diff options
Diffstat (limited to 'drivers/acpi/executer/exfldio.c')
| -rw-r--r-- | drivers/acpi/executer/exfldio.c | 71 |
1 files changed, 55 insertions, 16 deletions
diff --git a/drivers/acpi/executer/exfldio.c b/drivers/acpi/executer/exfldio.c index 051053f7cccb..40f0bee6faa5 100644 --- a/drivers/acpi/executer/exfldio.c +++ b/drivers/acpi/executer/exfldio.c @@ -727,11 +727,23 @@ acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, return_ACPI_STATUS(status); } - /* Merge with previous datum if necessary */ - - merged_datum |= raw_datum << - (obj_desc->common_field.access_bit_width - - obj_desc->common_field.start_field_bit_offset); + /* + * Merge with previous datum if necessary. + * + * Note: Before the shift, check if the shift value will be larger than + * the integer size. If so, there is no need to perform the operation. + * This avoids the differences in behavior between different compilers + * concerning shift values larger than the target data width. + */ + if ((obj_desc->common_field.access_bit_width - + obj_desc->common_field.start_field_bit_offset) < + ACPI_INTEGER_BIT_SIZE) { + merged_datum |= + raw_datum << (obj_desc->common_field. + access_bit_width - + obj_desc->common_field. + start_field_bit_offset); + } if (i == datum_count) { break; @@ -808,13 +820,23 @@ acpi_ex_insert_into_field(union acpi_operand_object *obj_desc, return_ACPI_STATUS(AE_BUFFER_OVERFLOW); } - /* Compute the number of datums (access width data items) */ + /* + * Create the bitmasks used for bit insertion. + * Note: This if/else is used to bypass compiler differences with the + * shift operator + */ + if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) { + width_mask = ACPI_INTEGER_MAX; + } else { + width_mask = + ACPI_MASK_BITS_ABOVE(obj_desc->common_field. + access_bit_width); + } - width_mask = - ACPI_MASK_BITS_ABOVE(obj_desc->common_field.access_bit_width); - mask = - width_mask & ACPI_MASK_BITS_BELOW(obj_desc->common_field. - start_field_bit_offset); + mask = width_mask & + ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset); + + /* Compute the number of datums (access width data items) */ datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, obj_desc->common_field.access_bit_width); @@ -848,12 +870,29 @@ acpi_ex_insert_into_field(union acpi_operand_object *obj_desc, return_ACPI_STATUS(status); } - /* Start new output datum by merging with previous input datum */ - field_offset += obj_desc->common_field.access_byte_width; - merged_datum = raw_datum >> - (obj_desc->common_field.access_bit_width - - obj_desc->common_field.start_field_bit_offset); + + /* + * Start new output datum by merging with previous input datum + * if necessary. + * + * Note: Before the shift, check if the shift value will be larger than + * the integer size. If so, there is no need to perform the operation. + * This avoids the differences in behavior between different compilers + * concerning shift values larger than the target data width. + */ + if ((obj_desc->common_field.access_bit_width - + obj_desc->common_field.start_field_bit_offset) < + ACPI_INTEGER_BIT_SIZE) { + merged_datum = + raw_datum >> (obj_desc->common_field. + access_bit_width - + obj_desc->common_field. + start_field_bit_offset); + } else { + merged_datum = 0; + } + mask = width_mask; if (i == datum_count) { |