Initial import

1 files changed, 2551 insertions, 0 deletions

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
new file mode 100644
index 000000000..e948e2147
--- /dev/null
+++ b/drivers/ata/libahci.c
@@ -0,0 +1,2551 @@
+/*
+ *  libahci.c - Common AHCI SATA low-level routines
+ *
+ *  Maintained by:  Tejun Heo <tj@kernel.org>
+ *    		    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/gfp.h>
+#include <linux/module.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"
+#include "libata.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_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+			unsigned hints);
+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 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_set_aggressive_devslp(struct ata_port *ap, bool sleep);
+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_pmp_retry_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_post_internal_cmd(struct ata_queued_cmd *qc);
+static void ahci_dev_config(struct ata_device *dev);
+#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 ssize_t ahci_read_em_buffer(struct device *dev,
+				   struct device_attribute *attr, char *buf);
+static ssize_t ahci_store_em_buffer(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size);
+static ssize_t ahci_show_em_supported(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 DEVICE_ATTR(em_buffer, S_IWUSR | S_IRUGO,
+		   ahci_read_em_buffer, ahci_store_em_buffer);
+static DEVICE_ATTR(em_message_supported, S_IRUGO, ahci_show_em_supported, NULL);
+
+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,
+	&dev_attr_em_buffer,
+	&dev_attr_em_message_supported,
+	NULL
+};
+EXPORT_SYMBOL_GPL(ahci_shost_attrs);
+
+struct device_attribute *ahci_sdev_attrs[] = {
+	&dev_attr_sw_activity,
+	&dev_attr_unload_heads,
+	NULL
+};
+EXPORT_SYMBOL_GPL(ahci_sdev_attrs);
+
+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,
+
+	.set_lpm		= ahci_set_lpm,
+	.em_show		= ahci_led_show,
+	.em_store		= ahci_led_store,
+	.sw_activity_show	= ahci_activity_show,
+	.sw_activity_store	= ahci_activity_store,
+	.transmit_led_message	= ahci_transmit_led_message,
+#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);
+
+struct ata_port_operations ahci_pmp_retry_srst_ops = {
+	.inherits		= &ahci_ops,
+	.softreset		= ahci_pmp_retry_softreset,
+};
+EXPORT_SYMBOL_GPL(ahci_pmp_retry_srst_ops);
+
+static bool ahci_em_messages __read_mostly = true;
+EXPORT_SYMBOL_GPL(ahci_em_messages);
+module_param(ahci_em_messages, bool, 0444);
+/* add other LED protocol types when they become supported */
+MODULE_PARM_DESC(ahci_em_messages,
+	"AHCI Enclosure Management Message control (0 = off, 1 = on)");
+
+/* device sleep idle timeout in ms */
+static int devslp_idle_timeout __read_mostly = 1000;
+module_param(devslp_idle_timeout, int, 0644);
+MODULE_PARM_DESC(devslp_idle_timeout, "device sleep idle timeout");
+
+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));
+}
+
+static ssize_t ahci_read_em_buffer(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;
+	void __iomem *em_mmio = mmio + hpriv->em_loc;
+	u32 em_ctl, msg;
+	unsigned long flags;
+	size_t count;
+	int i;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	em_ctl = readl(mmio + HOST_EM_CTL);
+	if (!(ap->flags & ATA_FLAG_EM) || em_ctl & EM_CTL_XMT ||
+	    !(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO)) {
+		spin_unlock_irqrestore(ap->lock, flags);
+		return -EINVAL;
+	}
+
+	if (!(em_ctl & EM_CTL_MR)) {
+		spin_unlock_irqrestore(ap->lock, flags);
+		return -EAGAIN;
+	}
+
+	if (!(em_ctl & EM_CTL_SMB))
+		em_mmio += hpriv->em_buf_sz;
+
+	count = hpriv->em_buf_sz;
+
+	/* the count should not be larger than PAGE_SIZE */
+	if (count > PAGE_SIZE) {
+		if (printk_ratelimit())
+			ata_port_warn(ap,
+				      "EM read buffer size too large: "
+				      "buffer size %u, page size %lu\n",
+				      hpriv->em_buf_sz, PAGE_SIZE);
+		count = PAGE_SIZE;
+	}
+
+	for (i = 0; i < count; i += 4) {
+		msg = readl(em_mmio + i);
+		buf[i] = msg & 0xff;
+		buf[i + 1] = (msg >> 8) & 0xff;
+		buf[i + 2] = (msg >> 16) & 0xff;
+		buf[i + 3] = (msg >> 24) & 0xff;
+	}
+
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	return i;
+}
+
+static ssize_t ahci_store_em_buffer(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size)
+{
+	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;
+	void __iomem *em_mmio = mmio + hpriv->em_loc;
+	const unsigned char *msg_buf = buf;
+	u32 em_ctl, msg;
+	unsigned long flags;
+	int i;
+
+	/* check size validity */
+	if (!(ap->flags & ATA_FLAG_EM) ||
+	    !(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO) ||
+	    size % 4 || size > hpriv->em_buf_sz)
+		return -EINVAL;
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	em_ctl = readl(mmio + HOST_EM_CTL);
+	if (em_ctl & EM_CTL_TM) {
+		spin_unlock_irqrestore(ap->lock, flags);
+		return -EBUSY;
+	}
+
+	for (i = 0; i < size; i += 4) {
+		msg = msg_buf[i] | msg_buf[i + 1] << 8 |
+		      msg_buf[i + 2] << 16 | msg_buf[i + 3] << 24;
+		writel(msg, em_mmio + i);
+	}
+
+	writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	return size;
+}
+
+static ssize_t ahci_show_em_supported(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;
+	u32 em_ctl;
+
+	em_ctl = readl(mmio + HOST_EM_CTL);
+
+	return sprintf(buf, "%s%s%s%s\n",
+		       em_ctl & EM_CTL_LED ? "led " : "",
+		       em_ctl & EM_CTL_SAFTE ? "saf-te " : "",
+		       em_ctl & EM_CTL_SES ? "ses-2 " : "",
+		       em_ctl & EM_CTL_SGPIO ? "sgpio " : "");
+}
+
+/**
+ *	ahci_save_initial_config - Save and fixup initial config values
+ *	@dev: target AHCI device
+ *	@hpriv: host private area to store config values
+ *
+ *	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.
+ *
+ *	If it is not set already this function sets hpriv->start_engine to
+ *	ahci_start_engine.
+ *
+ *	LOCKING:
+ *	None.
+ */
+void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
+{
+	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_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_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_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_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_info(dev,
+			 "controller can't do SNTF, turning off CAP_SNTF\n");
+		cap &= ~HOST_CAP_SNTF;
+	}
+
+	if ((cap2 & HOST_CAP2_SDS) && (hpriv->flags & AHCI_HFLAG_NO_DEVSLP)) {
+		dev_info(dev,
+			 "controller can't do DEVSLP, turning off\n");
+		cap2 &= ~HOST_CAP2_SDS;
+		cap2 &= ~HOST_CAP2_SADM;
+	}
+
+	if (!(cap & HOST_CAP_FBS) && (hpriv->flags & AHCI_HFLAG_YES_FBS)) {
+		dev_info(dev, "controller can do FBS, turning on CAP_FBS\n");
+		cap |= HOST_CAP_FBS;
+	}
+
+	if ((cap & HOST_CAP_FBS) && (hpriv->flags & AHCI_HFLAG_NO_FBS)) {
+		dev_info(dev, "controller can't do FBS, turning off CAP_FBS\n");
+		cap &= ~HOST_CAP_FBS;
+	}
+
+	if (hpriv->force_port_map && port_map != hpriv->force_port_map) {
+		dev_info(dev, "forcing port_map 0x%x -> 0x%x\n",
+			 port_map, hpriv->force_port_map);
+		port_map = hpriv->force_port_map;
+	}
+
+	if (hpriv->mask_port_map) {
+		dev_warn(dev, "masking port_map 0x%x -> 0x%x\n",
+			port_map,
+			port_map & hpriv->mask_port_map);
+		port_map &= hpriv->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_warn(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_warn(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;
+
+	if (!hpriv->start_engine)
+		hpriv->start_engine = ahci_start_engine;
+}
+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(ap, 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);
+
+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);
+}
+EXPORT_SYMBOL_GPL(ahci_start_fis_rx);
+
+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(ap, 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 int ahci_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+			unsigned int hints)
+{
+	struct ata_port *ap = link->ap;
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *ppriv = ap->private_data;
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+
+	if (policy != ATA_LPM_MAX_POWER) {
+		/*
+		 * Disable interrupts on Phy Ready. This keeps us from
+		 * getting woken up due to spurious phy ready
+		 * interrupts.
+		 */
+		pp->intr_mask &= ~PORT_IRQ_PHYRDY;
+		writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+		sata_link_scr_lpm(link, policy, false);
+	}
+
+	if (hpriv->cap & HOST_CAP_ALPM) {
+		u32 cmd = readl(port_mmio + PORT_CMD);
+		cmd &= ~(PORT_CMD_ASP | PORT_CMD_ALPE);
+
+		if (policy == ATA_LPM_MAX_POWER || !(hints & ATA_LPM_HIPM)) {
+			cmd |= PORT_CMD_ICC_ACTIVE;
+
+			writel(cmd, port_mmio + PORT_CMD);
+			readl(port_mmio + PORT_CMD);
+
+			/* wait 10ms to be sure we've come out of LPM state */
+			ata_msleep(ap, 10);
+		} else if (policy == ATA_LPM_FIRMWARE_DEFAULTS) {
+			if (ppriv->init_alpe)
+				cmd |= PORT_CMD_ALPE;
+			if (ppriv->init_asp)
+				cmd |= PORT_CMD_ASP;
+
+			writel(cmd, port_mmio + PORT_CMD);
+		} else {
+			cmd |= PORT_CMD_ALPE;
+			if (policy == ATA_LPM_MIN_POWER)
+				cmd |= PORT_CMD_ASP;
+
+			/* write out new cmd value */
+			writel(cmd, port_mmio + PORT_CMD);
+		}
+	}
+
+	/* set aggressive device sleep */
+	if ((hpriv->cap2 & HOST_CAP2_SDS) &&
+	    (hpriv->cap2 & HOST_CAP2_SADM) &&
+	    (link->device->flags & ATA_DFLAG_DEVSLP)) {
+		switch (policy) {
+		case ATA_LPM_MIN_POWER:
+			ahci_set_aggressive_devslp(ap, true);
+			break;
+		case ATA_LPM_FIRMWARE_DEFAULTS:
+			ahci_set_aggressive_devslp(ap, ppriv->init_devslp);
+			break;
+		default:
+			ahci_set_aggressive_devslp(ap, false);
+			break;
+		}
+	}
+
+	if (policy == ATA_LPM_MAX_POWER) {
+		sata_link_scr_lpm(link, policy, false);
+
+		/* turn PHYRDY IRQ back on */
+		pp->intr_mask |= PORT_IRQ_PHYRDY;
+		writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+	}
+
+	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_host_priv *hpriv = ap->host->private_data;
+	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 */
+	if (!(hpriv->flags & AHCI_HFLAG_DELAY_ENGINE))
+		hpriv->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 = ap->ops->transmit_led_message(ap,
+							       emp->led_state,
+							       4);
+				/*
+				 * If busy, give a breather but do not
+				 * release EH ownership by using msleep()
+				 * instead of ata_msleep().  EM Transmit
+				 * bit is busy for the whole host and
+				 * releasing ownership will cause other
+				 * ports to fail the same way.
+				 */
+				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(NULL, mmio + HOST_CTL, HOST_RESET,
+					HOST_RESET, 10, 1000);
+
+		if (tmp & HOST_RESET) {
+			dev_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_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);
+	ap->ops->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;
+	}
+
+	if (hpriv->em_msg_type & EM_MSG_TYPE_LED) {
+		/*
+		 * 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);
+
+		/*
+		 * tell hardware to transmit the message
+		 */
+		writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+	}
+
+	/* save off new led state for port/slot */
+	emp->led_state = state;
+
+	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)
+{
+	unsigned int state;
+	int pmp;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct ahci_em_priv *emp;
+
+	if (kstrtouint(buf, 0, &state) < 0)
+		return -EINVAL;
+
+	/* 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 ap->ops->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));
+		ap->ops->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 */
+			ap->ops->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_info(dev,
+			     "SB600 AHCI: limiting to 255 sectors per cmd\n");
+	}
+}
+
+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);
+}
+EXPORT_SYMBOL_GPL(ahci_dev_classify);
+
+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);
+}
+EXPORT_SYMBOL_GPL(ahci_fill_cmd_slot);
+
+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(ap, port_mmio + PORT_CMD,
+				PORT_CMD_CLO, PORT_CMD_CLO, 1, 500);
+	if (tmp & PORT_CMD_CLO)
+		rc = -EIO;
+
+	/* restart engine */
+ out_restart:
+	hpriv->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(ap, 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;
+	struct ahci_port_priv *pp = ap->private_data;
+	const char *reason = NULL;
+	unsigned long now, msecs;
+	struct ata_taskfile tf;
+	bool fbs_disabled = false;
+	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_warn(link, "failed to reset engine (errno=%d)\n", rc);
+
+	/*
+	 * According to AHCI-1.2 9.3.9: if FBS is enable, software shall
+	 * clear PxFBS.EN to '0' prior to issuing software reset to devices
+	 * that is attached to port multiplier.
+	 */
+	if (!ata_is_host_link(link) && pp->fbs_enabled) {
+		ahci_disable_fbs(ap);
+		fbs_disabled = true;
+	}
+
+	ata_tf_init(link->device, &tf);
+
+	/* issue the first D2H Register FIS */
+	msecs = 0;
+	now = jiffies;
+	if (time_after(deadline, now))
+		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 */
+	ata_msleep(ap, 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_info(link, "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);
+
+	/* re-enable FBS if disabled before */
+	if (fbs_disabled)
+		ahci_enable_fbs(ap);
+
+	DPRINTK("EXIT, class=%u\n", *class);
+	return 0;
+
+ fail:
+	ata_link_err(link, "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_bad_pmp_check_ready(struct ata_link *link)
+{
+	void __iomem *port_mmio = ahci_port_base(link->ap);
+	u8 status = readl(port_mmio + PORT_TFDATA) & 0xFF;
+	u32 irq_status = readl(port_mmio + PORT_IRQ_STAT);
+
+	/*
+	 * There is no need to check TFDATA if BAD PMP is found due to HW bug,
+	 * which can save timeout delay.
+	 */
+	if (irq_status & PORT_IRQ_BAD_PMP)
+		return -EIO;
+
+	return ata_check_ready(status);
+}
+
+static int ahci_pmp_retry_softreset(struct ata_link *link, unsigned int *class,
+				    unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	int pmp = sata_srst_pmp(link);
+	int rc;
+	u32 irq_sts;
+
+	DPRINTK("ENTER\n");
+
+	rc = ahci_do_softreset(link, class, pmp, deadline,
+			       ahci_bad_pmp_check_ready);
+
+	/*
+	 * Soft reset fails with IPMS set when PMP is enabled but
+	 * SATA HDD/ODD is connected to SATA port, do soft reset
+	 * again to port 0.
+	 */
+	if (rc == -EIO) {
+		irq_sts = readl(port_mmio + PORT_IRQ_STAT);
+		if (irq_sts & PORT_IRQ_BAD_PMP) {
+			ata_link_warn(link,
+					"applying PMP SRST workaround "
+					"and retrying\n");
+			rc = ahci_do_softreset(link, class, 0, deadline,
+					       ahci_check_ready);
+		}
+	}
+
+	return rc;
+}
+
+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;
+	struct ahci_host_priv *hpriv = ap->host->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 = ATA_BUSY;
+	ata_tf_to_fis(&tf, 0, 0, d2h_fis);
+
+	rc = sata_link_hardreset(link, timing, deadline, &online,
+				 ahci_check_ready);
+
+	hpriv->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_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)) {
+			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 = 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_handle_port_interrupt(struct ata_port *ap,
+				       void __iomem *port_mmio, u32 status)
+{
+	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 qc_active = 0;
+	int rc;
+
+	/* ignore BAD_PMP while resetting */
+	if (unlikely(resetting))
+		status &= ~PORT_IRQ_BAD_PMP;
+
+	if (sata_lpm_ignore_phy_events(&ap->link)) {
+		status &= ~PORT_IRQ_PHYRDY;
+		ahci_scr_write(&ap->link, SCR_ERROR, SERR_PHYRDY_CHG);
+	}
+
+	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);
+	}
+}
+
+static void ahci_port_intr(struct ata_port *ap)
+{
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 status;
+
+	status = readl(port_mmio + PORT_IRQ_STAT);
+	writel(status, port_mmio + PORT_IRQ_STAT);
+
+	ahci_handle_port_interrupt(ap, port_mmio, status);
+}
+
+static irqreturn_t ahci_port_thread_fn(int irq, void *dev_instance)
+{
+	struct ata_port *ap = dev_instance;
+	struct ahci_port_priv *pp = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	u32 status;
+
+	status = atomic_xchg(&pp->intr_status, 0);
+	if (!status)
+		return IRQ_NONE;
+
+	spin_lock_bh(ap->lock);
+	ahci_handle_port_interrupt(ap, port_mmio, status);
+	spin_unlock_bh(ap->lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ahci_multi_irqs_intr(int irq, void *dev_instance)
+{
+	struct ata_port *ap = dev_instance;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ahci_port_priv *pp = ap->private_data;
+	u32 status;
+
+	VPRINTK("ENTER\n");
+
+	status = readl(port_mmio + PORT_IRQ_STAT);
+	writel(status, port_mmio + PORT_IRQ_STAT);
+
+	atomic_or(status, &pp->intr_status);
+
+	VPRINTK("EXIT\n");
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t ahci_single_irq_intr(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_warn(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);
+}
+
+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;
+}
+EXPORT_SYMBOL_GPL(ahci_qc_issue);
+
+static bool ahci_qc_fill_rtf(struct ata_queued_cmd *qc)
+{
+	struct ahci_port_priv *pp = qc->ap->private_data;
+	u8 *rx_fis = pp->rx_fis;
+
+	if (pp->fbs_enabled)
+		rx_fis += qc->dev->link->pmp * AHCI_RX_FIS_SZ;
+
+	/*
+	 * After a successful execution of an ATA PIO data-in command,
+	 * the device doesn't send D2H Reg FIS to update the TF and
+	 * the host should take TF and E_Status from the preceding PIO
+	 * Setup FIS.
+	 */
+	if (qc->tf.protocol == ATA_PROT_PIO && qc->dma_dir == DMA_FROM_DEVICE &&
+	    !(qc->flags & ATA_QCFLAG_FAILED)) {
+		ata_tf_from_fis(rx_fis + RX_FIS_PIO_SETUP, &qc->result_tf);
+		qc->result_tf.command = (rx_fis + RX_FIS_PIO_SETUP)[15];
+	} else
+		ata_tf_from_fis(rx_fis + RX_FIS_D2H_REG, &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);
+}
+
+void ahci_error_handler(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+
+	if (!(ap->pflags & ATA_PFLAG_FROZEN)) {
+		/* restart engine */
+		ahci_stop_engine(ap);
+		hpriv->start_engine(ap);
+	}
+
+	sata_pmp_error_handler(ap);
+
+	if (!ata_dev_enabled(ap->link.device))
+		ahci_stop_engine(ap);
+}
+EXPORT_SYMBOL_GPL(ahci_error_handler);
+
+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_set_aggressive_devslp(struct ata_port *ap, bool sleep)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *ppriv = ap->private_data;
+	void __iomem *port_mmio = ahci_port_base(ap);
+	struct ata_device *dev = ap->link.device;
+	u32 devslp, dm, dito, mdat, deto;
+	int rc;
+	unsigned int err_mask;
+
+	devslp = readl(port_mmio + PORT_DEVSLP);
+	if (!(devslp & PORT_DEVSLP_DSP)) {
+		dev_info(ap->host->dev, "port does not support device sleep\n");
+		return;
+	}
+
+	/* disable device sleep */
+	if (!sleep) {
+		if (devslp & PORT_DEVSLP_ADSE) {
+			writel(devslp & ~PORT_DEVSLP_ADSE,
+			       port_mmio + PORT_DEVSLP);
+			err_mask = ata_dev_set_feature(dev,
+						       SETFEATURES_SATA_DISABLE,
+						       SATA_DEVSLP);
+			if (err_mask && err_mask != AC_ERR_DEV)
+				ata_dev_warn(dev, "failed to disable DEVSLP\n");
+		}
+		return;
+	}
+
+	/* device sleep was already enabled */
+	if (devslp & PORT_DEVSLP_ADSE)
+		return;
+
+	/* set DITO, MDAT, DETO and enable DevSlp, need to stop engine first */
+	rc = ahci_stop_engine(ap);
+	if (rc)
+		return;
+
+	if (ppriv->init_devslp) {
+		dito = ppriv->init_dito;
+		deto = ppriv->init_deto;
+		mdat = ppriv->init_mdat;
+	} else {
+		dm = (devslp & PORT_DEVSLP_DM_MASK) >> PORT_DEVSLP_DM_OFFSET;
+		dito = devslp_idle_timeout / (dm + 1);
+		if (dito > 0x3ff)
+			dito = 0x3ff;
+
+		/* Use the nominal value 10 ms if the read MDAT is zero,
+		 * the nominal value of DETO is 20 ms.
+		 */
+		if (dev->devslp_timing[ATA_LOG_DEVSLP_VALID] &
+		    ATA_LOG_DEVSLP_VALID_MASK) {
+			mdat = dev->devslp_timing[ATA_LOG_DEVSLP_MDAT] &
+				ATA_LOG_DEVSLP_MDAT_MASK;
+			if (!mdat)
+				mdat = 10;
+			deto = dev->devslp_timing[ATA_LOG_DEVSLP_DETO];
+			if (!deto)
+				deto = 20;
+		} else {
+			mdat = 10;
+			deto = 20;
+		}
+	}
+
+	devslp |= ((dito << PORT_DEVSLP_DITO_OFFSET) |
+		   (mdat << PORT_DEVSLP_MDAT_OFFSET) |
+		   (deto << PORT_DEVSLP_DETO_OFFSET) |
+		   PORT_DEVSLP_ADSE);
+	writel(devslp, port_mmio + PORT_DEVSLP);
+
+	hpriv->start_engine(ap);
+
+	/* enable device sleep feature for the drive */
+	err_mask = ata_dev_set_feature(dev,
+				       SETFEATURES_SATA_ENABLE,
+				       SATA_DEVSLP);
+	if (err_mask && err_mask != AC_ERR_DEV)
+		ata_dev_warn(dev, "failed to enable DEVSLP\n");
+}
+
+static void ahci_enable_fbs(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	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_info(ap->host->dev, "FBS is enabled\n");
+		pp->fbs_enabled = true;
+		pp->fbs_last_dev = -1; /* initialization */
+	} else
+		dev_err(ap->host->dev, "Failed to enable FBS\n");
+
+	hpriv->start_engine(ap);
+}
+
+static void ahci_disable_fbs(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	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_err(ap->host->dev, "Failed to disable FBS\n");
+	else {
+		dev_info(ap->host->dev, "FBS is disabled\n");
+		pp->fbs_enabled = false;
+	}
+
+	hpriv->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;
+
+	/*
+	 * We must not change the port interrupt mask register if the
+	 * port is marked frozen, the value in pp->intr_mask will be
+	 * restored later when the port is thawed.
+	 *
+	 * Note that during initialization, the port is marked as
+	 * frozen since the irq handler is not yet registered.
+	 */
+	if (!(ap->pflags & ATA_PFLAG_FROZEN))
+		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;
+
+	/* see comment above in ahci_pmp_attach() */
+	if (!(ap->pflags & ATA_PFLAG_FROZEN))
+		writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+}
+
+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;
+}
+EXPORT_SYMBOL_GPL(ahci_port_resume);
+
+#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_err(ap, "%s (%d)\n", emsg, rc);
+		ata_port_freeze(ap);
+	}
+
+	return rc;
+}
+#endif
+
+/*
+ * Allocate port privdata and read back initial power management configuration
+ */
+int ahci_setup_port_privdata(struct ata_port *ap)
+{
+	struct ahci_port_priv *pp;
+	u32 cmd, devslp;
+	void __iomem *port_mmio = ahci_port_base(ap);
+
+	pp = kzalloc(sizeof(*pp), GFP_KERNEL);
+	if (!pp)
+		return -ENOMEM;
+
+	ap->private_data = pp;
+
+	cmd = readl(port_mmio + PORT_CMD);
+
+	if (cmd & PORT_CMD_ALPE)
+		pp->init_alpe = true;
+
+	if (cmd & PORT_CMD_ASP)
+		pp->init_asp = true;
+
+	devslp = readl(port_mmio + PORT_DEVSLP);
+
+	/* devslp unsupported or disabled */
+	if (!(devslp & PORT_DEVSLP_DSP) || !(devslp & PORT_DEVSLP_ADSE))
+		return 0;
+
+	pp->init_devslp = true;
+	pp->init_dito = (devslp >> PORT_DEVSLP_DITO_OFFSET) & 0x3ff;
+	pp->init_deto = (devslp >> PORT_DEVSLP_DETO_OFFSET) & 0xff;
+	pp->init_mdat = (devslp >> PORT_DEVSLP_MDAT_OFFSET) & 0x1f;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ahci_setup_port_privdata);
+
+static int ahci_port_start(struct ata_port *ap)
+{
+	struct ahci_host_priv *hpriv = ap->host->private_data;
+	struct ahci_port_priv *pp = ap->private_data;
+	struct device *dev = ap->host->dev;
+	void *mem;
+	dma_addr_t mem_dma;
+	size_t dma_sz, rx_fis_sz;
+
+	if (ap->host->n_ports > 1) {
+		pp->irq_desc = devm_kzalloc(dev, 8, GFP_KERNEL);
+		if (!pp->irq_desc) {
+			devm_kfree(dev, pp);
+			return -ENOMEM;
+		}
+		snprintf(pp->irq_desc, 8,
+			 "%s%d", dev_driver_string(dev), ap->port_no);
+	}
+
+	/* 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 if (hpriv->flags & AHCI_HFLAG_YES_FBS) {
+			dev_info(dev, "port %d can do FBS, forcing FBSCP\n",
+				 ap->port_no);
+			pp->fbs_supported = true;
+		} else
+			dev_warn(dev, "port %d is not capable of FBS\n",
+				 ap->port_no);
+	}
+
+	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;
+
+	/*
+	 * Switch to per-port locking in case each port has its own MSI vector.
+	 */
+	if ((hpriv->flags & AHCI_HFLAG_MULTI_MSI)) {
+		spin_lock_init(&pp->lock);
+		ap->lock = &pp->lock;
+	}
+
+	/* 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_warn(ap, "%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%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_DESO ? "deso " : "",
+		cap2 & HOST_CAP2_SADM ? "sadm " : "",
+		cap2 & HOST_CAP2_SDS ? "sds " : "",
+		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;
+
+	if (messages) {
+		/* store em_loc */
+		hpriv->em_loc = ((em_loc >> 16) * 4);
+		hpriv->em_buf_sz = ((em_loc & 0xff) * 4);
+		hpriv->em_msg_type = messages;
+		pi->flags |= ATA_FLAG_EM;
+		if (!(em_ctl & EM_CTL_ALHD))
+			pi->flags |= ATA_FLAG_SW_ACTIVITY;
+	}
+}
+EXPORT_SYMBOL_GPL(ahci_set_em_messages);
+
+static int ahci_host_activate_multi_irqs(struct ata_host *host, int irq,
+					 struct scsi_host_template *sht)
+{
+	int i, rc;
+
+	rc = ata_host_start(host);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ahci_port_priv *pp = host->ports[i]->private_data;
+
+		/* Do not receive interrupts sent by dummy ports */
+		if (!pp) {
+			disable_irq(irq + i);
+			continue;
+		}
+
+		rc = devm_request_threaded_irq(host->dev, irq + i,
+					       ahci_multi_irqs_intr,
+					       ahci_port_thread_fn, IRQF_SHARED,
+					       pp->irq_desc, host->ports[i]);
+		if (rc)
+			goto out_free_irqs;
+	}
+
+	for (i = 0; i < host->n_ports; i++)
+		ata_port_desc(host->ports[i], "irq %d", irq + i);
+
+	rc = ata_host_register(host, sht);
+	if (rc)
+		goto out_free_all_irqs;
+
+	return 0;
+
+out_free_all_irqs:
+	i = host->n_ports;
+out_free_irqs:
+	for (i--; i >= 0; i--)
+		devm_free_irq(host->dev, irq + i, host->ports[i]);
+
+	return rc;
+}
+
+/**
+ *	ahci_host_activate - start AHCI host, request IRQs and register it
+ *	@host: target ATA host
+ *	@irq: base IRQ number to request
+ *	@sht: scsi_host_template to use when registering the host
+ *
+ *	Similar to ata_host_activate, but requests IRQs according to AHCI-1.1
+ *	when multiple MSIs were allocated. That is one MSI per port, starting
+ *	from @irq.
+ *
+ *	LOCKING:
+ *	Inherited from calling layer (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int ahci_host_activate(struct ata_host *host, int irq,
+		       struct scsi_host_template *sht)
+{
+	struct ahci_host_priv *hpriv = host->private_data;
+	int rc;
+
+	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI)
+		rc = ahci_host_activate_multi_irqs(host, irq, sht);
+	else
+		rc = ata_host_activate(host, irq, ahci_single_irq_intr,
+				       IRQF_SHARED, sht);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_host_activate);
+
+MODULE_AUTHOR("Jeff Garzik");
+MODULE_DESCRIPTION("Common AHCI SATA low-level routines");
+MODULE_LICENSE("GPL");