acpiphp_glue.c

audio driver for hotplug pci on linux 2.6.27

/*
 * ACPI PCI HotPlug glue functions to ACPI CA subsystem
 *
 * Copyright (C) 2002,2003 Takayoshi Kochi ([e-mail])
 * Copyright (C) 2002 Hiroshi Aono ([e-mail])
 * Copyright (C) 2002,2003 NEC Corporation
 * Copyright (C) 2003-2005 Matthew Wilcox ([e-mail])
 * Copyright (C) 2003-2005 Hewlett Packard
 * Copyright (C) 2005 Rajesh Shah ([e-mail])
 * Copyright (C) 2005 Intel Corporation
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <[e-mail]>
 *
 */

/*
 * Lifetime rules for pci_dev:
 *  - The one in acpiphp_func has its refcount elevated by pci_get_slot()
 *    when the driver is loaded or when an insertion event occurs.  It loses
 *    a refcount when its ejected or the driver unloads.
 *  - The one in acpiphp_bridge has its refcount elevated by pci_get_slot()
 *    when the bridge is scanned and it loses a refcount when the bridge
 *    is removed.
 */

#include <linux/init.h>
#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/mutex.h>

#include "../pci.h"
#include "acpiphp.h"

static LIST_HEAD(bridge_list);
static LIST_HEAD(ioapic_list);
static DEFINE_SPINLOCK(ioapic_list_lock);

#define MY_NAME "acpiphp_glue"

static void handle_hotplug_event_bridge (acpi_handle, u32, void *);
static void acpiphp_sanitize_bus(struct pci_bus *bus);
static void acpiphp_set_hpp_values(acpi_handle handle, struct pci_bus *bus);
static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *context);


/*
 * initialization & terminatation routines
 */

/**
 * is_ejectable - determine if a slot is ejectable
 * @handle: handle to acpi namespace
 *
 * Ejectable slot should satisfy at least these conditions:
 *
 *  1. has _ADR method
 *  2. has _EJ0 method
 *
 * optionally
 *
 *  1. has _STA method
 *  2. has _PS0 method
 *  3. has _PS3 method
 *  4. ..
 */
static int is_ejectable(acpi_handle handle)
{
	acpi_status status;
	acpi_handle tmp;

	status = acpi_get_handle(handle, "_ADR", &tmp);
	if (ACPI_FAILURE(status)) {
		return 0;
	}

	status = acpi_get_handle(handle, "_EJ0", &tmp);
	if (ACPI_FAILURE(status)) {
		return 0;
	}

	return 1;
}


/* callback routine to check for the existence of ejectable slots */
static acpi_status
is_ejectable_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	int *count = (int *)context;

	if (is_ejectable(handle)) {
		(*count)++;
		/* only one ejectable slot is enough */
		return AE_CTRL_TERMINATE;
	} else {
		return AE_OK;
	}
}

/* callback routine to check for the existence of a pci dock device */
static acpi_status
is_pci_dock_device(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	int *count = (int *)context;

	if (is_dock_device(handle)) {
		(*count)++;
		return AE_CTRL_TERMINATE;
	} else {
		return AE_OK;
	}
}




/*
 * the _DCK method can do funny things... and sometimes not
 * hah-hah funny.
 *
 * TBD - figure out a way to only call fixups for
 * systems that require them.
 */
static int post_dock_fixups(struct notifier_block *nb, unsigned long val,
	void *v)
{
	struct acpiphp_func *func = container_of(nb, struct acpiphp_func, nb);
	struct pci_bus *bus = func->slot->bridge->pci_bus;
	u32 buses;

	if (!bus->self)
		return  NOTIFY_OK;

	/* fixup bad _DCK function that rewrites
	 * secondary bridge on slot
	 */
	pci_read_config_dword(bus->self,
			PCI_PRIMARY_BUS,
			&buses);

	if (((buses >> 8) & 0xff) != bus->secondary) {
		buses = (buses & 0xff000000)
	     		| ((unsigned int)(bus->primary)     <<  0)
	     		| ((unsigned int)(bus->secondary)   <<  8)
	     		| ((unsigned int)(bus->subordinate) << 16);
		pci_write_config_dword(bus->self, PCI_PRIMARY_BUS, buses);
	}
	return NOTIFY_OK;
}


static struct acpi_dock_ops acpiphp_dock_ops = {
	.handler = handle_hotplug_event_func,
};

/* callback routine to register each ACPI PCI slot object */
static acpi_status
register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	struct acpiphp_bridge *bridge = (struct acpiphp_bridge *)context;
	struct acpiphp_slot *slot;
	struct acpiphp_func *newfunc;
	acpi_handle tmp;
	acpi_status status = AE_OK;
	unsigned long long adr, sun;
	int device, function, retval;

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);

	if (ACPI_FAILURE(status))
		return AE_OK;

	status = acpi_get_handle(handle, "_EJ0", &tmp);

	if (ACPI_FAILURE(status) && !(is_dock_device(handle)))
		return AE_OK;

	device = (adr >> 16) & 0xffff;
	function = adr & 0xffff;

	newfunc = kzalloc(sizeof(struct acpiphp_func), GFP_KERNEL);
	if (!newfunc)
		return AE_NO_MEMORY;

	INIT_LIST_HEAD(&newfunc->sibling);
	newfunc->handle = handle;
	newfunc->function = function;
	if (ACPI_SUCCESS(status))
		newfunc->flags = FUNC_HAS_EJ0;

	if (ACPI_SUCCESS(acpi_get_handle(handle, "_STA", &tmp)))
		newfunc->flags |= FUNC_HAS_STA;

	if (ACPI_SUCCESS(acpi_get_handle(handle, "_PS0", &tmp)))
		newfunc->flags |= FUNC_HAS_PS0;

	if (ACPI_SUCCESS(acpi_get_handle(handle, "_PS3", &tmp)))
		newfunc->flags |= FUNC_HAS_PS3;

	if (ACPI_SUCCESS(acpi_get_handle(handle, "_DCK", &tmp)))
		newfunc->flags |= FUNC_HAS_DCK;

	status = acpi_evaluate_integer(handle, "_SUN", NULL, &sun);
	if (ACPI_FAILURE(status)) {
		/*
		 * use the count of the number of slots we've found
		 * for the number of the slot
		 */
		sun = bridge->nr_slots+1;
	}

	/* search for objects that share the same slot */
	for (slot = bridge->slots; slot; slot = slot->next)
		if (slot->device == device) {
			if (slot->sun != sun)
				warn("sibling found, but _SUN doesn't match!\n");
			break;
		}

	if (!slot) {
		slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL);
		if (!slot) {
			kfree(newfunc);
			return AE_NO_MEMORY;
		}

		slot->bridge = bridge;
		slot->device = device;
		slot->sun = sun;
		INIT_LIST_HEAD(&slot->funcs);
		mutex_init(&slot->crit_sect);

		slot->next = bridge->slots;
		bridge->slots = slot;

		bridge->nr_slots++;

		dbg("found ACPI PCI Hotplug slot %d at PCI %04x:%02x:%02x\n",
				slot->sun, pci_domain_nr(bridge->pci_bus),
				bridge->pci_bus->number, slot->device);
		retval = acpiphp_register_hotplug_slot(slot);
		if (retval) {
			if (retval == -EBUSY)
				warn("Slot %d already registered by another "
					"hotplug driver\n", slot->sun);
			else
				warn("acpiphp_register_hotplug_slot failed "
					"(err code = 0x%x)\n", retval);
			goto err_exit;
		}
	}

	newfunc->slot = slot;
	list_add_tail(&newfunc->sibling, &slot->funcs);

	/* associate corresponding pci_dev */
	newfunc->pci_dev = pci_get_slot(bridge->pci_bus,
					 PCI_DEVFN(device, function));
	if (newfunc->pci_dev) {
		slot->flags |= (SLOT_ENABLED | SLOT_POWEREDON);
	}

	if (is_dock_device(handle)) {
		/* we don't want to call this device's _EJ0
		 * because we want the dock notify handler
		 * to call it after it calls _DCK
		 */
		newfunc->flags &= ~FUNC_HAS_EJ0;
		if (register_hotplug_dock_device(handle,
			&acpiphp_dock_ops, newfunc))
			dbg("failed to register dock device\n");

		/* we need to be notified when dock events happen
		 * outside of the hotplug operation, since we may
		 * need to do fixups before we can hotplug.
		 */
		newfunc->nb.notifier_call = post_dock_fixups;
		if (register_dock_notifier(&newfunc->nb))
			dbg("failed to register a dock notifier");
	}

	/* install notify handler */
	if (!(newfunc->flags & FUNC_HAS_DCK)) {
		status = acpi_install_notify_handler(handle,
					     ACPI_SYSTEM_NOTIFY,
					     handle_hotplug_event_func,
					     newfunc);

		if (ACPI_FAILURE(status))
			err("failed to register interrupt notify handler\n");
	} else
		status = AE_OK;

	return status;

 err_exit:
	bridge->nr_slots--;
	bridge->slots = slot->next;
	kfree(slot);
	kfree(newfunc);

	return AE_OK;
}


/* see if it's worth looking at this bridge */
static int detect_ejectable_slots(acpi_handle *bridge_handle)
{
	acpi_status status;
	int count;

	count = 0;

	/* only check slots defined directly below bridge object */
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge_handle, (u32)1,
				     is_ejectable_slot, (void *)&count, NULL);

	/*
	 * we also need to add this bridge if there is a dock bridge or
	 * other pci device on a dock station (removable)
	 */
	if (!count)
		status = acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge_handle,
				(u32)1, is_pci_dock_device, (void *)&count,
				NULL);

	return count;
}


/* decode ACPI 2.0 _HPP hot plug parameters */
static void decode_hpp(struct acpiphp_bridge *bridge)
{
	acpi_status status;

	status = acpi_get_hp_params_from_firmware(bridge->pci_bus, &bridge->hpp);
	if (ACPI_FAILURE(status) ||
	    !bridge->hpp.t0 || (bridge->hpp.t0->revision > 1)) {
		/* use default numbers */
		printk(KERN_WARNING
		       "%s: Could not get hotplug parameters. Use defaults\n",
		       __func__);
		bridge->hpp.t0 = &bridge->hpp.type0_data;
		bridge->hpp.t0->revision = 0;
		bridge->hpp.t0->cache_line_size = 0x10;
		bridge->hpp.t0->latency_timer = 0x40;
		bridge->hpp.t0->enable_serr = 0;
		bridge->hpp.t0->enable_perr = 0;
	}
}



/* initialize miscellaneous stuff for both root and PCI-to-PCI bridge */
static void init_bridge_misc(struct acpiphp_bridge *bridge)
{
	acpi_status status;

	/* decode ACPI 2.0 _HPP (hot plug parameters) */
	decode_hpp(bridge);

	/* must be added to the list prior to calling register_slot */
	list_add(&bridge->list, &bridge_list);

	/* register all slot objects under this bridge */
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge->handle, (u32)1,
				     register_slot, bridge, NULL);
	if (ACPI_FAILURE(status)) {
		list_del(&bridge->list);
		return;
	}

	/* install notify handler */
	if (bridge->type != BRIDGE_TYPE_HOST) {
		if ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->func) {
			status = acpi_remove_notify_handler(bridge->func->handle,
						ACPI_SYSTEM_NOTIFY,
						handle_hotplug_event_func);
			if (ACPI_FAILURE(status))
				err("failed to remove notify handler\n");
		}
		status = acpi_install_notify_handler(bridge->handle,
					     ACPI_SYSTEM_NOTIFY,
					     handle_hotplug_event_bridge,
					     bridge);

		if (ACPI_FAILURE(status)) {
			err("failed to register interrupt notify handler\n");
		}
	}
}


/* find acpiphp_func from acpiphp_bridge */
static struct acpiphp_func *acpiphp_bridge_handle_to_function(acpi_handle handle)
{
	struct list_head *node, *l;
	struct acpiphp_bridge *bridge;
	struct acpiphp_slot *slot;
	struct acpiphp_func *func;

	list_for_each(node, &bridge_list) {
		bridge = list_entry(node, struct acpiphp_bridge, list);
		for (slot = bridge->slots; slot; slot = slot->next) {
			list_for_each(l, &slot->funcs) {
				func = list_entry(l, struct acpiphp_func,
							sibling);
				if (func->handle == handle)
					return func;
			}
		}
	}

	return NULL;
}


static inline void config_p2p_bridge_flags(struct acpiphp_bridge *bridge)
{
	acpi_handle dummy_handle;

	if (ACPI_SUCCESS(acpi_get_handle(bridge->handle,
					"_STA", &dummy_handle)))
		bridge->flags |= BRIDGE_HAS_STA;

	if (ACPI_SUCCESS(acpi_get_handle(bridge->handle,
					"_EJ0", &dummy_handle)))
		bridge->flags |= BRIDGE_HAS_EJ0;

	if (ACPI_SUCCESS(acpi_get_handle(bridge->handle,
					"_PS0", &dummy_handle)))
		bridge->flags |= BRIDGE_HAS_PS0;

	if (ACPI_SUCCESS(acpi_get_handle(bridge->handle,
					"_PS3", &dummy_handle)))
		bridge->flags |= BRIDGE_HAS_PS3;

	/* is this ejectable p2p bridge? */
	if (bridge->flags & BRIDGE_HAS_EJ0) {
		struct acpiphp_func *func;

		dbg("found ejectable p2p bridge\n");

		/* make link between PCI bridge and PCI function */
		func = acpiphp_bridge_handle_to_function(bridge->handle);
		if (!func)
			return;
		bridge->func = func;
		func->bridge = bridge;
	}
}


/* allocate and initialize host bridge data structure */
static void add_host_bridge(acpi_handle *handle, struct pci_bus *pci_bus)
{
	struct acpiphp_bridge *bridge;

	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
	if (bridge == NULL)
		return;

	bridge->type = BRIDGE_TYPE_HOST;
	bridge->handle = handle;

	bridge->pci_bus = pci_bus;

	spin_lock_init(&bridge->res_lock);

	init_bridge_misc(bridge);
}


/* allocate and initialize PCI-to-PCI bridge data structure */
static void add_p2p_bridge(acpi_handle *handle, struct pci_dev *pci_dev)
{
	struct acpiphp_bridge *bridge;

	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
	if (bridge == NULL) {
		err("out of memory\n");
		return;
	}

	bridge->type = BRIDGE_TYPE_P2P;
	bridge->handle = handle;
	config_p2p_bridge_flags(bridge);

	bridge->pci_dev = pci_dev_get(pci_dev);
	bridge->pci_bus = pci_dev->subordinate;
	if (!bridge->pci_bus) {
		err("This is not a PCI-to-PCI bridge!\n");
		goto err;
	}

	spin_lock_init(&bridge->res_lock);

	init_bridge_misc(bridge);
	return;
 err:
	pci_dev_put(pci_dev);
	kfree(bridge);
	return;
}


/* callback routine to find P2P bridges */
static acpi_status
find_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	acpi_status status;
	acpi_handle dummy_handle;
	unsigned long long tmp;
	int device, function;
	struct pci_dev *dev;
	struct pci_bus *pci_bus = context;

	status = acpi_get_handle(handle, "_ADR", &dummy_handle);
	if (ACPI_FAILURE(status))
		return AE_OK;		/* continue */

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &tmp);
	if (ACPI_FAILURE(status)) {
		dbg("%s: _ADR evaluation failure\n", __func__);
		return AE_OK;
	}

	device = (tmp >> 16) & 0xffff;
	function = tmp & 0xffff;

	dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));

	if (!dev || !dev->subordinate)
		goto out;

	/* check if this bridge has ejectable slots */
	if ((detect_ejectable_slots(handle) > 0)) {
		dbg("found PCI-to-PCI bridge at PCI %s\n", pci_name(dev));
		add_p2p_bridge(handle, dev);
	}

	/* search P2P bridges under this p2p bridge */
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     find_p2p_bridge, dev->subordinate, NULL);
	if (ACPI_FAILURE(status))
		warn("find_p2p_bridge failed (error code = 0x%x)\n", status);

 out:
	pci_dev_put(dev);
	return AE_OK;
}


/* find hot-pluggable slots, and then find P2P bridge */
static int add_bridge(acpi_handle handle)
{
	acpi_status status;
	unsigned long long tmp;
	int seg, bus;
	acpi_handle dummy_handle;
	struct pci_bus *pci_bus;

	/* if the bridge doesn't have _STA, we assume it is always there */
	status = acpi_get_handle(handle, "_STA", &dummy_handle);
	if (ACPI_SUCCESS(status)) {
		status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
		if (ACPI_FAILURE(status)) {
			dbg("%s: _STA evaluation failure\n", __func__);
			return 0;
		}
		if ((tmp & ACPI_STA_FUNCTIONING) == 0)
			/* don't register this object */
			return 0;
	}

	/* get PCI segment number */
	status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);

	seg = ACPI_SUCCESS(status) ? tmp : 0;

	/* get PCI bus number */
	status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);

	if (ACPI_SUCCESS(status)) {
		bus = tmp;
	} else {
		warn("can't get bus number, assuming 0\n");
		bus = 0;
	}

	pci_bus = pci_find_bus(seg, bus);
	if (!pci_bus) {
		err("Can't find bus %04x:%02x\n", seg, bus);
		return 0;
	}

	/* check if this bridge has ejectable slots */
	if (detect_ejectable_slots(handle) > 0) {
		dbg("found PCI host-bus bridge with hot-pluggable slots\n");
		add_host_bridge(handle, pci_bus);
	}

	/* search P2P bridges under this host bridge */
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     find_p2p_bridge, pci_bus, NULL);

	if (ACPI_FAILURE(status))
		warn("find_p2p_bridge failed (error code = 0x%x)\n", status);

	return 0;