drivers/ata/libata-acpi.c - fp2-dev/kernel/msm - Gitiles

 /*
  * 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 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_associate_sata_port(struct ata_port *ap)
 {
 	acpi_integer adr = SATA_ADR(ap->port_no, NO_PORT_MULT);

 	ap->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->device[i];

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

 /**
  * 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;

 	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);
 	}
 }

 /**
  * 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.
  */
 static int ata_acpi_gtm(const 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_printk(ap, KERN_ERR,
 				"ACPI get timing mode failed (AE 0x%x)\n",
 				status);
 		goto out_free;
 	}

 	out_obj = output.pointer;
 	if (out_obj->type != ACPI_TYPE_BUFFER) {
 		ata_port_printk(ap, KERN_WARNING,
 				"_GTM returned unexpected object type 0x%x\n",
 				out_obj->type);

 		goto out_free;
 	}

 	if (out_obj->buffer.length != sizeof(struct ata_acpi_gtm)) {
 		ata_port_printk(ap, KERN_ERR,
 				"_GTM returned invalid length %d\n",
 				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;
 }

 /**
  * 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.
  */
 static int ata_acpi_stm(const struct ata_port *ap, struct ata_acpi_gtm *stm)
 {
 	acpi_status status;
 	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;
 	/* 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->device[0].id;
 	in_params[2].type = ACPI_TYPE_BUFFER;
 	in_params[2].buffer.length = 512;
 	in_params[2].buffer.pointer = (u8 *)ap->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_printk(ap, KERN_ERR,
 			"ACPI set timing mode failed (status=0x%x)\n", status);
 		return -EINVAL;
 	}
 	return 0;
 }

 /**
  * ata_dev_get_GTF - get the drive bootup default taskfile settings
  * @dev: target ATA device
  * @gtf: output parameter for buffer containing _GTF taskfile arrays
  * @ptr_to_free: pointer which should be freed
  *
  * 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 or doesn't
  * contain valid data.  -errno on other errors.
  */
 static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf,
 			   void **ptr_to_free)
 {
 	struct ata_port *ap = dev->ap;
 	acpi_status status;
 	struct acpi_buffer output;
 	union acpi_object *out_obj;
 	int rc = 0;

 	/* 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_printk(dev, KERN_DEBUG, "%s: ENTER: port#: %d\n",
 			       __FUNCTION__, ap->port_no);

 	/* _GTF has no input parameters */
 	status = acpi_evaluate_object(dev->acpi_handle, "_GTF", NULL, &output);

 	if (ACPI_FAILURE(status)) {
 		if (status != AE_NOT_FOUND) {
 			ata_dev_printk(dev, KERN_WARNING,
 				       "_GTF evaluation failed (AE 0x%x)\n",
 				       status);
 			rc = -EIO;
 		}
 		goto out_free;
 	}

 	if (!output.length || !output.pointer) {
 		if (ata_msg_probe(ap))
 			ata_dev_printk(dev, KERN_DEBUG, "%s: Run _GTF: "
 				"length or ptr is NULL (0x%llx, 0x%p)\n",
 				__FUNCTION__,
 				(unsigned long long)output.length,
 				output.pointer);
 		goto out_free;
 	}

 	out_obj = output.pointer;
 	if (out_obj->type != ACPI_TYPE_BUFFER) {
 		ata_dev_printk(dev, KERN_WARNING,
 			       "_GTF unexpected object type 0x%x\n",
 			       out_obj->type);
 		rc = -EINVAL;
 		goto out_free;
 	}

 	if (out_obj->buffer.length % REGS_PER_GTF) {
 		ata_dev_printk(dev, KERN_WARNING,
 			       "unexpected _GTF length (%d)\n",
 			       out_obj->buffer.length);
 		rc = -EINVAL;
 		goto out_free;
 	}

 	*ptr_to_free = out_obj;
 	*gtf = (void *)out_obj->buffer.pointer;
 	rc = out_obj->buffer.length / REGS_PER_GTF;

 	if (ata_msg_probe(ap))
 		ata_dev_printk(dev, KERN_DEBUG, "%s: returning "
 			"gtf=%p, gtf_count=%d, ptr_to_free=%p\n",
 			__FUNCTION__, *gtf, rc, *ptr_to_free);
 	return rc;

  out_free:
 	kfree(output.pointer);
 	return rc;
 }

 /**
  * taskfile_load_raw - 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 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:
  * EH context.
  *
  * RETURNS:
  * 0 on success, -errno on failure.
  */
 static int taskfile_load_raw(struct ata_device *dev,
 			      const struct ata_acpi_gtf *gtf)
 {
 	struct ata_port *ap = dev->ap;
 	struct ata_taskfile tf, rtf;
 	unsigned int err_mask;

 	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_tf_init(dev, &tf);

 	/* convert gtf to tf */
 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; /* TBD */
 	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 */

 	if (ata_msg_probe(ap))
 		ata_dev_printk(dev, KERN_DEBUG, "executing ACPI cmd "
 			       "%02x/%02x:%02x:%02x:%02x:%02x:%02x\n",
 			       tf.command, tf.feature, tf.nsect,
 			       tf.lbal, tf.lbam, tf.lbah, tf.device);

 	rtf = tf;
 	err_mask = ata_exec_internal(dev, &rtf, NULL, DMA_NONE, NULL, 0);
 	if (err_mask) {
 		ata_dev_printk(dev, KERN_ERR,
 			"ACPI cmd %02x/%02x:%02x:%02x:%02x:%02x:%02x failed "
 			"(Emask=0x%x Stat=0x%02x Err=0x%02x)\n",
 			tf.command, tf.feature, tf.nsect, tf.lbal, tf.lbam,
 			tf.lbah, tf.device, err_mask, rtf.command, rtf.feature);
 		return -EIO;
 	}

 	return 0;
 }

 /**
  * ata_acpi_exec_tfs - get then write drive taskfile settings
  * @dev: target ATA device
  *
  * Evaluate _GTF and excute returned taskfiles.
  *
  * LOCKING:
  * EH context.
  *
  * RETURNS:
  * Number of executed taskfiles on success, 0 if _GTF doesn't exist or
  * doesn't contain valid data.  -errno on other errors.
  */
 static int ata_acpi_exec_tfs(struct ata_device *dev)
 {
 	struct ata_acpi_gtf *gtf = NULL;
 	void *ptr_to_free = NULL;
 	int gtf_count, i, rc;

 	/* get taskfiles */
 	rc = ata_dev_get_GTF(dev, &gtf, &ptr_to_free);
 	if (rc < 0)
 		return rc;
 	gtf_count = rc;

 	/* execute them */
 	for (i = 0, rc = 0; i < gtf_count; i++) {
 		int tmp;

 		/* ACPI errors are eventually ignored.  Run till the
 		 * end even after errors.
 		 */
 		tmp = taskfile_load_raw(dev, gtf++);
 		if (!rc)
 			rc = tmp;
 	}

 	kfree(ptr_to_free);

 	if (rc == 0)
 		return gtf_count;
 	return rc;
 }

 /**
  * 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, -errno on failure.
  */
 static int ata_acpi_push_id(struct ata_device *dev)
 {
 	struct ata_port *ap = dev->ap;
 	int err;
 	acpi_status status;
 	struct acpi_object_list input;
 	union acpi_object in_params[1];

 	if (ata_msg_probe(ap))
 		ata_dev_printk(dev, KERN_DEBUG, "%s: ix = %d, port#: %d\n",
 			       __FUNCTION__, 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);

 	err = ACPI_FAILURE(status) ? -EIO : 0;
 	if (err < 0)
 		ata_dev_printk(dev, KERN_WARNING,
 			       "ACPI _SDD failed (AE 0x%x)\n", status);

 	return err;
 }

 /**
  * 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)
 {
 	unsigned long flags;
 	int rc;

 	/* proceed iff per-port acpi_handle is valid */
 	if (!ap->acpi_handle)
 		return 0;
 	BUG_ON(ap->flags & ATA_FLAG_ACPI_SATA);

 	/* store timing parameters */
 	rc = ata_acpi_gtm(ap, &ap->acpi_gtm);

 	spin_lock_irqsave(ap->lock, flags);
 	if (rc == 0)
 		ap->pflags |= ATA_PFLAG_GTM_VALID;
 	else
 		ap->pflags &= ~ATA_PFLAG_GTM_VALID;
 	spin_unlock_irqrestore(ap->lock, flags);

 	if (rc == -ENOENT)
 		rc = 0;
 	return rc;
 }

 /**
  * 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)
 {
 	int i;

 	if (ap->acpi_handle && (ap->pflags & ATA_PFLAG_GTM_VALID)) {
 		BUG_ON(ap->flags & ATA_FLAG_ACPI_SATA);

 		/* restore timing parameters */
 		ata_acpi_stm(ap, &ap->acpi_gtm);
 	}

 	/* schedule _GTF */
 	for (i = 0; i < ATA_MAX_DEVICES; i++)
 		ap->device[i].flags |= ATA_DFLAG_ACPI_PENDING;
 }

 /**
  * 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->ap;
 	struct ata_eh_context *ehc = &ap->eh_context;
 	int acpi_sata = ap->flags & ATA_FLAG_ACPI_SATA;
 	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)
 			goto acpi_err;
 	}

 	/* do _GTF */
 	rc = ata_acpi_exec_tfs(dev);
 	if (rc < 0)
 		goto acpi_err;

 	dev->flags &= ~ATA_DFLAG_ACPI_PENDING;

 	/* refresh IDENTIFY page if any _GTF command has been executed */
 	if (rc > 0) {
 		rc = ata_dev_reread_id(dev, 0);
 		if (rc < 0) {
 			ata_dev_printk(dev, KERN_ERR, "failed to IDENTIFY "
 				       "after ACPI commands\n");
 			return rc;
 		}
 	}

 	return 0;

  acpi_err:
 	/* let EH retry on the first failure, disable ACPI on the second */
 	if (dev->flags & ATA_DFLAG_ACPI_FAILED) {
 		ata_dev_printk(dev, KERN_WARNING, "ACPI on devcfg failed the "
 			       "second time, disabling (errno=%d)\n", rc);

 		dev->acpi_handle = NULL;

 		/* if port is working, request IDENTIFY reload and continue */
 		if (!(ap->pflags & ATA_PFLAG_FROZEN))
 			rc = 1;
 	}
 	dev->flags |= ATA_DFLAG_ACPI_FAILED;
 	return rc;
 }
	/*
	* 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 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_associate_sata_port(struct ata_port *ap)
	{
	acpi_integer adr = SATA_ADR(ap->port_no, NO_PORT_MULT);

	ap->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->device[i];

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

	/**
	* 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;

	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);
	}
	}

	/**
	* 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.
	*/
	static int ata_acpi_gtm(const 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_printk(ap, KERN_ERR,
	"ACPI get timing mode failed (AE 0x%x)\n",
	status);
	goto out_free;
	}

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
	ata_port_printk(ap, KERN_WARNING,
	"_GTM returned unexpected object type 0x%x\n",
	out_obj->type);

	goto out_free;
	}

	if (out_obj->buffer.length != sizeof(struct ata_acpi_gtm)) {
	ata_port_printk(ap, KERN_ERR,
	"_GTM returned invalid length %d\n",
	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;
	}

	/**
	* 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.
	*/
	static int ata_acpi_stm(const struct ata_port ap, struct ata_acpi_gtm stm)
	{
	acpi_status status;
	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;
	/* 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->device[0].id;
	in_params[2].type = ACPI_TYPE_BUFFER;
	in_params[2].buffer.length = 512;
	in_params[2].buffer.pointer = (u8 *)ap->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_printk(ap, KERN_ERR,
	"ACPI set timing mode failed (status=0x%x)\n", status);
	return -EINVAL;
	}
	return 0;
	}

	/**
	* ata_dev_get_GTF - get the drive bootup default taskfile settings
	* @dev: target ATA device
	* @gtf: output parameter for buffer containing _GTF taskfile arrays
	* @ptr_to_free: pointer which should be freed
	*
	* 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 or doesn't
	* contain valid data. -errno on other errors.
	*/
	static int ata_dev_get_GTF(struct ata_device dev, struct ata_acpi_gtf *gtf,
	void **ptr_to_free)
	{
	struct ata_port *ap = dev->ap;
	acpi_status status;
	struct acpi_buffer output;
	union acpi_object *out_obj;
	int rc = 0;

	/* 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_printk(dev, KERN_DEBUG, "%s: ENTER: port#: %d\n",
	__FUNCTION__, ap->port_no);

	/* _GTF has no input parameters */
	status = acpi_evaluate_object(dev->acpi_handle, "_GTF", NULL, &output);

	if (ACPI_FAILURE(status)) {
	if (status != AE_NOT_FOUND) {
	ata_dev_printk(dev, KERN_WARNING,
	"_GTF evaluation failed (AE 0x%x)\n",
	status);
	rc = -EIO;
	}
	goto out_free;
	}

	if (!output.length \|\| !output.pointer) {
	if (ata_msg_probe(ap))
	ata_dev_printk(dev, KERN_DEBUG, "%s: Run _GTF: "
	"length or ptr is NULL (0x%llx, 0x%p)\n",
	__FUNCTION__,
	(unsigned long long)output.length,
	output.pointer);
	goto out_free;
	}

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
	ata_dev_printk(dev, KERN_WARNING,
	"_GTF unexpected object type 0x%x\n",
	out_obj->type);
	rc = -EINVAL;
	goto out_free;
	}

	if (out_obj->buffer.length % REGS_PER_GTF) {
	ata_dev_printk(dev, KERN_WARNING,
	"unexpected _GTF length (%d)\n",
	out_obj->buffer.length);
	rc = -EINVAL;
	goto out_free;
	}

	*ptr_to_free = out_obj;
	gtf = (void )out_obj->buffer.pointer;
	rc = out_obj->buffer.length / REGS_PER_GTF;

	if (ata_msg_probe(ap))
	ata_dev_printk(dev, KERN_DEBUG, "%s: returning "
	"gtf=%p, gtf_count=%d, ptr_to_free=%p\n",
	__FUNCTION__, gtf, rc, ptr_to_free);
	return rc;

	out_free:
	kfree(output.pointer);
	return rc;
	}

	/**
	* taskfile_load_raw - 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 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:
	* EH context.
	*
	* RETURNS:
	* 0 on success, -errno on failure.
	*/
	static int taskfile_load_raw(struct ata_device *dev,
	const struct ata_acpi_gtf *gtf)
	{
	struct ata_port *ap = dev->ap;
	struct ata_taskfile tf, rtf;
	unsigned int err_mask;

	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_tf_init(dev, &tf);

	/* convert gtf to tf */
	tf.flags \|= ATA_TFLAG_ISADDR \| ATA_TFLAG_DEVICE; /* TBD */
	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 */

	if (ata_msg_probe(ap))
	ata_dev_printk(dev, KERN_DEBUG, "executing ACPI cmd "
	"%02x/%02x:%02x:%02x:%02x:%02x:%02x\n",
	tf.command, tf.feature, tf.nsect,
	tf.lbal, tf.lbam, tf.lbah, tf.device);

	rtf = tf;
	err_mask = ata_exec_internal(dev, &rtf, NULL, DMA_NONE, NULL, 0);
	if (err_mask) {
	ata_dev_printk(dev, KERN_ERR,
	"ACPI cmd %02x/%02x:%02x:%02x:%02x:%02x:%02x failed "
	"(Emask=0x%x Stat=0x%02x Err=0x%02x)\n",
	tf.command, tf.feature, tf.nsect, tf.lbal, tf.lbam,
	tf.lbah, tf.device, err_mask, rtf.command, rtf.feature);
	return -EIO;
	}

	return 0;
	}

	/**
	* ata_acpi_exec_tfs - get then write drive taskfile settings
	* @dev: target ATA device
	*
	* Evaluate _GTF and excute returned taskfiles.
	*
	* LOCKING:
	* EH context.
	*
	* RETURNS:
	* Number of executed taskfiles on success, 0 if _GTF doesn't exist or
	* doesn't contain valid data. -errno on other errors.
	*/
	static int ata_acpi_exec_tfs(struct ata_device *dev)
	{
	struct ata_acpi_gtf *gtf = NULL;
	void *ptr_to_free = NULL;
	int gtf_count, i, rc;

	/* get taskfiles */
	rc = ata_dev_get_GTF(dev, &gtf, &ptr_to_free);
	if (rc < 0)
	return rc;
	gtf_count = rc;

	/* execute them */
	for (i = 0, rc = 0; i < gtf_count; i++) {
	int tmp;

	/* ACPI errors are eventually ignored. Run till the
	* end even after errors.
	*/
	tmp = taskfile_load_raw(dev, gtf++);
	if (!rc)
	rc = tmp;
	}

	kfree(ptr_to_free);

	if (rc == 0)
	return gtf_count;
	return rc;
	}

	/**
	* 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, -errno on failure.
	*/
	static int ata_acpi_push_id(struct ata_device *dev)
	{
	struct ata_port *ap = dev->ap;
	int err;
	acpi_status status;
	struct acpi_object_list input;
	union acpi_object in_params[1];

	if (ata_msg_probe(ap))
	ata_dev_printk(dev, KERN_DEBUG, "%s: ix = %d, port#: %d\n",
	__FUNCTION__, 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);

	err = ACPI_FAILURE(status) ? -EIO : 0;
	if (err < 0)
	ata_dev_printk(dev, KERN_WARNING,
	"ACPI _SDD failed (AE 0x%x)\n", status);

	return err;
	}

	/**
	* 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)
	{
	unsigned long flags;
	int rc;

	/* proceed iff per-port acpi_handle is valid */
	if (!ap->acpi_handle)
	return 0;
	BUG_ON(ap->flags & ATA_FLAG_ACPI_SATA);

	/* store timing parameters */
	rc = ata_acpi_gtm(ap, &ap->acpi_gtm);

	spin_lock_irqsave(ap->lock, flags);
	if (rc == 0)
	ap->pflags \|= ATA_PFLAG_GTM_VALID;
	else
	ap->pflags &= ~ATA_PFLAG_GTM_VALID;
	spin_unlock_irqrestore(ap->lock, flags);

	if (rc == -ENOENT)
	rc = 0;
	return rc;
	}

	/**
	* 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)
	{
	int i;

	if (ap->acpi_handle && (ap->pflags & ATA_PFLAG_GTM_VALID)) {
	BUG_ON(ap->flags & ATA_FLAG_ACPI_SATA);

	/* restore timing parameters */
	ata_acpi_stm(ap, &ap->acpi_gtm);
	}

	/* schedule _GTF */
	for (i = 0; i < ATA_MAX_DEVICES; i++)
	ap->device[i].flags \|= ATA_DFLAG_ACPI_PENDING;
	}

	/**
	* 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->ap;
	struct ata_eh_context *ehc = &ap->eh_context;
	int acpi_sata = ap->flags & ATA_FLAG_ACPI_SATA;
	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)
	goto acpi_err;
	}

	/* do _GTF */
	rc = ata_acpi_exec_tfs(dev);
	if (rc < 0)
	goto acpi_err;

	dev->flags &= ~ATA_DFLAG_ACPI_PENDING;

	/* refresh IDENTIFY page if any _GTF command has been executed */
	if (rc > 0) {
	rc = ata_dev_reread_id(dev, 0);
	if (rc < 0) {
	ata_dev_printk(dev, KERN_ERR, "failed to IDENTIFY "
	"after ACPI commands\n");
	return rc;
	}
	}

	return 0;

	acpi_err:
	/* let EH retry on the first failure, disable ACPI on the second */
	if (dev->flags & ATA_DFLAG_ACPI_FAILED) {
	ata_dev_printk(dev, KERN_WARNING, "ACPI on devcfg failed the "
	"second time, disabling (errno=%d)\n", rc);

	dev->acpi_handle = NULL;

	/* if port is working, request IDENTIFY reload and continue */
	if (!(ap->pflags & ATA_PFLAG_FROZEN))
	rc = 1;
	}
	dev->flags \|= ATA_DFLAG_ACPI_FAILED;
	return rc;
	}