0)
+ return parent;
+
+ ac = fdt_address_cells(fdt, parent);
+ if (ac < 0)
+ return ac;
+
+ sc = fdt_size_cells(fdt, parent);
+ if (sc < 0)
+ return sc;
+
+ reg_stride = ac + sc;
+
+ /* res is the number of bytes read and must be an even multiple of the
+ * sum of address cells and size cells */
+ if ((res % (reg_stride * sizeof(*reg))) != 0)
+ return -FDT_ERR_BADVALUE;
+
+ if (addrp) {
+ res = fdt_read_int_(®[reg_stride * idx], ac, addrp);
+ if (res < 0)
+ return res;
+ }
+ if (sizep) {
+ res = fdt_read_int_(®[ac + reg_stride * idx], sc, sizep);
+ if (res < 0)
+ return res;
+ }
+
+ return 0;
+}
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index c8c00fa..93121e1 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -1101,6 +1101,39 @@ int fdt_address_cells(const void *fdt, int nodeoffset);
*/
int fdt_size_cells(const void *fdt, int nodeoffset);
+/**
+ *
+ * fdt_simple_read_reg - read address and/or size from the reg property of a
+ * device node.
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to find the address and/or size from
+ * @idx: which address/size pair to read
+ * @addrp: pointer to where address will be stored (will be overwritten) or NULL
+ * @sizep: pointer to where size will be stored (will be overwritten) or NULL
+ *
+ * When the node has a valid reg property, returns the address and/or size
+ * values stored there. It does not perform any type of translation based on
+ * the parent bus(es).
+ *
+ * NOTE: This function is expensive, as it must scan the device tree
+ * structure from the start to nodeoffset, *twice*, with fdt_parent_offset.
+ *
+ * returns:
+ * 0, on success
+ * -FDT_ERR_BADVALUE, if there is an unexpected number of entries in the
+ * reg property
+ * -FDT_ERR_NOTFOUND, if the node does not have a reg property
+ * -FDT_ERR_BADNCELLS, if the number of address or size cells is invalid
+ * or greater than 2 (which is the maximum currently supported)
+ * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADSTATE,
+ * -FDT_ERR_BADSTRUCTURE,
+ * -FDT_ERR_BADVERSION,
+ * -FDT_ERR_TRUNCATED, standard meanings
+ */
+
+int fdt_simple_read_reg(const void *fdt, int nodeoffset, int idx,
+ uint64_t *addrp, uint64_t *sizep);
/**********************************************************************/
/* Write-in-place functions */
diff --git a/libfdt/version.lds b/libfdt/version.lds
index 18fb69f..bd432a1 100644
--- a/libfdt/version.lds
+++ b/libfdt/version.lds
@@ -59,6 +59,7 @@ LIBFDT_1.2 {
fdt_next_subnode;
fdt_address_cells;
fdt_size_cells;
+ fdt_simple_read_reg;
fdt_stringlist_contains;
fdt_stringlist_count;
fdt_stringlist_search;
diff --git a/tests/.gitignore b/tests/.gitignore
index 9e209d5..acb9335 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -43,6 +43,7 @@ tmp.*
/path_offset
/path_offset_aliases
/phandle_format
+/addr_size
/property_iterate
/propname_escapes
/references
diff --git a/tests/Makefile.tests b/tests/Makefile.tests
index 262944a..1e326ea 100644
--- a/tests/Makefile.tests
+++ b/tests/Makefile.tests
@@ -8,7 +8,7 @@ LIB_TESTS_L = get_mem_rsv \
char_literal \
sized_cells \
notfound \
- addr_size_cells \
+ addr_size_cells addr_size \
stringlist \
setprop_inplace nop_property nop_node \
sw_tree1 \
diff --git a/tests/addr_size.c b/tests/addr_size.c
new file mode 100644
index 0000000..b279c8f
--- /dev/null
+++ b/tests/addr_size.c
@@ -0,0 +1,81 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Testcase for address and size handling
+ * Copyright (C) 2016-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Based on addr_size_cells.c by David Gibson, <david@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+static void check_node(const void *fdt, const char *path, int err,
+ int idx, uint64_t addr, uint64_t size)
+{
+ int offset, res;
+ uint64_t xaddr, xsize;
+
+ offset = fdt_path_offset(fdt, path);
+ if (offset < 0)
+ FAIL("Couldn't find path %s", path);
+
+ res = fdt_simple_read_reg(fdt, offset, idx, &xaddr, &xsize);
+ if (res != err)
+ FAIL("fdt_simple_read_reg returned %s instead of %s",
+ fdt_strerror(res), fdt_strerror(err));
+ if (res < 0)
+ return;
+
+ if (xaddr != addr)
+ FAIL("Physical address for %s is %p instead of %p\n",
+ path, (void *) xaddr, (void *) addr);
+
+ if (xsize != size)
+ FAIL("Size for %s is %zx instead of %zx\n",
+ path, xsize, size);
+}
+
+int main(int argc, char *argv[])
+{
+ void *fdt;
+
+ if (argc != 2)
+ CONFIG("Usage: %s <dtb file>\n", argv[0]);
+
+ test_init(argc, argv);
+ fdt = load_blob(argv[1]);
+
+ check_node(fdt, "/identity-bus@0/id-device@400",
+ 0, 0, 0x400, 0x100);
+ check_node(fdt, "/simple-bus@1000000/sb-device@8000000800",
+ 0, 0, 0x8000000800, 0x200);
+ check_node(fdt, "/identity-bus@0/id-device@400",
+ 0, 1, 0x400000000, 0x100000030);
+ check_node(fdt, "/simple-bus@1000000/sb-device@8000000800",
+ 0, 1, 0x70000000, 0x700);
+ check_node(fdt, "/simple-bus@1000000/sb-device@8000000800",
+ 0, 2, 0x1050000000, 0x20);
+ check_node(fdt, "/identity-bus@0",
+ -FDT_ERR_NOTFOUND, 0, 0x0, 0x0);
+ check_node(fdt, "/narrow-bus@2000000/sb-device@80000000",
+ 0, 0, 0x00000800, 0x200);
+
+ PASS();
+}
diff --git a/tests/addresses.dts b/tests/addresses.dts
index a2faaf5..4eb2a46 100644
--- a/tests/addresses.dts
+++ b/tests/addresses.dts
@@ -6,10 +6,31 @@
#size-cells = <2>;
identity-bus@0 {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ranges;
+ id-device@400 {
+ reg = <0x0 0x00000400 0x0 0x00000100>,
+ <0x4 0x00000000 0x1 0x00000030>;
+ };
};
simple-bus@1000000 {
#address-cells = <2>;
#size-cells = <1>;
+ sb-device@8000000800 {
+ reg = <0x80 0x00000800 0x200>,
+ <0x00 0x70000000 0x700>,
+ <0x10 0x50000000 0x020>;
+ };
+ };
+
+ narrow-bus@2000000 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ sb-device@80000000 {
+ reg = <0x00000800 0x200>,
+ <0x50000000 0x020>;
+ };
};
};
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index d937260..32ef715 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -336,6 +336,7 @@ libfdt_tests () {
run_dtc_test -I dts -O dtb -o addresses.test.dtb addresses.dts
run_test addr_size_cells addresses.test.dtb
+ run_test addr_size addresses.test.dtb
run_dtc_test -I dts -O dtb -o stringlist.test.dtb stringlist.dts
run_test stringlist stringlist.test.dtb
--
2.16.2
--
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