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path: root/drivers/acpi/executer/exfldio.c
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Diffstat (limited to 'drivers/acpi/executer/exfldio.c')
-rw-r--r--drivers/acpi/executer/exfldio.c71
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) {