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authorBob Moore <robert.moore@intel.com>2008-09-27 11:34:48 +0800
committerLen Brown <len.brown@intel.com>2008-10-22 23:14:48 -0400
commit68e125c40597802b9789bc696775bf0246e7667d (patch)
treec0d5bd0d1a377447e37f2451af673a6db725cfa8 /drivers/acpi
parentcf058bd1c84df9921ecc517d8a8a413f4d6b5b45 (diff)
ACPICA: Optimize buffer allocation procedure
Eliminate duplicate code. Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/utilities/utalloc.c53
1 files changed, 28 insertions, 25 deletions
diff --git a/drivers/acpi/utilities/utalloc.c b/drivers/acpi/utilities/utalloc.c
index 7dcb67e0b215..241c535c1753 100644
--- a/drivers/acpi/utilities/utalloc.c
+++ b/drivers/acpi/utilities/utalloc.c
@@ -232,7 +232,7 @@ acpi_status acpi_ut_validate_buffer(struct acpi_buffer * buffer)
* RETURN: Status
*
* DESCRIPTION: Validate that the buffer is of the required length or
- * allocate a new buffer. Returned buffer is always zeroed.
+ * allocate a new buffer. Returned buffer is always zeroed.
*
******************************************************************************/
@@ -240,7 +240,7 @@ acpi_status
acpi_ut_initialize_buffer(struct acpi_buffer * buffer,
acpi_size required_length)
{
- acpi_status status = AE_OK;
+ acpi_size input_buffer_length;
/* Parameter validation */
@@ -248,55 +248,58 @@ acpi_ut_initialize_buffer(struct acpi_buffer * buffer,
return (AE_BAD_PARAMETER);
}
- switch (buffer->length) {
+ /*
+ * Buffer->Length is used as both an input and output parameter. Get the
+ * input actual length and set the output required buffer length.
+ */
+ input_buffer_length = buffer->length;
+ buffer->length = required_length;
+
+ /*
+ * The input buffer length contains the actual buffer length, or the type
+ * of buffer to be allocated by this routine.
+ */
+ switch (input_buffer_length) {
case ACPI_NO_BUFFER:
- /* Set the exception and returned the required length */
+ /* Return the exception (and the required buffer length) */
- status = AE_BUFFER_OVERFLOW;
- break;
+ return (AE_BUFFER_OVERFLOW);
case ACPI_ALLOCATE_BUFFER:
/* Allocate a new buffer */
buffer->pointer = acpi_os_allocate(required_length);
- if (!buffer->pointer) {
- return (AE_NO_MEMORY);
- }
-
- /* Clear the buffer */
-
- ACPI_MEMSET(buffer->pointer, 0, required_length);
break;
case ACPI_ALLOCATE_LOCAL_BUFFER:
/* Allocate a new buffer with local interface to allow tracking */
- buffer->pointer = ACPI_ALLOCATE_ZEROED(required_length);
- if (!buffer->pointer) {
- return (AE_NO_MEMORY);
- }
+ buffer->pointer = ACPI_ALLOCATE(required_length);
break;
default:
/* Existing buffer: Validate the size of the buffer */
- if (buffer->length < required_length) {
- status = AE_BUFFER_OVERFLOW;
- break;
+ if (input_buffer_length < required_length) {
+ return (AE_BUFFER_OVERFLOW);
}
+ break;
+ }
- /* Clear the buffer */
+ /* Validate allocation from above or input buffer pointer */
- ACPI_MEMSET(buffer->pointer, 0, required_length);
- break;
+ if (!buffer->pointer) {
+ return (AE_NO_MEMORY);
}
- buffer->length = required_length;
- return (status);
+ /* Have a valid buffer, clear it */
+
+ ACPI_MEMSET(buffer->pointer, 0, required_length);
+ return (AE_OK);
}
#ifdef NOT_USED_BY_LINUX