![David Howells](/assets/img/avatar_default.png)
When the kernel is running in secure boot mode, we lock down the kernel to prevent userspace from modifying the running kernel image. Whilst this includes prohibiting access to things like /dev/mem, it must also prevent access by means of configuring driver modules in such a way as to cause a device to access or modify the kernel image. To this end, annotate module_param* statements that refer to hardware configuration and indicate for future reference what type of parameter they specify. The parameter parser in the core sees this information and can skip such parameters with an error message if the kernel is locked down. The module initialisation then runs as normal, but just sees whatever the default values for those parameters is. Note that we do still need to do the module initialisation because some drivers have viable defaults set in case parameters aren't specified and some drivers support automatic configuration (e.g. PNP or PCI) in addition to manually coded parameters. This patch annotates drivers in drivers/pci/hotplug/. Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> cc: Scott Murray <scott@spiteful.org> cc: linux-pci@vger.kernel.org
227 lines
6.3 KiB
C
227 lines
6.3 KiB
C
/*
|
|
* cpcihp_generic.c
|
|
*
|
|
* Generic port I/O CompactPCI driver
|
|
*
|
|
* Copyright 2002 SOMA Networks, Inc.
|
|
* Copyright 2001 Intel San Luis Obispo
|
|
* Copyright 2000,2001 MontaVista Software Inc.
|
|
*
|
|
* 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 SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
|
|
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
|
|
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* 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.
|
|
*
|
|
* This generic CompactPCI hotplug driver should allow using the PCI hotplug
|
|
* mechanism on any CompactPCI board that exposes the #ENUM signal as a bit
|
|
* in a system register that can be read through standard port I/O.
|
|
*
|
|
* Send feedback to <scottm@somanetworks.com>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/string.h>
|
|
#include "cpci_hotplug.h"
|
|
|
|
#define DRIVER_VERSION "0.1"
|
|
#define DRIVER_AUTHOR "Scott Murray <scottm@somanetworks.com>"
|
|
#define DRIVER_DESC "Generic port I/O CompactPCI Hot Plug Driver"
|
|
|
|
#if !defined(MODULE)
|
|
#define MY_NAME "cpcihp_generic"
|
|
#else
|
|
#define MY_NAME THIS_MODULE->name
|
|
#endif
|
|
|
|
#define dbg(format, arg...) \
|
|
do { \
|
|
if (debug) \
|
|
printk(KERN_DEBUG "%s: " format "\n", \
|
|
MY_NAME, ## arg); \
|
|
} while (0)
|
|
#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
|
|
#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
|
|
#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
|
|
|
|
/* local variables */
|
|
static bool debug;
|
|
static char *bridge;
|
|
static u8 bridge_busnr;
|
|
static u8 bridge_slot;
|
|
static struct pci_bus *bus;
|
|
static u8 first_slot;
|
|
static u8 last_slot;
|
|
static u16 port;
|
|
static unsigned int enum_bit;
|
|
static u8 enum_mask;
|
|
|
|
static struct cpci_hp_controller_ops generic_hpc_ops;
|
|
static struct cpci_hp_controller generic_hpc;
|
|
|
|
static int __init validate_parameters(void)
|
|
{
|
|
char *str;
|
|
char *p;
|
|
unsigned long tmp;
|
|
|
|
if (!bridge) {
|
|
info("not configured, disabling.");
|
|
return -EINVAL;
|
|
}
|
|
str = bridge;
|
|
if (!*str)
|
|
return -EINVAL;
|
|
|
|
tmp = simple_strtoul(str, &p, 16);
|
|
if (p == str || tmp > 0xff) {
|
|
err("Invalid hotplug bus bridge device bus number");
|
|
return -EINVAL;
|
|
}
|
|
bridge_busnr = (u8) tmp;
|
|
dbg("bridge_busnr = 0x%02x", bridge_busnr);
|
|
if (*p != ':') {
|
|
err("Invalid hotplug bus bridge device");
|
|
return -EINVAL;
|
|
}
|
|
str = p + 1;
|
|
tmp = simple_strtoul(str, &p, 16);
|
|
if (p == str || tmp > 0x1f) {
|
|
err("Invalid hotplug bus bridge device slot number");
|
|
return -EINVAL;
|
|
}
|
|
bridge_slot = (u8) tmp;
|
|
dbg("bridge_slot = 0x%02x", bridge_slot);
|
|
|
|
dbg("first_slot = 0x%02x", first_slot);
|
|
dbg("last_slot = 0x%02x", last_slot);
|
|
if (!(first_slot && last_slot)) {
|
|
err("Need to specify first_slot and last_slot");
|
|
return -EINVAL;
|
|
}
|
|
if (last_slot < first_slot) {
|
|
err("first_slot must be less than last_slot");
|
|
return -EINVAL;
|
|
}
|
|
|
|
dbg("port = 0x%04x", port);
|
|
dbg("enum_bit = 0x%02x", enum_bit);
|
|
if (enum_bit > 7) {
|
|
err("Invalid #ENUM bit");
|
|
return -EINVAL;
|
|
}
|
|
enum_mask = 1 << enum_bit;
|
|
return 0;
|
|
}
|
|
|
|
static int query_enum(void)
|
|
{
|
|
u8 value;
|
|
|
|
value = inb_p(port);
|
|
return ((value & enum_mask) == enum_mask);
|
|
}
|
|
|
|
static int __init cpcihp_generic_init(void)
|
|
{
|
|
int status;
|
|
struct resource *r;
|
|
struct pci_dev *dev;
|
|
|
|
info(DRIVER_DESC " version: " DRIVER_VERSION);
|
|
status = validate_parameters();
|
|
if (status)
|
|
return status;
|
|
|
|
r = request_region(port, 1, "#ENUM hotswap signal register");
|
|
if (!r)
|
|
return -EBUSY;
|
|
|
|
dev = pci_get_domain_bus_and_slot(0, bridge_busnr,
|
|
PCI_DEVFN(bridge_slot, 0));
|
|
if (!dev || dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
|
|
err("Invalid bridge device %s", bridge);
|
|
pci_dev_put(dev);
|
|
return -EINVAL;
|
|
}
|
|
bus = dev->subordinate;
|
|
pci_dev_put(dev);
|
|
|
|
memset(&generic_hpc, 0, sizeof(struct cpci_hp_controller));
|
|
generic_hpc_ops.query_enum = query_enum;
|
|
generic_hpc.ops = &generic_hpc_ops;
|
|
|
|
status = cpci_hp_register_controller(&generic_hpc);
|
|
if (status != 0) {
|
|
err("Could not register cPCI hotplug controller");
|
|
return -ENODEV;
|
|
}
|
|
dbg("registered controller");
|
|
|
|
status = cpci_hp_register_bus(bus, first_slot, last_slot);
|
|
if (status != 0) {
|
|
err("Could not register cPCI hotplug bus");
|
|
goto init_bus_register_error;
|
|
}
|
|
dbg("registered bus");
|
|
|
|
status = cpci_hp_start();
|
|
if (status != 0) {
|
|
err("Could not started cPCI hotplug system");
|
|
goto init_start_error;
|
|
}
|
|
dbg("started cpci hp system");
|
|
return 0;
|
|
init_start_error:
|
|
cpci_hp_unregister_bus(bus);
|
|
init_bus_register_error:
|
|
cpci_hp_unregister_controller(&generic_hpc);
|
|
err("status = %d", status);
|
|
return status;
|
|
|
|
}
|
|
|
|
static void __exit cpcihp_generic_exit(void)
|
|
{
|
|
cpci_hp_stop();
|
|
cpci_hp_unregister_bus(bus);
|
|
cpci_hp_unregister_controller(&generic_hpc);
|
|
release_region(port, 1);
|
|
}
|
|
|
|
module_init(cpcihp_generic_init);
|
|
module_exit(cpcihp_generic_exit);
|
|
|
|
MODULE_AUTHOR(DRIVER_AUTHOR);
|
|
MODULE_DESCRIPTION(DRIVER_DESC);
|
|
MODULE_LICENSE("GPL");
|
|
module_param(debug, bool, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
|
|
module_param(bridge, charp, 0);
|
|
MODULE_PARM_DESC(bridge, "Hotswap bus bridge device, <bus>:<slot> (bus and slot are in hexadecimal)");
|
|
module_param(first_slot, byte, 0);
|
|
MODULE_PARM_DESC(first_slot, "Hotswap bus first slot number");
|
|
module_param(last_slot, byte, 0);
|
|
MODULE_PARM_DESC(last_slot, "Hotswap bus last slot number");
|
|
module_param_hw(port, ushort, ioport, 0);
|
|
MODULE_PARM_DESC(port, "#ENUM signal I/O port");
|
|
module_param(enum_bit, uint, 0);
|
|
MODULE_PARM_DESC(enum_bit, "#ENUM signal bit (0-7)");
|