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path: root/drivers/acpi/tables/tbfadt.c
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Diffstat (limited to 'drivers/acpi/tables/tbfadt.c')
-rw-r--r--drivers/acpi/tables/tbfadt.c44
1 files changed, 26 insertions, 18 deletions
diff --git a/drivers/acpi/tables/tbfadt.c b/drivers/acpi/tables/tbfadt.c
index 1285e91474f..002bb33003a 100644
--- a/drivers/acpi/tables/tbfadt.c
+++ b/drivers/acpi/tables/tbfadt.c
@@ -211,14 +211,17 @@ void acpi_tb_parse_fadt(acpi_native_uint table_index, u8 flags)
* DESCRIPTION: Get a local copy of the FADT and convert it to a common format.
* Performs validation on some important FADT fields.
*
+ * NOTE: We create a local copy of the FADT regardless of the version.
+ *
******************************************************************************/
void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
{
/*
- * Check if the FADT is larger than what we know about (ACPI 2.0 version).
- * Truncate the table, but make some noise.
+ * Check if the FADT is larger than the largest table that we expect
+ * (the ACPI 2.0/3.0 version). If so, truncate the table, and issue
+ * a warning.
*/
if (length > sizeof(struct acpi_table_fadt)) {
ACPI_WARNING((AE_INFO,
@@ -227,10 +230,12 @@ void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
sizeof(struct acpi_table_fadt)));
}
- /* Copy the entire FADT locally. Zero first for tb_convert_fadt */
+ /* Clear the entire local FADT */
ACPI_MEMSET(&acpi_gbl_FADT, 0, sizeof(struct acpi_table_fadt));
+ /* Copy the original FADT, up to sizeof (struct acpi_table_fadt) */
+
ACPI_MEMCPY(&acpi_gbl_FADT, table,
ACPI_MIN(length, sizeof(struct acpi_table_fadt)));
@@ -251,7 +256,7 @@ void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
* RETURN: None
*
* DESCRIPTION: Converts all versions of the FADT to a common internal format.
- * -> Expand all 32-bit addresses to 64-bit.
+ * Expand all 32-bit addresses to 64-bit.
*
* NOTE: acpi_gbl_FADT must be of size (struct acpi_table_fadt),
* and must contain a copy of the actual FADT.
@@ -292,8 +297,23 @@ static void acpi_tb_convert_fadt(void)
}
/*
- * Expand the 32-bit V1.0 addresses to the 64-bit "X" generic address
- * structures as necessary.
+ * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
+ * should be zero are indeed zero. This will workaround BIOSs that
+ * inadvertently place values in these fields.
+ *
+ * The ACPI 1.0 reserved fields that will be zeroed are the bytes located at
+ * offset 45, 55, 95, and the word located at offset 109, 110.
+ */
+ if (acpi_gbl_FADT.header.revision < 3) {
+ acpi_gbl_FADT.preferred_profile = 0;
+ acpi_gbl_FADT.pstate_control = 0;
+ acpi_gbl_FADT.cst_control = 0;
+ acpi_gbl_FADT.boot_flags = 0;
+ }
+
+ /*
+ * Expand the ACPI 1.0 32-bit V1.0 addresses to the ACPI 2.0 64-bit "X"
+ * generic address structures as necessary.
*/
for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
target =
@@ -349,18 +369,6 @@ static void acpi_tb_convert_fadt(void)
acpi_gbl_FADT.xpm1a_event_block.space_id;
}
-
- /*
- * For ACPI 1.0 FADTs, ensure that reserved fields (which should be zero)
- * are indeed zero. This will workaround BIOSs that inadvertently placed
- * values in these fields.
- */
- if (acpi_gbl_FADT.header.revision < 3) {
- acpi_gbl_FADT.preferred_profile = 0;
- acpi_gbl_FADT.pstate_control = 0;
- acpi_gbl_FADT.cst_control = 0;
- acpi_gbl_FADT.boot_flags = 0;
- }
}
/******************************************************************************