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path: root/drivers/acpi/acpica/hwxface.c
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Diffstat (limited to 'drivers/acpi/acpica/hwxface.c')
-rw-r--r--drivers/acpi/acpica/hwxface.c43
1 files changed, 26 insertions, 17 deletions
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index 5ee7a814cd92..b4b47db2dee2 100644
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -41,7 +41,8 @@
* POSSIBILITY OF SUCH DAMAGES.
*/
-#include <linux/export.h>
+#define EXPORT_ACPI_INTERFACES
+
#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
@@ -83,11 +84,17 @@ acpi_status acpi_reset(void)
* For I/O space, write directly to the OSL. This bypasses the port
* validation mechanism, which may block a valid write to the reset
* register.
- * Spec section 4.7.3.6 requires register width to be 8.
+ *
+ * NOTE:
+ * The ACPI spec requires the reset register width to be 8, so we
+ * hardcode it here and ignore the FADT value. This maintains
+ * compatibility with other ACPI implementations that have allowed
+ * BIOS code with bad register width values to go unnoticed.
*/
status =
acpi_os_write_port((acpi_io_address) reset_reg->address,
- acpi_gbl_FADT.reset_value, 8);
+ acpi_gbl_FADT.reset_value,
+ ACPI_RESET_REGISTER_WIDTH);
} else {
/* Write the reset value to the reset register */
@@ -119,7 +126,8 @@ ACPI_EXPORT_SYMBOL(acpi_reset)
******************************************************************************/
acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg)
{
- u32 value;
+ u32 value_lo;
+ u32 value_hi;
u32 width;
u64 address;
acpi_status status;
@@ -137,13 +145,8 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg)
return (status);
}
- /* Initialize entire 64-bit return value to zero */
-
- *return_value = 0;
- value = 0;
-
/*
- * Two address spaces supported: Memory or IO. PCI_Config is
+ * Two address spaces supported: Memory or I/O. PCI_Config is
* not supported here because the GAS structure is insufficient
*/
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
@@ -155,29 +158,35 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg)
}
} else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
+ value_lo = 0;
+ value_hi = 0;
+
width = reg->bit_width;
if (width == 64) {
width = 32; /* Break into two 32-bit transfers */
}
status = acpi_hw_read_port((acpi_io_address)
- address, &value, width);
+ address, &value_lo, width);
if (ACPI_FAILURE(status)) {
return (status);
}
- *return_value = value;
if (reg->bit_width == 64) {
/* Read the top 32 bits */
status = acpi_hw_read_port((acpi_io_address)
- (address + 4), &value, 32);
+ (address + 4), &value_hi,
+ 32);
if (ACPI_FAILURE(status)) {
return (status);
}
- *return_value |= ((u64)value << 32);
}
+
+ /* Set the return value only if status is AE_OK */
+
+ *return_value = (value_lo | ((u64)value_hi << 32));
}
ACPI_DEBUG_PRINT((ACPI_DB_IO,
@@ -186,7 +195,7 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg)
ACPI_FORMAT_UINT64(address),
acpi_ut_get_region_name(reg->space_id)));
- return (status);
+ return (AE_OK);
}
ACPI_EXPORT_SYMBOL(acpi_read)
@@ -561,10 +570,10 @@ acpi_get_sleep_type_data(u8 sleep_state, u8 *sleep_type_a, u8 *sleep_type_b)
break;
}
- cleanup1:
+cleanup1:
acpi_ut_remove_reference(info->return_object);
- cleanup:
+cleanup:
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"While evaluating Sleep State [%s]",