kernel-ark/drivers/pcmcia/cardbus.c
Rafael J. Wysocki 5ef68e8867 pcmcia: Use global PCI rescan-remove locking
Multiple race conditions are possible between the cardbus PCI device
addition and removal and the generic PCI bus rescan and device removal that
can be triggered via sysfs.

To avoid those race conditions make the cardbus code use global PCI
rescan-remove locking.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-01-14 12:14:25 -07:00

128 lines
3.0 KiB
C

/*
* cardbus.c -- 16-bit PCMCIA core support
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The initial developer of the original code is David A. Hinds
* <dahinds@users.sourceforge.net>. Portions created by David A. Hinds
* are Copyright (C) 1999 David A. Hinds. All Rights Reserved.
*
* (C) 1999 David A. Hinds
*/
/*
* Cardbus handling has been re-written to be more of a PCI bridge thing,
* and the PCI code basically does all the resource handling.
*
* Linus, Jan 2000
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <pcmcia/ss.h>
static void cardbus_config_irq_and_cls(struct pci_bus *bus, int irq)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
u8 irq_pin;
/*
* Since there is only one interrupt available to
* CardBus devices, all devices downstream of this
* device must be using this IRQ.
*/
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq_pin);
if (irq_pin) {
dev->irq = irq;
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
}
/*
* Some controllers transfer very slowly with 0 CLS.
* Configure it. This may fail as CLS configuration
* is mandatory only for MWI.
*/
pci_set_cacheline_size(dev);
if (dev->subordinate)
cardbus_config_irq_and_cls(dev->subordinate, irq);
}
}
/**
* cb_alloc() - add CardBus device
* @s: the pcmcia_socket where the CardBus device is located
*
* cb_alloc() allocates the kernel data structures for a Cardbus device
* and handles the lowest level PCI device setup issues.
*/
int __ref cb_alloc(struct pcmcia_socket *s)
{
struct pci_bus *bus = s->cb_dev->subordinate;
struct pci_dev *dev;
unsigned int max, pass;
pci_lock_rescan_remove();
s->functions = pci_scan_slot(bus, PCI_DEVFN(0, 0));
pci_fixup_cardbus(bus);
max = bus->busn_res.start;
for (pass = 0; pass < 2; pass++)
list_for_each_entry(dev, &bus->devices, bus_list)
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
max = pci_scan_bridge(bus, dev, max, pass);
/*
* Size all resources below the CardBus controller.
*/
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
cardbus_config_irq_and_cls(bus, s->pci_irq);
/* socket specific tune function */
if (s->tune_bridge)
s->tune_bridge(s, bus);
pci_bus_add_devices(bus);
pci_unlock_rescan_remove();
return 0;
}
/**
* cb_free() - remove CardBus device
* @s: the pcmcia_socket where the CardBus device was located
*
* cb_free() handles the lowest level PCI device cleanup.
*/
void cb_free(struct pcmcia_socket *s)
{
struct pci_dev *bridge, *dev, *tmp;
struct pci_bus *bus;
bridge = s->cb_dev;
if (!bridge)
return;
bus = bridge->subordinate;
if (!bus)
return;
pci_lock_rescan_remove();
list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list)
pci_stop_and_remove_bus_device(dev);
pci_unlock_rescan_remove();
}