libata: detect Device Attention support

Add a new flag ATA_DFLAG_DA to indicate that device supports "Device
Attention".

Acked-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-core.c

@@ -2374,6 +2374,9 @@ int ata_dev_configure(struct ata_device *dev)
 			dma_dir_string = ", DMADIR";
 		}
 
+		if (ata_id_has_da(dev->id))
+			dev->flags |= ATA_DFLAG_DA;
+
 		/* print device info to dmesg */
 		if (ata_msg_drv(ap) && print_info)
 			ata_dev_info(dev,

include/linux/ata.h

@@ -578,6 +578,7 @@ static inline int ata_is_data(u8 prot)
 	  ((u64) (id)[(n) + 0]) )
 
 #define ata_id_cdb_intr(id)	(((id)[ATA_ID_CONFIG] & 0x60) == 0x20)
+#define ata_id_has_da(id)	((id)[77] & (1 << 4))
 
 static inline bool ata_id_has_hipm(const u16 *id)
 {

include/linux/libata.h

@@ -161,6 +161,8 @@ enum {
 	ATA_DFLAG_DETACH	= (1 << 24),
 	ATA_DFLAG_DETACHED	= (1 << 25),
 
+	ATA_DFLAG_DA		= (1 << 26), /* device supports Device Attention */
+
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */
 	ATA_DEV_ATA_UNSUP	= 2,	/* ATA device (unsupported) */