alistair23-linux/drivers/net/arcnet/com20020-isa.c
David Howells 06a5128a29 Annotate hardware config module parameters in drivers/net/arcnet/
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/net/arcnet/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
cc: netdev@vger.kernel.org
2017-04-20 12:02:32 +01:00

224 lines
5.4 KiB
C

/*
* Linux ARCnet driver - COM20020 chipset support
*
* Written 1997 by David Woodhouse.
* Written 1994-1999 by Avery Pennarun.
* Written 1999-2000 by Martin Mares <mj@ucw.cz>.
* Derived from skeleton.c by Donald Becker.
*
* Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
* for sponsoring the further development of this driver.
*
* **********************
*
* The original copyright of skeleton.c was as follows:
*
* skeleton.c Written 1993 by Donald Becker.
* Copyright 1993 United States Government as represented by the
* Director, National Security Agency. This software may only be used
* and distributed according to the terms of the GNU General Public License as
* modified by SRC, incorporated herein by reference.
*
* **********************
*
* For more details, see drivers/net/arcnet.c
*
* **********************
*/
#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/bootmem.h>
#include <linux/io.h>
#include "arcdevice.h"
#include "com20020.h"
/* We cannot (yet) probe for an IO mapped card, although we can check that
* it's where we were told it was, and even do autoirq.
*/
static int __init com20020isa_probe(struct net_device *dev)
{
int ioaddr;
unsigned long airqmask;
struct arcnet_local *lp = netdev_priv(dev);
int err;
if (BUGLVL(D_NORMAL))
pr_info("%s\n", "COM20020 ISA support (by David Woodhouse et al.)");
ioaddr = dev->base_addr;
if (!ioaddr) {
arc_printk(D_NORMAL, dev, "No autoprobe (yet) for IO mapped cards; you must specify the base address!\n");
return -ENODEV;
}
if (!request_region(ioaddr, ARCNET_TOTAL_SIZE, "arcnet (COM20020)")) {
arc_printk(D_NORMAL, dev, "IO region %xh-%xh already allocated.\n",
ioaddr, ioaddr + ARCNET_TOTAL_SIZE - 1);
return -ENXIO;
}
if (arcnet_inb(ioaddr, COM20020_REG_R_STATUS) == 0xFF) {
arc_printk(D_NORMAL, dev, "IO address %x empty\n", ioaddr);
err = -ENODEV;
goto out;
}
if (com20020_check(dev)) {
err = -ENODEV;
goto out;
}
if (!dev->irq) {
/* if we do this, we're sure to get an IRQ since the
* card has just reset and the NORXflag is on until
* we tell it to start receiving.
*/
arc_printk(D_INIT_REASONS, dev, "intmask was %02Xh\n",
arcnet_inb(ioaddr, COM20020_REG_R_STATUS));
arcnet_outb(0, ioaddr, COM20020_REG_W_INTMASK);
airqmask = probe_irq_on();
arcnet_outb(NORXflag, ioaddr, COM20020_REG_W_INTMASK);
udelay(1);
arcnet_outb(0, ioaddr, COM20020_REG_W_INTMASK);
dev->irq = probe_irq_off(airqmask);
if ((int)dev->irq <= 0) {
arc_printk(D_INIT_REASONS, dev, "Autoprobe IRQ failed first time\n");
airqmask = probe_irq_on();
arcnet_outb(NORXflag, ioaddr, COM20020_REG_W_INTMASK);
udelay(5);
arcnet_outb(0, ioaddr, COM20020_REG_W_INTMASK);
dev->irq = probe_irq_off(airqmask);
if ((int)dev->irq <= 0) {
arc_printk(D_NORMAL, dev, "Autoprobe IRQ failed.\n");
err = -ENODEV;
goto out;
}
}
}
lp->card_name = "ISA COM20020";
err = com20020_found(dev, 0);
if (err != 0)
goto out;
return 0;
out:
release_region(ioaddr, ARCNET_TOTAL_SIZE);
return err;
}
static int node = 0;
static int io = 0x0; /* <--- EDIT THESE LINES FOR YOUR CONFIGURATION */
static int irq = 0; /* or use the insmod io= irq= shmem= options */
static char device[9]; /* use eg. device="arc1" to change name */
static int timeout = 3;
static int backplane = 0;
static int clockp = 0;
static int clockm = 0;
module_param(node, int, 0);
module_param_hw(io, int, ioport, 0);
module_param_hw(irq, int, irq, 0);
module_param_string(device, device, sizeof(device), 0);
module_param(timeout, int, 0);
module_param(backplane, int, 0);
module_param(clockp, int, 0);
module_param(clockm, int, 0);
MODULE_LICENSE("GPL");
static struct net_device *my_dev;
static int __init com20020_init(void)
{
struct net_device *dev;
struct arcnet_local *lp;
dev = alloc_arcdev(device);
if (!dev)
return -ENOMEM;
if (node && node != 0xff)
dev->dev_addr[0] = node;
dev->netdev_ops = &com20020_netdev_ops;
lp = netdev_priv(dev);
lp->backplane = backplane;
lp->clockp = clockp & 7;
lp->clockm = clockm & 3;
lp->timeout = timeout & 3;
lp->hw.owner = THIS_MODULE;
dev->base_addr = io;
dev->irq = irq;
if (dev->irq == 2)
dev->irq = 9;
if (com20020isa_probe(dev)) {
free_netdev(dev);
return -EIO;
}
my_dev = dev;
return 0;
}
static void __exit com20020_exit(void)
{
unregister_netdev(my_dev);
free_irq(my_dev->irq, my_dev);
release_region(my_dev->base_addr, ARCNET_TOTAL_SIZE);
free_netdev(my_dev);
}
#ifndef MODULE
static int __init com20020isa_setup(char *s)
{
int ints[8];
s = get_options(s, 8, ints);
if (!ints[0])
return 1;
switch (ints[0]) {
default: /* ERROR */
pr_info("Too many arguments\n");
case 6: /* Timeout */
timeout = ints[6];
case 5: /* CKP value */
clockp = ints[5];
case 4: /* Backplane flag */
backplane = ints[4];
case 3: /* Node ID */
node = ints[3];
case 2: /* IRQ */
irq = ints[2];
case 1: /* IO address */
io = ints[1];
}
if (*s)
snprintf(device, sizeof(device), "%s", s);
return 1;
}
__setup("com20020=", com20020isa_setup);
#endif /* MODULE */
module_init(com20020_init)
module_exit(com20020_exit)