/*
   * libata-acpi.c
   * Provides ACPI support for PATA/SATA.
   *
   * Copyright (C) 2006 Intel Corp.
   * Copyright (C) 2006 Randy Dunlap
   */

  #include <linux/module.h>

  #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 <linux/slab.h>

  #include <scsi/scsi_device.h>

  #include "libata.h"
  
  #include <acpi/acpi_bus.h>

  unsigned int ata_acpi_gtf_filter = ATA_ACPI_FILTER_DEFAULT;

  module_param_named(acpi_gtf_filter, ata_acpi_gtf_filter, int, 0644);

  MODULE_PARM_DESC(acpi_gtf_filter, "filter mask for ACPI _GTF commands, set to filter out (0x1=set xfermode, 0x2=lock/freeze lock, 0x4=DIPM, 0x8=FPDMA non-zero offset, 0x10=FPDMA DMA Setup FIS auto-activate)");

  #define NO_PORT_MULT		0xffff

  #define SATA_ADR(root, pmp)	(((root) << 16) | (pmp))

  
  #define REGS_PER_GTF		7

  struct ata_acpi_gtf {
  	u8	tf[REGS_PER_GTF];	/* regs. 0x1f1 - 0x1f7 */
  } __packed;

  /*
   *	Helper - belongs in the PCI layer somewhere eventually
   */
  static int is_pci_dev(struct device *dev)
  {
  	return (dev->bus == &pci_bus_type);
  }

  static void ata_acpi_clear_gtf(struct ata_device *dev)
  {
  	kfree(dev->gtf_cache);
  	dev->gtf_cache = NULL;
  }

  /**
   * ata_acpi_associate_sata_port - associate SATA port with ACPI objects
   * @ap: target SATA port
   *
   * Look up ACPI objects associated with @ap and initialize acpi_handle
   * fields of @ap, the port and devices accordingly.
   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:
   * 0 on success, -errno on failure.
   */
  void ata_acpi_associate_sata_port(struct ata_port *ap)

  {

  	WARN_ON(!(ap->flags & ATA_FLAG_ACPI_SATA));

  	if (!sata_pmp_attached(ap)) {

  		u64 adr = SATA_ADR(ap->port_no, NO_PORT_MULT);

  
  		ap->link.device->acpi_handle =
  			acpi_get_child(ap->host->acpi_handle, adr);
  	} else {
  		struct ata_link *link;
  
  		ap->link.device->acpi_handle = NULL;

  		ata_for_each_link(link, ap, EDGE) {

  			u64 adr = SATA_ADR(ap->port_no, link->pmp);

  			link->device->acpi_handle =
  				acpi_get_child(ap->host->acpi_handle, adr);
  		}
  	}

  }

  static void ata_acpi_associate_ide_port(struct ata_port *ap)

  {

  	int max_devices, i;

  	ap->acpi_handle = acpi_get_child(ap->host->acpi_handle, ap->port_no);
  	if (!ap->acpi_handle)
  		return;

  	max_devices = 1;
  	if (ap->flags & ATA_FLAG_SLAVE_POSS)
  		max_devices++;

  	for (i = 0; i < max_devices; i++) {

  		struct ata_device *dev = &ap->link.device[i];

  		dev->acpi_handle = acpi_get_child(ap->acpi_handle, i);

  	}

  
  	if (ata_acpi_gtm(ap, &ap->__acpi_init_gtm) == 0)
  		ap->pflags |= ATA_PFLAG_INIT_GTM_VALID;

  }

  /* @ap and @dev are the same as ata_acpi_handle_hotplug() */
  static void ata_acpi_detach_device(struct ata_port *ap, struct ata_device *dev)
  {
  	if (dev)
  		dev->flags |= ATA_DFLAG_DETACH;
  	else {
  		struct ata_link *tlink;
  		struct ata_device *tdev;

  		ata_for_each_link(tlink, ap, EDGE)
  			ata_for_each_dev(tdev, tlink, ALL)

  				tdev->flags |= ATA_DFLAG_DETACH;
  	}
  
  	ata_port_schedule_eh(ap);
  }
  
  /**
   * ata_acpi_handle_hotplug - ACPI event handler backend
   * @ap: ATA port ACPI event occurred
   * @dev: ATA device ACPI event occurred (can be NULL)
   * @event: ACPI event which occurred

   *
   * All ACPI bay / device realted events end up in this function.  If
   * the event is port-wide @dev is NULL.  If the event is specific to a
   * device, @dev points to it.
   *
   * Hotplug (as opposed to unplug) notification is always handled as
   * port-wide while unplug only kills the target device on device-wide
   * event.
   *
   * LOCKING:
   * ACPI notify handler context.  May sleep.
   */
  static void ata_acpi_handle_hotplug(struct ata_port *ap, struct ata_device *dev,

  				    u32 event)

  {

  	struct ata_eh_info *ehi = &ap->link.eh_info;

  	int wait = 0;
  	unsigned long flags;

  	spin_lock_irqsave(ap->lock, flags);

  	/*
  	 * When dock driver calls into the routine, it will always use
  	 * ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
  	 * ACPI_NOTIFY_EJECT_REQUEST for remove
  	 */

  	switch (event) {
  	case ACPI_NOTIFY_BUS_CHECK:
  	case ACPI_NOTIFY_DEVICE_CHECK:
  		ata_ehi_push_desc(ehi, "ACPI event");

  		ata_ehi_hotplugged(ehi);
  		ata_port_freeze(ap);

  		break;
  	case ACPI_NOTIFY_EJECT_REQUEST:
  		ata_ehi_push_desc(ehi, "ACPI event");

  		ata_acpi_detach_device(ap, dev);
  		wait = 1;
  		break;

  	}

  	spin_unlock_irqrestore(ap->lock, flags);

  	if (wait)

  		ata_port_wait_eh(ap);

  }
  
  static void ata_acpi_dev_notify_dock(acpi_handle handle, u32 event, void *data)
  {
  	struct ata_device *dev = data;

  	ata_acpi_handle_hotplug(dev->link->ap, dev, event);

  }
  
  static void ata_acpi_ap_notify_dock(acpi_handle handle, u32 event, void *data)
  {
  	struct ata_port *ap = data;

  	ata_acpi_handle_hotplug(ap, NULL, event);

  }

  static void ata_acpi_uevent(struct ata_port *ap, struct ata_device *dev,
  	u32 event)
  {
  	struct kobject *kobj = NULL;
  	char event_string[20];
  	char *envp[] = { event_string, NULL };
  
  	if (dev) {
  		if (dev->sdev)
  			kobj = &dev->sdev->sdev_gendev.kobj;
  	} else
  		kobj = &ap->dev->kobj;
  
  	if (kobj) {
  		snprintf(event_string, 20, "BAY_EVENT=%d", event);
  		kobject_uevent_env(kobj, KOBJ_CHANGE, envp);
  	}
  }
  
  static void ata_acpi_ap_uevent(acpi_handle handle, u32 event, void *data)
  {
  	ata_acpi_uevent(data, NULL, event);
  }
  
  static void ata_acpi_dev_uevent(acpi_handle handle, u32 event, void *data)
  {
  	struct ata_device *dev = data;
  	ata_acpi_uevent(dev->link->ap, dev, event);
  }

  static const struct acpi_dock_ops ata_acpi_dev_dock_ops = {

  	.handler = ata_acpi_dev_notify_dock,
  	.uevent = ata_acpi_dev_uevent,
  };

  static const struct acpi_dock_ops ata_acpi_ap_dock_ops = {

  	.handler = ata_acpi_ap_notify_dock,
  	.uevent = ata_acpi_ap_uevent,
  };

  /**
   * ata_acpi_associate - associate ATA host with ACPI objects
   * @host: target ATA host
   *
   * Look up ACPI objects associated with @host and initialize
   * acpi_handle fields of @host, its ports and devices accordingly.
   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:
   * 0 on success, -errno on failure.
   */
  void ata_acpi_associate(struct ata_host *host)

  {

  	int i, j;

  	if (!is_pci_dev(host->dev) || libata_noacpi)
  		return;

  	host->acpi_handle = DEVICE_ACPI_HANDLE(host->dev);
  	if (!host->acpi_handle)
  		return;

  	for (i = 0; i < host->n_ports; i++) {
  		struct ata_port *ap = host->ports[i];
  
  		if (host->ports[0]->flags & ATA_FLAG_ACPI_SATA)
  			ata_acpi_associate_sata_port(ap);
  		else
  			ata_acpi_associate_ide_port(ap);

  		if (ap->acpi_handle) {

  			/* we might be on a docking station */
  			register_hotplug_dock_device(ap->acpi_handle,

  					     &ata_acpi_ap_dock_ops, ap);

  		}

  
  		for (j = 0; j < ata_link_max_devices(&ap->link); j++) {
  			struct ata_device *dev = &ap->link.device[j];

  			if (dev->acpi_handle) {

  				/* we might be on a docking station */
  				register_hotplug_dock_device(dev->acpi_handle,

  					     &ata_acpi_dev_dock_ops, dev);

  			}

  		}

  	}

  }
  
  /**

   * ata_acpi_dissociate - dissociate ATA host from ACPI objects
   * @host: target ATA host
   *
   * This function is called during driver detach after the whole host
   * is shut down.
   *
   * LOCKING:
   * EH context.
   */
  void ata_acpi_dissociate(struct ata_host *host)
  {

  	int i;
  
  	/* Restore initial _GTM values so that driver which attaches
  	 * afterward can use them too.
  	 */
  	for (i = 0; i < host->n_ports; i++) {
  		struct ata_port *ap = host->ports[i];
  		const struct ata_acpi_gtm *gtm = ata_acpi_init_gtm(ap);
  
  		if (ap->acpi_handle && gtm)
  			ata_acpi_stm(ap, gtm);
  	}

  }
  
  /**

   * ata_acpi_gtm - execute _GTM
   * @ap: target ATA port
   * @gtm: out parameter for _GTM result
   *
   * Evaluate _GTM and store the result in @gtm.
   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:
   * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
   */

  int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *gtm)

  {
  	struct acpi_buffer output = { .length = ACPI_ALLOCATE_BUFFER };
  	union acpi_object *out_obj;
  	acpi_status status;
  	int rc = 0;
  
  	status = acpi_evaluate_object(ap->acpi_handle, "_GTM", NULL, &output);
  
  	rc = -ENOENT;
  	if (status == AE_NOT_FOUND)
  		goto out_free;
  
  	rc = -EINVAL;
  	if (ACPI_FAILURE(status)) {

  		ata_port_err(ap, "ACPI get timing mode failed (AE 0x%x)
  ",
  			     status);

  		goto out_free;
  	}
  
  	out_obj = output.pointer;
  	if (out_obj->type != ACPI_TYPE_BUFFER) {

  		ata_port_warn(ap, "_GTM returned unexpected object type 0x%x
  ",
  			      out_obj->type);

  
  		goto out_free;
  	}
  
  	if (out_obj->buffer.length != sizeof(struct ata_acpi_gtm)) {

  		ata_port_err(ap, "_GTM returned invalid length %d
  ",
  			     out_obj->buffer.length);

  		goto out_free;
  	}
  
  	memcpy(gtm, out_obj->buffer.pointer, sizeof(struct ata_acpi_gtm));
  	rc = 0;
   out_free:
  	kfree(output.pointer);
  	return rc;
  }

  EXPORT_SYMBOL_GPL(ata_acpi_gtm);

  /**
   * ata_acpi_stm - execute _STM
   * @ap: target ATA port
   * @stm: timing parameter to _STM
   *
   * Evaluate _STM with timing parameter @stm.
   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:
   * 0 on success, -ENOENT if _STM doesn't exist, -errno on failure.
   */

  int ata_acpi_stm(struct ata_port *ap, const struct ata_acpi_gtm *stm)

  {
  	acpi_status status;

  	struct ata_acpi_gtm		stm_buf = *stm;

  	struct acpi_object_list         input;
  	union acpi_object               in_params[3];
  
  	in_params[0].type = ACPI_TYPE_BUFFER;
  	in_params[0].buffer.length = sizeof(struct ata_acpi_gtm);

  	in_params[0].buffer.pointer = (u8 *)&stm_buf;

  	/* Buffers for id may need byteswapping ? */
  	in_params[1].type = ACPI_TYPE_BUFFER;
  	in_params[1].buffer.length = 512;

  	in_params[1].buffer.pointer = (u8 *)ap->link.device[0].id;

  	in_params[2].type = ACPI_TYPE_BUFFER;
  	in_params[2].buffer.length = 512;

  	in_params[2].buffer.pointer = (u8 *)ap->link.device[1].id;

  
  	input.count = 3;
  	input.pointer = in_params;
  
  	status = acpi_evaluate_object(ap->acpi_handle, "_STM", &input, NULL);
  
  	if (status == AE_NOT_FOUND)
  		return -ENOENT;
  	if (ACPI_FAILURE(status)) {

  		ata_port_err(ap, "ACPI set timing mode failed (status=0x%x)
  ",
  			     status);

  		return -EINVAL;
  	}
  	return 0;
  }

  EXPORT_SYMBOL_GPL(ata_acpi_stm);

  /**

   * ata_dev_get_GTF - get the drive bootup default taskfile settings

   * @dev: target ATA device

   * @gtf: output parameter for 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.
   *

   * LOCKING:
   * EH context.
   *
   * RETURNS:

   * Number of taskfiles on success, 0 if _GTF doesn't exist.  -EINVAL
   * if _GTF is invalid.

   */

  static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf)

  {

  	struct ata_port *ap = dev->link->ap;

  	acpi_status status;

  	struct acpi_buffer output;
  	union acpi_object *out_obj;

  	int rc = 0;

  	/* if _GTF is cached, use the cached value */
  	if (dev->gtf_cache) {
  		out_obj = dev->gtf_cache;
  		goto done;
  	}

  	/* set up output buffer */
  	output.length = ACPI_ALLOCATE_BUFFER;
  	output.pointer = NULL;	/* ACPI-CA sets this; save/free it later */

  	if (ata_msg_probe(ap))

  		ata_dev_dbg(dev, "%s: ENTER: port#: %d
  ",
  			    __func__, ap->port_no);

  	/* _GTF has no input parameters */

  	status = acpi_evaluate_object(dev->acpi_handle, "_GTF", NULL, &output);

  	out_obj = dev->gtf_cache = output.pointer;

  	if (ACPI_FAILURE(status)) {

  		if (status != AE_NOT_FOUND) {

  			ata_dev_warn(dev, "_GTF evaluation failed (AE 0x%x)
  ",
  				     status);

  			rc = -EINVAL;

  		}
  		goto out_free;

  	}
  
  	if (!output.length || !output.pointer) {
  		if (ata_msg_probe(ap))

  			ata_dev_dbg(dev, "%s: Run _GTF: length or ptr is NULL (0x%llx, 0x%p)
  ",
  				    __func__,
  				    (unsigned long long)output.length,
  				    output.pointer);

  		rc = -EINVAL;

  		goto out_free;

  	}

  	if (out_obj->type != ACPI_TYPE_BUFFER) {

  		ata_dev_warn(dev, "_GTF unexpected object type 0x%x
  ",
  			     out_obj->type);

  		rc = -EINVAL;

  		goto out_free;

  	}

  	if (out_obj->buffer.length % REGS_PER_GTF) {

  		ata_dev_warn(dev, "unexpected _GTF length (%d)
  ",
  			     out_obj->buffer.length);

  		rc = -EINVAL;

  		goto out_free;

  	}

   done:

  	rc = out_obj->buffer.length / REGS_PER_GTF;

  	if (gtf) {
  		*gtf = (void *)out_obj->buffer.pointer;
  		if (ata_msg_probe(ap))

  			ata_dev_dbg(dev, "%s: returning gtf=%p, gtf_count=%d
  ",
  				    __func__, *gtf, rc);

  	}

  	return rc;
  
   out_free:

  	ata_acpi_clear_gtf(dev);

  	return rc;

  }

  /**
   * ata_acpi_gtm_xfermode - determine xfermode from GTM parameter
   * @dev: target device
   * @gtm: GTM parameter to use
   *
   * Determine xfermask for @dev from @gtm.
   *
   * LOCKING:
   * None.
   *
   * RETURNS:
   * Determined xfermask.
   */
  unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
  				    const struct ata_acpi_gtm *gtm)
  {

  	unsigned long xfer_mask = 0;
  	unsigned int type;
  	int unit;
  	u8 mode;

  
  	/* we always use the 0 slot for crap hardware */
  	unit = dev->devno;
  	if (!(gtm->flags & 0x10))
  		unit = 0;

  	/* PIO */
  	mode = ata_timing_cycle2mode(ATA_SHIFT_PIO, gtm->drive[unit].pio);
  	xfer_mask |= ata_xfer_mode2mask(mode);

  
  	/* See if we have MWDMA or UDMA data. We don't bother with
  	 * MWDMA if UDMA is available as this means the BIOS set UDMA
  	 * and our error changedown if it works is UDMA to PIO anyway.
  	 */

  	if (!(gtm->flags & (1 << (2 * unit))))
  		type = ATA_SHIFT_MWDMA;
  	else
  		type = ATA_SHIFT_UDMA;
  
  	mode = ata_timing_cycle2mode(type, gtm->drive[unit].dma);
  	xfer_mask |= ata_xfer_mode2mask(mode);

  	return xfer_mask;

  }
  EXPORT_SYMBOL_GPL(ata_acpi_gtm_xfermask);

  /**

   * ata_acpi_cbl_80wire		-	Check for 80 wire cable
   * @ap: Port to check

   * @gtm: GTM data to use

   *

   * Return 1 if the @gtm indicates the BIOS selected an 80wire mode.

   */

  int ata_acpi_cbl_80wire(struct ata_port *ap, const struct ata_acpi_gtm *gtm)

  {

  	struct ata_device *dev;

  	ata_for_each_dev(dev, &ap->link, ENABLED) {

  		unsigned long xfer_mask, udma_mask;

  		xfer_mask = ata_acpi_gtm_xfermask(dev, gtm);
  		ata_unpack_xfermask(xfer_mask, NULL, NULL, &udma_mask);
  
  		if (udma_mask & ~ATA_UDMA_MASK_40C)
  			return 1;
  	}

  	return 0;
  }

  EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);

  static void ata_acpi_gtf_to_tf(struct ata_device *dev,
  			       const struct ata_acpi_gtf *gtf,
  			       struct ata_taskfile *tf)
  {
  	ata_tf_init(dev, tf);
  
  	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
  	tf->protocol = ATA_PROT_NODATA;
  	tf->feature = gtf->tf[0];	/* 0x1f1 */
  	tf->nsect   = gtf->tf[1];	/* 0x1f2 */
  	tf->lbal    = gtf->tf[2];	/* 0x1f3 */
  	tf->lbam    = gtf->tf[3];	/* 0x1f4 */
  	tf->lbah    = gtf->tf[4];	/* 0x1f5 */
  	tf->device  = gtf->tf[5];	/* 0x1f6 */
  	tf->command = gtf->tf[6];	/* 0x1f7 */
  }

  static int ata_acpi_filter_tf(struct ata_device *dev,
  			      const struct ata_taskfile *tf,

  			      const struct ata_taskfile *ptf)
  {

  	if (dev->gtf_filter & ATA_ACPI_FILTER_SETXFER) {

  		/* libata doesn't use ACPI to configure transfer mode.
  		 * It will only confuse device configuration.  Skip.
  		 */
  		if (tf->command == ATA_CMD_SET_FEATURES &&
  		    tf->feature == SETFEATURES_XFER)
  			return 1;
  	}

  	if (dev->gtf_filter & ATA_ACPI_FILTER_LOCK) {

  		/* BIOS writers, sorry but we don't wanna lock
  		 * features unless the user explicitly said so.
  		 */
  
  		/* DEVICE CONFIGURATION FREEZE LOCK */
  		if (tf->command == ATA_CMD_CONF_OVERLAY &&
  		    tf->feature == ATA_DCO_FREEZE_LOCK)
  			return 1;
  
  		/* SECURITY FREEZE LOCK */
  		if (tf->command == ATA_CMD_SEC_FREEZE_LOCK)
  			return 1;
  
  		/* SET MAX LOCK and SET MAX FREEZE LOCK */
  		if ((!ptf || ptf->command != ATA_CMD_READ_NATIVE_MAX) &&
  		    tf->command == ATA_CMD_SET_MAX &&
  		    (tf->feature == ATA_SET_MAX_LOCK ||
  		     tf->feature == ATA_SET_MAX_FREEZE_LOCK))
  			return 1;
  	}

  	if (tf->command == ATA_CMD_SET_FEATURES &&
  	    tf->feature == SETFEATURES_SATA_ENABLE) {

  		/* inhibit enabling DIPM */

  		if (dev->gtf_filter & ATA_ACPI_FILTER_DIPM &&

  		    tf->nsect == SATA_DIPM)
  			return 1;

  
  		/* inhibit FPDMA non-zero offset */

  		if (dev->gtf_filter & ATA_ACPI_FILTER_FPDMA_OFFSET &&

  		    (tf->nsect == SATA_FPDMA_OFFSET ||
  		     tf->nsect == SATA_FPDMA_IN_ORDER))
  			return 1;
  
  		/* inhibit FPDMA auto activation */

  		if (dev->gtf_filter & ATA_ACPI_FILTER_FPDMA_AA &&

  		    tf->nsect == SATA_FPDMA_AA)
  			return 1;

  	}

  	return 0;
  }

  /**

   * ata_acpi_run_tf - send taskfile registers to host controller

   * @dev: target ATA device

   * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
   *

   * Outputs ATA taskfile to standard ATA host controller.

   * 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:
   * EH context.
   *
   * RETURNS:

   * 1 if command is executed successfully.  0 if ignored, rejected or
   * filtered out, -errno on other errors.

   */

  static int ata_acpi_run_tf(struct ata_device *dev,

  			   const struct ata_acpi_gtf *gtf,
  			   const struct ata_acpi_gtf *prev_gtf)

  {

  	struct ata_taskfile *pptf = NULL;
  	struct ata_taskfile tf, ptf, rtf;

  	unsigned int err_mask;

  	const char *level;

  	const char *descr;

  	char msg[60];
  	int rc;

  	if ((gtf->tf[0] == 0) && (gtf->tf[1] == 0) && (gtf->tf[2] == 0)
  	    && (gtf->tf[3] == 0) && (gtf->tf[4] == 0) && (gtf->tf[5] == 0)
  	    && (gtf->tf[6] == 0))
  		return 0;

  	ata_acpi_gtf_to_tf(dev, gtf, &tf);
  	if (prev_gtf) {
  		ata_acpi_gtf_to_tf(dev, prev_gtf, &ptf);
  		pptf = &ptf;
  	}

  	if (!ata_acpi_filter_tf(dev, &tf, pptf)) {

  		rtf = tf;
  		err_mask = ata_exec_internal(dev, &rtf, NULL,
  					     DMA_NONE, NULL, 0, 0);
  
  		switch (err_mask) {
  		case 0:
  			level = KERN_DEBUG;
  			snprintf(msg, sizeof(msg), "succeeded");
  			rc = 1;
  			break;
  
  		case AC_ERR_DEV:
  			level = KERN_INFO;
  			snprintf(msg, sizeof(msg),
  				 "rejected by device (Stat=0x%02x Err=0x%02x)",
  				 rtf.command, rtf.feature);
  			rc = 0;
  			break;
  
  		default:
  			level = KERN_ERR;
  			snprintf(msg, sizeof(msg),
  				 "failed (Emask=0x%x Stat=0x%02x Err=0x%02x)",
  				 err_mask, rtf.command, rtf.feature);
  			rc = -EIO;
  			break;
  		}
  	} else {

  		level = KERN_INFO;

  		snprintf(msg, sizeof(msg), "filtered out");

  		rc = 0;

  	}

  	descr = ata_get_cmd_descript(tf.command);

  	ata_dev_printk(dev, level,

  		       "ACPI cmd %02x/%02x:%02x:%02x:%02x:%02x:%02x (%s) %s
  ",

  		       tf.command, tf.feature, tf.nsect, tf.lbal,

  		       tf.lbam, tf.lbah, tf.device,
  		       (descr ? descr : "unknown"), msg);

  
  	return rc;

  }
  
  /**

   * ata_acpi_exec_tfs - get then write drive taskfile settings

   * @dev: target ATA device

   * @nr_executed: out parameter for the number of executed commands

   *

   * Evaluate _GTF and execute returned taskfiles.

   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:

   * Number of executed taskfiles on success, 0 if _GTF doesn't exist.
   * -errno on other errors.

   */

  static int ata_acpi_exec_tfs(struct ata_device *dev, int *nr_executed)

  {

  	struct ata_acpi_gtf *gtf = NULL, *pgtf = NULL;

  	int gtf_count, i, rc;
  
  	/* get taskfiles */

  	rc = ata_dev_get_GTF(dev, &gtf);
  	if (rc < 0)
  		return rc;
  	gtf_count = rc;

  
  	/* execute them */

  	for (i = 0; i < gtf_count; i++, gtf++) {
  		rc = ata_acpi_run_tf(dev, gtf, pgtf);

  		if (rc < 0)
  			break;

  		if (rc) {

  			(*nr_executed)++;

  			pgtf = gtf;
  		}

  	}

  	ata_acpi_clear_gtf(dev);

  	if (rc < 0)
  		return rc;
  	return 0;

  }

  /**
   * ata_acpi_push_id - send Identify data to drive

   * @dev: target ATA device

   *
   * _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.

   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:

   * 0 on success, -ENOENT if _SDD doesn't exist, -errno on failure.

   */

  static int ata_acpi_push_id(struct ata_device *dev)

  {

  	struct ata_port *ap = dev->link->ap;

  	acpi_status status;
  	struct acpi_object_list input;
  	union acpi_object in_params[1];

  	if (ata_msg_probe(ap))

  		ata_dev_dbg(dev, "%s: ix = %d, port#: %d
  ",
  			    __func__, dev->devno, ap->port_no);

  	/* 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(dev->id[0]) * ATA_ID_WORDS;
  	in_params[0].buffer.pointer = (u8 *)dev->id;

  	/* Output buffer: _SDD has no output */
  
  	/* It's OK for _SDD to be missing too. */

  	swap_buf_le16(dev->id, ATA_ID_WORDS);

  	status = acpi_evaluate_object(dev->acpi_handle, "_SDD", &input, NULL);

  	swap_buf_le16(dev->id, ATA_ID_WORDS);

  	if (status == AE_NOT_FOUND)
  		return -ENOENT;
  
  	if (ACPI_FAILURE(status)) {

  		ata_dev_warn(dev, "ACPI _SDD failed (AE 0x%x)
  ", status);

  		return -EIO;
  	}

  	return 0;

  }
  
  /**

   * ata_acpi_on_suspend - ATA ACPI hook called on suspend
   * @ap: target ATA port
   *
   * This function is called when @ap is about to be suspended.  All
   * devices are already put to sleep but the port_suspend() callback
   * hasn't been executed yet.  Error return from this function aborts
   * suspend.
   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:
   * 0 on success, -errno on failure.
   */
  int ata_acpi_on_suspend(struct ata_port *ap)
  {

  	/* nada */
  	return 0;

  }
  
  /**

   * ata_acpi_on_resume - ATA ACPI hook called on resume
   * @ap: target ATA port
   *
   * This function is called when @ap is resumed - right after port
   * itself is resumed but before any EH action is taken.
   *
   * LOCKING:
   * EH context.
   */
  void ata_acpi_on_resume(struct ata_port *ap)
  {

  	const struct ata_acpi_gtm *gtm = ata_acpi_init_gtm(ap);

  	struct ata_device *dev;

  	if (ap->acpi_handle && gtm) {
  		/* _GTM valid */
  
  		/* restore timing parameters */

  		ata_acpi_stm(ap, gtm);

  		/* _GTF should immediately follow _STM so that it can
  		 * use values set by _STM.  Cache _GTF result and
  		 * schedule _GTF.
  		 */

  		ata_for_each_dev(dev, &ap->link, ALL) {

  			ata_acpi_clear_gtf(dev);

  			if (ata_dev_enabled(dev) &&
  			    ata_dev_get_GTF(dev, NULL) >= 0)

  				dev->flags |= ATA_DFLAG_ACPI_PENDING;
  		}
  	} else {
  		/* SATA _GTF needs to be evaulated after _SDD and
  		 * there's no reason to evaluate IDE _GTF early
  		 * without _STM.  Clear cache and schedule _GTF.
  		 */

  		ata_for_each_dev(dev, &ap->link, ALL) {

  			ata_acpi_clear_gtf(dev);

  			if (ata_dev_enabled(dev))
  				dev->flags |= ATA_DFLAG_ACPI_PENDING;

  		}
  	}

  }

  /**

   * ata_acpi_set_state - set the port power state
   * @ap: target ATA port
   * @state: state, on/off
   *
   * This function executes the _PS0/_PS3 ACPI method to set the power state.
   * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
   */
  void ata_acpi_set_state(struct ata_port *ap, pm_message_t state)
  {
  	struct ata_device *dev;
  
  	if (!ap->acpi_handle || (ap->flags & ATA_FLAG_ACPI_SATA))
  		return;
  
  	/* channel first and then drives for power on and vica versa
  	   for power off */
  	if (state.event == PM_EVENT_ON)
  		acpi_bus_set_power(ap->acpi_handle, ACPI_STATE_D0);

  	ata_for_each_dev(dev, &ap->link, ENABLED) {
  		if (dev->acpi_handle)

  			acpi_bus_set_power(dev->acpi_handle,
  				state.event == PM_EVENT_ON ?
  					ACPI_STATE_D0 : ACPI_STATE_D3);
  	}
  	if (state.event != PM_EVENT_ON)
  		acpi_bus_set_power(ap->acpi_handle, ACPI_STATE_D3);
  }
  
  /**

   * ata_acpi_on_devcfg - ATA ACPI hook called on device donfiguration
   * @dev: target ATA device
   *
   * This function is called when @dev is about to be configured.
   * IDENTIFY data might have been modified after this hook is run.
   *
   * LOCKING:
   * EH context.
   *
   * RETURNS:
   * Positive number if IDENTIFY data needs to be refreshed, 0 if not,
   * -errno on failure.
   */
  int ata_acpi_on_devcfg(struct ata_device *dev)
  {

  	struct ata_port *ap = dev->link->ap;
  	struct ata_eh_context *ehc = &ap->link.eh_context;

  	int acpi_sata = ap->flags & ATA_FLAG_ACPI_SATA;

  	int nr_executed = 0;

  	int rc;

  	if (!dev->acpi_handle)
  		return 0;
  
  	/* do we need to do _GTF? */
  	if (!(dev->flags & ATA_DFLAG_ACPI_PENDING) &&
  	    !(acpi_sata && (ehc->i.flags & ATA_EHI_DID_HARDRESET)))
  		return 0;
  
  	/* do _SDD if SATA */
  	if (acpi_sata) {
  		rc = ata_acpi_push_id(dev);

  		if (rc && rc != -ENOENT)

  			goto acpi_err;
  	}
  
  	/* do _GTF */

  	rc = ata_acpi_exec_tfs(dev, &nr_executed);
  	if (rc)

  		goto acpi_err;
  
  	dev->flags &= ~ATA_DFLAG_ACPI_PENDING;
  
  	/* refresh IDENTIFY page if any _GTF command has been executed */

  	if (nr_executed) {

  		rc = ata_dev_reread_id(dev, 0);
  		if (rc < 0) {

  			ata_dev_err(dev,
  				    "failed to IDENTIFY after ACPI commands
  ");

  			return rc;
  		}
  	}
  
  	return 0;
  
   acpi_err:

  	/* ignore evaluation failure if we can continue safely */
  	if (rc == -EINVAL && !nr_executed && !(ap->pflags & ATA_PFLAG_FROZEN))
  		return 0;

  	/* fail and let EH retry once more for unknown IO errors */
  	if (!(dev->flags & ATA_DFLAG_ACPI_FAILED)) {
  		dev->flags |= ATA_DFLAG_ACPI_FAILED;
  		return rc;

  	}

  	ata_dev_warn(dev, "ACPI: failed the second time, disabled
  ");

  	dev->acpi_handle = NULL;
  
  	/* We can safely continue if no _GTF command has been executed
  	 * and port is not frozen.
  	 */
  	if (!nr_executed && !(ap->pflags & ATA_PFLAG_FROZEN))
  		return 0;

  	return rc;
  }

  
  /**
   * ata_acpi_on_disable - ATA ACPI hook called when a device is disabled
   * @dev: target ATA device
   *
   * This function is called when @dev is about to be disabled.
   *
   * LOCKING:
   * EH context.
   */
  void ata_acpi_on_disable(struct ata_device *dev)
  {

  	ata_acpi_clear_gtf(dev);

  }