From: Guanghui Feng guanghuifeng@linux.alibaba.com
commit 003e6b56d780095a9adc23efc9cb4b4b4717169b upstream.
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 guanghuifeng@linux.alibaba.com Cc: stable@vger.kernel.org # 6.0.x Acked-by: Lorenzo Pieralisi lpieralisi@kernel.org Tested-by: Hanjun Guo guohanjun@huawei.com Link: https://lore.kernel.org/r/1689593625-45213-1-git-send-email-guanghuifeng@lin... Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/arm64/iort.c | 3 --- 1 file changed, 3 deletions(-)
--- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -998,9 +998,6 @@ static void iort_node_get_rmr_info(struc 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)