From c9af433b113892e7141990ab9574dccc53608bd5 Mon Sep 17 00:00:00 2001 From: Guanghui Feng Date: Mon, 17 Jul 2023 19:33:45 +0800 Subject: [PATCH] ACPI/IORT: Remove erroneous id_count check in iort_node_get_rmr_info() 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 Cc: # 6.0.x Acked-by: Lorenzo Pieralisi Tested-by: Hanjun Guo Link: https://lore.kernel.org/r/1689593625-45213-1-git-send-email-guanghuifeng@linux.alibaba.com Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/arm64/iort.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index 8059baf4ef27..2e1cae53536f 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -998,9 +998,6 @@ 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)