From 54ea41c22415cb0e283d22faf71202051c89400c Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 20 Mar 2019 16:10:03 +0100 Subject: libfdt: Add phandle generation helper The new fdt_generate_phandle() function can be used to generate a new, unused phandle given a specific device tree blob. The implementation is somewhat naive in that it simply walks the entire device tree to find the highest phandle value and then returns a phandle value one higher than that. A more clever implementation might try to find holes in the current set of phandle values and fill them. But this implementation is relatively simple and works reliably. Also add a test that validates that phandles generated by this new API are indeed unique. Signed-off-by: Thierry Reding Message-Id: <20190320151003.28941-1-thierry.reding@gmail.com> Signed-off-by: David Gibson --- tests/get_phandle.c | 31 ++++++++++++++++++++++++++++++- tests/multilabel.dts | 5 +++++ tests/multilabel_merge.dts | 5 +++++ tests/references.c | 19 +++++++++++++++++-- tests/references.dts | 5 +++++ 5 files changed, 62 insertions(+), 3 deletions(-) (limited to 'tests') diff --git a/tests/get_phandle.c b/tests/get_phandle.c index 22bd7b8..d87aee5 100644 --- a/tests/get_phandle.c +++ b/tests/get_phandle.c @@ -17,6 +17,7 @@ * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ +#include #include #include #include @@ -42,10 +43,32 @@ static void check_phandle(void *fdt, const char *path, uint32_t checkhandle) path, phandle, checkhandle); } +static void check_phandle_unique(const void *fdt, uint32_t checkhandle) +{ + uint32_t phandle; + int offset = -1; + + while (true) { + offset = fdt_next_node(fdt, offset, NULL); + if (offset < 0) { + if (offset == -FDT_ERR_NOTFOUND) + break; + + FAIL("error looking for phandle %#x", checkhandle); + } + + phandle = fdt_get_phandle(fdt, offset); + + if (phandle == checkhandle) + FAIL("generated phandle already exists"); + } +} + int main(int argc, char *argv[]) { - uint32_t max; + uint32_t max, phandle; void *fdt; + int err; test_init(argc, argv); fdt = load_blob_arg(argc, argv); @@ -59,5 +82,11 @@ int main(int argc, char *argv[]) FAIL("fdt_get_max_phandle returned 0x%x instead of 0x%x\n", max, PHANDLE_2); + err = fdt_generate_phandle(fdt, &phandle); + if (err < 0) + FAIL("failed to generate phandle: %d", err); + + check_phandle_unique(fdt, phandle); + PASS(); } diff --git a/tests/multilabel.dts b/tests/multilabel.dts index 77da06c..d80ebe1 100644 --- a/tests/multilabel.dts +++ b/tests/multilabel.dts @@ -41,4 +41,9 @@ m1: mq: /memreserve/ 0 0x1000; n2 = &n2; n3 = &n3; }; + + node6 { + linux,phandle = <0xfffffffe>; + phandle = <0xfffffffe>; + }; }; diff --git a/tests/multilabel_merge.dts b/tests/multilabel_merge.dts index 3e80298..a27d856 100644 --- a/tests/multilabel_merge.dts +++ b/tests/multilabel_merge.dts @@ -39,6 +39,11 @@ m1: mq: /memreserve/ 0 0x1000; n2 = &n2; n3 = &n3; }; + + node6 { + linux,phandle = <0xfffffffe>; + phandle = <0xfffffffe>; + }; }; / { diff --git a/tests/references.c b/tests/references.c index cab70f6..5b233a4 100644 --- a/tests/references.c +++ b/tests/references.c @@ -76,8 +76,8 @@ static void check_rref(const void *fdt) int main(int argc, char *argv[]) { void *fdt; - int n1, n2, n3, n4, n5; - uint32_t h1, h2, h4, h5; + int n1, n2, n3, n4, n5, n6, err; + uint32_t h1, h2, h4, h5, h6, hn; test_init(argc, argv); fdt = load_blob_arg(argc, argv); @@ -97,11 +97,15 @@ int main(int argc, char *argv[]) n5 = fdt_path_offset(fdt, "/node5"); if (n5 < 0) FAIL("fdt_path_offset(/node5): %s", fdt_strerror(n5)); + n6 = fdt_path_offset(fdt, "/node6"); + if (n6 < 0) + FAIL("fdt_path_offset(/node6): %s", fdt_strerror(n6)); h1 = fdt_get_phandle(fdt, n1); h2 = fdt_get_phandle(fdt, n2); h4 = fdt_get_phandle(fdt, n4); h5 = fdt_get_phandle(fdt, n5); + h6 = fdt_get_phandle(fdt, n6); if (h1 != 0x2000) FAIL("/node1 has wrong phandle, 0x%x instead of 0x%x", @@ -109,6 +113,9 @@ int main(int argc, char *argv[]) if (h2 != 0x1) FAIL("/node2 has wrong phandle, 0x%x instead of 0x%x", h2, 0x1); + if (h6 != FDT_MAX_PHANDLE) + FAIL("/node6 has wrong phandle, 0x%x instead of 0x%x", + h6, FDT_MAX_PHANDLE); if ((h4 == 0x2000) || (h4 == 0x1) || (h4 == 0)) FAIL("/node4 has bad phandle, 0x%x", h4); @@ -117,6 +124,14 @@ int main(int argc, char *argv[]) if ((h5 == h4) || (h5 == h2) || (h5 == h1)) FAIL("/node5 has duplicate phandle, 0x%x", h5); + /* + * /node6 has phandle FDT_MAX_PHANDLE, so fdt_generate_phandle() is + * expected to fail. + */ + err = fdt_generate_phandle(fdt, &hn); + if (err != -FDT_ERR_NOPHANDLES) + FAIL("generated invalid phandle 0x%x\n", hn); + check_ref(fdt, n1, h2); check_ref(fdt, n2, h1); check_ref(fdt, n3, h4); diff --git a/tests/references.dts b/tests/references.dts index f783e8b..b390639 100644 --- a/tests/references.dts +++ b/tests/references.dts @@ -33,4 +33,9 @@ linux,phandle = <&n5>; phandle = <&n5>; }; + + node6 { + linux,phandle = <0xfffffffe>; + phandle = <0xfffffffe>; + }; }; -- cgit v1.1