drivers/ide/ide-acpi.c - linux/kernel/git/bpf/bpf - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * 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/acpi.h>
 #include <linux/ata.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/ide.h>
 #include <linux/pci.h>
 #include <linux/dmi.h>
 #include <linux/module.h>

 #define REGS_PER_GTF		7

 struct GTM_buffer {
 	u32	PIO_speed0;
 	u32	DMA_speed0;
 	u32	PIO_speed1;
 	u32	DMA_speed1;
 	u32	GTM_flags;
 };

 struct ide_acpi_drive_link {
 	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, __func__, ## args)
 #else
 #define DEBPRINT(fmt, args...)	do {} while (0)
 #endif	/* DEBUGGING */

 static bool ide_noacpi;
 module_param_named(noacpi, ide_noacpi, bool, 0);
 MODULE_PARM_DESC(noacpi, "disable IDE ACPI support");

 static bool ide_acpigtf;
 module_param_named(acpigtf, ide_acpigtf, bool, 0);
 MODULE_PARM_DESC(acpigtf, "enable IDE ACPI _GTF support");

 static bool ide_acpionboot;
 module_param_named(acpionboot, ide_acpionboot, bool, 0);
 MODULE_PARM_DESC(acpionboot, "call IDE ACPI methods on boot");

 static bool ide_noacpi_psx;
 static int no_acpi_psx(const struct dmi_system_id *id)
 {
 	ide_noacpi_psx = true;
 	printk(KERN_NOTICE"%s detected - disable ACPI _PSx.\n", id->ident);
 	return 0;
 }

 static const struct dmi_system_id ide_acpi_dmi_table[] = {
 	/* Bug 9673. */
 	/* We should check if this is because ACPI NVS isn't save/restored. */
 	{
 		.callback = no_acpi_psx,
 		.ident    = "HP nx9005",
 		.matches  = {
 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies Ltd."),
 			DMI_MATCH(DMI_BIOS_VERSION, "KAM1.60")
 		},
 	},

 	{ }	/* terminate list */
 };

 int ide_acpi_init(void)
 {
 	dmi_check_system(ide_acpi_dmi_table);
 	return 0;
 }

 bool ide_port_acpi(ide_hwif_t *hwif)
 {
 	return ide_noacpi == 0 && hwif->acpidata;
 }

 static acpi_handle acpi_get_child(acpi_handle handle, u64 addr)
 {
 	struct acpi_device *adev;

 	if (!handle || acpi_bus_get_device(handle, &adev))
 		return NULL;

 	adev = acpi_find_child_device(adev, addr, false);
 	return adev ? adev->handle : NULL;
 }

 /**
  * 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,
 			       u64 *pcidevfn)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	unsigned int bus, devnum, func;
 	u64 addr;
 	acpi_handle dev_handle;
 	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 = (u64)(devnum << 16 | func);

 	DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);

 	dev_handle = ACPI_HANDLE(dev);
 	if (!dev_handle) {
 		DEBPRINT("no acpi handle for device\n");
 		goto err;
 	}

 	status = acpi_get_object_info(dev_handle, &dinfo);
 	if (ACPI_FAILURE(status)) {
 		DEBPRINT("get_object_info for device failed\n");
 		goto err;
 	}
 	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		uninitialized_var(dev_handle);
 	u64			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;
 }

 /**
  * 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;
 	int				err = -ENODEV;

 	*gtf_length = 0;
 	*gtf_address = 0UL;
 	*obj_loc = 0UL;

 	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",
 		       __func__, 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",
 		       __func__, 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;
 }

 /**
  * 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 = 0, err;
 	int			gtf_count = gtf_length / REGS_PER_GTF;
 	int			ix;

 	DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
 		 gtf_length, gtf_length, gtf_count, gtf_address);

 	/* send all taskfile registers (0x1f1-0x1f7) *in*that*order* */
 	for (ix = 0; ix < gtf_count; ix++) {
 		u8 *gtf = (u8 *)(gtf_address + ix * REGS_PER_GTF);
 		struct ide_cmd cmd;

 		DEBPRINT("(0x1f1-1f7): "
 			 "hex: %02x %02x %02x %02x %02x %02x %02x\n",
 			 gtf[0], gtf[1], gtf[2],
 			 gtf[3], gtf[4], gtf[5], gtf[6]);

 		if (!ide_acpigtf) {
 			DEBPRINT("_GTF execution disabled\n");
 			continue;
 		}

 		/* convert GTF to taskfile */
 		memset(&cmd, 0, sizeof(cmd));
 		memcpy(&cmd.tf.feature, gtf, REGS_PER_GTF);
 		cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
 		cmd.valid.in.tf  = IDE_VALID_IN_TF  | IDE_VALID_DEVICE;

 		err = ide_no_data_taskfile(drive, &cmd);
 		if (err) {
 			printk(KERN_ERR "%s: ide_no_data_taskfile failed: %u\n",
 					__func__, err);
 			rc = err;
 		}
 	}

 	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;

 	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;
 }

 /**
  * 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;

 	/* 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) {
 		DEBPRINT("Run _GTM: error: "
 		       "expected object type of ACPI_TYPE_BUFFER, "
 		       "got 0x%x\n", out_obj->type);
 		kfree(output.pointer);
 		return;
 	}

 	if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 	    out_obj->buffer.length != sizeof(struct GTM_buffer)) {
 		printk(KERN_ERR
 			"%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
 			"addr (0x%p)\n",
 			__func__, out_obj->buffer.length,
 			sizeof(struct GTM_buffer), out_obj->buffer.pointer);
 		kfree(output.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);
 }

 /**
  * 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 drive->id 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;

 	/* 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 = ATA_ID_WORDS * 2;
 	in_params[1].buffer.pointer = (u8 *)&master->idbuff;
 	in_params[2].type = ACPI_TYPE_BUFFER;
 	in_params[2].buffer.length = ATA_ID_WORDS * 2;
 	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);
 }

 /**
  * ide_acpi_set_state - set the channel power state
  * @hwif: target IDE interface
  * @on: 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 ide_acpi_set_state(ide_hwif_t *hwif, int on)
 {
 	ide_drive_t *drive;
 	int i;

 	if (ide_noacpi_psx)
 		return;

 	DEBPRINT("ENTER:\n");

 	/* channel first and then drives for power on and verse versa for power off */
 	if (on)
 		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);

 	ide_port_for_each_present_dev(i, drive, hwif) {
 		if (drive->acpidata->obj_handle)
 			acpi_bus_set_power(drive->acpidata->obj_handle,
 				on ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
 	}

 	if (!on)
 		acpi_bus_set_power(hwif->acpidata->obj_handle,
 				   ACPI_STATE_D3_COLD);
 }

 /**
  * ide_acpi_init_port - 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_port(ide_hwif_t *hwif)
 {
 	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;
 	}
 }

 void ide_acpi_port_init_devices(ide_hwif_t *hwif)
 {
 	ide_drive_t *drive;
 	int i, err;

 	if (hwif->acpidata == NULL)
 		return;

 	/*
 	 * The ACPI spec mandates that we send information
 	 * for both drives, regardless whether they are connected
 	 * or not.
 	 */
 	hwif->devices[0]->acpidata = &hwif->acpidata->master;
 	hwif->devices[1]->acpidata = &hwif->acpidata->slave;

 	/* get _ADR info for each device */
 	ide_port_for_each_present_dev(i, drive, hwif) {
 		acpi_handle dev_handle;

 		DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
 			 drive->name, hwif->channel, drive->dn & 1);

 		/* TBD: could also check ACPI object VALID bits */
 		dev_handle = acpi_get_child(hwif->acpidata->obj_handle,
 					    drive->dn & 1);

 		DEBPRINT("drive %s handle 0x%p\n", drive->name, dev_handle);

 		drive->acpidata->obj_handle = dev_handle;
 	}

 	/* send IDENTIFY for each device */
 	ide_port_for_each_present_dev(i, drive, hwif) {
 		err = taskfile_lib_get_identify(drive, drive->acpidata->idbuff);
 		if (err)
 			DEBPRINT("identify device %s failed (%d)\n",
 				 drive->name, err);
 	}

 	if (ide_noacpi || ide_acpionboot == 0) {
 		DEBPRINT("ACPI methods disabled on boot\n");
 		return;
 	}

 	/* ACPI _PS0 before _STM */
 	ide_acpi_set_state(hwif, 1);
 	/*
 	 * ACPI requires us to call _STM on startup
 	 */
 	ide_acpi_get_timing(hwif);
 	ide_acpi_push_timing(hwif);

 	ide_port_for_each_present_dev(i, drive, hwif) {
 		ide_acpi_exec_tfs(drive);
 	}
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* 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/acpi.h>
	#include <linux/ata.h>
	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/ide.h>
	#include <linux/pci.h>
	#include <linux/dmi.h>
	#include <linux/module.h>

	#define REGS_PER_GTF 7

	struct GTM_buffer {
	u32 PIO_speed0;
	u32 DMA_speed0;
	u32 PIO_speed1;
	u32 DMA_speed1;
	u32 GTM_flags;
	};

	struct ide_acpi_drive_link {
	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, __func__, ## args)
	#else
	#define DEBPRINT(fmt, args...) do {} while (0)
	#endif /* DEBUGGING */

	static bool ide_noacpi;
	module_param_named(noacpi, ide_noacpi, bool, 0);
	MODULE_PARM_DESC(noacpi, "disable IDE ACPI support");

	static bool ide_acpigtf;
	module_param_named(acpigtf, ide_acpigtf, bool, 0);
	MODULE_PARM_DESC(acpigtf, "enable IDE ACPI _GTF support");

	static bool ide_acpionboot;
	module_param_named(acpionboot, ide_acpionboot, bool, 0);
	MODULE_PARM_DESC(acpionboot, "call IDE ACPI methods on boot");

	static bool ide_noacpi_psx;
	static int no_acpi_psx(const struct dmi_system_id *id)
	{
	ide_noacpi_psx = true;
	printk(KERN_NOTICE"%s detected - disable ACPI _PSx.\n", id->ident);
	return 0;
	}

	static const struct dmi_system_id ide_acpi_dmi_table[] = {
	/* Bug 9673. */
	/* We should check if this is because ACPI NVS isn't save/restored. */
	{
	.callback = no_acpi_psx,
	.ident = "HP nx9005",
	.matches = {
	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies Ltd."),
	DMI_MATCH(DMI_BIOS_VERSION, "KAM1.60")
	},
	},

	{ } /* terminate list */
	};

	int ide_acpi_init(void)
	{
	dmi_check_system(ide_acpi_dmi_table);
	return 0;
	}

	bool ide_port_acpi(ide_hwif_t *hwif)
	{
	return ide_noacpi == 0 && hwif->acpidata;
	}

	static acpi_handle acpi_get_child(acpi_handle handle, u64 addr)
	{
	struct acpi_device *adev;

	if (!handle \|\| acpi_bus_get_device(handle, &adev))
	return NULL;

	adev = acpi_find_child_device(adev, addr, false);
	return adev ? adev->handle : NULL;
	}

	/**
	* 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,
	u64 *pcidevfn)
	{
	struct pci_dev *pdev = to_pci_dev(dev);
	unsigned int bus, devnum, func;
	u64 addr;
	acpi_handle dev_handle;
	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 = (u64)(devnum << 16 \| func);

	DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);

	dev_handle = ACPI_HANDLE(dev);
	if (!dev_handle) {
	DEBPRINT("no acpi handle for device\n");
	goto err;
	}

	status = acpi_get_object_info(dev_handle, &dinfo);
	if (ACPI_FAILURE(status)) {
	DEBPRINT("get_object_info for device failed\n");
	goto err;
	}
	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 uninitialized_var(dev_handle);
	u64 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;
	}

	/**
	* 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;
	int err = -ENODEV;

	*gtf_length = 0;
	*gtf_address = 0UL;
	*obj_loc = 0UL;

	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",
	__func__, 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",
	__func__, 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;
	}

	/**
	* 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 = 0, err;
	int gtf_count = gtf_length / REGS_PER_GTF;
	int ix;

	DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
	gtf_length, gtf_length, gtf_count, gtf_address);

	/* send all taskfile registers (0x1f1-0x1f7) inthatorder */
	for (ix = 0; ix < gtf_count; ix++) {
	u8 gtf = (u8 )(gtf_address + ix * REGS_PER_GTF);
	struct ide_cmd cmd;

	DEBPRINT("(0x1f1-1f7): "
	"hex: %02x %02x %02x %02x %02x %02x %02x\n",
	gtf[0], gtf[1], gtf[2],
	gtf[3], gtf[4], gtf[5], gtf[6]);

	if (!ide_acpigtf) {
	DEBPRINT("_GTF execution disabled\n");
	continue;
	}

	/* convert GTF to taskfile */
	memset(&cmd, 0, sizeof(cmd));
	memcpy(&cmd.tf.feature, gtf, REGS_PER_GTF);
	cmd.valid.out.tf = IDE_VALID_OUT_TF \| IDE_VALID_DEVICE;
	cmd.valid.in.tf = IDE_VALID_IN_TF \| IDE_VALID_DEVICE;

	err = ide_no_data_taskfile(drive, &cmd);
	if (err) {
	printk(KERN_ERR "%s: ide_no_data_taskfile failed: %u\n",
	__func__, err);
	rc = err;
	}
	}

	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;

	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;
	}

	/**
	* 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;

	/* 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) {
	DEBPRINT("Run _GTM: error: "
	"expected object type of ACPI_TYPE_BUFFER, "
	"got 0x%x\n", out_obj->type);
	kfree(output.pointer);
	return;
	}

	if (!out_obj->buffer.length \|\| !out_obj->buffer.pointer \|\|
	out_obj->buffer.length != sizeof(struct GTM_buffer)) {
	printk(KERN_ERR
	"%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
	"addr (0x%p)\n",
	__func__, out_obj->buffer.length,
	sizeof(struct GTM_buffer), out_obj->buffer.pointer);
	kfree(output.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);
	}

	/**
	* 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 drive->id 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;

	/* 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 = ATA_ID_WORDS * 2;
	in_params[1].buffer.pointer = (u8 *)&master->idbuff;
	in_params[2].type = ACPI_TYPE_BUFFER;
	in_params[2].buffer.length = ATA_ID_WORDS * 2;
	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);
	}

	/**
	* ide_acpi_set_state - set the channel power state
	* @hwif: target IDE interface
	* @on: 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 ide_acpi_set_state(ide_hwif_t *hwif, int on)
	{
	ide_drive_t *drive;
	int i;

	if (ide_noacpi_psx)
	return;

	DEBPRINT("ENTER:\n");

	/* channel first and then drives for power on and verse versa for power off */
	if (on)
	acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);

	ide_port_for_each_present_dev(i, drive, hwif) {
	if (drive->acpidata->obj_handle)
	acpi_bus_set_power(drive->acpidata->obj_handle,
	on ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
	}

	if (!on)
	acpi_bus_set_power(hwif->acpidata->obj_handle,
	ACPI_STATE_D3_COLD);
	}

	/**
	* ide_acpi_init_port - 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_port(ide_hwif_t *hwif)
	{
	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;
	}
	}

	void ide_acpi_port_init_devices(ide_hwif_t *hwif)
	{
	ide_drive_t *drive;
	int i, err;

	if (hwif->acpidata == NULL)
	return;

	/*
	* The ACPI spec mandates that we send information
	* for both drives, regardless whether they are connected
	* or not.
	*/
	hwif->devices[0]->acpidata = &hwif->acpidata->master;
	hwif->devices[1]->acpidata = &hwif->acpidata->slave;

	/* get _ADR info for each device */
	ide_port_for_each_present_dev(i, drive, hwif) {
	acpi_handle dev_handle;

	DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
	drive->name, hwif->channel, drive->dn & 1);

	/* TBD: could also check ACPI object VALID bits */
	dev_handle = acpi_get_child(hwif->acpidata->obj_handle,
	drive->dn & 1);

	DEBPRINT("drive %s handle 0x%p\n", drive->name, dev_handle);

	drive->acpidata->obj_handle = dev_handle;
	}

	/* send IDENTIFY for each device */
	ide_port_for_each_present_dev(i, drive, hwif) {
	err = taskfile_lib_get_identify(drive, drive->acpidata->idbuff);
	if (err)
	DEBPRINT("identify device %s failed (%d)\n",
	drive->name, err);
	}

	if (ide_noacpi \|\| ide_acpionboot == 0) {
	DEBPRINT("ACPI methods disabled on boot\n");
	return;
	}

	/* ACPI _PS0 before _STM */
	ide_acpi_set_state(hwif, 1);
	/*
	* ACPI requires us to call _STM on startup
	*/
	ide_acpi_get_timing(hwif);
	ide_acpi_push_timing(hwif);

	ide_port_for_each_present_dev(i, drive, hwif) {
	ide_acpi_exec_tfs(drive);
	}
	}