6 files changed, 770 insertions, 0 deletions

diff --git a/drivers/ide/Kconfig b/drivers/ide/Kconfig
index 0e511ca50b84..ec03341d2bd8 100644
--- a/drivers/ide/Kconfig
+++ b/drivers/ide/Kconfig
@@ -271,6 +271,13 @@ config BLK_DEV_IDESCSI
           If both this SCSI emulation and native ATAPI support are compiled
           into the kernel, the native support will be used.
 
+config BLK_DEV_IDEACPI
+        bool "IDE ACPI support"
+        depends on ACPI
+        ---help---
+          Implement ACPI support for generic IDE devices. On modern
+          machines ACPI support is required to properly handle ACPI S3 states.
+
 config IDE_TASK_IOCTL
         bool "IDE Taskfile Access"
         help
diff --git a/drivers/ide/Makefile b/drivers/ide/Makefile
index 569fae717503..d9f029e8ff74 100644
--- a/drivers/ide/Makefile
+++ b/drivers/ide/Makefile
@@ -22,6 +22,7 @@ ide-core-$(CONFIG_BLK_DEV_IDEPCI)	+= setup-pci.o
 ide-core-$(CONFIG_BLK_DEV_IDEDMA)       += ide-dma.o
 ide-core-$(CONFIG_PROC_FS)              += ide-proc.o
 ide-core-$(CONFIG_BLK_DEV_IDEPNP)       += ide-pnp.o
+ide-core-$(CONFIG_BLK_DEV_IDEACPI)      += ide-acpi.o
 
 # built-in only drivers from arm/
 ide-core-$(CONFIG_IDE_ARM)              += arm/ide_arm.o
diff --git a/drivers/ide/ide-acpi.c b/drivers/ide/ide-acpi.c
new file mode 100644
index 000000000000..1eb734951dc9
--- /dev/null
+++ b/drivers/ide/ide-acpi.c
@@ -0,0 +1,696 @@
+/*
+ * ide-acpi.c
+ * Provides ACPI support for IDE drives.
+ *
+ * Copyright (C) 2005 Intel Corp.
+ * Copyright (C) 2005 Randy Dunlap
+ * Copyright (C) 2006 SUSE Linux Products GmbH
+ * Copyright (C) 2006 Hannes Reinecke
+ */
+
+#include <linux/ata.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <acpi/acpi.h>
+#include <linux/ide.h>
+#include <linux/pci.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 REGS_PER_GTF            7
+struct taskfile_array {
+        u8      tfa[REGS_PER_GTF];      /* regs. 0x1f1 - 0x1f7 */
+};
+
+struct GTM_buffer {
+        u32     PIO_speed0;
+        u32     DMA_speed0;
+        u32     PIO_speed1;
+        u32     DMA_speed1;
+        u32     GTM_flags;
+};
+
+struct ide_acpi_drive_link {
+        ide_drive_t     *drive;
+        acpi_handle      obj_handle;
+        u8               idbuff[512];
+};
+
+struct ide_acpi_hwif_link {
+        ide_hwif_t                      *hwif;
+        acpi_handle                      obj_handle;
+        struct GTM_buffer                gtm;
+        struct ide_acpi_drive_link       master;
+        struct ide_acpi_drive_link       slave;
+};
+
+#undef DEBUGGING
+/* note: adds function name and KERN_DEBUG */
+#ifdef DEBUGGING
+#define DEBPRINT(fmt, args...)  \
+                printk(KERN_DEBUG "%s: " fmt, __FUNCTION__, ## args)
+#else
+#define DEBPRINT(fmt, args...)  do {} while (0)
+#endif  /* DEBUGGING */
+
+extern int ide_noacpi;
+extern int ide_noacpitfs;
+extern int ide_noacpionboot;
+
+/**
+ * ide_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
+ *
+ * Returns the ACPI object handle to the corresponding PCI device.
+ *
+ * Returns 0 on success, <0 on error.
+ */
+static int ide_get_dev_handle(struct device *dev, acpi_handle *handle,
+                               acpi_integer *pcidevfn)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        unsigned int bus, devnum, func;
+        acpi_integer addr;
+        acpi_handle dev_handle;
+        struct acpi_buffer buffer = {.length = ACPI_ALLOCATE_BUFFER,
+                                        .pointer = NULL};
+        acpi_status status;
+        struct acpi_device_info *dinfo = NULL;
+        int ret = -ENODEV;
+
+        bus = pdev->bus->number;
+        devnum = PCI_SLOT(pdev->devfn);
+        func = PCI_FUNC(pdev->devfn);
+        /* ACPI _ADR encoding for PCI bus: */
+        addr = (acpi_integer)(devnum << 16 | func);
+
+        DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);
+
+        dev_handle = DEVICE_ACPI_HANDLE(dev);
+        if (!dev_handle) {
+                DEBPRINT("no acpi handle for device\n");
+                goto err;
+        }
+
+        status = acpi_get_object_info(dev_handle, &buffer);
+        if (ACPI_FAILURE(status)) {
+                DEBPRINT("get_object_info for device failed\n");
+                goto err;
+        }
+        dinfo = buffer.pointer;
+        if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
+            dinfo->address == addr) {
+                *pcidevfn = addr;
+                *handle = dev_handle;
+        } else {
+                DEBPRINT("get_object_info for device has wrong "
+                        " address: %llu, should be %u\n",
+                        dinfo ? (unsigned long long)dinfo->address : -1ULL,
+                        (unsigned int)addr);
+                goto err;
+        }
+
+        DEBPRINT("for dev=0x%x.%x, addr=0x%llx, *handle=0x%p\n",
+                 devnum, func, (unsigned long long)addr, *handle);
+        ret = 0;
+err:
+        kfree(dinfo);
+        return ret;
+}
+
+/**
+ * ide_acpi_hwif_get_handle - Get ACPI object handle for a given hwif
+ * @hwif: device to locate
+ *
+ * Retrieves the object handle for a given hwif.
+ *
+ * Returns handle on success, 0 on error.
+ */
+static acpi_handle ide_acpi_hwif_get_handle(ide_hwif_t *hwif)
+{
+        struct device           *dev = hwif->gendev.parent;
+        acpi_handle             dev_handle;
+        acpi_integer            pcidevfn;
+        acpi_handle             chan_handle;
+        int                     err;
+
+        DEBPRINT("ENTER: device %s\n", hwif->name);
+
+        if (!dev) {
+                DEBPRINT("no PCI device for %s\n", hwif->name);
+                return NULL;
+        }
+
+        err = ide_get_dev_handle(dev, &dev_handle, &pcidevfn);
+        if (err < 0) {
+                DEBPRINT("ide_get_dev_handle failed (%d)\n", err);
+                return NULL;
+        }
+
+        /* get child objects of dev_handle == channel objects,
+         * + _their_ children == drive objects */
+        /* channel is hwif->channel */
+        chan_handle = acpi_get_child(dev_handle, hwif->channel);
+        DEBPRINT("chan adr=%d: handle=0x%p\n",
+                 hwif->channel, chan_handle);
+
+        return chan_handle;
+}
+
+/**
+ * ide_acpi_drive_get_handle - Get ACPI object handle for a given drive
+ * @drive: device to locate
+ *
+ * Retrieves the object handle of a given drive. According to the ACPI
+ * spec the drive is a child of the hwif.
+ *
+ * Returns handle on success, 0 on error.
+ */
+static acpi_handle ide_acpi_drive_get_handle(ide_drive_t *drive)
+{
+        ide_hwif_t      *hwif = HWIF(drive);
+        int              port;
+        acpi_handle      drive_handle;
+
+        if (!hwif->acpidata)
+                return NULL;
+
+        if (!hwif->acpidata->obj_handle)
+                return NULL;
+
+        port = hwif->channel ? drive->dn - 2: drive->dn;
+
+        DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
+                 drive->name, hwif->channel, port);
+
+
+        /* TBD: could also check ACPI object VALID bits */
+        drive_handle = acpi_get_child(hwif->acpidata->obj_handle, port);
+        DEBPRINT("drive %s handle 0x%p\n", drive->name, drive_handle);
+
+        return drive_handle;
+}
+
+/**
+ * do_drive_get_GTF - get the drive bootup default taskfile settings
+ * @drive: the drive for which the taskfile settings should be retrieved
+ * @gtf_length: number of bytes of _GTF data returned at @gtf_address
+ * @gtf_address: buffer containing _GTF taskfile arrays
+ *
+ * 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(ide_drive_t *drive,
+                     unsigned int *gtf_length, unsigned long *gtf_address,
+                     unsigned long *obj_loc)
+{
+        acpi_status                     status;
+        struct acpi_buffer              output;
+        union acpi_object               *out_obj;
+        ide_hwif_t                      *hwif = HWIF(drive);
+        struct device                   *dev = hwif->gendev.parent;
+        int                             err = -ENODEV;
+        int                             port;
+
+        *gtf_length = 0;
+        *gtf_address = 0UL;
+        *obj_loc = 0UL;
+
+        if (ide_noacpi)
+                return 0;
+
+        if (!dev) {
+                DEBPRINT("no PCI device for %s\n", hwif->name);
+                goto out;
+        }
+
+        if (!hwif->acpidata) {
+                DEBPRINT("no ACPI data for %s\n", hwif->name);
+                goto out;
+        }
+
+        port = hwif->channel ? drive->dn - 2: drive->dn;
+
+        if (!drive->acpidata) {
+                if (port == 0) {
+                        drive->acpidata = &hwif->acpidata->master;
+                        hwif->acpidata->master.drive = drive;
+                } else {
+                        drive->acpidata = &hwif->acpidata->slave;
+                        hwif->acpidata->slave.drive = drive;
+                }
+        }
+
+        DEBPRINT("ENTER: %s at %s, port#: %d, hard_port#: %d\n",
+                 hwif->name, dev->bus_id, port, hwif->channel);
+
+        if (!drive->present) {
+                DEBPRINT("%s drive %d:%d not present\n",
+                         hwif->name, hwif->channel, port);
+                goto out;
+        }
+
+        /* Get this drive's _ADR info. if not already known. */
+        if (!drive->acpidata->obj_handle) {
+                drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
+                if (!drive->acpidata->obj_handle) {
+                        DEBPRINT("No ACPI object found for %s\n",
+                                 drive->name);
+                        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(drive->acpidata->obj_handle, "_GTF",
+                                      NULL, &output);
+        if (ACPI_FAILURE(status)) {
+                printk(KERN_DEBUG
+                       "%s: Run _GTF error: status = 0x%x\n",
+                       __FUNCTION__, status);
+                goto out;
+        }
+
+        if (!output.length || !output.pointer) {
+                DEBPRINT("Run _GTF: "
+                       "length or ptr is NULL (0x%llx, 0x%p)\n",
+                       (unsigned long long)output.length,
+                       output.pointer);
+                goto out;
+        }
+
+        out_obj = output.pointer;
+        if (out_obj->type != ACPI_TYPE_BUFFER) {
+                DEBPRINT("Run _GTF: error: "
+                       "expected object type of ACPI_TYPE_BUFFER, "
+                       "got 0x%x\n", out_obj->type);
+                err = -ENOENT;
+                kfree(output.pointer);
+                goto out;
+        }
+
+        if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
+            out_obj->buffer.length % REGS_PER_GTF) {
+                printk(KERN_ERR
+                       "%s: unexpected GTF length (%d) or addr (0x%p)\n",
+                       __FUNCTION__, out_obj->buffer.length,
+                       out_obj->buffer.pointer);
+                err = -ENOENT;
+                kfree(output.pointer);
+                goto out;
+        }
+
+        *gtf_length = out_obj->buffer.length;
+        *gtf_address = (unsigned long)out_obj->buffer.pointer;
+        *obj_loc = (unsigned long)out_obj;
+        DEBPRINT("returning gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx\n",
+                 *gtf_length, *gtf_address, *obj_loc);
+        err = 0;
+out:
+        return err;
+}
+
+/**
+ * taskfile_load_raw - send taskfile registers to drive
+ * @drive: drive to which output is sent
+ * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
+ *
+ * Outputs IDE taskfile to the drive.
+ */
+static int taskfile_load_raw(ide_drive_t *drive,
+                              const struct taskfile_array *gtf)
+{
+        ide_task_t args;
+        int err = 0;
+
+        DEBPRINT("(0x1f1-1f7): hex: "
+               "%02x %02x %02x %02x %02x %02x %02x\n",
+               gtf->tfa[0], gtf->tfa[1], gtf->tfa[2],
+               gtf->tfa[3], gtf->tfa[4], gtf->tfa[5], gtf->tfa[6]);
+
+        memset(&args, 0, sizeof(ide_task_t));
+        args.command_type = IDE_DRIVE_TASK_NO_DATA;
+        args.data_phase   = TASKFILE_IN;
+        args.handler      = &task_no_data_intr;
+
+        /* convert gtf to IDE Taskfile */
+        args.tfRegister[1] = gtf->tfa[0];       /* 0x1f1 */
+        args.tfRegister[2] = gtf->tfa[1];       /* 0x1f2 */
+        args.tfRegister[3] = gtf->tfa[2];       /* 0x1f3 */
+        args.tfRegister[4] = gtf->tfa[3];       /* 0x1f4 */
+        args.tfRegister[5] = gtf->tfa[4];       /* 0x1f5 */
+        args.tfRegister[6] = gtf->tfa[5];       /* 0x1f6 */
+        args.tfRegister[7] = gtf->tfa[6];       /* 0x1f7 */
+
+        if (ide_noacpitfs) {
+                DEBPRINT("_GTF execution disabled\n");
+                return err;
+        }
+
+        err = ide_raw_taskfile(drive, &args, NULL);
+        if (err)
+                printk(KERN_ERR "%s: ide_raw_taskfile failed: %u\n",
+                       __FUNCTION__, err);
+
+        return err;
+}
+
+/**
+ * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
+ * @drive: the drive to which the taskfile command should be sent
+ * @gtf_length: total number of bytes of _GTF taskfiles
+ * @gtf_address: location of _GTF taskfile arrays
+ *
+ * Write {gtf_address, length gtf_length} in groups of
+ * REGS_PER_GTF bytes.
+ */
+static int do_drive_set_taskfiles(ide_drive_t *drive,
+                                  unsigned int gtf_length,
+                                  unsigned long gtf_address)
+{
+        int                     rc = -ENODEV, err;
+        int                     gtf_count = gtf_length / REGS_PER_GTF;
+        int                     ix;
+        struct taskfile_array   *gtf;
+
+        if (ide_noacpi)
+                return 0;
+
+        DEBPRINT("ENTER: %s, hard_port#: %d\n", drive->name, drive->dn);
+
+        if (!drive->present)
+                goto out;
+        if (!gtf_count)         /* shouldn't be here */
+                goto out;
+
+        DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
+                 gtf_length, gtf_length, gtf_count, gtf_address);
+
+        if (gtf_length % REGS_PER_GTF) {
+                printk(KERN_ERR "%s: unexpected GTF length (%d)\n",
+                       __FUNCTION__, gtf_length);
+                goto out;
+        }
+
+        rc = 0;
+        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* */
+                err = taskfile_load_raw(drive, gtf);
+                if (err)
+                        rc = err;
+        }
+
+out:
+        return rc;
+}
+
+/**
+ * ide_acpi_exec_tfs - get then write drive taskfile settings
+ * @drive: the drive for which the taskfile settings should be
+ *         written.
+ *
+ * According to the ACPI spec this should be called after _STM
+ * has been evaluated for the interface. Some ACPI vendors interpret
+ * that as a hard requirement and modify the taskfile according
+ * to the Identify Drive information passed down with _STM.
+ * So one should really make sure to call this only after _STM has
+ * been executed.
+ */
+int ide_acpi_exec_tfs(ide_drive_t *drive)
+{
+        int             ret;
+        unsigned int    gtf_length;
+        unsigned long   gtf_address;
+        unsigned long   obj_loc;
+
+        if (ide_noacpi)
+                return 0;
+
+        DEBPRINT("call get_GTF, drive=%s port=%d\n", drive->name, drive->dn);
+
+        ret = do_drive_get_GTF(drive, &gtf_length, &gtf_address, &obj_loc);
+        if (ret < 0) {
+                DEBPRINT("get_GTF error (%d)\n", ret);
+                return ret;
+        }
+
+        DEBPRINT("call set_taskfiles, drive=%s\n", drive->name);
+
+        ret = do_drive_set_taskfiles(drive, gtf_length, gtf_address);
+        kfree((void *)obj_loc);
+        if (ret < 0) {
+                DEBPRINT("set_taskfiles error (%d)\n", ret);
+        }
+
+        DEBPRINT("ret=%d\n", ret);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(ide_acpi_exec_tfs);
+
+/**
+ * ide_acpi_get_timing - get the channel (controller) timings
+ * @hwif: target IDE interface (channel)
+ *
+ * This function executes the _GTM ACPI method for the target channel.
+ *
+ */
+void ide_acpi_get_timing(ide_hwif_t *hwif)
+{
+        acpi_status             status;
+        struct acpi_buffer      output;
+        union acpi_object       *out_obj;
+
+        if (ide_noacpi)
+                return;
+
+        DEBPRINT("ENTER:\n");
+
+        if (!hwif->acpidata) {
+                DEBPRINT("no ACPI data for %s\n", hwif->name);
+                return;
+        }
+
+        /* Setting up output buffer for _GTM */
+        output.length = ACPI_ALLOCATE_BUFFER;
+        output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
+
+        /* _GTM has no input parameters */
+        status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_GTM",
+                                      NULL, &output);
+
+        DEBPRINT("_GTM status: %d, outptr: 0x%p, outlen: 0x%llx\n",
+                 status, output.pointer,
+                 (unsigned long long)output.length);
+
+        if (ACPI_FAILURE(status)) {
+                DEBPRINT("Run _GTM error: status = 0x%x\n", status);
+                return;
+        }
+
+        if (!output.length || !output.pointer) {
+                DEBPRINT("Run _GTM: length or ptr is NULL (0x%llx, 0x%p)\n",
+                       (unsigned long long)output.length,
+                       output.pointer);
+                kfree(output.pointer);
+                return;
+        }
+
+        out_obj = output.pointer;
+        if (out_obj->type != ACPI_TYPE_BUFFER) {
+                kfree(output.pointer);
+                DEBPRINT("Run _GTM: error: "
+                       "expected object type of ACPI_TYPE_BUFFER, "
+                       "got 0x%x\n", out_obj->type);
+                return;
+        }
+
+        if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
+            out_obj->buffer.length != sizeof(struct GTM_buffer)) {
+                kfree(output.pointer);
+                printk(KERN_ERR
+                       "%s: unexpected _GTM length (0x%x)[should be 0x%x] or addr (0x%p)\n",
+                       __FUNCTION__, out_obj->buffer.length,
+                       sizeof(struct GTM_buffer), out_obj->buffer.pointer);
+                return;
+        }
+
+        memcpy(&hwif->acpidata->gtm, out_obj->buffer.pointer,
+               sizeof(struct GTM_buffer));
+
+        DEBPRINT("_GTM info: ptr: 0x%p, len: 0x%x, exp.len: 0x%Zx\n",
+                 out_obj->buffer.pointer, out_obj->buffer.length,
+                 sizeof(struct GTM_buffer));
+
+        DEBPRINT("_GTM fields: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
+                 hwif->acpidata->gtm.PIO_speed0,
+                 hwif->acpidata->gtm.DMA_speed0,
+                 hwif->acpidata->gtm.PIO_speed1,
+                 hwif->acpidata->gtm.DMA_speed1,
+                 hwif->acpidata->gtm.GTM_flags);
+
+        kfree(output.pointer);
+}
+EXPORT_SYMBOL_GPL(ide_acpi_get_timing);
+
+/**
+ * ide_acpi_push_timing - set the channel (controller) timings
+ * @hwif: target IDE interface (channel)
+ *
+ * This function executes the _STM ACPI method for the target channel.
+ *
+ * _STM requires Identify Drive data, which has to passed as an argument.
+ * Unfortunately hd_driveid is a mangled version which we can't readily
+ * use; hence we'll get the information afresh.
+ */
+void ide_acpi_push_timing(ide_hwif_t *hwif)
+{
+        acpi_status             status;
+        struct acpi_object_list input;
+        union acpi_object       in_params[3];
+        struct ide_acpi_drive_link      *master = &hwif->acpidata->master;
+        struct ide_acpi_drive_link      *slave = &hwif->acpidata->slave;
+
+        if (ide_noacpi)
+                return;
+
+        DEBPRINT("ENTER:\n");
+
+        if (!hwif->acpidata) {
+                DEBPRINT("no ACPI data for %s\n", hwif->name);
+                return;
+        }
+
+        /* Give the GTM buffer + drive Identify data to the channel via the
+         * _STM method: */
+        /* setup input parameters buffer for _STM */
+        input.count = 3;
+        input.pointer = in_params;
+        in_params[0].type = ACPI_TYPE_BUFFER;
+        in_params[0].buffer.length = sizeof(struct GTM_buffer);
+        in_params[0].buffer.pointer = (u8 *)&hwif->acpidata->gtm;
+        in_params[1].type = ACPI_TYPE_BUFFER;
+        in_params[1].buffer.length = sizeof(struct hd_driveid);
+        in_params[1].buffer.pointer = (u8 *)&master->idbuff;
+        in_params[2].type = ACPI_TYPE_BUFFER;
+        in_params[2].buffer.length = sizeof(struct hd_driveid);
+        in_params[2].buffer.pointer = (u8 *)&slave->idbuff;
+        /* Output buffer: _STM has no output */
+
+        status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_STM",
+                                      &input, NULL);
+
+        if (ACPI_FAILURE(status)) {
+                DEBPRINT("Run _STM error: status = 0x%x\n", status);
+        }
+        DEBPRINT("_STM status: %d\n", status);
+}
+EXPORT_SYMBOL_GPL(ide_acpi_push_timing);
+
+/**
+ * ide_acpi_init - initialize the ACPI link for an IDE interface
+ * @hwif: target IDE interface (channel)
+ *
+ * The ACPI spec is not quite clear when the drive identify buffer
+ * should be obtained. Calling IDENTIFY DEVICE during shutdown
+ * is not the best of ideas as the drive might already being put to
+ * sleep. And obviously we can't call it during resume.
+ * So we get the information during startup; but this means that
+ * any changes during run-time will be lost after resume.
+ */
+void ide_acpi_init(ide_hwif_t *hwif)
+{
+        int unit;
+        int                     err;
+        struct ide_acpi_drive_link      *master;
+        struct ide_acpi_drive_link      *slave;
+
+        hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
+        if (!hwif->acpidata)
+                return;
+
+        hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
+        if (!hwif->acpidata->obj_handle) {
+                DEBPRINT("no ACPI object for %s found\n", hwif->name);
+                kfree(hwif->acpidata);
+                hwif->acpidata = NULL;
+                return;
+        }
+
+        /*
+         * The ACPI spec mandates that we send information
+         * for both drives, regardless whether they are connected
+         * or not.
+         */
+        hwif->acpidata->master.drive = &hwif->drives[0];
+        hwif->drives[0].acpidata = &hwif->acpidata->master;
+        master = &hwif->acpidata->master;
+
+        hwif->acpidata->slave.drive = &hwif->drives[1];
+        hwif->drives[1].acpidata = &hwif->acpidata->slave;
+        slave = &hwif->acpidata->slave;
+
+
+        /*
+         * Send IDENTIFY for each drive
+         */
+        if (master->drive->present) {
+                err = taskfile_lib_get_identify(master->drive, master->idbuff);
+                if (err) {
+                        DEBPRINT("identify device %s failed (%d)\n",
+                                 master->drive->name, err);
+                }
+        }
+
+        if (slave->drive->present) {
+                err = taskfile_lib_get_identify(slave->drive, slave->idbuff);
+                if (err) {
+                        DEBPRINT("identify device %s failed (%d)\n",
+                                 slave->drive->name, err);
+                }
+        }
+
+        if (ide_noacpionboot) {
+                DEBPRINT("ACPI methods disabled on boot\n");
+                return;
+        }
+
+        /*
+         * ACPI requires us to call _STM on startup
+         */
+        ide_acpi_get_timing(hwif);
+        ide_acpi_push_timing(hwif);
+
+        for (unit = 0; unit < MAX_DRIVES; ++unit) {
+                ide_drive_t *drive = &hwif->drives[unit];
+
+                if (drive->present) {
+                        /* Execute ACPI startup code */
+                        ide_acpi_exec_tfs(drive);
+                }
+        }
+}
+EXPORT_SYMBOL_GPL(ide_acpi_init);
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 5a5c565a32a8..176bbc850d6b 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1384,6 +1384,9 @@ static int hwif_init(ide_hwif_t *hwif)
 
 done:
         init_gendisk(hwif);
+
+        ide_acpi_init(hwif);
+
         hwif->present = 1;      /* success */
         return 1;
 
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 6c9bd5165bdb..c750f6ce770a 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -187,6 +187,12 @@ int noautodma = 1;
 
 EXPORT_SYMBOL(noautodma);
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+int ide_noacpi = 0;
+int ide_noacpitfs = 1;
+int ide_noacpionboot = 1;
+#endif
+
 /*
  * This is declared extern in ide.h, for access by other IDE modules:
  */
@@ -1214,10 +1220,15 @@ EXPORT_SYMBOL(system_bus_clock);
 static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 {
         ide_drive_t *drive = dev->driver_data;
+        ide_hwif_t *hwif = HWIF(drive);
         struct request rq;
         struct request_pm_state rqpm;
         ide_task_t args;
 
+        /* Call ACPI _GTM only once */
+        if (!(drive->dn % 2))
+                ide_acpi_get_timing(hwif);
+
         memset(&rq, 0, sizeof(rq));
         memset(&rqpm, 0, sizeof(rqpm));
         memset(&args, 0, sizeof(args));
@@ -1235,10 +1246,17 @@ static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 static int generic_ide_resume(struct device *dev)
 {
         ide_drive_t *drive = dev->driver_data;
+        ide_hwif_t *hwif = HWIF(drive);
         struct request rq;
         struct request_pm_state rqpm;
         ide_task_t args;
 
+        /* Call ACPI _STM only once */
+        if (!(drive->dn % 2))
+                ide_acpi_push_timing(hwif);
+
+        ide_acpi_exec_tfs(drive);
+
         memset(&rq, 0, sizeof(rq));
         memset(&rqpm, 0, sizeof(rqpm));
         memset(&args, 0, sizeof(args));
@@ -1543,6 +1561,24 @@ static int __init ide_setup(char *s)
         }
 #endif /* CONFIG_BLK_DEV_IDEPCI */
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+        if (!strcmp(s, "ide=noacpi")) {
+                //printk(" : Disable IDE ACPI support.\n");
+                ide_noacpi = 1;
+                return 1;
+        }
+        if (!strcmp(s, "ide=acpigtf")) {
+                //printk(" : Enable IDE ACPI _GTF support.\n");
+                ide_noacpitfs = 0;
+                return 1;
+        }
+        if (!strcmp(s, "ide=acpionboot")) {
+                //printk(" : Call IDE ACPI methods on boot.\n");
+                ide_noacpionboot = 0;
+                return 1;
+        }
+#endif /* CONFIG_BLK_DEV_IDEACPI */
+
         /*
          * Look for drive options:  "hdx="
          */
diff --git a/include/linux/ide.h b/include/linux/ide.h
index e26a03981a94..ba1c92999f6e 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -18,6 +18,9 @@
 #include <linux/device.h>
 #include <linux/pci.h>
 #include <linux/completion.h>
+#ifdef CONFIG_BLK_DEV_IDEACPI
+#include <acpi/acpi.h>
+#endif
 #include <asm/byteorder.h>
 #include <asm/system.h>
 #include <asm/io.h>
@@ -541,6 +544,11 @@ typedef enum {
 struct ide_driver_s;
 struct ide_settings_s;
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+struct ide_acpi_drive_link;
+struct ide_acpi_hwif_link;
+#endif
+
 typedef struct ide_drive_s {
         char            name[4];        /* drive name, such as "hda" */
         char            driver_req[10]; /* requests specific driver */
@@ -637,6 +645,9 @@ typedef struct ide_drive_s {
 
         int             lun;            /* logical unit */
         int             crc_count;      /* crc counter to reduce drive speed */
+#ifdef CONFIG_BLK_DEV_IDEACPI
+        struct ide_acpi_drive_link *acpidata;
+#endif
         struct list_head list;
         struct device   gendev;
         struct completion gendev_rel_comp;      /* to deal with device release() */
@@ -804,6 +815,10 @@ typedef struct hwif_s {
         void            *hwif_data;     /* extra hwif data */
 
         unsigned dma;
+
+#ifdef CONFIG_BLK_DEV_IDEACPI
+        struct ide_acpi_hwif_link *acpidata;
+#endif
 } ____cacheline_internodealigned_in_smp ide_hwif_t;
 
 /*
@@ -1298,6 +1313,18 @@ static inline void ide_dma_verbose(ide_drive_t *drive) { ; }
 static inline void ide_release_dma(ide_hwif_t *drive) {;}
 #endif
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+extern int ide_acpi_exec_tfs(ide_drive_t *drive);
+extern void ide_acpi_get_timing(ide_hwif_t *hwif);
+extern void ide_acpi_push_timing(ide_hwif_t *hwif);
+extern void ide_acpi_init(ide_hwif_t *hwif);
+#else
+static inline int ide_acpi_exec_tfs(ide_drive_t *drive) { return 0; }
+static inline void ide_acpi_get_timing(ide_hwif_t *hwif) { ; }
+static inline void ide_acpi_push_timing(ide_hwif_t *hwif) { ; }
+static inline void ide_acpi_init(ide_hwif_t *hwif) { ; }
+#endif
+
 extern int ide_hwif_request_regions(ide_hwif_t *hwif);
 extern void ide_hwif_release_regions(ide_hwif_t* hwif);
 extern void ide_unregister (unsigned int index);