[libata] new driver acard_ahci, for ATP8620 host controller

Add support for Acard ATP8620 host controller.

Based upon initial version by Jeff Garzik.

Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

5 files changed, 545 insertions, 6 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 36e2319264bd..e3e0e95c7aa5 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -90,6 +90,14 @@ config SATA_INIC162X
 	help
 	  This option enables support for Initio 162x Serial ATA.
 
+config SATA_ACARD_AHCI
+	tristate "ACard AHCI variant (ATP 8620)"
+	depends on PCI
+	help
+	  This option enables support for Acard.
+
+	  If unsure, say N.
+
 config SATA_SIL24
 	tristate "Silicon Image 3124/3132 SATA support"
 	depends on PCI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 2b67c900a459..27291aad6ca7 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_ATA)		+= libata.o
 
 # non-SFF interface
 obj-$(CONFIG_SATA_AHCI)		+= ahci.o libahci.o
+obj-$(CONFIG_SATA_ACARD_AHCI)	+= acard-ahci.o libahci.o
 obj-$(CONFIG_SATA_AHCI_PLATFORM) += ahci_platform.o libahci.o
 obj-$(CONFIG_SATA_FSL)		+= sata_fsl.o
 obj-$(CONFIG_SATA_INIC162X)	+= sata_inic162x.o
diff --git a/drivers/ata/acard-ahci.c b/drivers/ata/acard-ahci.c
new file mode 100644
index 000000000000..339c210f03a6
--- /dev/null
+++ b/drivers/ata/acard-ahci.c
@@ -0,0 +1,528 @@
+
+/*
+ *  acard-ahci.c - ACard AHCI SATA support
+ *
+ *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
+ *		    Please ALWAYS copy linux-ide@vger.kernel.org
+ *		    on emails.
+ *
+ *  Copyright 2010 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/pci.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 <linux/dmi.h>
+#include <linux/gfp.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+#include <linux/libata.h>
+#include "ahci.h"
+
+#define DRV_NAME	"acard-ahci"
+#define DRV_VERSION	"1.0"
+
+/*
+  Received FIS structure limited to 80h.
+*/
+
+#define ACARD_AHCI_RX_FIS_SZ 128
+
+enum {
+	AHCI_PCI_BAR		= 5,
+};
+
+enum board_ids {
+	board_acard_ahci,
+};
+
+struct acard_sg {
+	__le32			addr;
+	__le32			addr_hi;
+	__le32			reserved;
+	__le32			size;	 /* bit 31 (EOT) max==0x10000 (64k) */
+};
+
+static void acard_ahci_qc_prep(struct ata_queued_cmd *qc);
+static bool acard_ahci_qc_fill_rtf(struct ata_queued_cmd *qc);
+static int acard_ahci_port_start(struct ata_port *ap);
+static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
+
+#ifdef CONFIG_PM
+static int acard_ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
+static int acard_ahci_pci_device_resume(struct pci_dev *pdev);
+#endif
+
+static struct scsi_host_template acard_ahci_sht = {
+	AHCI_SHT("acard-ahci"),
+};
+
+static struct ata_port_operations acard_ops = {
+	.inherits		= &ahci_ops,
+	.qc_prep		= acard_ahci_qc_prep,
+	.qc_fill_rtf		= acard_ahci_qc_fill_rtf,
+	.port_start             = acard_ahci_port_start,
+};
+
+#define AHCI_HFLAGS(flags)	.private_data	= (void *)(flags)
+
+static const struct ata_port_info acard_ahci_port_info[] = {
+	[board_acard_ahci] =
+	{
+		AHCI_HFLAGS	(AHCI_HFLAG_NO_NCQ),
+		.flags		= AHCI_FLAG_COMMON,
+		.pio_mask	= ATA_PIO4,
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &acard_ops,
+	},
+};
+
+static const struct pci_device_id acard_ahci_pci_tbl[] = {
+	/* ACard */
+	{ PCI_VDEVICE(ARTOP, 0x000d), board_acard_ahci }, /* ATP8620 */
+
+	{ }    /* terminate list */
+};
+
+static struct pci_driver acard_ahci_pci_driver = {
+	.name			= DRV_NAME,
+	.id_table		= acard_ahci_pci_tbl,
+	.probe			= acard_ahci_init_one,
+	.remove			= ata_pci_remove_one,
+#ifdef CONFIG_PM
+	.suspend		= acard_ahci_pci_device_suspend,
+	.resume			= acard_ahci_pci_device_resume,
+#endif
+};
+
+#ifdef CONFIG_PM
+static int acard_ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
+{
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	struct ahci_host_priv *hpriv = host->private_data;
+	void __iomem *mmio = hpriv->mmio;
+	u32 ctl;
+
+	if (mesg.event & PM_EVENT_SUSPEND &&
+	    hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "BIOS update required for suspend/resume\n");
+		return -EIO;
+	}
+
+	if (mesg.event & PM_EVENT_SLEEP) {
+		/* AHCI spec rev1.1 section 8.3.3:
+		 * Software must disable interrupts prior to requesting a
+		 * transition of the HBA to D3 state.
+		 */
+		ctl = readl(mmio + HOST_CTL);
+		ctl &= ~HOST_IRQ_EN;
+		writel(ctl, mmio + HOST_CTL);
+		readl(mmio + HOST_CTL); /* flush */
+	}
+
+	return ata_pci_device_suspend(pdev, mesg);
+}
+
+static int acard_ahci_pci_device_resume(struct pci_dev *pdev)
+{
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	int rc;
+
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
+
+	if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND) {
+		rc = ahci_reset_controller(host);
+		if (rc)
+			return rc;
+
+		ahci_init_controller(host);
+	}
+
+	ata_host_resume(host);
+
+	return 0;
+}
+#endif
+
+static int acard_ahci_configure_dma_masks(struct pci_dev *pdev, int using_dac)
+{
+	int rc;
+
+	if (using_dac &&
+	    !pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
+		rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
+		if (rc) {
+			rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+			if (rc) {
+				dev_printk(KERN_ERR, &pdev->dev,
+					   "64-bit DMA enable failed\n");
+				return rc;
+			}
+		}
+	} else {
+		rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (rc) {
+			dev_printk(KERN_ERR, &pdev->dev,
+				   "32-bit DMA enable failed\n");
+			return rc;
+		}
+		rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (rc) {
+			dev_printk(KERN_ERR, &pdev->dev,
+				   "32-bit consistent DMA enable failed\n");
+			return rc;
+		}
+	}
+	return 0;
+}
+
+static void acard_ahci_pci_print_info(struct ata_host *host)
+{
+	struct pci_dev *pdev = to_pci_dev(host->dev);
+	u16 cc;
+	const char *scc_s;
+
+	pci_read_config_word(pdev, 0x0a, &cc);
+	if (cc == PCI_CLASS_STORAGE_IDE)
+		scc_s = "IDE";
+	else if (cc == PCI_CLASS_STORAGE_SATA)
+		scc_s = "SATA";
+	else if (cc == PCI_CLASS_STORAGE_RAID)
+		scc_s = "RAID";
+	else
+		scc_s = "unknown";
+
+	ahci_print_info(host, scc_s);
+}
+
+static unsigned int acard_ahci_fill_sg(struct ata_queued_cmd *qc, void *cmd_tbl)
+{
+	struct scatterlist *sg;
+	struct acard_sg *acard_sg = cmd_tbl + AHCI_CMD_TBL_HDR_SZ;
+	unsigned int si, last_si = 0;
+
+	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);
+
+		/*
+		 * ACard note:
+		 * We must set an end-of-table (EOT) bit,
+		 * and the segment cannot exceed 64k (0x10000)
+		 */
+		acard_sg[si].addr = cpu_to_le32(addr & 0xffffffff);
+		acard_sg[si].addr_hi = cpu_to_le32((addr >> 16) >> 16);
+		acard_sg[si].size = cpu_to_le32(sg_len);
+		last_si = si;
+	}
+
+	acard_sg[last_si].size |= cpu_to_le32(1 << 31);	/* set EOT */
+
+	return si;
+}
+
+static void acard_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 = acard_ahci_fill_sg(qc, cmd_tbl);
+
+	/*
+	 * Fill in command slot information.
+	 *
+	 * ACard note: prd table length not filled in
+	 */
+	opts = cmd_fis_len | (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 bool acard_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 * ACARD_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 int acard_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 if (hpriv->flags & AHCI_HFLAG_YES_FBS) {
+			dev_printk(KERN_INFO, dev,
+				   "port %d can do FBS, forcing FBSCP\n",
+				   ap->port_no);
+			pp->fbs_supported = true;
+		} else
+			dev_printk(KERN_WARNING, 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 = ACARD_AHCI_RX_FIS_SZ * 16;
+	} else {
+		dma_sz = AHCI_PORT_PRIV_DMA_SZ;
+		rx_fis_sz = ACARD_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 int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	static int printed_version;
+	unsigned int board_id = ent->driver_data;
+	struct ata_port_info pi = acard_ahci_port_info[board_id];
+	const struct ata_port_info *ppi[] = { &pi, NULL };
+	struct device *dev = &pdev->dev;
+	struct ahci_host_priv *hpriv;
+	struct ata_host *host;
+	int n_ports, i, rc;
+
+	VPRINTK("ENTER\n");
+
+	WARN_ON(ATA_MAX_QUEUE > AHCI_MAX_CMDS);
+
+	if (!printed_version++)
+		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");
+
+	/* acquire resources */
+	rc = pcim_enable_device(pdev);
+	if (rc)
+		return rc;
+
+	/* AHCI controllers often implement SFF compatible interface.
+	 * Grab all PCI BARs just in case.
+	 */
+	rc = pcim_iomap_regions_request_all(pdev, 1 << AHCI_PCI_BAR, DRV_NAME);
+	if (rc == -EBUSY)
+		pcim_pin_device(pdev);
+	if (rc)
+		return rc;
+
+	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
+	if (!hpriv)
+		return -ENOMEM;
+	hpriv->flags |= (unsigned long)pi.private_data;
+
+	if (!(hpriv->flags & AHCI_HFLAG_NO_MSI))
+		pci_enable_msi(pdev);
+
+	hpriv->mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR];
+
+	/* save initial config */
+	ahci_save_initial_config(&pdev->dev, hpriv, 0, 0);
+
+	/* prepare host */
+	if (hpriv->cap & HOST_CAP_NCQ)
+		pi.flags |= ATA_FLAG_NCQ;
+
+	if (hpriv->cap & HOST_CAP_PMP)
+		pi.flags |= ATA_FLAG_PMP;
+
+	ahci_set_em_messages(hpriv, &pi);
+
+	/* CAP.NP sometimes indicate the index of the last enabled
+	 * port, at other times, that of the last possible port, so
+	 * determining the maximum port number requires looking at
+	 * both CAP.NP and port_map.
+	 */
+	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
+
+	host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
+	if (!host)
+		return -ENOMEM;
+	host->private_data = hpriv;
+
+	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
+		host->flags |= ATA_HOST_PARALLEL_SCAN;
+	else
+		printk(KERN_INFO "ahci: SSS flag set, parallel bus scan disabled\n");
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap = host->ports[i];
+
+		ata_port_pbar_desc(ap, AHCI_PCI_BAR, -1, "abar");
+		ata_port_pbar_desc(ap, AHCI_PCI_BAR,
+				   0x100 + ap->port_no * 0x80, "port");
+
+		/* set initial link pm policy */
+		/*
+		ap->pm_policy = NOT_AVAILABLE;
+		*/
+		/* disabled/not-implemented port */
+		if (!(hpriv->port_map & (1 << i)))
+			ap->ops = &ata_dummy_port_ops;
+	}
+
+	/* initialize adapter */
+	rc = acard_ahci_configure_dma_masks(pdev, hpriv->cap & HOST_CAP_64);
+	if (rc)
+		return rc;
+
+	rc = ahci_reset_controller(host);
+	if (rc)
+		return rc;
+
+	ahci_init_controller(host);
+	acard_ahci_pci_print_info(host);
+
+	pci_set_master(pdev);
+	return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED,
+				 &acard_ahci_sht);
+}
+
+static int __init acard_ahci_init(void)
+{
+	return pci_register_driver(&acard_ahci_pci_driver);
+}
+
+static void __exit acard_ahci_exit(void)
+{
+	pci_unregister_driver(&acard_ahci_pci_driver);
+}
+
+MODULE_AUTHOR("Jeff Garzik");
+MODULE_DESCRIPTION("ACard AHCI SATA low-level driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(pci, acard_ahci_pci_tbl);
+MODULE_VERSION(DRV_VERSION);
+
+module_init(acard_ahci_init);
+module_exit(acard_ahci_exit);
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 329cbbb91284..3e606c34f57b 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -311,6 +311,8 @@ extern struct device_attribute *ahci_sdev_attrs[];
 
 extern struct ata_port_operations ahci_ops;
 
+void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,
+			u32 opts);
 void ahci_save_initial_config(struct device *dev,
 			      struct ahci_host_priv *hpriv,
 			      unsigned int force_port_map,
@@ -326,6 +328,7 @@ int ahci_stop_engine(struct ata_port *ap);
 void ahci_start_engine(struct ata_port *ap);
 int ahci_check_ready(struct ata_link *link);
 int ahci_kick_engine(struct ata_port *ap);
+int ahci_port_resume(struct ata_port *ap);
 void ahci_set_em_messages(struct ahci_host_priv *hpriv,
 			  struct ata_port_info *pi);
 int ahci_reset_em(struct ata_host *host);
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index ebc08d65b3dd..26d452339e98 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -87,10 +87,7 @@ static int ahci_hardreset(struct ata_link *link, unsigned int *class,
 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
@@ -1133,8 +1130,8 @@ static unsigned int ahci_dev_classify(struct ata_port *ap)
 	return ata_dev_classify(&tf);
 }
 
-static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,
-			       u32 opts)
+void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,
+			u32 opts)
 {
 	dma_addr_t cmd_tbl_dma;
 
@@ -1145,6 +1142,7 @@ static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, unsigned int tag,
 	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)
 {
@@ -1918,7 +1916,7 @@ static void ahci_pmp_detach(struct ata_port *ap)
 	writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
 }
 
-static int ahci_port_resume(struct ata_port *ap)
+int ahci_port_resume(struct ata_port *ap)
 {
 	ahci_power_up(ap);
 	ahci_start_port(ap);
@@ -1930,6 +1928,7 @@ static int ahci_port_resume(struct ata_port *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)