From: Guanghui Feng <guanghuifeng@xxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 6.0.x
Acked-by: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
Tested-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1689593625-45213-1-git-send-email-guanghuifeng@xxxxxxxxxxxxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)
