]> git.karo-electronics.de Git - linux-beck.git/commitdiff
[libata] new driver acard_ahci, for ATP8620 host controller
authorDavid Milburn <dmilburn@redhat.com>
Fri, 12 Nov 2010 21:38:21 +0000 (15:38 -0600)
committerJeff Garzik <jgarzik@redhat.com>
Thu, 6 Jan 2011 00:43:22 +0000 (19:43 -0500)
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>
drivers/ata/Kconfig
drivers/ata/Makefile
drivers/ata/acard-ahci.c [new file with mode: 0644]
drivers/ata/ahci.h
drivers/ata/libahci.c

index 36e2319264bd33d7918979105a4f641da36d3dcd..e3e0e95c7aa5c55b4ce04d95da625acfef7a4385 100644 (file)
@@ -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
index 2b67c900a459865c694e0cf012ebcacbfd8f76bd..27291aad6ca7f5a022aefef220adeaa8f1865f8c 100644 (file)
@@ -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 (file)
index 0000000..339c210
--- /dev/null
@@ -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);
index 329cbbb91284ad4dd3b7e4f486ea82f2737ae1b3..3e606c34f57ba58af87ab7014e51cc32d2f5d67b 100644 (file)
@@ -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);
index ebc08d65b3dd04c9af94da0d7146d3a165ce9803..26d452339e98f59fc483cbc85e9c53f56b2a0183 100644 (file)
@@ -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)