Commit 3b63aaa7 authored by Jiang Liu's avatar Jiang Liu Committed by Bjorn Helgaas
Browse files

PCI: acpiphp: Do not use ACPI PCI subdriver mechanism 



Previously the acpiphp driver registered itself as an ACPI PCI subdriver,
so its callbacks were invoked when creating/destroying PCI root
buses to manage ACPI-based PCI hotplug slots.  But it doesn't handle
P2P bridge hotplug events, so it will cause strange behaviour if there
are hotplug slots associated with a hot-removed P2P bridge.

This patch fixes this issue by:
1) Directly hooking into PCI core to update hotplug slot devices when
   creating/destroying PCI buses through:
	pci_{add|remove}_bus() -> acpi_pci_{add|remove}_bus()
2) Getting rid of unused ACPI PCI subdriver-related code

It also cleans up unused code in the acpiphp driver.

[bhelgaas: keep acpi_pci_add_bus() stub for CONFIG_ACPI=n]
Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Signed-off-by: default avatarYijing Wang <wangyijing@huawei.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>
parent 6037a803

drivers/pci/hotplug/acpiphp.h

+0 −3
Original line number Diff line number Diff line
@@ -119,7 +119,6 @@ struct acpiphp_slot { 
 */

struct acpiphp_func {

	struct acpiphp_slot *slot;	/* parent */

	struct acpiphp_bridge *bridge;	/* Ejectable PCI-to-PCI bridge */



	struct list_head sibling;

	struct notifier_block nb;
@@ -176,8 +175,6 @@ extern int acpiphp_register_hotplug_slot(struct acpiphp_slot *slot); 
extern void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *slot);



/* acpiphp_glue.c */

extern int acpiphp_glue_init (void);

extern void acpiphp_glue_exit (void);

typedef int (*acpiphp_callback)(struct acpiphp_slot *slot, void *data);



extern int acpiphp_enable_slot (struct acpiphp_slot *slot);

drivers/pci/hotplug/acpiphp_core.c

+2 −11
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 


#include <linux/kernel.h>

#include <linux/pci.h>

#include <linux/pci-acpi.h>

#include <linux/pci_hotplug.h>

#include <linux/slab.h>

#include <linux/smp.h>
@@ -354,19 +355,9 @@ void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot) 
}





static int __init acpiphp_init(void)

void __init acpiphp_init(void)

{

	info(DRIVER_DESC " version: " DRIVER_VERSION "%s\n",

		acpiphp_disabled ? ", disabled by user; please report a bug"

				 : "");



	if (acpi_pci_disabled || acpiphp_disabled)

		return 0;



	/* read all the ACPI info from the system */

	/* initialize internal data structure etc. */

	return acpiphp_glue_init();

}
 




module_init(acpiphp_init);

drivers/pci/hotplug/acpiphp_glue.c

+55 −233
Original line number Diff line number Diff line
@@ -157,6 +157,7 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) 
	int device, function, retval;

	struct pci_bus *pbus = bridge->pci_bus;

	struct pci_dev *pdev;

	u32 val;



	if (!acpi_pci_check_ejectable(pbus, handle) && !is_dock_device(handle))

		return AE_OK;
@@ -249,11 +250,9 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) 
	newfunc->slot = slot;

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



	pdev = pci_get_slot(pbus, PCI_DEVFN(device, function));

	if (pdev) {

	if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),

				       &val, 60*1000))

		slot->flags |= (SLOT_ENABLED | SLOT_POWEREDON);

		pci_dev_put(pdev);

	}



	if (is_dock_device(handle)) {

		/* we don't want to call this device's _EJ0
@@ -366,148 +365,6 @@ static struct acpiphp_func *acpiphp_bridge_handle_to_function(acpi_handle handle 
}





static inline void config_p2p_bridge_flags(struct acpiphp_bridge *bridge)

{

	acpi_handle dummy_handle;

	struct acpiphp_func *func;



	if (ACPI_SUCCESS(acpi_get_handle(bridge->handle,

					"_EJ0", &dummy_handle))) {

		bridge->flags |= BRIDGE_HAS_EJ0;



		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(struct acpi_pci_root *root)

{

	struct acpiphp_bridge *bridge;

	acpi_handle handle = root->device->handle;



	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);

	if (bridge == NULL)

		return;



	bridge->handle = handle;



	bridge->pci_bus = root->bus;



	init_bridge_misc(bridge);

}





/* allocate and initialize PCI-to-PCI bridge data structure */

static void add_p2p_bridge(acpi_handle *handle)

{

	struct acpiphp_bridge *bridge;



	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);

	if (bridge == NULL) {

		err("out of memory\n");

		return;

	}



	bridge->handle = handle;

	config_p2p_bridge_flags(bridge);



	bridge->pci_dev = acpi_get_pci_dev(handle);

	bridge->pci_bus = bridge->pci_dev->subordinate;

	if (!bridge->pci_bus) {

		err("This is not a PCI-to-PCI bridge!\n");

		goto err;

	}



	/*

	 * Grab a ref to the subordinate PCI bus in case the bus is

	 * removed via PCI core logical hotplug. The ref pins the bus

	 * (which we access during module unload).

	 */

	get_device(&bridge->pci_bus->dev);



	init_bridge_misc(bridge);

	return;

 err:

	pci_dev_put(bridge->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;

	struct pci_dev *dev;



	dev = acpi_get_pci_dev(handle);

	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);

	}



	/* search P2P bridges under this p2p bridge */

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,

				     find_p2p_bridge, NULL, NULL, 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(struct acpi_pci_root *root)

{

	acpi_status status;

	unsigned long long tmp;

	acpi_handle dummy_handle;

	acpi_handle handle = root->device->handle;



	/* 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_DEVICE_FUNCTIONING) == 0)

			/* don't register this object */

			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(root);

	}



	/* search P2P bridges under this host bridge */

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,

				     find_p2p_bridge, NULL, NULL, NULL);



	if (ACPI_FAILURE(status))

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



	return 0;

}



static struct acpiphp_bridge *acpiphp_handle_to_bridge(acpi_handle handle)

{

	struct acpiphp_bridge *bridge;
@@ -567,56 +424,12 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge) 
		slot = next;

	}



	/*

	 * Only P2P bridges have a pci_dev

	 */

	if (bridge->pci_dev)

	put_device(&bridge->pci_bus->dev);



	pci_dev_put(bridge->pci_dev);

	list_del(&bridge->list);

	kfree(bridge);

}



static acpi_status

cleanup_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)

{

	struct acpiphp_bridge *bridge;



	/* cleanup p2p bridges under this P2P bridge

	   in a depth-first manner */

	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,

				cleanup_p2p_bridge, NULL, NULL, NULL);



	bridge = acpiphp_handle_to_bridge(handle);

	if (bridge)

		cleanup_bridge(bridge);



	return AE_OK;

}



static void remove_bridge(struct acpi_pci_root *root)

{

	struct acpiphp_bridge *bridge;

	acpi_handle handle = root->device->handle;



	/* cleanup p2p bridges under this host bridge

	   in a depth-first manner */

	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,

				(u32)1, cleanup_p2p_bridge, NULL, NULL, NULL);



	/*

	 * On root bridges with hotplug slots directly underneath (ie,

	 * no p2p bridge between), we call cleanup_bridge(). 

	 *

	 * The else clause cleans up root bridges that either had no

	 * hotplug slots at all, or had a p2p bridge underneath.

	 */

	bridge = acpiphp_handle_to_bridge(handle);

	if (bridge)

		cleanup_bridge(bridge);

}



static int power_on_slot(struct acpiphp_slot *slot)

{

	acpi_status status;
@@ -798,6 +611,7 @@ static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev) 
		}

	}

}



/**

 * enable_device - enable, configure a slot

 * @slot: slot to be enabled
@@ -812,7 +626,6 @@ static int __ref enable_device(struct acpiphp_slot *slot) 
	struct acpiphp_func *func;

	int retval = 0;

	int num, max, pass;

	acpi_status status;



	if (slot->flags & SLOT_ENABLED)

		goto err_exit;
@@ -867,18 +680,6 @@ static int __ref enable_device(struct acpiphp_slot *slot) 
			slot->flags &= (~SLOT_ENABLED);

			continue;

		}



		if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE &&

		    dev->hdr_type != PCI_HEADER_TYPE_CARDBUS) {

			pci_dev_put(dev);

			continue;

		}



		status = find_p2p_bridge(func->handle, (u32)1, bus, NULL);

		if (ACPI_FAILURE(status))

			warn("find_p2p_bridge failed (error code = 0x%x)\n",

				status);

		pci_dev_put(dev);

	}
@@ -912,16 +713,6 @@ static int disable_device(struct acpiphp_slot *slot) 
{

	struct acpiphp_func *func;

	struct pci_dev *pdev;

	struct pci_bus *bus = slot->bridge->pci_bus;



	list_for_each_entry(func, &slot->funcs, sibling) {

		if (func->bridge) {

			/* cleanup p2p bridges under this P2P bridge */

			cleanup_p2p_bridge(func->bridge->handle,

						(u32)1, NULL, NULL);

			func->bridge = NULL;

		}

	}



	/*

	 * enable_device() enumerates all functions in this device via
@@ -940,7 +731,6 @@ static int disable_device(struct acpiphp_slot *slot) 


	slot->flags &= (~SLOT_ENABLED);



err_exit:

	return 0;

}
@@ -1287,30 +1077,62 @@ static void handle_hotplug_event_func(acpi_handle handle, u32 type, 
	alloc_acpi_hp_work(handle, type, context, _handle_hotplug_event_func);

}



static struct acpi_pci_driver acpi_pci_hp_driver = {

	.add =		add_bridge,

	.remove =	remove_bridge,

};



/**

 * acpiphp_glue_init - initializes all PCI hotplug - ACPI glue data structures

/*

 * Create hotplug slots for the PCI bus.

 * It should always return 0 to avoid skipping following notifiers.

 */

int __init acpiphp_glue_init(void)

void acpiphp_enumerate_slots(struct pci_bus *bus, acpi_handle handle)

{

	acpi_pci_register_driver(&acpi_pci_hp_driver);

	acpi_handle dummy_handle;

	struct acpiphp_bridge *bridge;



	return 0;

	if (acpiphp_disabled)

		return;



	if (detect_ejectable_slots(handle) <= 0)

		return;



	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);

	if (bridge == NULL) {

		err("out of memory\n");

		return;

	}



	bridge->handle = handle;

	bridge->pci_dev = pci_dev_get(bus->self);

	bridge->pci_bus = bus;



/**

 * acpiphp_glue_exit - terminates all PCI hotplug - ACPI glue data structures

 *

 * This function frees all data allocated in acpiphp_glue_init().

	/*

	 * Grab a ref to the subordinate PCI bus in case the bus is

	 * removed via PCI core logical hotplug. The ref pins the bus

	 * (which we access during module unload).

	 */

void  acpiphp_glue_exit(void)

	get_device(&bus->dev);



	if (!pci_is_root_bus(bridge->pci_bus) &&

	    ACPI_SUCCESS(acpi_get_handle(bridge->handle,

					"_EJ0", &dummy_handle))) {

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

		bridge->flags |= BRIDGE_HAS_EJ0;

		bridge->func = acpiphp_bridge_handle_to_function(handle);

	}



	init_bridge_misc(bridge);

}



/* Destroy hotplug slots associated with the PCI bus */

void acpiphp_remove_slots(struct pci_bus *bus)

{

	acpi_pci_unregister_driver(&acpi_pci_hp_driver);

	struct acpiphp_bridge *bridge, *tmp;



	if (acpiphp_disabled)

		return;



	list_for_each_entry_safe(bridge, tmp, &bridge_list, list)

		if (bridge->pci_bus == bus) {

			cleanup_bridge(bridge);

			break;

		}

}



/**

drivers/pci/pci-acpi.c

+3 −0
Original line number Diff line number Diff line
@@ -297,6 +297,7 @@ void acpi_pci_add_bus(struct pci_bus *bus) 
		return;



	acpi_pci_slot_enumerate(bus, handle);

	acpiphp_enumerate_slots(bus, handle);

}



void acpi_pci_remove_bus(struct pci_bus *bus)
@@ -308,6 +309,7 @@ void acpi_pci_remove_bus(struct pci_bus *bus) 
	if (acpi_pci_disabled)

		return;



	acpiphp_remove_slots(bus);

	acpi_pci_slot_remove(bus);

}
@@ -388,6 +390,7 @@ static int __init acpi_pci_init(void) 


	pci_set_platform_pm(&acpi_pci_platform_pm);

	acpi_pci_slot_init();

	acpiphp_init();



	return 0;

}

include/linux/pci-acpi.h

+11 −0
Original line number Diff line number Diff line
@@ -56,6 +56,17 @@ static inline void acpi_pci_slot_enumerate(struct pci_bus *bus, 
static inline void acpi_pci_slot_remove(struct pci_bus *bus) { }

#endif



#ifdef	CONFIG_HOTPLUG_PCI_ACPI

void acpiphp_init(void);

void acpiphp_enumerate_slots(struct pci_bus *bus, acpi_handle handle);

void acpiphp_remove_slots(struct pci_bus *bus);

#else

static inline void acpiphp_init(void) { }

static inline void acpiphp_enumerate_slots(struct pci_bus *bus,

					   acpi_handle handle) { }

static inline void acpiphp_remove_slots(struct pci_bus *bus) { }

#endif



#else	/* CONFIG_ACPI */

static inline void acpi_pci_add_bus(struct pci_bus *bus) { }

static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }

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