alistair23-linux/drivers/net/arcnet/com90io.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

425 lines
12 KiB
C

/*
* Linux ARCnet driver - COM90xx chipset (IO-mapped buffers)
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include "arcdevice.h"
#include "com9026.h"
/* Internal function declarations */
static int com90io_found(struct net_device *dev);
static void com90io_command(struct net_device *dev, int command);
static int com90io_status(struct net_device *dev);
static void com90io_setmask(struct net_device *dev, int mask);
static int com90io_reset(struct net_device *dev, int really_reset);
static void com90io_copy_to_card(struct net_device *dev, int bufnum, int offset,
void *buf, int count);
static void com90io_copy_from_card(struct net_device *dev, int bufnum,
int offset, void *buf, int count);
/* Handy defines for ARCnet specific stuff */
/* The number of low I/O ports used by the card. */
#define ARCNET_TOTAL_SIZE 16
/****************************************************************************
* *
* IO-mapped operation routines *
* *
****************************************************************************/
#undef ONE_AT_A_TIME_TX
#undef ONE_AT_A_TIME_RX
static u_char get_buffer_byte(struct net_device *dev, unsigned offset)
{
int ioaddr = dev->base_addr;
arcnet_outb(offset >> 8, ioaddr, COM9026_REG_W_ADDR_HI);
arcnet_outb(offset & 0xff, ioaddr, COM9026_REG_W_ADDR_LO);
return arcnet_inb(ioaddr, COM9026_REG_RW_MEMDATA);
}
#ifdef ONE_AT_A_TIME_TX
static void put_buffer_byte(struct net_device *dev, unsigned offset,
u_char datum)
{
int ioaddr = dev->base_addr;
arcnet_outb(offset >> 8, ioaddr, COM9026_REG_W_ADDR_HI);
arcnet_outb(offset & 0xff, ioaddr, COM9026_REG_W_ADDR_LO);
arcnet_outb(datum, ioaddr, COM9026_REG_RW_MEMDATA);
}
#endif
static void get_whole_buffer(struct net_device *dev, unsigned offset,
unsigned length, char *dest)
{
int ioaddr = dev->base_addr;
arcnet_outb((offset >> 8) | AUTOINCflag, ioaddr, COM9026_REG_W_ADDR_HI);
arcnet_outb(offset & 0xff, ioaddr, COM9026_REG_W_ADDR_LO);
while (length--)
#ifdef ONE_AT_A_TIME_RX
*(dest++) = get_buffer_byte(dev, offset++);
#else
*(dest++) = arcnet_inb(ioaddr, COM9026_REG_RW_MEMDATA);
#endif
}
static void put_whole_buffer(struct net_device *dev, unsigned offset,
unsigned length, char *dest)
{
int ioaddr = dev->base_addr;
arcnet_outb((offset >> 8) | AUTOINCflag, ioaddr, COM9026_REG_W_ADDR_HI);
arcnet_outb(offset & 0xff, ioaddr,COM9026_REG_W_ADDR_LO);
while (length--)
#ifdef ONE_AT_A_TIME_TX
put_buffer_byte(dev, offset++, *(dest++));
#else
arcnet_outb(*(dest++), ioaddr, COM9026_REG_RW_MEMDATA);
#endif
}
/* We cannot probe for an IO mapped card either, although we can check that
* it's where we were told it was, and even autoirq
*/
static int __init com90io_probe(struct net_device *dev)
{
int ioaddr = dev->base_addr, status;
unsigned long airqmask;
if (BUGLVL(D_NORMAL)) {
pr_info("%s\n", "COM90xx IO-mapped mode support (by David Woodhouse et el.)");
pr_info("E-mail me if you actually test this driver, please!\n");
}
if (!ioaddr) {
arc_printk(D_NORMAL, dev, "No autoprobe for IO mapped cards; you must specify the base address!\n");
return -ENODEV;
}
if (!request_region(ioaddr, ARCNET_TOTAL_SIZE, "com90io probe")) {
arc_printk(D_INIT_REASONS, dev, "IO request_region %x-%x failed\n",
ioaddr, ioaddr + ARCNET_TOTAL_SIZE - 1);
return -ENXIO;
}
if (arcnet_inb(ioaddr, COM9026_REG_R_STATUS) == 0xFF) {
arc_printk(D_INIT_REASONS, dev, "IO address %x empty\n",
ioaddr);
goto err_out;
}
arcnet_inb(ioaddr, COM9026_REG_R_RESET);
mdelay(RESETtime);
status = arcnet_inb(ioaddr, COM9026_REG_R_STATUS);
if ((status & 0x9D) != (NORXflag | RECONflag | TXFREEflag | RESETflag)) {
arc_printk(D_INIT_REASONS, dev, "Status invalid (%Xh)\n",
status);
goto err_out;
}
arc_printk(D_INIT_REASONS, dev, "Status after reset: %X\n", status);
arcnet_outb(CFLAGScmd | RESETclear | CONFIGclear,
ioaddr, COM9026_REG_W_COMMAND);
arc_printk(D_INIT_REASONS, dev, "Status after reset acknowledged: %X\n",
status);
status = arcnet_inb(ioaddr, COM9026_REG_R_STATUS);
if (status & RESETflag) {
arc_printk(D_INIT_REASONS, dev, "Eternal reset (status=%Xh)\n",
status);
goto err_out;
}
arcnet_outb((0x16 | IOMAPflag) & ~ENABLE16flag,
ioaddr, COM9026_REG_RW_CONFIG);
/* Read first loc'n of memory */
arcnet_outb(AUTOINCflag, ioaddr, COM9026_REG_W_ADDR_HI);
arcnet_outb(0, ioaddr, COM9026_REG_W_ADDR_LO);
status = arcnet_inb(ioaddr, COM9026_REG_RW_MEMDATA);
if (status != 0xd1) {
arc_printk(D_INIT_REASONS, dev, "Signature byte not found (%Xh instead).\n",
status);
goto err_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.
*/
airqmask = probe_irq_on();
arcnet_outb(NORXflag, ioaddr, COM9026_REG_W_INTMASK);
udelay(1);
arcnet_outb(0, ioaddr, COM9026_REG_W_INTMASK);
dev->irq = probe_irq_off(airqmask);
if ((int)dev->irq <= 0) {
arc_printk(D_INIT_REASONS, dev, "Autoprobe IRQ failed\n");
goto err_out;
}
}
release_region(ioaddr, ARCNET_TOTAL_SIZE); /* end of probing */
return com90io_found(dev);
err_out:
release_region(ioaddr, ARCNET_TOTAL_SIZE);
return -ENODEV;
}
/* Set up the struct net_device associated with this card. Called after
* probing succeeds.
*/
static int __init com90io_found(struct net_device *dev)
{
struct arcnet_local *lp;
int ioaddr = dev->base_addr;
int err;
/* Reserve the irq */
if (request_irq(dev->irq, arcnet_interrupt, 0,
"arcnet (COM90xx-IO)", dev)) {
arc_printk(D_NORMAL, dev, "Can't get IRQ %d!\n", dev->irq);
return -ENODEV;
}
/* Reserve the I/O region */
if (!request_region(dev->base_addr, ARCNET_TOTAL_SIZE,
"arcnet (COM90xx-IO)")) {
free_irq(dev->irq, dev);
return -EBUSY;
}
lp = netdev_priv(dev);
lp->card_name = "COM90xx I/O";
lp->hw.command = com90io_command;
lp->hw.status = com90io_status;
lp->hw.intmask = com90io_setmask;
lp->hw.reset = com90io_reset;
lp->hw.owner = THIS_MODULE;
lp->hw.copy_to_card = com90io_copy_to_card;
lp->hw.copy_from_card = com90io_copy_from_card;
lp->config = (0x16 | IOMAPflag) & ~ENABLE16flag;
arcnet_outb(lp->config, ioaddr, COM9026_REG_RW_CONFIG);
/* get and check the station ID from offset 1 in shmem */
dev->dev_addr[0] = get_buffer_byte(dev, 1);
err = register_netdev(dev);
if (err) {
arcnet_outb(arcnet_inb(ioaddr, COM9026_REG_RW_CONFIG) & ~IOMAPflag,
ioaddr, COM9026_REG_RW_CONFIG);
free_irq(dev->irq, dev);
release_region(dev->base_addr, ARCNET_TOTAL_SIZE);
return err;
}
arc_printk(D_NORMAL, dev, "COM90IO: station %02Xh found at %03lXh, IRQ %d.\n",
dev->dev_addr[0], dev->base_addr, dev->irq);
return 0;
}
/* Do a hardware reset on the card, and set up necessary registers.
*
* This should be called as little as possible, because it disrupts the
* token on the network (causes a RECON) and requires a significant delay.
*
* However, it does make sure the card is in a defined state.
*/
static int com90io_reset(struct net_device *dev, int really_reset)
{
struct arcnet_local *lp = netdev_priv(dev);
short ioaddr = dev->base_addr;
arc_printk(D_INIT, dev, "Resetting %s (status=%02Xh)\n",
dev->name, arcnet_inb(ioaddr, COM9026_REG_R_STATUS));
if (really_reset) {
/* reset the card */
arcnet_inb(ioaddr, COM9026_REG_R_RESET);
mdelay(RESETtime);
}
/* Set the thing to IO-mapped, 8-bit mode */
lp->config = (0x1C | IOMAPflag) & ~ENABLE16flag;
arcnet_outb(lp->config, ioaddr, COM9026_REG_RW_CONFIG);
arcnet_outb(CFLAGScmd | RESETclear, ioaddr, COM9026_REG_W_COMMAND);
/* clear flags & end reset */
arcnet_outb(CFLAGScmd | CONFIGclear, ioaddr, COM9026_REG_W_COMMAND);
/* verify that the ARCnet signature byte is present */
if (get_buffer_byte(dev, 0) != TESTvalue) {
arc_printk(D_NORMAL, dev, "reset failed: TESTvalue not present.\n");
return 1;
}
/* enable extended (512-byte) packets */
arcnet_outb(CONFIGcmd | EXTconf, ioaddr, COM9026_REG_W_COMMAND);
/* done! return success. */
return 0;
}
static void com90io_command(struct net_device *dev, int cmd)
{
short ioaddr = dev->base_addr;
arcnet_outb(cmd, ioaddr, COM9026_REG_W_COMMAND);
}
static int com90io_status(struct net_device *dev)
{
short ioaddr = dev->base_addr;
return arcnet_inb(ioaddr, COM9026_REG_R_STATUS);
}
static void com90io_setmask(struct net_device *dev, int mask)
{
short ioaddr = dev->base_addr;
arcnet_outb(mask, ioaddr, COM9026_REG_W_INTMASK);
}
static void com90io_copy_to_card(struct net_device *dev, int bufnum,
int offset, void *buf, int count)
{
TIME(dev, "put_whole_buffer", count,
put_whole_buffer(dev, bufnum * 512 + offset, count, buf));
}
static void com90io_copy_from_card(struct net_device *dev, int bufnum,
int offset, void *buf, int count)
{
TIME(dev, "get_whole_buffer", count,
get_whole_buffer(dev, bufnum * 512 + offset, count, buf));
}
static int io; /* use the insmod io= irq= shmem= options */
static int irq;
static char device[9]; /* use eg. device=arc1 to change name */
module_param_hw(io, int, ioport, 0);
module_param_hw(irq, int, irq, 0);
module_param_string(device, device, sizeof(device), 0);
MODULE_LICENSE("GPL");
#ifndef MODULE
static int __init com90io_setup(char *s)
{
int ints[4];
s = get_options(s, 4, ints);
if (!ints[0])
return 0;
switch (ints[0]) {
default: /* ERROR */
pr_err("Too many arguments\n");
case 2: /* IRQ */
irq = ints[2];
case 1: /* IO address */
io = ints[1];
}
if (*s)
snprintf(device, sizeof(device), "%s", s);
return 1;
}
__setup("com90io=", com90io_setup);
#endif
static struct net_device *my_dev;
static int __init com90io_init(void)
{
struct net_device *dev;
int err;
dev = alloc_arcdev(device);
if (!dev)
return -ENOMEM;
dev->base_addr = io;
dev->irq = irq;
if (dev->irq == 2)
dev->irq = 9;
err = com90io_probe(dev);
if (err) {
free_netdev(dev);
return err;
}
my_dev = dev;
return 0;
}
static void __exit com90io_exit(void)
{
struct net_device *dev = my_dev;
int ioaddr = dev->base_addr;
unregister_netdev(dev);
/* In case the old driver is loaded later,
* set the thing back to MMAP mode
*/
arcnet_outb(arcnet_inb(ioaddr, COM9026_REG_RW_CONFIG) & ~IOMAPflag,
ioaddr, COM9026_REG_RW_CONFIG);
free_irq(dev->irq, dev);
release_region(dev->base_addr, ARCNET_TOTAL_SIZE);
free_netdev(dev);
}
module_init(com90io_init)
module_exit(com90io_exit)