ata: ahci: find eSATA ports and flag them as removable

If the AHCI ports' HPCP or ESP bits are set, the port
should be considered external (e.g. eSATA) and is marked
as removable.  Userspace tools like udisks then treat it
like an usb drive.

With this patch applied, when I plug a drive into the esata port,
KDE pops up a window asking what to do with the drives(s), just
like it does for any random USB stick.

Removability is indicated to the upper layers by way of the
SCSI RMB bit, as I haven't found another way to signal
userspace to treat a sata disk like any usb stick.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/ahci.h

@@ -181,6 +181,8 @@ enum {
 	PORT_CMD_ALPE		= (1 << 26), /* Aggressive Link PM enable */
 	PORT_CMD_ATAPI		= (1 << 24), /* Device is ATAPI */
 	PORT_CMD_FBSCP		= (1 << 22), /* FBS Capable Port */
+	PORT_CMD_ESP		= (1 << 21), /* External Sata Port */
+	PORT_CMD_HPCP		= (1 << 18), /* HotPlug Capable Port */
 	PORT_CMD_PMP		= (1 << 17), /* PMP attached */
 	PORT_CMD_LIST_ON	= (1 << 15), /* cmd list DMA engine running */
 	PORT_CMD_FIS_ON		= (1 << 14), /* FIS DMA engine running */

drivers/ata/libahci.c

@@ -1117,6 +1117,7 @@ static void ahci_port_init(struct device *dev, struct ata_port *ap,
 			   int port_no, void __iomem *mmio,
 			   void __iomem *port_mmio)
 {
+	struct ahci_host_priv *hpriv = ap->host->private_data;
 	const char *emsg = NULL;
 	int rc;
 	u32 tmp;
@@ -1138,6 +1139,12 @@ static void ahci_port_init(struct device *dev, struct ata_port *ap,
 		writel(tmp, port_mmio + PORT_IRQ_STAT);
 
 	writel(1 << port_no, mmio + HOST_IRQ_STAT);
+
+	/* mark esata ports */
+	tmp = readl(port_mmio + PORT_CMD);
+	if ((tmp & PORT_CMD_HPCP) ||
+	    ((tmp & PORT_CMD_ESP) && (hpriv->cap & HOST_CAP_SXS)))
+		ap->pflags |= ATA_PFLAG_EXTERNAL;
 }
 
 void ahci_init_controller(struct ata_host *host)

drivers/ata/libata-scsi.c

@@ -2015,8 +2015,11 @@ static unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf)
 
 	VPRINTK("ENTER\n");
 
-	/* set scsi removable (RMB) bit per ata bit */
-	if (ata_id_removable(args->id))
+	/* set scsi removable (RMB) bit per ata bit, or if the
+	 * AHCI port says it's external (Hotplug-capable, eSATA).
+	 */
+	if (ata_id_removable(args->id) ||
+	    (args->dev->link->ap->pflags & ATA_PFLAG_EXTERNAL))
 		hdr[1] |= (1 << 7);
 
 	if (args->dev->class == ATA_DEV_ZAC) {

include/linux/libata.h

@@ -254,6 +254,7 @@ enum {
 
 	ATA_PFLAG_PIO32		= (1 << 20),  /* 32bit PIO */
 	ATA_PFLAG_PIO32CHANGE	= (1 << 21),  /* 32bit PIO can be turned on/off */
+	ATA_PFLAG_EXTERNAL	= (1 << 22),  /* eSATA/external port */
 
 	/* struct ata_queued_cmd flags */
 	ATA_QCFLAG_ACTIVE	= (1 << 0), /* cmd not yet ack'd to scsi lyer */