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Subject[PATCH 51/85] ACPI: fix FADT parsing
From: Jan Beulich <jbeulich@novell.com>

The (1.0 inherited) separate length fields in the FADT are byte granular.
Further, PM1a/b may have distinct lengths (if using the v2 fields was
okay) and may live in distinct address spaces. acpi_tb_convert_fadt()
should account for all of these conditions.

Apart from these changes I'm puzzled by the fact that, not just for
acpi_gbl_xpm1{a,b}_enable, acpi_hw_low_level_{read,write}() get an
explicit size passed rather than using the size found in the passed GAS.
What happens on a platform that defines PM1{a,b} wider than 16 bits? Of
course, acpi_hw_low_level_{read,write}() at present are entirely
un-prepared to deal with sizes other than 8, 16, or 32, not to speak of a
non-zero bit_offset or access_width...

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/tables/tbfadt.c | 32 +++++++++++++++++++++++++-------
1 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/tables/tbfadt.c b/drivers/acpi/tables/tbfadt.c
index a4a41ba..2c7885e 100644
--- a/drivers/acpi/tables/tbfadt.c
+++ b/drivers/acpi/tables/tbfadt.c
@@ -50,7 +50,7 @@ ACPI_MODULE_NAME("tbfadt")
/* Local prototypes */
static void inline
acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
- u8 bit_width, u64 address);
+ u8 byte_width, u64 address);

static void acpi_tb_convert_fadt(void);

@@ -111,7 +111,7 @@ static struct acpi_fadt_info fadt_info_table[] = {
* FUNCTION: acpi_tb_init_generic_address
*
* PARAMETERS: generic_address - GAS struct to be initialized
- * bit_width - Width of this register
+ * byte_width - Width of this register
* Address - Address of the register
*
* RETURN: None
@@ -124,7 +124,7 @@ static struct acpi_fadt_info fadt_info_table[] = {

static void inline
acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
- u8 bit_width, u64 address)
+ u8 byte_width, u64 address)
{

/*
@@ -136,7 +136,7 @@ acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
/* All other fields are byte-wide */

generic_address->space_id = ACPI_ADR_SPACE_SYSTEM_IO;
- generic_address->bit_width = bit_width;
+ generic_address->bit_width = byte_width << 3;
generic_address->bit_offset = 0;
generic_address->access_width = 0;
}
@@ -342,9 +342,20 @@ static void acpi_tb_convert_fadt(void)
* useful to calculate them once, here.
*
* The PM event blocks are split into two register blocks, first is the
- * PM Status Register block, followed immediately by the PM Enable Register
- * block. Each is of length (pm1_event_length/2)
+ * PM Status Register block, followed immediately by the PM Enable
+ * Register block. Each is of length (xpm1x_event_block.bit_width/2).
+ *
+ * On various systems the v2 fields (and particularly the bit widths)
+ * cannot be relied upon, though. Hence resort to using the v1 length
+ * here (and warn about the inconsistency).
*/
+ if (acpi_gbl_FADT.xpm1a_event_block.bit_width
+ != acpi_gbl_FADT.pm1_event_length * 8)
+ printk(KERN_WARNING "FADT: "
+ "X_PM1a_EVT_BLK.bit_width (%u) does not match"
+ " PM1_EVT_LEN (%u)\n",
+ acpi_gbl_FADT.xpm1a_event_block.bit_width,
+ acpi_gbl_FADT.pm1_event_length);
pm1_register_length = (u8) ACPI_DIV_2(acpi_gbl_FADT.pm1_event_length);

/* The PM1A register block is required */
@@ -360,13 +371,20 @@ static void acpi_tb_convert_fadt(void)
/* The PM1B register block is optional, ignore if not present */

if (acpi_gbl_FADT.xpm1b_event_block.address) {
+ if (acpi_gbl_FADT.xpm1b_event_block.bit_width
+ != acpi_gbl_FADT.pm1_event_length * 8)
+ printk(KERN_WARNING "FADT: "
+ "X_PM1b_EVT_BLK.bit_width (%u) does not match"
+ " PM1_EVT_LEN (%u)\n",
+ acpi_gbl_FADT.xpm1b_event_block.bit_width,
+ acpi_gbl_FADT.pm1_event_length);
acpi_tb_init_generic_address(&acpi_gbl_xpm1b_enable,
pm1_register_length,
(acpi_gbl_FADT.xpm1b_event_block.
address + pm1_register_length));
/* Don't forget to copy space_id of the GAS */
acpi_gbl_xpm1b_enable.space_id =
- acpi_gbl_FADT.xpm1a_event_block.space_id;
+ acpi_gbl_FADT.xpm1b_event_block.space_id;

}
}
--
1.5.5.1


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