[PATCH] lib: utils: fdt_domain: Make opensbi-domain optional in CPU specification

[Gregor Haas]

The domain_support.md documentation states that "the HART to domain instance
assignment can be parsed from the device tree using *optional* DT property
opensbi-domain in each CPU DT node". However, the current implementation does
not treat this parameter as optional when determining which HARTs to assign to
a freshly discovered domain from the device tree, causing an effect where every
HART in the system must be explicitly assigned to a domain only if a domain is
specified in the device tree. Instead, this patch simply ignores CPUs that do
not specify a domain, and does not attempt to assign them into the recently
discovered domain.
---
 lib/utils/fdt/fdt_domain.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/utils/fdt/fdt_domain.c b/lib/utils/fdt/fdt_domain.c
index fa1c357..3623c6b 100644
--- a/lib/utils/fdt/fdt_domain.c
+++ b/lib/utils/fdt/fdt_domain.c
@@ -459,12 +459,12 @@ static int __fdt_parse_domain(void *fdt, int domain_offset, void *opaque)
 		if (!fdt_node_is_enabled(fdt, cpu_offset))
 			continue;
 
+		// This is an optional property for CPUs, so just continue if not present
 		val = fdt_getprop(fdt, cpu_offset, "opensbi-domain", &len);
-		if (!val || len < 4) {
-			err = SBI_EINVAL;
-			goto fail_free_all;
-		}
+		if (!val || len < 4)
+			continue;
 
+		// However, if the tag exists, it should point to a valid domain instance
 		doffset = fdt_node_offset_by_phandle(fdt, fdt32_to_cpu(*val));
 		if (doffset < 0) {
 			err = doffset;
-- 
2.45.2