Commit 6d3b29d0 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Will Deacon
Browse files

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



This reverts commit 3c23b83a.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200501161014.5935-2-ardb@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 7fb89e1d

drivers/acpi/arm64/iort.c

+2 −55
Original line number Diff line number Diff line
@@ -299,59 +299,6 @@ static acpi_status iort_match_node_callback(struct acpi_iort_node *node, 
	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();

}