libata-acpi: implement _GTM/_STM support

Implement _GTM/_STM support.  acpi_gtm is added to ata_port which
stores _GTM parameters over suspend/resume cycle.  A new hook
ata_acpi_on_suspend() is responsible for storing _GTM parameters
during suspend.  _STM is executed in ata_acpi_on_resume().  With this
change, invoking _GTF is safe on IDE hierarchy and acpi_sata check
before _GTF is removed.

ata_acpi_gtm() and ata_acpi_stm() implementation is taken from Alan
Cox's pata_acpi implementation.  ata_acpi_gtm() is fixed such that the
result parameter is not shifted by sizeof(union acpi_object).

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 0c4f63b55ec6..8d3e391ab8d3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -198,6 +198,7 @@ enum {
         ATA_PFLAG_FLUSH_PORT_TASK = (1 << 16), /* flush port task */
         ATA_PFLAG_SUSPENDED     = (1 << 17), /* port is suspended (power) */
         ATA_PFLAG_PM_PENDING    = (1 << 18), /* PM operation pending */
+        ATA_PFLAG_GTM_VALID     = (1 << 19), /* acpi_gtm data valid */
 
         /* struct ata_queued_cmd flags */
         ATA_QCFLAG_ACTIVE       = (1 << 0), /* cmd not yet ack'd to scsi lyer */
@@ -493,6 +494,17 @@ struct ata_eh_context {
         unsigned int            did_probe_mask;
 };
 
+struct ata_acpi_drive
+{
+        u32 pio;
+        u32 dma;
+} __packed;
+
+struct ata_acpi_gtm {
+        struct ata_acpi_drive drive[2];
+        u32 flags;
+} __packed;
+
 struct ata_port {
         struct Scsi_Host        *scsi_host; /* our co-allocated scsi host */
         const struct ata_port_operations *ops;
@@ -555,6 +567,7 @@ struct ata_port {
 
 #ifdef CONFIG_ATA_ACPI
         acpi_handle             acpi_handle;
+        struct ata_acpi_gtm     acpi_gtm;
 #endif
         u8                      sector_buf[ATA_SECT_SIZE]; /* owned by EH */
 };