ACPICA commit c49a751b4dae7baec1790748a2b4b6e8ab599f51 For Access Size = 0, it actually can use user expected access bit width. This patch implements this. Besides of the ACPICA upstream commit, this patch also includes a fix fixing the issue reported by the FreeBSD community. The old register descriptors are translated in acpi_tb_init_generic_address() with access_width being filled with 0. This breaks code in acpi_hw_get_access_bit_width() when the registers are 16-bit IO ports and their bit_width fields are filled with 16. The rapid fix is meant to make code written for acpi_hw_get_access_bit_width() regression safer before the issue is correctly fixed from acpi_tb_init_generic_address(). Reported by John Baldwin <jhb@xxxxxxxxxxx>, fixed by Lv Zheng <lv.zheng@xxxxxxxxx>, tested by Jung-uk Kim <jkim@xxxxxxxxxxx>. Link: https://github.com/acpica/acpica/commit/c49a751b Reported-by: John Baldwin <jhb@xxxxxxxxxxx> Tested-by Jung-uk Kim <jkim@xxxxxxxxxxx>. Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> --- drivers/acpi/acpica/hwregs.c | 49 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c index 035fb52..892e677 100644 --- a/drivers/acpi/acpica/hwregs.c +++ b/drivers/acpi/acpica/hwregs.c @@ -51,6 +51,10 @@ ACPI_MODULE_NAME("hwregs") #if (!ACPI_REDUCED_HARDWARE) /* Local Prototypes */ +static u8 +acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, + u8 max_bit_width); + static acpi_status acpi_hw_read_multiple(u32 *value, struct acpi_generic_address *register_a, @@ -65,6 +69,48 @@ acpi_hw_write_multiple(u32 value, /****************************************************************************** * + * FUNCTION: acpi_hw_get_access_bit_width + * + * PARAMETERS: reg - GAS register structure + * max_bit_width - Max bit_width supported (32 or 64) + * + * RETURN: Status + * + * DESCRIPTION: Obtain optimal access bit width + * + ******************************************************************************/ + +static u8 +acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, u8 max_bit_width) +{ + u64 address; + + if (!reg->access_width) { + /* + * Detect old register descriptors where only the bit_width field + * makes senses. The target address is copied to handle possible + * alignment issues. + */ + ACPI_MOVE_64_TO_64(&address, ®->address); + if (!reg->bit_offset && reg->bit_width && + ACPI_IS_POWER_OF_TWO(reg->bit_width) && + ACPI_IS_ALIGNED(reg->bit_width, 8) && + ACPI_IS_ALIGNED(address, reg->bit_width)) { + return (reg->bit_width); + } else { + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + return (32); + } else { + return (max_bit_width); + } + } + } else { + return (1 << (reg->access_width + 2)); + } +} + +/****************************************************************************** + * * FUNCTION: acpi_hw_validate_register * * PARAMETERS: reg - GAS register structure @@ -122,8 +168,7 @@ acpi_hw_validate_register(struct acpi_generic_address *reg, /* Validate the bit_width, convert access_width into number of bits */ - access_width = reg->access_width ? reg->access_width : 1; - access_width = 1 << (access_width + 2); + access_width = acpi_hw_get_access_bit_width(reg, max_bit_width); bit_width = ACPI_ROUND_UP(reg->bit_offset + reg->bit_width, access_width); if (max_bit_width < bit_width) { -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
