Revert "ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()"

This reverts commit 3c23b83a88d00383e1d498cfa515249aa2fe0238.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200501161014.5935-2-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 051b2ce..d2fb33a 100644 (file)
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -299,59 +299,6 @@ out:
        return status;
 }
 
-struct iort_workaround_oem_info {
-       char oem_id[ACPI_OEM_ID_SIZE + 1];
-       char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
-       u32 oem_revision;
-};
-
-static bool apply_id_count_workaround;
-
-static struct iort_workaround_oem_info wa_info[] __initdata = {
-       {
-               .oem_id         = "HISI  ",
-               .oem_table_id   = "HIP07   ",
-               .oem_revision   = 0,
-       }, {
-               .oem_id         = "HISI  ",
-               .oem_table_id   = "HIP08   ",
-               .oem_revision   = 0,
-       }
-};
-
-static void __init
-iort_check_id_count_workaround(struct acpi_table_header *tbl)
-{
-       int i;
-
-       for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
-               if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
-                   !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
-                   wa_info[i].oem_revision == tbl->oem_revision) {
-                       apply_id_count_workaround = true;
-                       pr_warn(FW_BUG "ID count for ID mapping entry is wrong, applying workaround\n");
-                       break;
-               }
-       }
-}
-
-static inline u32 iort_get_map_max(struct acpi_iort_id_mapping *map)
-{
-       u32 map_max = map->input_base + map->id_count;
-
-       /*
-        * The IORT specification revision D (Section 3, table 4, page 9) says
-        * Number of IDs = The number of IDs in the range minus one, but the
-        * IORT code ignored the "minus one", and some firmware did that too,
-        * so apply a workaround here to keep compatible with both the spec
-        * compliant and non-spec compliant firmwares.
-        */
-       if (apply_id_count_workaround)
-               map_max--;
-
-       return map_max;
-}
-
 static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
                       u32 *rid_out)
 {
@@ -368,7 +315,8 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
                return -ENXIO;
        }
 
-       if (rid_in < map->input_base || rid_in > iort_get_map_max(map))
+       if (rid_in < map->input_base ||
+           (rid_in >= map->input_base + map->id_count))
                return -ENXIO;
 
        *rid_out = map->output_base + (rid_in - map->input_base);
@@ -1700,6 +1648,5 @@ void __init acpi_iort_init(void)
                return;
        }
 
-       iort_check_id_count_workaround(iort_table);
        iort_init_platform_devices();
 }