linux/drivers/net/wan/sealevel.c
David Howells af28a03c1b Annotate hardware config module parameters in drivers/net/wan/
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/wan/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
cc: netdev@vger.kernel.org
2017-04-20 12:02:32 +01:00

398 lines
7.9 KiB
C

/*
* Sealevel Systems 4021 driver.
*
* 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.
*
* (c) Copyright 1999, 2001 Alan Cox
* (c) Copyright 2001 Red Hat Inc.
* Generic HDLC port Copyright (C) 2008 Krzysztof Halasa <khc@pm.waw.pl>
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/delay.h>
#include <linux/hdlc.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <net/arp.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/byteorder.h>
#include "z85230.h"
struct slvl_device
{
struct z8530_channel *chan;
int channel;
};
struct slvl_board
{
struct slvl_device dev[2];
struct z8530_dev board;
int iobase;
};
/*
* Network driver support routines
*/
static inline struct slvl_device* dev_to_chan(struct net_device *dev)
{
return (struct slvl_device *)dev_to_hdlc(dev)->priv;
}
/*
* Frame receive. Simple for our card as we do HDLC and there
* is no funny garbage involved
*/
static void sealevel_input(struct z8530_channel *c, struct sk_buff *skb)
{
/* Drop the CRC - it's not a good idea to try and negotiate it ;) */
skb_trim(skb, skb->len - 2);
skb->protocol = hdlc_type_trans(skb, c->netdevice);
skb_reset_mac_header(skb);
skb->dev = c->netdevice;
netif_rx(skb);
}
/*
* We've been placed in the UP state
*/
static int sealevel_open(struct net_device *d)
{
struct slvl_device *slvl = dev_to_chan(d);
int err = -1;
int unit = slvl->channel;
/*
* Link layer up.
*/
switch (unit) {
case 0:
err = z8530_sync_dma_open(d, slvl->chan);
break;
case 1:
err = z8530_sync_open(d, slvl->chan);
break;
}
if (err)
return err;
err = hdlc_open(d);
if (err) {
switch (unit) {
case 0:
z8530_sync_dma_close(d, slvl->chan);
break;
case 1:
z8530_sync_close(d, slvl->chan);
break;
}
return err;
}
slvl->chan->rx_function = sealevel_input;
/*
* Go go go
*/
netif_start_queue(d);
return 0;
}
static int sealevel_close(struct net_device *d)
{
struct slvl_device *slvl = dev_to_chan(d);
int unit = slvl->channel;
/*
* Discard new frames
*/
slvl->chan->rx_function = z8530_null_rx;
hdlc_close(d);
netif_stop_queue(d);
switch (unit) {
case 0:
z8530_sync_dma_close(d, slvl->chan);
break;
case 1:
z8530_sync_close(d, slvl->chan);
break;
}
return 0;
}
static int sealevel_ioctl(struct net_device *d, struct ifreq *ifr, int cmd)
{
/* struct slvl_device *slvl=dev_to_chan(d);
z8530_ioctl(d,&slvl->sync.chanA,ifr,cmd) */
return hdlc_ioctl(d, ifr, cmd);
}
/*
* Passed network frames, fire them downwind.
*/
static netdev_tx_t sealevel_queue_xmit(struct sk_buff *skb,
struct net_device *d)
{
return z8530_queue_xmit(dev_to_chan(d)->chan, skb);
}
static int sealevel_attach(struct net_device *dev, unsigned short encoding,
unsigned short parity)
{
if (encoding == ENCODING_NRZ && parity == PARITY_CRC16_PR1_CCITT)
return 0;
return -EINVAL;
}
static const struct net_device_ops sealevel_ops = {
.ndo_open = sealevel_open,
.ndo_stop = sealevel_close,
.ndo_start_xmit = hdlc_start_xmit,
.ndo_do_ioctl = sealevel_ioctl,
};
static int slvl_setup(struct slvl_device *sv, int iobase, int irq)
{
struct net_device *dev = alloc_hdlcdev(sv);
if (!dev)
return -1;
dev_to_hdlc(dev)->attach = sealevel_attach;
dev_to_hdlc(dev)->xmit = sealevel_queue_xmit;
dev->netdev_ops = &sealevel_ops;
dev->base_addr = iobase;
dev->irq = irq;
if (register_hdlc_device(dev)) {
pr_err("unable to register HDLC device\n");
free_netdev(dev);
return -1;
}
sv->chan->netdevice = dev;
return 0;
}
/*
* Allocate and setup Sealevel board.
*/
static __init struct slvl_board *slvl_init(int iobase, int irq,
int txdma, int rxdma, int slow)
{
struct z8530_dev *dev;
struct slvl_board *b;
/*
* Get the needed I/O space
*/
if (!request_region(iobase, 8, "Sealevel 4021")) {
pr_warn("I/O 0x%X already in use\n", iobase);
return NULL;
}
b = kzalloc(sizeof(struct slvl_board), GFP_KERNEL);
if (!b)
goto err_kzalloc;
b->dev[0].chan = &b->board.chanA;
b->dev[0].channel = 0;
b->dev[1].chan = &b->board.chanB;
b->dev[1].channel = 1;
dev = &b->board;
/*
* Stuff in the I/O addressing
*/
dev->active = 0;
b->iobase = iobase;
/*
* Select 8530 delays for the old board
*/
if (slow)
iobase |= Z8530_PORT_SLEEP;
dev->chanA.ctrlio = iobase + 1;
dev->chanA.dataio = iobase;
dev->chanB.ctrlio = iobase + 3;
dev->chanB.dataio = iobase + 2;
dev->chanA.irqs = &z8530_nop;
dev->chanB.irqs = &z8530_nop;
/*
* Assert DTR enable DMA
*/
outb(3 | (1 << 7), b->iobase + 4);
/* We want a fast IRQ for this device. Actually we'd like an even faster
IRQ ;) - This is one driver RtLinux is made for */
if (request_irq(irq, z8530_interrupt, 0,
"SeaLevel", dev) < 0) {
pr_warn("IRQ %d already in use\n", irq);
goto err_request_irq;
}
dev->irq = irq;
dev->chanA.private = &b->dev[0];
dev->chanB.private = &b->dev[1];
dev->chanA.dev = dev;
dev->chanB.dev = dev;
dev->chanA.txdma = 3;
dev->chanA.rxdma = 1;
if (request_dma(dev->chanA.txdma, "SeaLevel (TX)"))
goto err_dma_tx;
if (request_dma(dev->chanA.rxdma, "SeaLevel (RX)"))
goto err_dma_rx;
disable_irq(irq);
/*
* Begin normal initialise
*/
if (z8530_init(dev) != 0) {
pr_err("Z8530 series device not found\n");
enable_irq(irq);
goto free_hw;
}
if (dev->type == Z85C30) {
z8530_channel_load(&dev->chanA, z8530_hdlc_kilostream);
z8530_channel_load(&dev->chanB, z8530_hdlc_kilostream);
} else {
z8530_channel_load(&dev->chanA, z8530_hdlc_kilostream_85230);
z8530_channel_load(&dev->chanB, z8530_hdlc_kilostream_85230);
}
/*
* Now we can take the IRQ
*/
enable_irq(irq);
if (slvl_setup(&b->dev[0], iobase, irq))
goto free_hw;
if (slvl_setup(&b->dev[1], iobase, irq))
goto free_netdev0;
z8530_describe(dev, "I/O", iobase);
dev->active = 1;
return b;
free_netdev0:
unregister_hdlc_device(b->dev[0].chan->netdevice);
free_netdev(b->dev[0].chan->netdevice);
free_hw:
free_dma(dev->chanA.rxdma);
err_dma_rx:
free_dma(dev->chanA.txdma);
err_dma_tx:
free_irq(irq, dev);
err_request_irq:
kfree(b);
err_kzalloc:
release_region(iobase, 8);
return NULL;
}
static void __exit slvl_shutdown(struct slvl_board *b)
{
int u;
z8530_shutdown(&b->board);
for (u = 0; u < 2; u++) {
struct net_device *d = b->dev[u].chan->netdevice;
unregister_hdlc_device(d);
free_netdev(d);
}
free_irq(b->board.irq, &b->board);
free_dma(b->board.chanA.rxdma);
free_dma(b->board.chanA.txdma);
/* DMA off on the card, drop DTR */
outb(0, b->iobase);
release_region(b->iobase, 8);
kfree(b);
}
static int io=0x238;
static int txdma=1;
static int rxdma=3;
static int irq=5;
static bool slow=false;
module_param_hw(io, int, ioport, 0);
MODULE_PARM_DESC(io, "The I/O base of the Sealevel card");
module_param_hw(txdma, int, dma, 0);
MODULE_PARM_DESC(txdma, "Transmit DMA channel");
module_param_hw(rxdma, int, dma, 0);
MODULE_PARM_DESC(rxdma, "Receive DMA channel");
module_param_hw(irq, int, irq, 0);
MODULE_PARM_DESC(irq, "The interrupt line setting for the SeaLevel card");
module_param(slow, bool, 0);
MODULE_PARM_DESC(slow, "Set this for an older Sealevel card such as the 4012");
MODULE_AUTHOR("Alan Cox");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Modular driver for the SeaLevel 4021");
static struct slvl_board *slvl_unit;
static int __init slvl_init_module(void)
{
slvl_unit = slvl_init(io, irq, txdma, rxdma, slow);
return slvl_unit ? 0 : -ENODEV;
}
static void __exit slvl_cleanup_module(void)
{
if (slvl_unit)
slvl_shutdown(slvl_unit);
}
module_init(slvl_init_module);
module_exit(slvl_cleanup_module);