libata-acpi.c

linux 内核源代码

/*
 * 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 <scsi/scsi_device.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>

enum {
	ATA_ACPI_FILTER_SETXFER	= 1 << 0,
	ATA_ACPI_FILTER_LOCK	= 1 << 1,

	ATA_ACPI_FILTER_DEFAULT	= ATA_ACPI_FILTER_SETXFER |
				  ATA_ACPI_FILTER_LOCK,
};

static 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)");

#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 (!ap->nr_pmp_links) {
		acpi_integer 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_port_for_each_link(link, ap) {
			acpi_integer 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;
}

static void ata_acpi_handle_hotplug(struct ata_port *ap, struct kobject *kobj,
				    u32 event)
{
	char event_string[12];
	char *envp[] = { event_string, NULL };
	struct ata_eh_info *ehi = &ap->link.eh_info;

	if (event == 0 || event == 1) {
	       unsigned long flags;
	       spin_lock_irqsave(ap->lock, flags);
	       ata_ehi_clear_desc(ehi);
	       ata_ehi_push_desc(ehi, "ACPI event");
	       ata_ehi_hotplugged(ehi);
	       ata_port_freeze(ap);
	       spin_unlock_irqrestore(ap->lock, flags);
	}

	if (kobj) {
		sprintf(event_string, "BAY_EVENT=%d", event);
		kobject_uevent_env(kobj, KOBJ_CHANGE, envp);
	}
}

static void ata_acpi_dev_notify(acpi_handle handle, u32 event, void *data)
{
	struct ata_device *dev = data;
	struct kobject *kobj = NULL;

	if (dev->sdev)
		kobj = &dev->sdev->sdev_gendev.kobj;

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

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

	ata_acpi_handle_hotplug(ap, &ap->dev->kobj, event);
}

/**
 * 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)
			acpi_install_notify_handler (ap->acpi_handle,
						     ACPI_SYSTEM_NOTIFY,
						     ata_acpi_ap_notify,
						     ap);

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

			if (dev->acpi_handle)
				acpi_install_notify_handler (dev->acpi_handle,
							     ACPI_SYSTEM_NOTIFY,
							     ata_acpi_dev_notify,
							     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_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;
}

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_printk(ap, KERN_ERR,
			"ACPI set timing mode failed (status=0x%x)\n", 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_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);
	out_obj = dev->gtf_cache = output.pointer;

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

	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;
	}

 done:
	rc = out_obj->buffer.length / REGS_PER_GTF;
	if (gtf) {
		*gtf = (void *)out_obj->buffer.pointer;
		if (ata_msg_probe(ap))
			ata_dev_printk(dev, KERN_DEBUG,
				       "%s: returning gtf=%p, gtf_count=%d\n",
				       __FUNCTION__, *gtf, rc);
	}