ACPI/IORT: Remove erroneous id_count check in iort_node_get_rmr_info()

According to the ARM IORT specifications DEN 0049 issue E,
the "Number of IDs" field in the ID mapping format reports
the number of IDs in the mapping range minus one.

In iort_node_get_rmr_info(), we erroneously skip ID mappings
whose "Number of IDs" equal to 0, resulting in valid mapping
nodes with a single ID to map being skipped, which is wrong.

Fix iort_node_get_rmr_info() by removing the bogus id_count
check.

Fixes: 491cf4a6735a ("ACPI/IORT: Add support to retrieve IORT RMR reserved regions")
Signed-off-by: Guanghui Feng <[email protected]>
Cc: <[email protected]> # 6.0.x
Acked-by: Lorenzo Pieralisi <[email protected]>
Tested-by: Hanjun Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 3631230a61c8f52bc77334d5344b5b235eb405a2..56d887323ae5261d78316bc700a4f96b5b28fcf5 100644 (file)
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1007,9 +1007,6 @@ static void iort_node_get_rmr_info(struct acpi_iort_node *node,
        for (i = 0; i < node->mapping_count; i++, map++) {
                struct acpi_iort_node *parent;
 
-               if (!map->id_count)
-                       continue;
-
                parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
                                      map->output_reference);
                if (parent != iommu)