pcmcia: disable pcmcia ioctl for !ARM, prepare for removal

The PCMCIA ioctl -- deprecated for years -- suffers from insufficient
locking. As it already has been deprecated for years, with its removal
long overdue, limit it to !SMP and !PREEMPT.

Furthermore, the last legitimate use of the ioctl to be reported
relates to the ARM architecture in 2008.[1] Attempts to resolve
this issue turned out unsuccessful so far.[2] Other usages have only
been reported as hear-say. If there are any legitiate and necessary
use-cases remaining, please speak out before the end of the grace
period until 2.6.3{5,6}(-rc1).

[1] http://lists.infradead.org/pipermail/linux-pcmcia/2008-April/005440.html
    see also: http://lkml.org/lkml/2008/2/27/291
[2] http://lists.infradead.org/pipermail/linux-pcmcia/2008-April/005450.html
    http://lists.infradead.org/pipermail/linux-pcmcia/2010-January/006740.html
    see also: http://lists.infradead.org/pipermail/linux-pcmcia/2008-April/005453.html

CC: Russell King <rmk+kernel@arm.linux.org.uk>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: Robert P. J. Day <rpjday@crashcourse.ca>
CC: Jaswinder Singh Rajput <jaswinder@kernel.org>
CC: linux-kernel@vger.kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/pcmcia/Kconfig b/drivers/pcmcia/Kconfig
index 0a6601c76809..d189e4743e69 100644
--- a/drivers/pcmcia/Kconfig
+++ b/drivers/pcmcia/Kconfig
@@ -51,17 +51,23 @@ config PCMCIA_LOAD_CIS
 
 config PCMCIA_IOCTL
         bool "PCMCIA control ioctl (obsolete)"
-        depends on PCMCIA
+        depends on PCMCIA && ARM && !SMP && !PREEMPT
         default y
         help
           If you say Y here, the deprecated ioctl interface to the PCMCIA
-          subsystem will be built. It is needed by cardmgr and cardctl
-          (pcmcia-cs) to function properly.
+          subsystem will be built. It is needed by the deprecated pcmcia-cs
+          tools (cardmgr, cardctl) to function properly.
 
           You should use the new pcmciautils package instead (see
           <file:Documentation/Changes> for location and details).
 
-          If unsure, say Y.
+          This config option will most likely be removed from kernel 2.6.35,
+          the associated code from kernel 2.6.36.
+
+          As the PCMCIA ioctl is not locking safe, it depends on !SMP and
+          !PREEMPT.
+
+          If unsure, say N.
 
 config CARDBUS
         bool "32-bit CardBus support"