linux/drivers/char/mwave
David Howells 94b599bc07 Annotate hardware config module parameters in drivers/char/mwave/
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/char/mwave/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-20 12:02:32 +01:00
..
3780i.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
3780i.h
Makefile
mwavedd.c Annotate hardware config module parameters in drivers/char/mwave/ 2017-04-20 12:02:32 +01:00
mwavedd.h Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mwavepub.h
README
smapi.c
smapi.h
tp3780i.c
tp3780i.h

Module options
--------------

The mwave module takes the following options.  Note that these options
are not saved by the BIOS and so do not persist after unload and reload.

  mwave_debug=value, where value is bitwise OR of trace flags:
	0x0001 mwavedd api tracing
	0x0002 smapi api tracing
	0x0004 3780i tracing
	0x0008 tp3780i tracing

        Tracing only occurs if the driver has been compiled with the
        MW_TRACE macro #defined  (i.e. let ccflags-y := -DMW_TRACE
        in the Makefile).

  mwave_3780i_irq=5/7/10/11/15
	If the dsp irq has not been setup and stored in bios by the 
	thinkpad configuration utility then this parameter allows the
	irq used by the dsp to be configured.

  mwave_3780i_io=0x130/0x350/0x0070/0xDB0
	If the dsp io range has not been setup and stored in bios by the 
	thinkpad configuration utility then this parameter allows the
	io range used by the dsp to be configured.

  mwave_uart_irq=3/4
	If the mwave's uart irq has not been setup and stored in bios by the 
	thinkpad configuration utility then this parameter allows the
	irq used by the mwave uart to be configured.

  mwave_uart_io=0x3f8/0x2f8/0x3E8/0x2E8
	If the uart io range has not been setup and stored in bios by the 
	thinkpad configuration utility then this parameter allows the
	io range used by the mwave uart to be configured.

Example to enable the 3780i DSP using ttyS1 resources:
	
  insmod mwave mwave_3780i_irq=10 mwave_3780i_io=0x0130 mwave_uart_irq=3 mwave_uart_io=0x2f8

Accessing the driver
--------------------

You must also create a node for the driver:
  mkdir -p /dev/modems
  mknod --mode=660 /dev/modems/mwave c 10 219