[PATCH] libata: ACPI and _GTF support

_GTF is an acpi method that is used to reinitialize the drive.  It returns
a task file containing ata commands that are sent back to the drive to restore
it to boot up defaults.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
(cherry picked from 9c69cab24b51a89664f4c0dfaf8a436d32117624 commit)

7 files changed, 643 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index abd575c..5bc8970 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -48,6 +48,7 @@ parameter is applicable:
 	ISAPNP	ISA PnP code is enabled.
 	ISDN	Appropriate ISDN support is enabled.
 	JOY	Appropriate joystick support is enabled.
+	LIBATA  Libata driver is enabled
 	LP	Printer support is enabled.
 	LOOP	Loopback device support is enabled.
 	M68k	M68k architecture is enabled.
@@ -1038,6 +1039,10 @@ and is between 256 and 4096 characters. It is defined in the file
 			emulation library even if a 387 maths coprocessor
 			is present.
 
+	noacpi		[LIBATA] Disables use of ACPI in libata suspend/resume
+			when set.
+			Format: <int>
+
 	noaliencache	[MM, NUMA] Disables the allcoation of alien caches in
 			the slab allocator.  Saves per-node memory, but will
 			impact performance on real NUMA hardware.
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 3747457fe..4af0a4b 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -161,6 +161,19 @@ config SATA_INTEL_COMBINED
 	depends on IDE=y && !BLK_DEV_IDE_SATA && (SATA_AHCI || ATA_PIIX)
 	default y
 
+config SATA_ACPI
+	bool
+	depends on ACPI && PCI
+	default y
+	help
+	  This option adds support for SATA-related ACPI objects.
+	  These ACPI objects add the ability to retrieve taskfiles
+	  from the ACPI BIOS and write them to the disk controller.
+	  These objects may be related to performance, security,
+	  power management, or other areas.
+	  You can disable this at kernel boot time by using the
+	  option libata.noacpi=1
+
 config PATA_ALI
 	tristate "ALi PATA support (Experimental)"
 	depends on PCI && EXPERIMENTAL
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index cd096f0..74298af 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -66,4 +66,4 @@ obj-$(CONFIG_ATA_GENERIC)	+= ata_generic.o
 obj-$(CONFIG_PATA_LEGACY)	+= pata_legacy.o
 
 libata-objs	:= libata-core.o libata-scsi.o libata-sff.o libata-eh.o
-
+libata-$(CONFIG_SATA_ACPI) += libata-acpi.o
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
new file mode 100644
index 0000000..7b740fe
--- /dev/null
+++ b/drivers/ata/libata-acpi.c
@@ -0,0 +1,602 @@
+/*
+ * 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;
+}
+
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2cf8251..785bf50 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -93,6 +93,10 @@ static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
 module_param(ata_probe_timeout, int, 0444);
 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
 
+int noacpi;
+module_param(noacpi, int, 0444);
+MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in suspend/resume when set");
+
 MODULE_AUTHOR("Jeff Garzik");
 MODULE_DESCRIPTION("Library module for ATA devices");
 MODULE_LICENSE("GPL");
@@ -1778,6 +1782,9 @@ int ata_bus_probe(struct ata_port *ap)
 	/* reset and determine device classes */
 	ap->ops->phy_reset(ap);
 
+	/* retrieve and execute the ATA task file of _GTF */
+	ata_acpi_exec_tfs(ap);
+
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		dev = &ap->device[i];
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 06ccf23..ea02903 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -47,6 +47,7 @@ extern struct workqueue_struct *ata_aux_wq;
 extern int atapi_enabled;
 extern int atapi_dmadir;
 extern int libata_fua;
+extern int noacpi;
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 			   u64 block, u32 n_block, unsigned int tf_flags,
@@ -87,6 +88,15 @@ extern void ata_port_init(struct ata_port *ap, struct ata_host *host,
 extern struct ata_probe_ent *ata_probe_ent_alloc(struct device *dev,
 						 const struct ata_port_info *port);
 
+/* libata-acpi.c */
+#ifdef CONFIG_SATA_ACPI
+extern int ata_acpi_exec_tfs(struct ata_port *ap);
+#else
+static inline int ata_acpi_exec_tfs(struct ata_port *ap)
+{
+	return 0;
+}
+#endif
 
 /* libata-scsi.c */
 extern struct scsi_transport_template ata_scsi_transport_template;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index b870b20..86762a9 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -35,6 +35,7 @@
 #include <linux/ata.h>
 #include <linux/workqueue.h>
 #include <scsi/scsi_host.h>
+#include <linux/acpi.h>
 
 /*
  * Define if arch has non-standard setup.  This is a _PCI_ standard
@@ -495,6 +496,10 @@ struct ata_device {
 	/* error history */
 	struct ata_ering	ering;
 	unsigned int		horkage;	/* List of broken features */
+#ifdef CONFIG_SATA_ACPI
+	/* ACPI objects info */
+	acpi_handle obj_handle;
+#endif
 };
 
 /* Offset into struct ata_device.  Fields above it are maintained