ACPI/IORT: Fix PMCG node single ID mapping handling

[ Upstream commit 50c8ab8 ] An IORT PMCG node can have no ID mapping if its overflow interrupt is wire based therefore the code that parses the PMCG node can not assume the node will always have a single mapping present at index 0. Fix iort_get_id_mapping_index() by checking for an overflow interrupt and mapping count. Fixes: 24e5160 ("ACPI/IORT: Add support for PMCG") Signed-off-by: Tuan Phan <[email protected]> Reviewed-by: Hanjun Guo <[email protected]> Acked-by: Lorenzo Pieralisi <[email protected]> Link: https://lore.kernel.org/r/1589994787-28637-1-git-send-email-tuanphan@os.amperecomputing.com Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
AmpereComputing · Jun 22, 2020 · b1d2d3d · b1d2d3d
1 parent c2ad0dc
commit b1d2d3d
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
@@ -361,6 +361,7 @@ static struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
 static int iort_get_id_mapping_index(struct acpi_iort_node *node)
 {
 	struct acpi_iort_smmu_v3 *smmu;
+	struct acpi_iort_pmcg *pmcg;
 
 	switch (node->type) {
 	case ACPI_IORT_NODE_SMMU_V3:
@@ -388,6 +389,10 @@ static int iort_get_id_mapping_index(struct acpi_iort_node *node)
 
 		return smmu->id_mapping_index;
 	case ACPI_IORT_NODE_PMCG:
+		pmcg = (struct acpi_iort_pmcg *)node->node_data;
+		if (pmcg->overflow_gsiv || node->mapping_count == 0)
+			return -EINVAL;
+
 		return 0;
 	default:
 		return -EINVAL;