ACPI: ACPICA 20060623
Implemented a new acpi_spinlock type for the OSL lock
interfaces. This allows the type to be customized to
the host OS for improved efficiency (since a spinlock is
usually a very small object.)
Implemented support for "ignored" bits in the ACPI
registers. According to the ACPI specification, these
bits should be preserved when writing the registers via
a read/modify/write cycle. There are 3 bits preserved
in this manner: PM1_CONTROL[0] (SCI_EN), PM1_CONTROL[9],
and PM1_STATUS[11].
http://bugzilla.kernel.org/show_bug.cgi?id=3691
Implemented the initial deployment of new OSL mutex
interfaces. Since some host operating systems have
separate mutex and semaphore objects, this feature was
requested. The base code now uses mutexes (and the new
mutex interfaces) wherever a binary semaphore was used
previously. However, for the current release, the mutex
interfaces are defined as macros to map them to the
existing semaphore interfaces.
Fixed several problems with the support for the control
method SyncLevel parameter. The SyncLevel now works
according to the ACPI specification and in concert with the
Mutex SyncLevel parameter, since the current SyncLevel is
a property of the executing thread. Mutual exclusion for
control methods is now implemented with a mutex instead
of a semaphore.
Fixed three instances of the use of the C shift operator
in the bitfield support code (exfldio.c) to avoid the use
of a shift value larger than the target data width. The
behavior of C compilers is undefined in this case and can
cause unpredictable results, and therefore the case must
be detected and avoided. (Fiodor Suietov)
Added an info message whenever an SSDT or OEM table
is loaded dynamically via the Load() or LoadTable()
ASL operators. This should improve debugging capability
since it will show exactly what tables have been loaded
(beyond the tables present in the RSDT/XSDT.)
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/executer/exfldio.c b/drivers/acpi/executer/exfldio.c
index 051053f..40f0bee 100644
--- a/drivers/acpi/executer/exfldio.c
+++ b/drivers/acpi/executer/exfldio.c
@@ -727,11 +727,23 @@
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 @@
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 @@
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) {