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authorMatthew Garrett <mjg@redhat.com>2010-05-26 11:50:48 +0800
committerLen Brown <len.brown@intel.com>2010-06-12 00:55:50 -0400
commitb681f7d9ab4d697a214fa4428795790c3a937a89 (patch)
treec5653b6da518198ca3d7fd13f5f8442428955e1f /drivers/acpi/acpica
parent9cbfa18e8a7b34a32eddbd914a07f085962f50a8 (diff)
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ACPICA: Truncate I/O addresses to 16 bits for Windows compatibility
This feature is optional and is enabled if the BIOS requests any Windows OSI strings. It can also be enabled by the host OS. Signed-off-by: Matthew Garrett <mjg@redhat.com> 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/acpica')
-rw-r--r--drivers/acpi/acpica/acglobal.h8
-rw-r--r--drivers/acpi/acpica/hwvalid.c12
-rw-r--r--drivers/acpi/acpica/nsinit.c9
3 files changed, 29 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 9070f1f..899d68a 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -125,6 +125,14 @@ u8 ACPI_INIT_GLOBAL(acpi_gbl_enable_aml_debug_object, FALSE);
*/
u8 ACPI_INIT_GLOBAL(acpi_gbl_copy_dsdt_locally, FALSE);
+/*
+ * Optionally truncate I/O addresses to 16 bits. Provides compatibility
+ * with other ACPI implementations. NOTE: During ACPICA initialization,
+ * this value is set to TRUE if any Windows OSI strings have been
+ * requested by the BIOS.
+ */
+u8 ACPI_INIT_GLOBAL(acpi_gbl_truncate_io_addresses, FALSE);
+
/* acpi_gbl_FADT is a local copy of the FADT, converted to a common format. */
struct acpi_table_fadt acpi_gbl_FADT;
diff --git a/drivers/acpi/acpica/hwvalid.c b/drivers/acpi/acpica/hwvalid.c
index c10d587..e1d9c77 100644
--- a/drivers/acpi/acpica/hwvalid.c
+++ b/drivers/acpi/acpica/hwvalid.c
@@ -222,6 +222,12 @@ acpi_status acpi_hw_read_port(acpi_io_address address, u32 *value, u32 width)
u32 one_byte;
u32 i;
+ /* Truncate address to 16 bits if requested */
+
+ if (acpi_gbl_truncate_io_addresses) {
+ address &= ACPI_UINT16_MAX;
+ }
+
/* Validate the entire request and perform the I/O */
status = acpi_hw_validate_io_request(address, width);
@@ -279,6 +285,12 @@ acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width)
acpi_status status;
u32 i;
+ /* Truncate address to 16 bits if requested */
+
+ if (acpi_gbl_truncate_io_addresses) {
+ address &= ACPI_UINT16_MAX;
+ }
+
/* Validate the entire request and perform the I/O */
status = acpi_hw_validate_io_request(address, width);
diff --git a/drivers/acpi/acpica/nsinit.c b/drivers/acpi/acpica/nsinit.c
index 9bd6f05..4e5272c 100644
--- a/drivers/acpi/acpica/nsinit.c
+++ b/drivers/acpi/acpica/nsinit.c
@@ -193,6 +193,15 @@ acpi_status acpi_ns_initialize_devices(void)
acpi_ns_init_one_device, NULL, &info,
NULL);
+ /*
+ * Any _OSI requests should be completed by now. If the BIOS has
+ * requested any Windows OSI strings, we will always truncate
+ * I/O addresses to 16 bits -- for Windows compatibility.
+ */
+ if (acpi_gbl_osi_data >= ACPI_OSI_WIN_2000) {
+ acpi_gbl_truncate_io_addresses = TRUE;
+ }
+
ACPI_FREE(info.evaluate_info);
if (ACPI_FAILURE(status)) {
goto error_exit;