Merge branch 'acpi' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev

* 'acpi' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [PATCH] libata: wrong sizeof for BUFFER
  [PATCH] libata: change order of _SDD/_GTF execution (resend #3)
  [PATCH] libata: ACPI _SDD support
  [PATCH] libata: ACPI and _GTF support

1 files changed, 698 insertions, 0 deletions

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
new file mode 100644
index 000000000000..b4e8be5d292c
--- /dev/null
+++ b/drivers/ata/libata-acpi.c
@@ -0,0 +1,698 @@
+/*
+ * libata-acpi.c
+ * Provides ACPI support for PATA/SATA.
+ *
+ * Copyright (C) 2006 Intel Corp.
+ * Copyright (C) 2006 Randy Dunlap
+ */
+
+#include <linux/ata.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/libata.h>
+#include <linux/pci.h>
+#include "libata.h"
+
+#include <acpi/acpi_bus.h>
+#include <acpi/acnames.h>
+#include <acpi/acnamesp.h>
+#include <acpi/acparser.h>
+#include <acpi/acexcep.h>
+#include <acpi/acmacros.h>
+#include <acpi/actypes.h>
+
+#define SATA_ROOT_PORT(x)       (((x) >> 16) & 0xffff)
+#define SATA_PORT_NUMBER(x)     ((x) & 0xffff)  /* or NO_PORT_MULT */
+#define NO_PORT_MULT            0xffff
+#define SATA_ADR_RSVD           0xffffffff
+
+#define REGS_PER_GTF            7
+struct taskfile_array {
+        u8      tfa[REGS_PER_GTF];      /* regs. 0x1f1 - 0x1f7 */
+};
+
+
+/**
+ * sata_get_dev_handle - finds acpi_handle and PCI device.function
+ * @dev: device to locate
+ * @handle: returned acpi_handle for @dev
+ * @pcidevfn: return PCI device.func for @dev
+ *
+ * This function is somewhat SATA-specific.  Or at least the
+ * PATA & SATA versions of this function are different,
+ * so it's not entirely generic code.
+ *
+ * Returns 0 on success, <0 on error.
+ */
+static int sata_get_dev_handle(struct device *dev, acpi_handle *handle,
+                                        acpi_integer *pcidevfn)
+{
+        struct pci_dev  *pci_dev;
+        acpi_integer    addr;
+
+        pci_dev = to_pci_dev(dev);      /* NOTE: PCI-specific */
+        /* Please refer to the ACPI spec for the syntax of _ADR. */
+        addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
+        *pcidevfn = addr;
+        *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
+        if (!*handle)
+                return -ENODEV;
+        return 0;
+}
+
+/**
+ * pata_get_dev_handle - finds acpi_handle and PCI device.function
+ * @dev: device to locate
+ * @handle: returned acpi_handle for @dev
+ * @pcidevfn: return PCI device.func for @dev
+ *
+ * The PATA and SATA versions of this function are different.
+ *
+ * Returns 0 on success, <0 on error.
+ */
+static int pata_get_dev_handle(struct device *dev, acpi_handle *handle,
+                                acpi_integer *pcidevfn)
+{
+        unsigned int bus, devnum, func;
+        acpi_integer addr;
+        acpi_handle dev_handle, parent_handle;
+        struct acpi_buffer buffer = {.length = ACPI_ALLOCATE_BUFFER,
+                                        .pointer = NULL};
+        acpi_status status;
+        struct acpi_device_info *dinfo = NULL;
+        int ret = -ENODEV;
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        bus = pdev->bus->number;
+        devnum = PCI_SLOT(pdev->devfn);
+        func = PCI_FUNC(pdev->devfn);
+
+        dev_handle = DEVICE_ACPI_HANDLE(dev);
+        parent_handle = DEVICE_ACPI_HANDLE(dev->parent);
+
+        status = acpi_get_object_info(parent_handle, &buffer);
+        if (ACPI_FAILURE(status))
+                goto err;
+
+        dinfo = buffer.pointer;
+        if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
+            dinfo->address == bus) {
+                /* ACPI spec for _ADR for PCI bus: */
+                addr = (acpi_integer)(devnum << 16 | func);
+                *pcidevfn = addr;
+                *handle = dev_handle;
+        } else {
+                goto err;
+        }
+
+        if (!*handle)
+                goto err;
+        ret = 0;
+err:
+        kfree(dinfo);
+        return ret;
+}
+
+struct walk_info {              /* can be trimmed some */
+        struct device   *dev;
+        struct acpi_device *adev;
+        acpi_handle     handle;
+        acpi_integer    pcidevfn;
+        unsigned int    drivenum;
+        acpi_handle     obj_handle;
+        struct ata_port *ataport;
+        struct ata_device *atadev;
+        u32             sata_adr;
+        int             status;
+        char            basepath[ACPI_PATHNAME_MAX];
+        int             basepath_len;
+};
+
+static acpi_status get_devices(acpi_handle handle,
+                                u32 level, void *context, void **return_value)
+{
+        acpi_status             status;
+        struct walk_info        *winfo = context;
+        struct acpi_buffer      namebuf = {ACPI_ALLOCATE_BUFFER, NULL};
+        char                    *pathname;
+        struct acpi_buffer      buffer;
+        struct acpi_device_info *dinfo;
+
+        status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &namebuf);
+        if (status)
+                goto ret;
+        pathname = namebuf.pointer;
+
+        buffer.length = ACPI_ALLOCATE_BUFFER;
+        buffer.pointer = NULL;
+        status = acpi_get_object_info(handle, &buffer);
+        if (ACPI_FAILURE(status))
+                goto out2;
+
+        dinfo = buffer.pointer;
+
+        /* find full device path name for pcidevfn */
+        if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
+            dinfo->address == winfo->pcidevfn) {
+                if (ata_msg_probe(winfo->ataport))
+                        ata_dev_printk(winfo->atadev, KERN_DEBUG,
+                                ":%s: matches pcidevfn (0x%llx)\n",
+                                pathname, winfo->pcidevfn);
+                strlcpy(winfo->basepath, pathname,
+                        sizeof(winfo->basepath));
+                winfo->basepath_len = strlen(pathname);
+                goto out;
+        }
+
+        /* if basepath is not yet known, ignore this object */
+        if (!winfo->basepath_len)
+                goto out;
+
+        /* if this object is in scope of basepath, maybe use it */
+        if (strncmp(pathname, winfo->basepath,
+            winfo->basepath_len) == 0) {
+                if (!(dinfo->valid & ACPI_VALID_ADR))
+                        goto out;
+                if (ata_msg_probe(winfo->ataport))
+                        ata_dev_printk(winfo->atadev, KERN_DEBUG,
+                                "GOT ONE: (%s) root_port = 0x%llx,"
+                                " port_num = 0x%llx\n", pathname,
+                                SATA_ROOT_PORT(dinfo->address),
+                                SATA_PORT_NUMBER(dinfo->address));
+                /* heuristics: */
+                if (SATA_PORT_NUMBER(dinfo->address) != NO_PORT_MULT)
+                        if (ata_msg_probe(winfo->ataport))
+                                ata_dev_printk(winfo->atadev,
+                                        KERN_DEBUG, "warning: don't"
+                                        " know how to handle SATA port"
+                                        " multiplier\n");
+                if (SATA_ROOT_PORT(dinfo->address) ==
+                        winfo->ataport->port_no &&
+                    SATA_PORT_NUMBER(dinfo->address) == NO_PORT_MULT) {
+                        if (ata_msg_probe(winfo->ataport))
+                                ata_dev_printk(winfo->atadev,
+                                        KERN_DEBUG,
+                                        "THIS ^^^^^ is the requested"
+                                        " SATA drive (handle = 0x%p)\n",
+                                        handle);
+                        winfo->sata_adr = dinfo->address;
+                        winfo->obj_handle = handle;
+                }
+        }
+out:
+        kfree(dinfo);
+out2:
+        kfree(pathname);
+
+ret:
+        return status;
+}
+
+/* Get the SATA drive _ADR object. */
+static int get_sata_adr(struct device *dev, acpi_handle handle,
+                        acpi_integer pcidevfn, unsigned int drive,
+                        struct ata_port *ap,
+                        struct ata_device *atadev, u32 *dev_adr)
+{
+        acpi_status     status;
+        struct walk_info *winfo;
+        int             err = -ENOMEM;
+
+        winfo = kzalloc(sizeof(struct walk_info), GFP_KERNEL);
+        if (!winfo)
+                goto out;
+
+        winfo->dev = dev;
+        winfo->atadev = atadev;
+        winfo->ataport = ap;
+        if (acpi_bus_get_device(handle, &winfo->adev) < 0)
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(winfo->atadev, KERN_DEBUG,
+                                "acpi_bus_get_device failed\n");
+        winfo->handle = handle;
+        winfo->pcidevfn = pcidevfn;
+        winfo->drivenum = drive;
+
+        status = acpi_get_devices(NULL, get_devices, winfo, NULL);
+        if (ACPI_FAILURE(status)) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(winfo->atadev, KERN_DEBUG,
+                                "%s: acpi_get_devices failed\n",
+                                __FUNCTION__);
+                err = -ENODEV;
+        } else {
+                *dev_adr = winfo->sata_adr;
+                atadev->obj_handle = winfo->obj_handle;
+                err = 0;
+        }
+        kfree(winfo);
+out:
+        return err;
+}
+
+/**
+ * do_drive_get_GTF - get the drive bootup default taskfile settings
+ * @ap: the ata_port for the drive
+ * @ix: target ata_device (drive) index
+ * @gtf_length: number of bytes of _GTF data returned at @gtf_address
+ * @gtf_address: buffer containing _GTF taskfile arrays
+ *
+ * This applies to both PATA and SATA drives.
+ *
+ * The _GTF method has no input parameters.
+ * It returns a variable number of register set values (registers
+ * hex 1F1..1F7, taskfiles).
+ * The <variable number> is not known in advance, so have ACPI-CA
+ * allocate the buffer as needed and return it, then free it later.
+ *
+ * The returned @gtf_length and @gtf_address are only valid if the
+ * function return value is 0.
+ */
+static int do_drive_get_GTF(struct ata_port *ap, int ix,
+                        unsigned int *gtf_length, unsigned long *gtf_address,
+                        unsigned long *obj_loc)
+{
+        acpi_status                     status;
+        acpi_handle                     dev_handle = NULL;
+        acpi_handle                     chan_handle, drive_handle;
+        acpi_integer                    pcidevfn = 0;
+        u32                             dev_adr;
+        struct acpi_buffer              output;
+        union acpi_object               *out_obj;
+        struct device                   *dev = ap->host->dev;
+        struct ata_device               *atadev = &ap->device[ix];
+        int                             err = -ENODEV;
+
+        *gtf_length = 0;
+        *gtf_address = 0UL;
+        *obj_loc = 0UL;
+
+        if (noacpi)
+                return 0;
+
+        if (ata_msg_probe(ap))
+                ata_dev_printk(atadev, KERN_DEBUG,
+                        "%s: ENTER: ap->id: %d, port#: %d\n",
+                        __FUNCTION__, ap->id, ap->port_no);
+
+        if (!ata_dev_enabled(atadev) || (ap->flags & ATA_FLAG_DISABLED)) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG, "%s: ERR: "
+                                "ata_dev_present: %d, PORT_DISABLED: %lu\n",
+                                __FUNCTION__, ata_dev_enabled(atadev),
+                                ap->flags & ATA_FLAG_DISABLED);
+                goto out;
+        }
+
+        /* Don't continue if device has no _ADR method.
+         * _GTF is intended for known motherboard devices. */
+        if (!(ap->cbl == ATA_CBL_SATA)) {
+                err = pata_get_dev_handle(dev, &dev_handle, &pcidevfn);
+                if (err < 0) {
+                        if (ata_msg_probe(ap))
+                                ata_dev_printk(atadev, KERN_DEBUG,
+                                        "%s: pata_get_dev_handle failed (%d)\n",
+                                        __FUNCTION__, err);
+                        goto out;
+                }
+        } else {
+                err = sata_get_dev_handle(dev, &dev_handle, &pcidevfn);
+                if (err < 0) {
+                        if (ata_msg_probe(ap))
+                                ata_dev_printk(atadev, KERN_DEBUG,
+                                        "%s: sata_get_dev_handle failed (%d\n",
+                                        __FUNCTION__, err);
+                        goto out;
+                }
+        }
+
+        /* Get this drive's _ADR info. if not already known. */
+        if (!atadev->obj_handle) {
+                if (!(ap->cbl == ATA_CBL_SATA)) {
+                        /* get child objects of dev_handle == channel objects,
+                         * + _their_ children == drive objects */
+                        /* channel is ap->port_no */
+                        chan_handle = acpi_get_child(dev_handle,
+                                                ap->port_no);
+                        if (ata_msg_probe(ap))
+                                ata_dev_printk(atadev, KERN_DEBUG,
+                                        "%s: chan adr=%d: chan_handle=0x%p\n",
+                                        __FUNCTION__, ap->port_no,
+                                        chan_handle);
+                        if (!chan_handle) {
+                                err = -ENODEV;
+                                goto out;
+                        }
+                        /* TBD: could also check ACPI object VALID bits */
+                        drive_handle = acpi_get_child(chan_handle, ix);
+                        if (!drive_handle) {
+                                err = -ENODEV;
+                                goto out;
+                        }
+                        dev_adr = ix;
+                        atadev->obj_handle = drive_handle;
+                } else {        /* for SATA mode */
+                        dev_adr = SATA_ADR_RSVD;
+                        err = get_sata_adr(dev, dev_handle, pcidevfn, 0,
+                                        ap, atadev, &dev_adr);
+                }
+                if (err < 0 || dev_adr == SATA_ADR_RSVD ||
+                    !atadev->obj_handle) {
+                        if (ata_msg_probe(ap))
+                                ata_dev_printk(atadev, KERN_DEBUG,
+                                        "%s: get_sata/pata_adr failed: "
+                                        "err=%d, dev_adr=%u, obj_handle=0x%p\n",
+                                        __FUNCTION__, err, dev_adr,
+                                        atadev->obj_handle);
+                        goto out;
+                }
+        }
+
+        /* Setting up output buffer */
+        output.length = ACPI_ALLOCATE_BUFFER;
+        output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
+
+        /* _GTF has no input parameters */
+        err = -EIO;
+        status = acpi_evaluate_object(atadev->obj_handle, "_GTF",
+                                        NULL, &output);
+        if (ACPI_FAILURE(status)) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG,
+                                "%s: Run _GTF error: status = 0x%x\n",
+                                __FUNCTION__, status);
+                goto out;
+        }
+
+        if (!output.length || !output.pointer) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG, "%s: Run _GTF: "
+                                "length or ptr is NULL (0x%llx, 0x%p)\n",
+                                __FUNCTION__,
+                                (unsigned long long)output.length,
+                                output.pointer);
+                kfree(output.pointer);
+                goto out;
+        }
+
+        out_obj = output.pointer;
+        if (out_obj->type != ACPI_TYPE_BUFFER) {
+                kfree(output.pointer);
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG, "%s: Run _GTF: "
+                                "error: expected object type of "
+                                " ACPI_TYPE_BUFFER, got 0x%x\n",
+                                __FUNCTION__, out_obj->type);
+                err = -ENOENT;
+                goto out;
+        }
+
+        if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
+            out_obj->buffer.length % REGS_PER_GTF) {
+                if (ata_msg_drv(ap))
+                        ata_dev_printk(atadev, KERN_ERR,
+                                "%s: unexpected GTF length (%d) or addr (0x%p)\n",
+                                __FUNCTION__, out_obj->buffer.length,
+                                out_obj->buffer.pointer);
+                err = -ENOENT;
+                goto out;
+        }
+
+        *gtf_length = out_obj->buffer.length;
+        *gtf_address = (unsigned long)out_obj->buffer.pointer;
+        *obj_loc = (unsigned long)out_obj;
+        if (ata_msg_probe(ap))
+                ata_dev_printk(atadev, KERN_DEBUG, "%s: returning "
+                        "gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx\n",
+                        __FUNCTION__, *gtf_length, *gtf_address, *obj_loc);
+        err = 0;
+out:
+        return err;
+}
+
+/**
+ * taskfile_load_raw - send taskfile registers to host controller
+ * @ap: Port to which output is sent
+ * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
+ *
+ * Outputs ATA taskfile to standard ATA host controller using MMIO
+ * or PIO as indicated by the ATA_FLAG_MMIO flag.
+ * Writes the control, feature, nsect, lbal, lbam, and lbah registers.
+ * Optionally (ATA_TFLAG_LBA48) writes hob_feature, hob_nsect,
+ * hob_lbal, hob_lbam, and hob_lbah.
+ *
+ * This function waits for idle (!BUSY and !DRQ) after writing
+ * registers.  If the control register has a new value, this
+ * function also waits for idle after writing control and before
+ * writing the remaining registers.
+ *
+ * LOCKING: TBD:
+ * Inherited from caller.
+ */
+static void taskfile_load_raw(struct ata_port *ap,
+                                struct ata_device *atadev,
+                                const struct taskfile_array *gtf)
+{
+        if (ata_msg_probe(ap))
+                ata_dev_printk(atadev, KERN_DEBUG, "%s: (0x1f1-1f7): hex: "
+                        "%02x %02x %02x %02x %02x %02x %02x\n",
+                        __FUNCTION__,
+                        gtf->tfa[0], gtf->tfa[1], gtf->tfa[2],
+                        gtf->tfa[3], gtf->tfa[4], gtf->tfa[5], gtf->tfa[6]);
+
+        if ((gtf->tfa[0] == 0) && (gtf->tfa[1] == 0) && (gtf->tfa[2] == 0)
+            && (gtf->tfa[3] == 0) && (gtf->tfa[4] == 0) && (gtf->tfa[5] == 0)
+            && (gtf->tfa[6] == 0))
+                return;
+
+        if (ap->ops->qc_issue) {
+                struct ata_taskfile tf;
+                unsigned int err;
+
+                ata_tf_init(atadev, &tf);
+
+                /* convert gtf to tf */
+                tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; /* TBD */
+                tf.protocol = atadev->class == ATA_DEV_ATAPI ?
+                        ATA_PROT_ATAPI_NODATA : ATA_PROT_NODATA;
+                tf.feature = gtf->tfa[0];       /* 0x1f1 */
+                tf.nsect   = gtf->tfa[1];       /* 0x1f2 */
+                tf.lbal    = gtf->tfa[2];       /* 0x1f3 */
+                tf.lbam    = gtf->tfa[3];       /* 0x1f4 */
+                tf.lbah    = gtf->tfa[4];       /* 0x1f5 */
+                tf.device  = gtf->tfa[5];       /* 0x1f6 */
+                tf.command = gtf->tfa[6];       /* 0x1f7 */
+
+                err = ata_exec_internal(atadev, &tf, NULL, DMA_NONE, NULL, 0);
+                if (err && ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_ERR,
+                                "%s: ata_exec_internal failed: %u\n",
+                                __FUNCTION__, err);
+        } else
+                if (ata_msg_warn(ap))
+                        ata_dev_printk(atadev, KERN_WARNING,
+                                "%s: SATA driver is missing qc_issue function"
+                                " entry points\n",
+                                __FUNCTION__);
+}
+
+/**
+ * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
+ * @ap: the ata_port for the drive
+ * @atadev: target ata_device
+ * @gtf_length: total number of bytes of _GTF taskfiles
+ * @gtf_address: location of _GTF taskfile arrays
+ *
+ * This applies to both PATA and SATA drives.
+ *
+ * Write {gtf_address, length gtf_length} in groups of
+ * REGS_PER_GTF bytes.
+ */
+static int do_drive_set_taskfiles(struct ata_port *ap,
+                struct ata_device *atadev, unsigned int gtf_length,
+                unsigned long gtf_address)
+{
+        int                     err = -ENODEV;
+        int                     gtf_count = gtf_length / REGS_PER_GTF;
+        int                     ix;
+        struct taskfile_array   *gtf;
+
+        if (ata_msg_probe(ap))
+                ata_dev_printk(atadev, KERN_DEBUG,
+                        "%s: ENTER: ap->id: %d, port#: %d\n",
+                        __FUNCTION__, ap->id, ap->port_no);
+
+        if (noacpi || !(ap->cbl == ATA_CBL_SATA))
+                return 0;
+
+        if (!ata_dev_enabled(atadev) || (ap->flags & ATA_FLAG_DISABLED))
+                goto out;
+        if (!gtf_count)         /* shouldn't be here */
+                goto out;
+
+        if (gtf_length % REGS_PER_GTF) {
+                if (ata_msg_drv(ap))
+                        ata_dev_printk(atadev, KERN_ERR,
+                                "%s: unexpected GTF length (%d)\n",
+                                __FUNCTION__, gtf_length);
+                goto out;
+        }
+
+        for (ix = 0; ix < gtf_count; ix++) {
+                gtf = (struct taskfile_array *)
+                        (gtf_address + ix * REGS_PER_GTF);
+
+                /* send all TaskFile registers (0x1f1-0x1f7) *in*that*order* */
+                taskfile_load_raw(ap, atadev, gtf);
+        }
+
+        err = 0;
+out:
+        return err;
+}
+
+/**
+ * ata_acpi_exec_tfs - get then write drive taskfile settings
+ * @ap: the ata_port for the drive
+ *
+ * This applies to both PATA and SATA drives.
+ */
+int ata_acpi_exec_tfs(struct ata_port *ap)
+{
+        int             ix;
+        int             ret =0;
+        unsigned int    gtf_length;
+        unsigned long   gtf_address;
+        unsigned long   obj_loc;
+
+        if (noacpi)
+                return 0;
+
+        for (ix = 0; ix < ATA_MAX_DEVICES; ix++) {
+                if (!ata_dev_enabled(&ap->device[ix]))
+                        continue;
+
+                ret = do_drive_get_GTF(ap, ix,
+                                &gtf_length, &gtf_address, &obj_loc);
+                if (ret < 0) {
+                        if (ata_msg_probe(ap))
+                                ata_port_printk(ap, KERN_DEBUG,
+                                        "%s: get_GTF error (%d)\n",
+                                        __FUNCTION__, ret);
+                        break;
+                }
+
+                ret = do_drive_set_taskfiles(ap, &ap->device[ix],
+                                gtf_length, gtf_address);
+                kfree((void *)obj_loc);
+                if (ret < 0) {
+                        if (ata_msg_probe(ap))
+                                ata_port_printk(ap, KERN_DEBUG,
+                                        "%s: set_taskfiles error (%d)\n",
+                                        __FUNCTION__, ret);
+                        break;
+                }
+        }
+
+        return ret;
+}
+
+/**
+ * ata_acpi_push_id - send Identify data to drive
+ * @ap: the ata_port for the drive
+ * @ix: drive index
+ *
+ * _SDD ACPI object: for SATA mode only
+ * Must be after Identify (Packet) Device -- uses its data
+ * ATM this function never returns a failure.  It is an optional
+ * method and if it fails for whatever reason, we should still
+ * just keep going.
+ */
+int ata_acpi_push_id(struct ata_port *ap, unsigned int ix)
+{
+        acpi_handle                     handle;
+        acpi_integer                    pcidevfn;
+        int                             err;
+        struct device                   *dev = ap->host->dev;
+        struct ata_device               *atadev = &ap->device[ix];
+        u32                             dev_adr;
+        acpi_status                     status;
+        struct acpi_object_list         input;
+        union acpi_object               in_params[1];
+
+        if (noacpi)
+                return 0;
+
+        if (ata_msg_probe(ap))
+                ata_dev_printk(atadev, KERN_DEBUG,
+                        "%s: ap->id: %d, ix = %d, port#: %d\n",
+                        __FUNCTION__, ap->id, ix, ap->port_no);
+
+        /* Don't continue if not a SATA device. */
+        if (!(ap->cbl == ATA_CBL_SATA)) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG,
+                                "%s: Not a SATA device\n", __FUNCTION__);
+                goto out;
+        }
+
+        /* Don't continue if device has no _ADR method.
+         * _SDD is intended for known motherboard devices. */
+        err = sata_get_dev_handle(dev, &handle, &pcidevfn);
+        if (err < 0) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG,
+                                "%s: sata_get_dev_handle failed (%d\n",
+                                __FUNCTION__, err);
+                goto out;
+        }
+
+        /* Get this drive's _ADR info, if not already known */
+        if (!atadev->obj_handle) {
+                dev_adr = SATA_ADR_RSVD;
+                err = get_sata_adr(dev, handle, pcidevfn, ix, ap, atadev,
+                                        &dev_adr);
+                if (err < 0 || dev_adr == SATA_ADR_RSVD ||
+                        !atadev->obj_handle) {
+                        if (ata_msg_probe(ap))
+                                ata_dev_printk(atadev, KERN_DEBUG,
+                                        "%s: get_sata_adr failed: "
+                                        "err=%d, dev_adr=%u, obj_handle=0x%p\n",
+                                        __FUNCTION__, err, dev_adr,
+                                        atadev->obj_handle);
+                        goto out;
+                }
+        }
+
+        /* Give the drive Identify data to the drive via the _SDD method */
+        /* _SDD: set up input parameters */
+        input.count = 1;
+        input.pointer = in_params;
+        in_params[0].type = ACPI_TYPE_BUFFER;
+        in_params[0].buffer.length = sizeof(atadev->id[0]) * ATA_ID_WORDS;
+        in_params[0].buffer.pointer = (u8 *)atadev->id;
+        /* Output buffer: _SDD has no output */
+
+        /* It's OK for _SDD to be missing too. */
+        swap_buf_le16(atadev->id, ATA_ID_WORDS);
+        status = acpi_evaluate_object(atadev->obj_handle, "_SDD", &input, NULL);
+        swap_buf_le16(atadev->id, ATA_ID_WORDS);
+
+        err = ACPI_FAILURE(status) ? -EIO : 0;
+        if (err < 0) {
+                if (ata_msg_probe(ap))
+                        ata_dev_printk(atadev, KERN_DEBUG,
+                                "ata%u(%u): %s _SDD error: status = 0x%x\n",
+                                ap->id, ap->device->devno,
+                                __FUNCTION__, status);
+        }
+
+        /* always return success */
+out:
+        return 0;
+}
+
+