ahci: Move generic code into libahci

This patch should contain no functional changes, just moves code
around.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 2091 insertions, 0 deletions

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
new file mode 100644
index 000000000000..38e1b4e9ecf4
--- /dev/null
+++ b/drivers/ata/libahci.c
@@ -0,0 +1,2091 @@
+/*
+ *  libahci.c - Common AHCI SATA low-level routines
+ *
+ *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
+ *    		    Please ALWAYS copy linux-ide@vger.kernel.org
+ *		    on emails.
+ *
+ *  Copyright 2004-2005 Red Hat, Inc.
+ *
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2, or (at your option)
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * libata documentation is available via 'make {ps|pdf}docs',
+ * as Documentation/DocBook/libata.*
+ *
+ * AHCI hardware documentation:
+ * http://www.intel.com/technology/serialata/pdf/rev1_0.pdf
+ * http://www.intel.com/technology/serialata/pdf/rev1_1.pdf
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+#include <linux/libata.h>
+#include "ahci.h"
+
+static int ahci_skip_host_reset;
+int ahci_ignore_sss;
+EXPORT_SYMBOL_GPL(ahci_ignore_sss);
+
+module_param_named(skip_host_reset, ahci_skip_host_reset, int, 0444);
+MODULE_PARM_DESC(skip_host_reset, "skip global host reset (0=don't skip, 1=skip)");
+
+module_param_named(ignore_sss, ahci_ignore_sss, int, 0444);
+MODULE_PARM_DESC(ignore_sss, "Ignore staggered spinup flag (0=don't ignore, 1=ignore)");
+
+static int ahci_enable_alpm(struct ata_port *ap,
+		enum link_pm policy);
+static void ahci_disable_alpm(struct ata_port *ap);
+static ssize_t ahci_led_show(struct ata_port *ap, char *buf);
+static ssize_t ahci_led_store(struct ata_port *ap, const char *buf,
+			      size_t size);
+static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
+					ssize_t size);
+
+
+
+static int ahci_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
+static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
+static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc);
+static bool ahci_qc_fill_rtf(struct ata_queued_cmd *qc);
+static int ahci_port_start(struct ata_port *ap);
+static void ahci_port_stop(struct ata_port *ap);
+static void ahci_qc_prep(struct ata_queued_cmd *qc);
+static int ahci_pmp_qc_defer(struct ata_queued_cmd *qc);
+static void ahci_freeze(struct ata_port *ap);
+static void ahci_thaw(struct ata_port *ap);
+static void ahci_enable_fbs(struct ata_port *ap);
+static void ahci_disable_fbs(struct ata_port *ap);
+static void ahci_pmp_attach(struct ata_port *ap);
+static void ahci_pmp_detach(struct ata_port *ap);
+static int ahci_softreset(struct ata_link *link, unsigned int *class,
+			  unsigned long deadline);
+static int ahci_hardreset(struct ata_link *link, unsigned int *class,
+			  unsigned long deadline);
+static void ahci_postreset(struct ata_link *link, unsigned int *class);
+static void ahci_error_handler(struct ata_port *ap);
+static void ahci_post_internal_cmd(struct ata_queued_cmd *qc);
+static int ahci_port_resume(struct ata_port *ap);
+static void ahci_dev_config(struct ata_device *dev);
+static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,
+			       u32 opts);
+#ifdef CONFIG_PM
+static int ahci_port_suspend(struct ata_port *ap, pm_message_t mesg);
+#endif
+static ssize_t ahci_activity_show(struct ata_device *dev, char *buf);
+static ssize_t ahci_activity_store(struct ata_device *dev,
+				   enum sw_activity val);
+static void ahci_init_sw_activity(struct ata_link *link);
+
+static ssize_t ahci_show_host_caps(struct device *dev,
+				   struct device_attribute *attr, char *buf);
+static ssize_t ahci_show_host_cap2(struct device *dev,
+				   struct device_attribute *attr, char *buf);
+static ssize_t ahci_show_host_version(struct device *dev,
+				      struct device_attribute *attr, char *buf);
+static ssize_t ahci_show_port_cmd(struct device *dev,
+				  struct device_attribute *attr, char *buf);
+
+static DEVICE_ATTR(ahci_host_caps, S_IRUGO, ahci_show_host_caps, NULL);
+static DEVICE_ATTR(ahci_host_cap2, S_IRUGO, ahci_show_host_cap2, NULL);
+static DEVICE_ATTR(ahci_host_version, S_IRUGO, ahci_show_host_version, NULL);
+static DEVICE_ATTR(ahci_port_cmd, S_IRUGO, ahci_show_port_cmd, NULL);
+
+static struct device_attribute *ahci_shost_attrs[] = {
+	&dev_attr_link_power_management_policy,
+	&dev_attr_em_message_type,
+	&dev_attr_em_message,
+	&dev_attr_ahci_host_caps,
+	&dev_attr_ahci_host_cap2,
+	&dev_attr_ahci_host_version,
+	&dev_attr_ahci_port_cmd,
+	NULL
+};
+
+static struct device_attribute *ahci_sdev_attrs[] = {
+	&dev_attr_sw_activity,
+	&dev_attr_unload_heads,
+	NULL
+};
+
+struct scsi_host_template ahci_sht = {
+	ATA_NCQ_SHT("ahci"),
+	.can_queue		= AHCI_MAX_CMDS - 1,
+	.sg_tablesize		= AHCI_MAX_SG,
+	.dma_boundary		= AHCI_DMA_BOUNDARY,
+	.shost_attrs		= ahci_shost_attrs,
+	.sdev_attrs		= ahci_sdev_attrs,
+};
+EXPORT_SYMBOL_GPL(ahci_sht);
+
+struct ata_port_operations ahci_ops = {
+	.inherits		= &sata_pmp_port_ops,
+
+	.qc_defer		= ahci_pmp_qc_defer,
+	.qc_prep		= ahci_qc_prep,
+	.qc_issue		= ahci_qc_issue,
+	.qc_fill_rtf		= ahci_qc_fill_rtf,
+
+	.freeze			= ahci_freeze,
+	.thaw			= ahci_thaw,
+	.softreset		= ahci_softreset,
+	.hardreset		= ahci_hardreset,
+	.postreset		= ahci_postreset,
+	.pmp_softreset		= ahci_softreset,
+	.error_handler		= ahci_error_handler,
+	.post_internal_cmd	= ahci_post_internal_cmd,
+	.dev_config		= ahci_dev_config,
+
+	.scr_read		= ahci_scr_read,
+	.scr_write		= ahci_scr_write,
+	.pmp_attach		= ahci_pmp_attach,
+	.pmp_detach		= ahci_pmp_detach,
+
+	.enable_pm		= ahci_enable_alpm,
+	.disable_pm		= ahci_disable_alpm,
+	.em_show		= ahci_led_show,
+	.em_store		= ahci_led_store,
+	.sw_activity_show	= ahci_activity_show,
+	.sw_activity_store	= ahci_activity_store,
+#ifdef CONFIG_PM
+	.port_suspend		= ahci_port_suspend,
+	.port_resume		= ahci_port_resume,
+#endif
+	.port_start		= ahci_port_start,
+	.port_stop		= ahci_port_stop,
+};
+EXPORT_SYMBOL_GPL(ahci_ops);
+
+int ahci_em_messages = 1;
+EXPORT_SYMBOL_GPL(ahci_em_messages);
+module_param(ahci_em_messages, int, 0444);
+/* add other LED protocol types when they become supported */
+MODULE_PARM_DESC(ahci_em_messages,
+	"Set AHCI Enclosure Management Message type (0 = disabled, 1 = LED");
+
+static void ahci_enable_ahci(void __iomem *mmio)
+{
+	int i;
+	u32 tmp;
+
+	/* turn on AHCI_EN */
+	tmp = readl(mmio + HOST_CTL);
+	if (tmp & HOST_AHCI_EN)
+		return;
+
+	/* Some controllers need AHCI_EN to be written multiple times.
+	 * Try a few times before giving up.
+	 */
+	for (i = 0; i < 5; i++) {
+		tmp |= HOST_AHCI_EN;
+		writel(tmp, mmio + HOST_CTL);
+		tmp = readl(mmio + HOST_CTL);	/* flush && sanity check */
+		if (tmp & HOST_AHCI_EN)
+			return;
+		msleep(10);
+	}
+
+	WARN_ON(1);
+}
+
+static ssize_t ahci_show_host_caps(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+
+	return sprintf(buf, "%x\n", hpriv->cap);
+}
+
+static ssize_t ahci_show_host_cap2(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+
+	return sprintf(buf, "%x\n", hpriv->cap2);
+}
+
+static ssize_t ahci_show_host_version(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+
+	return sprintf(buf, "%x\n", readl(mmio + HOST_VERSION));
+}
+
+static ssize_t ahci_show_port_cmd(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	void __iomem *port_mmio = ahci_port_base(ap);
+
+	return sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));
+}
+
+/**
+ *	ahci_save_initial_config - Save and fixup initial config values
+ *	@dev: target AHCI device
+ *	@hpriv: host private area to store config values
+ *	@force_port_map: force port map to a specified value
+ *	@mask_port_map: mask out particular bits from port map
+ *
+ *	Some registers containing configuration info might be setup by
+ *	BIOS and might be cleared on reset.  This function saves the
+ *	initial values of those registers into @hpriv such that they
+ *	can be restored after controller reset.
+ *
+ *	If inconsistent, config values are fixed up by this function.
+ *
+ *	LOCKING:
+ *	None.
+ */
+void ahci_save_initial_config(struct device *dev,
+			      struct ahci_host_priv *hpriv,
+			      unsigned int force_port_map,
+			      unsigned int mask_port_map)
+{
+	void __iomem *mmio = hpriv->mmio;
+	u32 cap, cap2, vers, port_map;
+	int i;
+
+	/* make sure AHCI mode is enabled before accessing CAP */
+	ahci_enable_ahci(mmio);
+
+	/* Values prefixed with saved_ are written back to host after
+	 * reset.  Values without are used for driver operation.
+	 */
+	hpriv->saved_cap = cap = readl(mmio + HOST_CAP);
+	hpriv->saved_port_map = port_map = readl(mmio + HOST_PORTS_IMPL);
+
+	/* CAP2 register is only defined for AHCI 1.2 and later */
+	vers = readl(mmio + HOST_VERSION);
+	if ((vers >> 16) > 1 ||
+	   ((vers >> 16) == 1 && (vers & 0xFFFF) >= 0x200))
+		hpriv->saved_cap2 = cap2 = readl(mmio + HOST_CAP2);
+	else
+		hpriv->saved_cap2 = cap2 = 0;
+
+	/* some chips have errata preventing 64bit use */
+	if ((cap & HOST_CAP_64) && (hpriv->flags & AHCI_HFLAG_32BIT_ONLY)) {
+		dev_printk(KERN_INFO, dev,
+			   "controller can't do 64bit DMA, forcing 32bit\n");
+		cap &= ~HOST_CAP_64;
+	}
+
+	if ((cap & HOST_CAP_NCQ) && (hpriv->flags & AHCI_HFLAG_NO_NCQ)) {
+		dev_printk(KERN_INFO, dev,
+			   "controller can't do NCQ, turning off CAP_NCQ\n");
+		cap &= ~HOST_CAP_NCQ;
+	}
+
+	if (!(cap & HOST_CAP_NCQ) && (hpriv->flags & AHCI_HFLAG_YES_NCQ)) {
+		dev_printk(KERN_INFO, dev,
+			   "controller can do NCQ, turning on CAP_NCQ\n");
+		cap |= HOST_CAP_NCQ;
+	}
+
+	if ((cap & HOST_CAP_PMP) && (hpriv->flags & AHCI_HFLAG_NO_PMP)) {
+		dev_printk(KERN_INFO, dev,
+			   "controller can't do PMP, turning off CAP_PMP\n");
+		cap &= ~HOST_CAP_PMP;
+	}
+
+	if ((cap & HOST_CAP_SNTF) && (hpriv->flags & AHCI_HFLAG_NO_SNTF)) {
+		dev_printk(KERN_INFO, dev,
+			   "controller can't do SNTF, turning off CAP_SNTF\n");
+		cap &= ~HOST_CAP_SNTF;
+	}
+
+	if (force_port_map && port_map != force_port_map) {
+		dev_printk(KERN_INFO, dev, "forcing port_map 0x%x -> 0x%x\n",
+			   port_map, force_port_map);
+		port_map = force_port_map;
+	}
+
+	if (mask_port_map) {
+		dev_printk(KERN_ERR, dev, "masking port_map 0x%x -> 0x%x\n",
+			   port_map,
+			   port_map & mask_port_map);
+		port_map &= mask_port_map;
+	}
+
+	/* cross check port_map and cap.n_ports */
+	if (port_map) {
+		int map_ports = 0;
+
+		for (i = 0; i < AHCI_MAX_PORTS; i++)
+			if (port_map & (1 << i))
+				map_ports++;
+
+		/* If PI has more ports than n_ports, whine, clear
+		 * port_map and let it be generated from n_ports.
+		 */
+		if (map_ports > ahci_nr_ports(cap)) {
+			dev_printk(KERN_WARNING, dev,
+				   "implemented port map (0x%x) contains more "
+				   "ports than nr_ports (%u), using nr_ports\n",
+				   port_map, ahci_nr_ports(cap));
+			port_map = 0;
+		}
+	}
+
+	/* fabricate port_map from cap.nr_ports */
+	if (!port_map) {
+		port_map = (1 << ahci_nr_ports(cap)) - 1;
+		dev_printk(KERN_WARNING, dev,
+			   "forcing PORTS_IMPL to 0x%x\n", port_map);
+
+		/* write the fixed up value to the PI register */
+		hpriv->saved_port_map = port_map;
+	}
+
+	/* record values to use during operation */
+	hpriv->cap = cap;
+	hpriv->cap2 = cap2;
+	hpriv->port_map = port_map;
+}
+EXPORT_SYMBOL_GPL(ahci_save_initial_config);
+
+/**
+ *	ahci_restore_initial_config - Restore initial config
+ *	@host: target ATA host
+ *
+ *	Restore initial config stored by ahci_save_initial_config().
+ *
+ *	LOCKING:
+ *	None.
+ */
+static void ahci_restore_initial_config(struct ata_host *host)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+
+	writel(hpriv->saved_cap, mmio + HOST_CAP);
+	if (hpriv->saved_cap2)
+		writel(hpriv->saved_cap2, mmio + HOST_CAP2);
+	writel(hpriv->saved_port_map, mmio + HOST_PORTS_IMPL);
+	(void) readl(mmio + HOST_PORTS_IMPL);	/* flush */
+}
+
+static unsigned ahci_scr_offset(struct ata_port *ap, unsigned int sc_reg)
+{
+	static const int offset[] = {
+		[SCR_STATUS]		= PORT_SCR_STAT,
+		[SCR_CONTROL]		= PORT_SCR_CTL,
+		[SCR_ERROR]		= PORT_SCR_ERR,
+		[SCR_ACTIVE]		= PORT_SCR_ACT,
+		[SCR_NOTIFICATION]	= PORT_SCR_NTF,
+	};
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+
+	if (sc_reg < ARRAY_SIZE(offset) &&
+	    (sc_reg != SCR_NOTIFICATION || (hpriv->cap & HOST_CAP_SNTF)))
+		return offset[sc_reg];
+	return 0;
+}
+
+static int ahci_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
+{
+	void __iomem *port_mmio = ahci_port_base(link->ap);
+	int offset = ahci_scr_offset(link->ap, sc_reg);
+
+	if (offset) {
+		*val = readl(port_mmio + offset);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
+{
+	void __iomem *port_mmio = ahci_port_base(link->ap);
+	int offset = ahci_scr_offset(link->ap, sc_reg);
+
+	if (offset) {
+		writel(val, port_mmio + offset);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+void ahci_start_engine(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 tmp;
+
+	/* start DMA */
+	tmp = readl(port_mmio + PORT_CMD);
+	tmp |= PORT_CMD_START;
+	writel(tmp, port_mmio + PORT_CMD);
+	readl(port_mmio + PORT_CMD); /* flush */
+}
+EXPORT_SYMBOL_GPL(ahci_start_engine);
+
+int ahci_stop_engine(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 tmp;
+
+	tmp = readl(port_mmio + PORT_CMD);
+
+	/* check if the HBA is idle */
+	if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0)
+		return 0;
+
+	/* setting HBA to idle */
+	tmp &= ~PORT_CMD_START;
+	writel(tmp, port_mmio + PORT_CMD);
+
+	/* wait for engine to stop. This could be as long as 500 msec */
+	tmp = ata_wait_register(port_mmio + PORT_CMD,
+				PORT_CMD_LIST_ON, PORT_CMD_LIST_ON, 1, 500);
+	if (tmp & PORT_CMD_LIST_ON)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_stop_engine);
+
+static void ahci_start_fis_rx(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *pp = ap->private_data;
+	u32 tmp;
+
+	/* set FIS registers */
+	if (hpriv->cap & HOST_CAP_64)
+		writel((pp->cmd_slot_dma >> 16) >> 16,
+		       port_mmio + PORT_LST_ADDR_HI);
+	writel(pp->cmd_slot_dma & 0xffffffff, port_mmio + PORT_LST_ADDR);
+
+	if (hpriv->cap & HOST_CAP_64)
+		writel((pp->rx_fis_dma >> 16) >> 16,
+		       port_mmio + PORT_FIS_ADDR_HI);
+	writel(pp->rx_fis_dma & 0xffffffff, port_mmio + PORT_FIS_ADDR);
+
+	/* enable FIS reception */
+	tmp = readl(port_mmio + PORT_CMD);
+	tmp |= PORT_CMD_FIS_RX;
+	writel(tmp, port_mmio + PORT_CMD);
+
+	/* flush */
+	readl(port_mmio + PORT_CMD);
+}
+
+static int ahci_stop_fis_rx(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 tmp;
+
+	/* disable FIS reception */
+	tmp = readl(port_mmio + PORT_CMD);
+	tmp &= ~PORT_CMD_FIS_RX;
+	writel(tmp, port_mmio + PORT_CMD);
+
+	/* wait for completion, spec says 500ms, give it 1000 */
+	tmp = ata_wait_register(port_mmio + PORT_CMD, PORT_CMD_FIS_ON,
+				PORT_CMD_FIS_ON, 10, 1000);
+	if (tmp & PORT_CMD_FIS_ON)
+		return -EBUSY;
+
+	return 0;
+}
+
+static void ahci_power_up(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 cmd;
+
+	cmd = readl(port_mmio + PORT_CMD) & ~PORT_CMD_ICC_MASK;
+
+	/* spin up device */
+	if (hpriv->cap & HOST_CAP_SSS) {
+		cmd |= PORT_CMD_SPIN_UP;
+		writel(cmd, port_mmio + PORT_CMD);
+	}
+
+	/* wake up link */
+	writel(cmd | PORT_CMD_ICC_ACTIVE, port_mmio + PORT_CMD);
+}
+
+static void ahci_disable_alpm(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 cmd;
+	struct ahci_port_priv *pp = ap->private_data;
+
+	/* IPM bits should be disabled by libata-core */
+	/* get the existing command bits */
+	cmd = readl(port_mmio + PORT_CMD);
+
+	/* disable ALPM and ASP */
+	cmd &= ~PORT_CMD_ASP;
+	cmd &= ~PORT_CMD_ALPE;
+
+	/* force the interface back to active */
+	cmd |= PORT_CMD_ICC_ACTIVE;
+
+	/* write out new cmd value */
+	writel(cmd, port_mmio + PORT_CMD);
+	cmd = readl(port_mmio + PORT_CMD);
+
+	/* wait 10ms to be sure we've come out of any low power state */
+	msleep(10);
+
+	/* clear out any PhyRdy stuff from interrupt status */
+	writel(PORT_IRQ_PHYRDY, port_mmio + PORT_IRQ_STAT);
+
+	/* go ahead and clean out PhyRdy Change from Serror too */
+	ahci_scr_write(&ap->link, SCR_ERROR, ((1 << 16) | (1 << 18)));
+
+	/*
+	 * Clear flag to indicate that we should ignore all PhyRdy
+	 * state changes
+	 */
+	hpriv->flags &= ~AHCI_HFLAG_NO_HOTPLUG;
+
+	/*
+	 * Enable interrupts on Phy Ready.
+	 */
+	pp->intr_mask |= PORT_IRQ_PHYRDY;
+	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+	/*
+	 * don't change the link pm policy - we can be called
+	 * just to turn of link pm temporarily
+	 */
+}
+
+static int ahci_enable_alpm(struct ata_port *ap,
+	enum link_pm policy)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 cmd;
+	struct ahci_port_priv *pp = ap->private_data;
+	u32 asp;
+
+	/* Make sure the host is capable of link power management */
+	if (!(hpriv->cap & HOST_CAP_ALPM))
+		return -EINVAL;
+
+	switch (policy) {
+	case MAX_PERFORMANCE:
+	case NOT_AVAILABLE:
+		/*
+		 * if we came here with NOT_AVAILABLE,
+		 * it just means this is the first time we
+		 * have tried to enable - default to max performance,
+		 * and let the user go to lower power modes on request.
+		 */
+		ahci_disable_alpm(ap);
+		return 0;
+	case MIN_POWER:
+		/* configure HBA to enter SLUMBER */
+		asp = PORT_CMD_ASP;
+		break;
+	case MEDIUM_POWER:
+		/* configure HBA to enter PARTIAL */
+		asp = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * Disable interrupts on Phy Ready. This keeps us from
+	 * getting woken up due to spurious phy ready interrupts
+	 * TBD - Hot plug should be done via polling now, is
+	 * that even supported?
+	 */
+	pp->intr_mask &= ~PORT_IRQ_PHYRDY;
+	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+	/*
+	 * Set a flag to indicate that we should ignore all PhyRdy
+	 * state changes since these can happen now whenever we
+	 * change link state
+	 */
+	hpriv->flags |= AHCI_HFLAG_NO_HOTPLUG;
+
+	/* get the existing command bits */
+	cmd = readl(port_mmio + PORT_CMD);
+
+	/*
+	 * Set ASP based on Policy
+	 */
+	cmd |= asp;
+
+	/*
+	 * Setting this bit will instruct the HBA to aggressively
+	 * enter a lower power link state when it's appropriate and
+	 * based on the value set above for ASP
+	 */
+	cmd |= PORT_CMD_ALPE;
+
+	/* write out new cmd value */
+	writel(cmd, port_mmio + PORT_CMD);
+	cmd = readl(port_mmio + PORT_CMD);
+
+	/* IPM bits should be set by libata-core */
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static void ahci_power_down(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 cmd, scontrol;
+
+	if (!(hpriv->cap & HOST_CAP_SSS))
+		return;
+
+	/* put device into listen mode, first set PxSCTL.DET to 0 */
+	scontrol = readl(port_mmio + PORT_SCR_CTL);
+	scontrol &= ~0xf;
+	writel(scontrol, port_mmio + PORT_SCR_CTL);
+
+	/* then set PxCMD.SUD to 0 */
+	cmd = readl(port_mmio + PORT_CMD) & ~PORT_CMD_ICC_MASK;
+	cmd &= ~PORT_CMD_SPIN_UP;
+	writel(cmd, port_mmio + PORT_CMD);
+}
+#endif
+
+static void ahci_start_port(struct ata_port *ap)
+{
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ata_link *link;
+	struct ahci_em_priv *emp;
+	ssize_t rc;
+	int i;
+
+	/* enable FIS reception */
+	ahci_start_fis_rx(ap);
+
+	/* enable DMA */
+	ahci_start_engine(ap);
+
+	/* turn on LEDs */
+	if (ap->flags & ATA_FLAG_EM) {
+		ata_for_each_link(link, ap, EDGE) {
+			emp = &pp->em_priv[link->pmp];
+
+			/* EM Transmit bit maybe busy during init */
+			for (i = 0; i < EM_MAX_RETRY; i++) {
+				rc = ahci_transmit_led_message(ap,
+							       emp->led_state,
+							       4);
+				if (rc == -EBUSY)
+					msleep(1);
+				else
+					break;
+			}
+		}
+	}
+
+	if (ap->flags & ATA_FLAG_SW_ACTIVITY)
+		ata_for_each_link(link, ap, EDGE)
+			ahci_init_sw_activity(link);
+
+}
+
+static int ahci_deinit_port(struct ata_port *ap, const char **emsg)
+{
+	int rc;
+
+	/* disable DMA */
+	rc = ahci_stop_engine(ap);
+	if (rc) {
+		*emsg = "failed to stop engine";
+		return rc;
+	}
+
+	/* disable FIS reception */
+	rc = ahci_stop_fis_rx(ap);
+	if (rc) {
+		*emsg = "failed stop FIS RX";
+		return rc;
+	}
+
+	return 0;
+}
+
+int ahci_reset_controller(struct ata_host *host)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	u32 tmp;
+
+	/* we must be in AHCI mode, before using anything
+	 * AHCI-specific, such as HOST_RESET.
+	 */
+	ahci_enable_ahci(mmio);
+
+	/* global controller reset */
+	if (!ahci_skip_host_reset) {
+		tmp = readl(mmio + HOST_CTL);
+		if ((tmp & HOST_RESET) == 0) {
+			writel(tmp | HOST_RESET, mmio + HOST_CTL);
+			readl(mmio + HOST_CTL); /* flush */
+		}
+
+		/*
+		 * to perform host reset, OS should set HOST_RESET
+		 * and poll until this bit is read to be "0".
+		 * reset must complete within 1 second, or
+		 * the hardware should be considered fried.
+		 */
+		tmp = ata_wait_register(mmio + HOST_CTL, HOST_RESET,
+					HOST_RESET, 10, 1000);
+
+		if (tmp & HOST_RESET) {
+			dev_printk(KERN_ERR, host->dev,
+				   "controller reset failed (0x%x)\n", tmp);
+			return -EIO;
+		}
+
+		/* turn on AHCI mode */
+		ahci_enable_ahci(mmio);
+
+		/* Some registers might be cleared on reset.  Restore
+		 * initial values.
+		 */
+		ahci_restore_initial_config(host);
+	} else
+		dev_printk(KERN_INFO, host->dev,
+			   "skipping global host reset\n");
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_reset_controller);
+
+static void ahci_sw_activity(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+	if (!(link->flags & ATA_LFLAG_SW_ACTIVITY))
+		return;
+
+	emp->activity++;
+	if (!timer_pending(&emp->timer))
+		mod_timer(&emp->timer, jiffies + msecs_to_jiffies(10));
+}
+
+static void ahci_sw_activity_blink(unsigned long arg)
+{
+	struct ata_link *link = (struct ata_link *)arg;
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+	unsigned long led_message = emp->led_state;
+	u32 activity_led_state;
+	unsigned long flags;
+
+	led_message &= EM_MSG_LED_VALUE;
+	led_message |= ap->port_no | (link->pmp << 8);
+
+	/* check to see if we've had activity.  If so,
+	 * toggle state of LED and reset timer.  If not,
+	 * turn LED to desired idle state.
+	 */
+	spin_lock_irqsave(ap->lock, flags);
+	if (emp->saved_activity != emp->activity) {
+		emp->saved_activity = emp->activity;
+		/* get the current LED state */
+		activity_led_state = led_message & EM_MSG_LED_VALUE_ON;
+
+		if (activity_led_state)
+			activity_led_state = 0;
+		else
+			activity_led_state = 1;
+
+		/* clear old state */
+		led_message &= ~EM_MSG_LED_VALUE_ACTIVITY;
+
+		/* toggle state */
+		led_message |= (activity_led_state << 16);
+		mod_timer(&emp->timer, jiffies + msecs_to_jiffies(100));
+	} else {
+		/* switch to idle */
+		led_message &= ~EM_MSG_LED_VALUE_ACTIVITY;
+		if (emp->blink_policy == BLINK_OFF)
+			led_message |= (1 << 16);
+	}
+	spin_unlock_irqrestore(ap->lock, flags);
+	ahci_transmit_led_message(ap, led_message, 4);
+}
+
+static void ahci_init_sw_activity(struct ata_link *link)
+{
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+	/* init activity stats, setup timer */
+	emp->saved_activity = emp->activity = 0;
+	setup_timer(&emp->timer, ahci_sw_activity_blink, (unsigned long)link);
+
+	/* check our blink policy and set flag for link if it's enabled */
+	if (emp->blink_policy)
+		link->flags |= ATA_LFLAG_SW_ACTIVITY;
+}
+
+int ahci_reset_em(struct ata_host *host)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	u32 em_ctl;
+
+	em_ctl = readl(mmio + HOST_EM_CTL);
+	if ((em_ctl & EM_CTL_TM) || (em_ctl & EM_CTL_RST))
+		return -EINVAL;
+
+	writel(em_ctl | EM_CTL_RST, mmio + HOST_EM_CTL);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_reset_em);
+
+static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
+					ssize_t size)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	u32 em_ctl;
+	u32 message[] = {0, 0};
+	unsigned long flags;
+	int pmp;
+	struct ahci_em_priv *emp;
+
+	/* get the slot number from the message */
+	pmp = (state & EM_MSG_LED_PMP_SLOT) >> 8;
+	if (pmp < EM_MAX_SLOTS)
+		emp = &pp->em_priv[pmp];
+	else
+		return -EINVAL;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	/*
+	 * if we are still busy transmitting a previous message,
+	 * do not allow
+	 */
+	em_ctl = readl(mmio + HOST_EM_CTL);
+	if (em_ctl & EM_CTL_TM) {
+		spin_unlock_irqrestore(ap->lock, flags);
+		return -EBUSY;
+	}
+
+	/*
+	 * create message header - this is all zero except for
+	 * the message size, which is 4 bytes.
+	 */
+	message[0] |= (4 << 8);
+
+	/* ignore 0:4 of byte zero, fill in port info yourself */
+	message[1] = ((state & ~EM_MSG_LED_HBA_PORT) | ap->port_no);
+
+	/* write message to EM_LOC */
+	writel(message[0], mmio + hpriv->em_loc);
+	writel(message[1], mmio + hpriv->em_loc+4);
+
+	/* save off new led state for port/slot */
+	emp->led_state = state;
+
+	/*
+	 * tell hardware to transmit the message
+	 */
+	writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+
+	spin_unlock_irqrestore(ap->lock, flags);
+	return size;
+}
+
+static ssize_t ahci_led_show(struct ata_port *ap, char *buf)
+{
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ata_link *link;
+	struct ahci_em_priv *emp;
+	int rc = 0;
+
+	ata_for_each_link(link, ap, EDGE) {
+		emp = &pp->em_priv[link->pmp];
+		rc += sprintf(buf, "%lx\n", emp->led_state);
+	}
+	return rc;
+}
+
+static ssize_t ahci_led_store(struct ata_port *ap, const char *buf,
+				size_t size)
+{
+	int state;
+	int pmp;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp;
+
+	state = simple_strtoul(buf, NULL, 0);
+
+	/* get the slot number from the message */
+	pmp = (state & EM_MSG_LED_PMP_SLOT) >> 8;
+	if (pmp < EM_MAX_SLOTS)
+		emp = &pp->em_priv[pmp];
+	else
+		return -EINVAL;
+
+	/* mask off the activity bits if we are in sw_activity
+	 * mode, user should turn off sw_activity before setting
+	 * activity led through em_message
+	 */
+	if (emp->blink_policy)
+		state &= ~EM_MSG_LED_VALUE_ACTIVITY;
+
+	return ahci_transmit_led_message(ap, state, size);
+}
+
+static ssize_t ahci_activity_store(struct ata_device *dev, enum sw_activity val)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+	u32 port_led_state = emp->led_state;
+
+	/* save the desired Activity LED behavior */
+	if (val == OFF) {
+		/* clear LFLAG */
+		link->flags &= ~(ATA_LFLAG_SW_ACTIVITY);
+
+		/* set the LED to OFF */
+		port_led_state &= EM_MSG_LED_VALUE_OFF;
+		port_led_state |= (ap->port_no | (link->pmp << 8));
+		ahci_transmit_led_message(ap, port_led_state, 4);
+	} else {
+		link->flags |= ATA_LFLAG_SW_ACTIVITY;
+		if (val == BLINK_OFF) {
+			/* set LED to ON for idle */
+			port_led_state &= EM_MSG_LED_VALUE_OFF;
+			port_led_state |= (ap->port_no | (link->pmp << 8));
+			port_led_state |= EM_MSG_LED_VALUE_ON; /* check this */
+			ahci_transmit_led_message(ap, port_led_state, 4);
+		}
+	}
+	emp->blink_policy = val;
+	return 0;
+}
+
+static ssize_t ahci_activity_show(struct ata_device *dev, char *buf)
+{
+	struct ata_link *link = dev->link;
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+	/* display the saved value of activity behavior for this
+	 * disk.
+	 */
+	return sprintf(buf, "%d\n", emp->blink_policy);
+}
+
+static void ahci_port_init(struct device *dev, struct ata_port *ap,
+			   int port_no, void __iomem *mmio,
+			   void __iomem *port_mmio)
+{
+	const char *emsg = NULL;
+	int rc;
+	u32 tmp;
+
+	/* make sure port is not active */
+	rc = ahci_deinit_port(ap, &emsg);
+	if (rc)
+		dev_warn(dev, "%s (%d)\n", emsg, rc);
+
+	/* clear SError */
+	tmp = readl(port_mmio + PORT_SCR_ERR);
+	VPRINTK("PORT_SCR_ERR 0x%x\n", tmp);
+	writel(tmp, port_mmio + PORT_SCR_ERR);
+
+	/* clear port IRQ */
+	tmp = readl(port_mmio + PORT_IRQ_STAT);
+	VPRINTK("PORT_IRQ_STAT 0x%x\n", tmp);
+	if (tmp)
+		writel(tmp, port_mmio + PORT_IRQ_STAT);
+
+	writel(1 << port_no, mmio + HOST_IRQ_STAT);
+}
+
+void ahci_init_controller(struct ata_host *host)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	int i;
+	void __iomem *port_mmio;
+	u32 tmp;
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap = host->ports[i];
+
+		port_mmio = ahci_port_base(ap);
+		if (ata_port_is_dummy(ap))
+			continue;
+
+		ahci_port_init(host->dev, ap, i, mmio, port_mmio);
+	}
+
+	tmp = readl(mmio + HOST_CTL);
+	VPRINTK("HOST_CTL 0x%x\n", tmp);
+	writel(tmp | HOST_IRQ_EN, mmio + HOST_CTL);
+	tmp = readl(mmio + HOST_CTL);
+	VPRINTK("HOST_CTL 0x%x\n", tmp);
+}
+EXPORT_SYMBOL_GPL(ahci_init_controller);
+
+static void ahci_dev_config(struct ata_device *dev)
+{
+	struct ahci_host_priv *hpriv = dev->link->ap->host->private_data;
+
+	if (hpriv->flags & AHCI_HFLAG_SECT255) {
+		dev->max_sectors = 255;
+		ata_dev_printk(dev, KERN_INFO,
+			       "SB600 AHCI: limiting to 255 sectors per cmd\n");
+	}
+}
+
+static unsigned int ahci_dev_classify(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ata_taskfile tf;
+	u32 tmp;
+
+	tmp = readl(port_mmio + PORT_SIG);
+	tf.lbah		= (tmp >> 24)	& 0xff;
+	tf.lbam		= (tmp >> 16)	& 0xff;
+	tf.lbal		= (tmp >> 8)	& 0xff;
+	tf.nsect	= (tmp)		& 0xff;
+
+	return ata_dev_classify(&tf);
+}
+
+static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,
+			       u32 opts)
+{
+	dma_addr_t cmd_tbl_dma;
+
+	cmd_tbl_dma = pp->cmd_tbl_dma + tag * AHCI_CMD_TBL_SZ;
+
+	pp->cmd_slot[tag].opts = cpu_to_le32(opts);
+	pp->cmd_slot[tag].status = 0;
+	pp->cmd_slot[tag].tbl_addr = cpu_to_le32(cmd_tbl_dma & 0xffffffff);
+	pp->cmd_slot[tag].tbl_addr_hi = cpu_to_le32((cmd_tbl_dma >> 16) >> 16);
+}
+
+int ahci_kick_engine(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	u8 status = readl(port_mmio + PORT_TFDATA) & 0xFF;
+	u32 tmp;
+	int busy, rc;
+
+	/* stop engine */
+	rc = ahci_stop_engine(ap);
+	if (rc)
+		goto out_restart;
+
+	/* need to do CLO?
+	 * always do CLO if PMP is attached (AHCI-1.3 9.2)
+	 */
+	busy = status & (ATA_BUSY | ATA_DRQ);
+	if (!busy && !sata_pmp_attached(ap)) {
+		rc = 0;
+		goto out_restart;
+	}
+
+	if (!(hpriv->cap & HOST_CAP_CLO)) {
+		rc = -EOPNOTSUPP;
+		goto out_restart;
+	}
+
+	/* perform CLO */
+	tmp = readl(port_mmio + PORT_CMD);
+	tmp |= PORT_CMD_CLO;
+	writel(tmp, port_mmio + PORT_CMD);
+
+	rc = 0;
+	tmp = ata_wait_register(port_mmio + PORT_CMD,
+				PORT_CMD_CLO, PORT_CMD_CLO, 1, 500);
+	if (tmp & PORT_CMD_CLO)
+		rc = -EIO;
+
+	/* restart engine */
+ out_restart:
+	ahci_start_engine(ap);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_kick_engine);
+
+static int ahci_exec_polled_cmd(struct ata_port *ap, int pmp,
+				struct ata_taskfile *tf, int is_cmd, u16 flags,
+				unsigned long timeout_msec)
+{
+	const u32 cmd_fis_len = 5; /* five dwords */
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u8 *fis = pp->cmd_tbl;
+	u32 tmp;
+
+	/* prep the command */
+	ata_tf_to_fis(tf, pmp, is_cmd, fis);
+	ahci_fill_cmd_slot(pp, 0, cmd_fis_len | flags | (pmp << 12));
+
+	/* issue & wait */
+	writel(1, port_mmio + PORT_CMD_ISSUE);
+
+	if (timeout_msec) {
+		tmp = ata_wait_register(port_mmio + PORT_CMD_ISSUE, 0x1, 0x1,
+					1, timeout_msec);
+		if (tmp & 0x1) {
+			ahci_kick_engine(ap);
+			return -EBUSY;
+		}
+	} else
+		readl(port_mmio + PORT_CMD_ISSUE);	/* flush */
+
+	return 0;
+}
+
+int ahci_do_softreset(struct ata_link *link, unsigned int *class,
+		      int pmp, unsigned long deadline,
+		      int (*check_ready)(struct ata_link *link))
+{
+	struct ata_port *ap = link->ap;
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	const char *reason = NULL;
+	unsigned long now, msecs;
+	struct ata_taskfile tf;
+	int rc;
+
+	DPRINTK("ENTER\n");
+
+	/* prepare for SRST (AHCI-1.1 10.4.1) */
+	rc = ahci_kick_engine(ap);
+	if (rc && rc != -EOPNOTSUPP)
+		ata_link_printk(link, KERN_WARNING,
+				"failed to reset engine (errno=%d)\n", rc);
+
+	ata_tf_init(link->device, &tf);
+
+	/* issue the first D2H Register FIS */
+	msecs = 0;
+	now = jiffies;
+	if (time_after(now, deadline))
+		msecs = jiffies_to_msecs(deadline - now);
+
+	tf.ctl |= ATA_SRST;
+	if (ahci_exec_polled_cmd(ap, pmp, &tf, 0,
+				 AHCI_CMD_RESET | AHCI_CMD_CLR_BUSY, msecs)) {
+		rc = -EIO;
+		reason = "1st FIS failed";
+		goto fail;
+	}
+
+	/* spec says at least 5us, but be generous and sleep for 1ms */
+	msleep(1);
+
+	/* issue the second D2H Register FIS */
+	tf.ctl &= ~ATA_SRST;
+	ahci_exec_polled_cmd(ap, pmp, &tf, 0, 0, 0);
+
+	/* wait for link to become ready */
+	rc = ata_wait_after_reset(link, deadline, check_ready);
+	if (rc == -EBUSY && hpriv->flags & AHCI_HFLAG_SRST_TOUT_IS_OFFLINE) {
+		/*
+		 * Workaround for cases where link online status can't
+		 * be trusted.  Treat device readiness timeout as link
+		 * offline.
+		 */
+		ata_link_printk(link, KERN_INFO,
+				"device not ready, treating as offline\n");
+		*class = ATA_DEV_NONE;
+	} else if (rc) {
+		/* link occupied, -ENODEV too is an error */
+		reason = "device not ready";
+		goto fail;
+	} else
+		*class = ahci_dev_classify(ap);
+
+	DPRINTK("EXIT, class=%u\n", *class);
+	return 0;
+
+ fail:
+	ata_link_printk(link, KERN_ERR, "softreset failed (%s)\n", reason);
+	return rc;
+}
+
+int ahci_check_ready(struct ata_link *link)
+{
+	void __iomem *port_mmio = ahci_port_base(link->ap);
+	u8 status = readl(port_mmio + PORT_TFDATA) & 0xFF;
+
+	return ata_check_ready(status);
+}
+EXPORT_SYMBOL_GPL(ahci_check_ready);
+
+static int ahci_softreset(struct ata_link *link, unsigned int *class,
+			  unsigned long deadline)
+{
+	int pmp = sata_srst_pmp(link);
+
+	DPRINTK("ENTER\n");
+
+	return ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
+}
+EXPORT_SYMBOL_GPL(ahci_do_softreset);
+
+static int ahci_hardreset(struct ata_link *link, unsigned int *class,
+			  unsigned long deadline)
+{
+	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
+	struct ata_port *ap = link->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
+	struct ata_taskfile tf;
+	bool online;
+	int rc;
+
+	DPRINTK("ENTER\n");
+
+	ahci_stop_engine(ap);
+
+	/* clear D2H reception area to properly wait for D2H FIS */
+	ata_tf_init(link->device, &tf);
+	tf.command = 0x80;
+	ata_tf_to_fis(&tf, 0, 0, d2h_fis);
+
+	rc = sata_link_hardreset(link, timing, deadline, &online,
+				 ahci_check_ready);
+
+	ahci_start_engine(ap);
+
+	if (online)
+		*class = ahci_dev_classify(ap);
+
+	DPRINTK("EXIT, rc=%d, class=%u\n", rc, *class);
+	return rc;
+}
+
+static void ahci_postreset(struct ata_link *link, unsigned int *class)
+{
+	struct ata_port *ap = link->ap;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 new_tmp, tmp;
+
+	ata_std_postreset(link, class);
+
+	/* Make sure port's ATAPI bit is set appropriately */
+	new_tmp = tmp = readl(port_mmio + PORT_CMD);
+	if (*class == ATA_DEV_ATAPI)
+		new_tmp |= PORT_CMD_ATAPI;
+	else
+		new_tmp &= ~PORT_CMD_ATAPI;
+	if (new_tmp != tmp) {
+		writel(new_tmp, port_mmio + PORT_CMD);
+		readl(port_mmio + PORT_CMD); /* flush */
+	}
+}
+
+static unsigned int ahci_fill_sg(struct ata_queued_cmd *qc, void *cmd_tbl)
+{
+	struct scatterlist *sg;
+	struct ahci_sg *ahci_sg = cmd_tbl + AHCI_CMD_TBL_HDR_SZ;
+	unsigned int si;
+
+	VPRINTK("ENTER\n");
+
+	/*
+	 * Next, the S/G list.
+	 */
+	for_each_sg(qc->sg, sg, qc->n_elem, si) {
+		dma_addr_t addr = sg_dma_address(sg);
+		u32 sg_len = sg_dma_len(sg);
+
+		ahci_sg[si].addr = cpu_to_le32(addr & 0xffffffff);
+		ahci_sg[si].addr_hi = cpu_to_le32((addr >> 16) >> 16);
+		ahci_sg[si].flags_size = cpu_to_le32(sg_len - 1);
+	}
+
+	return si;
+}
+
+static int ahci_pmp_qc_defer(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+
+	if (!sata_pmp_attached(ap) || pp->fbs_enabled)
+		return ata_std_qc_defer(qc);
+	else
+		return sata_pmp_qc_defer_cmd_switch(qc);
+}
+
+static void ahci_qc_prep(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	struct ahci_port_priv *pp = ap->private_data;
+	int is_atapi = ata_is_atapi(qc->tf.protocol);
+	void *cmd_tbl;
+	u32 opts;
+	const u32 cmd_fis_len = 5; /* five dwords */
+	unsigned int n_elem;
+
+	/*
+	 * Fill in command table information.  First, the header,
+	 * a SATA Register - Host to Device command FIS.
+	 */
+	cmd_tbl = pp->cmd_tbl + qc->tag * AHCI_CMD_TBL_SZ;
+
+	ata_tf_to_fis(&qc->tf, qc->dev->link->pmp, 1, cmd_tbl);
+	if (is_atapi) {
+		memset(cmd_tbl + AHCI_CMD_TBL_CDB, 0, 32);
+		memcpy(cmd_tbl + AHCI_CMD_TBL_CDB, qc->cdb, qc->dev->cdb_len);
+	}
+
+	n_elem = 0;
+	if (qc->flags & ATA_QCFLAG_DMAMAP)
+		n_elem = ahci_fill_sg(qc, cmd_tbl);
+
+	/*
+	 * Fill in command slot information.
+	 */
+	opts = cmd_fis_len | n_elem << 16 | (qc->dev->link->pmp << 12);
+	if (qc->tf.flags & ATA_TFLAG_WRITE)
+		opts |= AHCI_CMD_WRITE;
+	if (is_atapi)
+		opts |= AHCI_CMD_ATAPI | AHCI_CMD_PREFETCH;
+
+	ahci_fill_cmd_slot(pp, qc->tag, opts);
+}
+
+static void ahci_fbs_dec_intr(struct ata_port *ap)
+{
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 fbs = readl(port_mmio + PORT_FBS);
+	int retries = 3;
+
+	DPRINTK("ENTER\n");
+	BUG_ON(!pp->fbs_enabled);
+
+	/* time to wait for DEC is not specified by AHCI spec,
+	 * add a retry loop for safety.
+	 */
+	writel(fbs | PORT_FBS_DEC, port_mmio + PORT_FBS);
+	fbs = readl(port_mmio + PORT_FBS);
+	while ((fbs & PORT_FBS_DEC) && retries--) {
+		udelay(1);
+		fbs = readl(port_mmio + PORT_FBS);
+	}
+
+	if (fbs & PORT_FBS_DEC)
+		dev_printk(KERN_ERR, ap->host->dev,
+			   "failed to clear device error\n");
+}
+
+static void ahci_error_intr(struct ata_port *ap, u32 irq_stat)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ata_eh_info *host_ehi = &ap->link.eh_info;
+	struct ata_link *link = NULL;
+	struct ata_queued_cmd *active_qc;
+	struct ata_eh_info *active_ehi;
+	bool fbs_need_dec = false;
+	u32 serror;
+
+	/* determine active link with error */
+	if (pp->fbs_enabled) {
+		void __iomem *port_mmio = ahci_port_base(ap);
+		u32 fbs = readl(port_mmio + PORT_FBS);
+		int pmp = fbs >> PORT_FBS_DWE_OFFSET;
+
+		if ((fbs & PORT_FBS_SDE) && (pmp < ap->nr_pmp_links) &&
+		    ata_link_online(&ap->pmp_link[pmp])) {
+			link = &ap->pmp_link[pmp];
+			fbs_need_dec = true;
+		}
+
+	} else
+		ata_for_each_link(link, ap, EDGE)
+			if (ata_link_active(link))
+				break;
+
+	if (!link)
+		link = &ap->link;
+
+	active_qc = ata_qc_from_tag(ap, link->active_tag);
+	active_ehi = &link->eh_info;
+
+	/* record irq stat */
+	ata_ehi_clear_desc(host_ehi);
+	ata_ehi_push_desc(host_ehi, "irq_stat 0x%08x", irq_stat);
+
+	/* AHCI needs SError cleared; otherwise, it might lock up */
+	ahci_scr_read(&ap->link, SCR_ERROR, &serror);
+	ahci_scr_write(&ap->link, SCR_ERROR, serror);
+	host_ehi->serror |= serror;
+
+	/* some controllers set IRQ_IF_ERR on device errors, ignore it */
+	if (hpriv->flags & AHCI_HFLAG_IGN_IRQ_IF_ERR)
+		irq_stat &= ~PORT_IRQ_IF_ERR;
+
+	if (irq_stat & PORT_IRQ_TF_ERR) {
+		/* If qc is active, charge it; otherwise, the active
+		 * link.  There's no active qc on NCQ errors.  It will
+		 * be determined by EH by reading log page 10h.
+		 */
+		if (active_qc)
+			active_qc->err_mask |= AC_ERR_DEV;
+		else
+			active_ehi->err_mask |= AC_ERR_DEV;
+
+		if (hpriv->flags & AHCI_HFLAG_IGN_SERR_INTERNAL)
+			host_ehi->serror &= ~SERR_INTERNAL;
+	}
+
+	if (irq_stat & PORT_IRQ_UNK_FIS) {
+		u32 *unk = (u32 *)(pp->rx_fis + RX_FIS_UNK);
+
+		active_ehi->err_mask |= AC_ERR_HSM;
+		active_ehi->action |= ATA_EH_RESET;
+		ata_ehi_push_desc(active_ehi,
+				  "unknown FIS %08x %08x %08x %08x" ,
+				  unk[0], unk[1], unk[2], unk[3]);
+	}
+
+	if (sata_pmp_attached(ap) && (irq_stat & PORT_IRQ_BAD_PMP)) {
+		active_ehi->err_mask |= AC_ERR_HSM;
+		active_ehi->action |= ATA_EH_RESET;
+		ata_ehi_push_desc(active_ehi, "incorrect PMP");
+	}
+
+	if (irq_stat & (PORT_IRQ_HBUS_ERR | PORT_IRQ_HBUS_DATA_ERR)) {
+		host_ehi->err_mask |= AC_ERR_HOST_BUS;
+		host_ehi->action |= ATA_EH_RESET;
+		ata_ehi_push_desc(host_ehi, "host bus error");
+	}
+
+	if (irq_stat & PORT_IRQ_IF_ERR) {
+		if (fbs_need_dec)
+			active_ehi->err_mask |= AC_ERR_DEV;
+		else {
+			host_ehi->err_mask |= AC_ERR_ATA_BUS;
+			host_ehi->action |= ATA_EH_RESET;
+		}
+
+		ata_ehi_push_desc(host_ehi, "interface fatal error");
+	}
+
+	if (irq_stat & (PORT_IRQ_CONNECT | PORT_IRQ_PHYRDY)) {
+		ata_ehi_hotplugged(host_ehi);
+		ata_ehi_push_desc(host_ehi, "%s",
+			irq_stat & PORT_IRQ_CONNECT ?
+			"connection status changed" : "PHY RDY changed");
+	}
+
+	/* okay, let's hand over to EH */
+
+	if (irq_stat & PORT_IRQ_FREEZE)
+		ata_port_freeze(ap);
+	else if (fbs_need_dec) {
+		ata_link_abort(link);
+		ahci_fbs_dec_intr(ap);
+	} else
+		ata_port_abort(ap);
+}
+
+static void ahci_port_intr(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ata_eh_info *ehi = &ap->link.eh_info;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	int resetting = !!(ap->pflags & ATA_PFLAG_RESETTING);
+	u32 status, qc_active = 0;
+	int rc;
+
+	status = readl(port_mmio + PORT_IRQ_STAT);
+	writel(status, port_mmio + PORT_IRQ_STAT);
+
+	/* ignore BAD_PMP while resetting */
+	if (unlikely(resetting))
+		status &= ~PORT_IRQ_BAD_PMP;
+
+	/* If we are getting PhyRdy, this is
+	 * just a power state change, we should
+	 * clear out this, plus the PhyRdy/Comm
+	 * Wake bits from Serror
+	 */
+	if ((hpriv->flags & AHCI_HFLAG_NO_HOTPLUG) &&
+		(status & PORT_IRQ_PHYRDY)) {
+		status &= ~PORT_IRQ_PHYRDY;
+		ahci_scr_write(&ap->link, SCR_ERROR, ((1 << 16) | (1 << 18)));
+	}
+
+	if (unlikely(status & PORT_IRQ_ERROR)) {
+		ahci_error_intr(ap, status);
+		return;
+	}
+
+	if (status & PORT_IRQ_SDB_FIS) {
+		/* If SNotification is available, leave notification
+		 * handling to sata_async_notification().  If not,
+		 * emulate it by snooping SDB FIS RX area.
+		 *
+		 * Snooping FIS RX area is probably cheaper than
+		 * poking SNotification but some constrollers which
+		 * implement SNotification, ICH9 for example, don't
+		 * store AN SDB FIS into receive area.
+		 */
+		if (hpriv->cap & HOST_CAP_SNTF)
+			sata_async_notification(ap);
+		else {
+			/* If the 'N' bit in word 0 of the FIS is set,
+			 * we just received asynchronous notification.
+			 * Tell libata about it.
+			 *
+			 * Lack of SNotification should not appear in
+			 * ahci 1.2, so the workaround is unnecessary
+			 * when FBS is enabled.
+			 */
+			if (pp->fbs_enabled)
+				WARN_ON_ONCE(1);
+			else {
+				const __le32 *f = pp->rx_fis + RX_FIS_SDB;
+				u32 f0 = le32_to_cpu(f[0]);
+				if (f0 & (1 << 15))
+					sata_async_notification(ap);
+			}
+		}
+	}
+
+	/* pp->active_link is not reliable once FBS is enabled, both
+	 * PORT_SCR_ACT and PORT_CMD_ISSUE should be checked because
+	 * NCQ and non-NCQ commands may be in flight at the same time.
+	 */
+	if (pp->fbs_enabled) {
+		if (ap->qc_active) {
+			qc_active = readl(port_mmio + PORT_SCR_ACT);
+			qc_active |= readl(port_mmio + PORT_CMD_ISSUE);
+		}
+	} else {
+		/* pp->active_link is valid iff any command is in flight */
+		if (ap->qc_active && pp->active_link->sactive)
+			qc_active = readl(port_mmio + PORT_SCR_ACT);
+		else
+			qc_active = readl(port_mmio + PORT_CMD_ISSUE);
+	}
+
+
+	rc = ata_qc_complete_multiple(ap, qc_active);
+
+	/* while resetting, invalid completions are expected */
+	if (unlikely(rc < 0 && !resetting)) {
+		ehi->err_mask |= AC_ERR_HSM;
+		ehi->action |= ATA_EH_RESET;
+		ata_port_freeze(ap);
+	}
+}
+
+irqreturn_t ahci_interrupt(int irq, void *dev_instance)
+{
+	struct ata_host *host = dev_instance;
+	struct ahci_host_priv *hpriv;
+	unsigned int i, handled = 0;
+	void __iomem *mmio;
+	u32 irq_stat, irq_masked;
+
+	VPRINTK("ENTER\n");
+
+	hpriv = host->private_data;
+	mmio = hpriv->mmio;
+
+	/* sigh.  0xffffffff is a valid return from h/w */
+	irq_stat = readl(mmio + HOST_IRQ_STAT);
+	if (!irq_stat)
+		return IRQ_NONE;
+
+	irq_masked = irq_stat & hpriv->port_map;
+
+	spin_lock(&host->lock);
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap;
+
+		if (!(irq_masked & (1 << i)))
+			continue;
+
+		ap = host->ports[i];
+		if (ap) {
+			ahci_port_intr(ap);
+			VPRINTK("port %u\n", i);
+		} else {
+			VPRINTK("port %u (no irq)\n", i);
+			if (ata_ratelimit())
+				dev_printk(KERN_WARNING, host->dev,
+					"interrupt on disabled port %u\n", i);
+		}
+
+		handled = 1;
+	}
+
+	/* HOST_IRQ_STAT behaves as level triggered latch meaning that
+	 * it should be cleared after all the port events are cleared;
+	 * otherwise, it will raise a spurious interrupt after each
+	 * valid one.  Please read section 10.6.2 of ahci 1.1 for more
+	 * information.
+	 *
+	 * Also, use the unmasked value to clear interrupt as spurious
+	 * pending event on a dummy port might cause screaming IRQ.
+	 */
+	writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+	spin_unlock(&host->lock);
+
+	VPRINTK("EXIT\n");
+
+	return IRQ_RETVAL(handled);
+}
+EXPORT_SYMBOL_GPL(ahci_interrupt);
+
+static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_port_priv *pp = ap->private_data;
+
+	/* Keep track of the currently active link.  It will be used
+	 * in completion path to determine whether NCQ phase is in
+	 * progress.
+	 */
+	pp->active_link = qc->dev->link;
+
+	if (qc->tf.protocol == ATA_PROT_NCQ)
+		writel(1 << qc->tag, port_mmio + PORT_SCR_ACT);
+
+	if (pp->fbs_enabled && pp->fbs_last_dev != qc->dev->link->pmp) {
+		u32 fbs = readl(port_mmio + PORT_FBS);
+		fbs &= ~(PORT_FBS_DEV_MASK | PORT_FBS_DEC);
+		fbs |= qc->dev->link->pmp << PORT_FBS_DEV_OFFSET;
+		writel(fbs, port_mmio + PORT_FBS);
+		pp->fbs_last_dev = qc->dev->link->pmp;
+	}
+
+	writel(1 << qc->tag, port_mmio + PORT_CMD_ISSUE);
+
+	ahci_sw_activity(qc->dev->link);
+
+	return 0;
+}
+
+static bool ahci_qc_fill_rtf(struct ata_queued_cmd *qc)
+{
+	struct ahci_port_priv *pp = qc->ap->private_data;
+	u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
+
+	if (pp->fbs_enabled)
+		d2h_fis += qc->dev->link->pmp * AHCI_RX_FIS_SZ;
+
+	ata_tf_from_fis(d2h_fis, &qc->result_tf);
+	return true;
+}
+
+static void ahci_freeze(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+
+	/* turn IRQ off */
+	writel(0, port_mmio + PORT_IRQ_MASK);
+}
+
+static void ahci_thaw(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 tmp;
+	struct ahci_port_priv *pp = ap->private_data;
+
+	/* clear IRQ */
+	tmp = readl(port_mmio + PORT_IRQ_STAT);
+	writel(tmp, port_mmio + PORT_IRQ_STAT);
+	writel(1 << ap->port_no, mmio + HOST_IRQ_STAT);
+
+	/* turn IRQ back on */
+	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+}
+
+static void ahci_error_handler(struct ata_port *ap)
+{
+	if (!(ap->pflags & ATA_PFLAG_FROZEN)) {
+		/* restart engine */
+		ahci_stop_engine(ap);
+		ahci_start_engine(ap);
+	}
+
+	sata_pmp_error_handler(ap);
+}
+
+static void ahci_post_internal_cmd(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+
+	/* make DMA engine forget about the failed command */
+	if (qc->flags & ATA_QCFLAG_FAILED)
+		ahci_kick_engine(ap);
+}
+
+static void ahci_enable_fbs(struct ata_port *ap)
+{
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 fbs;
+	int rc;
+
+	if (!pp->fbs_supported)
+		return;
+
+	fbs = readl(port_mmio + PORT_FBS);
+	if (fbs & PORT_FBS_EN) {
+		pp->fbs_enabled = true;
+		pp->fbs_last_dev = -1; /* initialization */
+		return;
+	}
+
+	rc = ahci_stop_engine(ap);
+	if (rc)
+		return;
+
+	writel(fbs | PORT_FBS_EN, port_mmio + PORT_FBS);
+	fbs = readl(port_mmio + PORT_FBS);
+	if (fbs & PORT_FBS_EN) {
+		dev_printk(KERN_INFO, ap->host->dev, "FBS is enabled.\n");
+		pp->fbs_enabled = true;
+		pp->fbs_last_dev = -1; /* initialization */
+	} else
+		dev_printk(KERN_ERR, ap->host->dev, "Failed to enable FBS\n");
+
+	ahci_start_engine(ap);
+}
+
+static void ahci_disable_fbs(struct ata_port *ap)
+{
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 fbs;
+	int rc;
+
+	if (!pp->fbs_supported)
+		return;
+
+	fbs = readl(port_mmio + PORT_FBS);
+	if ((fbs & PORT_FBS_EN) == 0) {
+		pp->fbs_enabled = false;
+		return;
+	}
+
+	rc = ahci_stop_engine(ap);
+	if (rc)
+		return;
+
+	writel(fbs & ~PORT_FBS_EN, port_mmio + PORT_FBS);
+	fbs = readl(port_mmio + PORT_FBS);
+	if (fbs & PORT_FBS_EN)
+		dev_printk(KERN_ERR, ap->host->dev, "Failed to disable FBS\n");
+	else {
+		dev_printk(KERN_INFO, ap->host->dev, "FBS is disabled.\n");
+		pp->fbs_enabled = false;
+	}
+
+	ahci_start_engine(ap);
+}
+
+static void ahci_pmp_attach(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_port_priv *pp = ap->private_data;
+	u32 cmd;
+
+	cmd = readl(port_mmio + PORT_CMD);
+	cmd |= PORT_CMD_PMP;
+	writel(cmd, port_mmio + PORT_CMD);
+
+	ahci_enable_fbs(ap);
+
+	pp->intr_mask |= PORT_IRQ_BAD_PMP;
+	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+}
+
+static void ahci_pmp_detach(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_port_priv *pp = ap->private_data;
+	u32 cmd;
+
+	ahci_disable_fbs(ap);
+
+	cmd = readl(port_mmio + PORT_CMD);
+	cmd &= ~PORT_CMD_PMP;
+	writel(cmd, port_mmio + PORT_CMD);
+
+	pp->intr_mask &= ~PORT_IRQ_BAD_PMP;
+	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+}
+
+static int ahci_port_resume(struct ata_port *ap)
+{
+	ahci_power_up(ap);
+	ahci_start_port(ap);
+
+	if (sata_pmp_attached(ap))
+		ahci_pmp_attach(ap);
+	else
+		ahci_pmp_detach(ap);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int ahci_port_suspend(struct ata_port *ap, pm_message_t mesg)
+{
+	const char *emsg = NULL;
+	int rc;
+
+	rc = ahci_deinit_port(ap, &emsg);
+	if (rc == 0)
+		ahci_power_down(ap);
+	else {
+		ata_port_printk(ap, KERN_ERR, "%s (%d)\n", emsg, rc);
+		ahci_start_port(ap);
+	}
+
+	return rc;
+}
+#endif
+
+static int ahci_port_start(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct device *dev = ap->host->dev;
+	struct ahci_port_priv *pp;
+	void *mem;
+	dma_addr_t mem_dma;
+	size_t dma_sz, rx_fis_sz;
+
+	pp = devm_kzalloc(dev, sizeof(*pp), GFP_KERNEL);
+	if (!pp)
+		return -ENOMEM;
+
+	/* check FBS capability */
+	if ((hpriv->cap & HOST_CAP_FBS) && sata_pmp_supported(ap)) {
+		void __iomem *port_mmio = ahci_port_base(ap);
+		u32 cmd = readl(port_mmio + PORT_CMD);
+		if (cmd & PORT_CMD_FBSCP)
+			pp->fbs_supported = true;
+		else
+			dev_printk(KERN_WARNING, dev,
+				   "The port is not capable of FBS\n");
+	}
+
+	if (pp->fbs_supported) {
+		dma_sz = AHCI_PORT_PRIV_FBS_DMA_SZ;
+		rx_fis_sz = AHCI_RX_FIS_SZ * 16;
+	} else {
+		dma_sz = AHCI_PORT_PRIV_DMA_SZ;
+		rx_fis_sz = AHCI_RX_FIS_SZ;
+	}
+
+	mem = dmam_alloc_coherent(dev, dma_sz, &mem_dma, GFP_KERNEL);
+	if (!mem)
+		return -ENOMEM;
+	memset(mem, 0, dma_sz);
+
+	/*
+	 * First item in chunk of DMA memory: 32-slot command table,
+	 * 32 bytes each in size
+	 */
+	pp->cmd_slot = mem;
+	pp->cmd_slot_dma = mem_dma;
+
+	mem += AHCI_CMD_SLOT_SZ;
+	mem_dma += AHCI_CMD_SLOT_SZ;
+
+	/*
+	 * Second item: Received-FIS area
+	 */
+	pp->rx_fis = mem;
+	pp->rx_fis_dma = mem_dma;
+
+	mem += rx_fis_sz;
+	mem_dma += rx_fis_sz;
+
+	/*
+	 * Third item: data area for storing a single command
+	 * and its scatter-gather table
+	 */
+	pp->cmd_tbl = mem;
+	pp->cmd_tbl_dma = mem_dma;
+
+	/*
+	 * Save off initial list of interrupts to be enabled.
+	 * This could be changed later
+	 */
+	pp->intr_mask = DEF_PORT_IRQ;
+
+	ap->private_data = pp;
+
+	/* engage engines, captain */
+	return ahci_port_resume(ap);
+}
+
+static void ahci_port_stop(struct ata_port *ap)
+{
+	const char *emsg = NULL;
+	int rc;
+
+	/* de-initialize port */
+	rc = ahci_deinit_port(ap, &emsg);
+	if (rc)
+		ata_port_printk(ap, KERN_WARNING, "%s (%d)\n", emsg, rc);
+}
+
+void ahci_print_info(struct ata_host *host, const char *scc_s)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	u32 vers, cap, cap2, impl, speed;
+	const char *speed_s;
+
+	vers = readl(mmio + HOST_VERSION);
+	cap = hpriv->cap;
+	cap2 = hpriv->cap2;
+	impl = hpriv->port_map;
+
+	speed = (cap >> 20) & 0xf;
+	if (speed == 1)
+		speed_s = "1.5";
+	else if (speed == 2)
+		speed_s = "3";
+	else if (speed == 3)
+		speed_s = "6";
+	else
+		speed_s = "?";
+
+	dev_info(host->dev,
+		"AHCI %02x%02x.%02x%02x "
+		"%u slots %u ports %s Gbps 0x%x impl %s mode\n"
+		,
+
+		(vers >> 24) & 0xff,
+		(vers >> 16) & 0xff,
+		(vers >> 8) & 0xff,
+		vers & 0xff,
+
+		((cap >> 8) & 0x1f) + 1,
+		(cap & 0x1f) + 1,
+		speed_s,
+		impl,
+		scc_s);
+
+	dev_info(host->dev,
+		"flags: "
+		"%s%s%s%s%s%s%s"
+		"%s%s%s%s%s%s%s"
+		"%s%s%s%s%s%s\n"
+		,
+
+		cap & HOST_CAP_64 ? "64bit " : "",
+		cap & HOST_CAP_NCQ ? "ncq " : "",
+		cap & HOST_CAP_SNTF ? "sntf " : "",
+		cap & HOST_CAP_MPS ? "ilck " : "",
+		cap & HOST_CAP_SSS ? "stag " : "",
+		cap & HOST_CAP_ALPM ? "pm " : "",
+		cap & HOST_CAP_LED ? "led " : "",
+		cap & HOST_CAP_CLO ? "clo " : "",
+		cap & HOST_CAP_ONLY ? "only " : "",
+		cap & HOST_CAP_PMP ? "pmp " : "",
+		cap & HOST_CAP_FBS ? "fbs " : "",
+		cap & HOST_CAP_PIO_MULTI ? "pio " : "",
+		cap & HOST_CAP_SSC ? "slum " : "",
+		cap & HOST_CAP_PART ? "part " : "",
+		cap & HOST_CAP_CCC ? "ccc " : "",
+		cap & HOST_CAP_EMS ? "ems " : "",
+		cap & HOST_CAP_SXS ? "sxs " : "",
+		cap2 & HOST_CAP2_APST ? "apst " : "",
+		cap2 & HOST_CAP2_NVMHCI ? "nvmp " : "",
+		cap2 & HOST_CAP2_BOH ? "boh " : ""
+		);
+}
+EXPORT_SYMBOL_GPL(ahci_print_info);
+
+void ahci_set_em_messages(struct ahci_host_priv *hpriv,
+			  struct ata_port_info *pi)
+{
+	u8 messages;
+	void __iomem *mmio = hpriv->mmio;
+	u32 em_loc = readl(mmio + HOST_EM_LOC);
+	u32 em_ctl = readl(mmio + HOST_EM_CTL);
+
+	if (!ahci_em_messages || !(hpriv->cap & HOST_CAP_EMS))
+		return;
+
+	messages = (em_ctl & EM_CTRL_MSG_TYPE) >> 16;
+
+	/* we only support LED message type right now */
+	if ((messages & 0x01) && (ahci_em_messages == 1)) {
+		/* store em_loc */
+		hpriv->em_loc = ((em_loc >> 16) * 4);
+		pi->flags |= ATA_FLAG_EM;
+		if (!(em_ctl & EM_CTL_ALHD))
+			pi->flags |= ATA_FLAG_SW_ACTIVITY;
+	}
+}
+EXPORT_SYMBOL_GPL(ahci_set_em_messages);
+
+MODULE_AUTHOR("Jeff Garzik");
+MODULE_DESCRIPTION("Common AHCI SATA low-level routines");
+MODULE_LICENSE("GPL");