arch/tile: Add driver to enable access to the user dynamic network.

This network (the "UDN") connects all the cpus on the chip in a
wormhole-routed dynamic network.  Subrectangles of the chip can
be allocated by a "create" ioctl on /dev/hardwall, and then to access the
UDN in that rectangle, tasks must perform an "activate" ioctl on that
same file object after affinitizing themselves to a single cpu in
the region.  Sending a wormhole-routed message that tries to leave
that subrectangle causes all activated tasks to receive a SIGILL
(just as they would if they tried to access the UDN without first
activating themselves to a hardwall rectangle).

The original submission of this code to LKML had the driver
instantiated under /proc/tile/hardwall.  Now we just use a character
device for this, conventionally /dev/hardwall.  Some futures planning
for the TILE-Gx chip suggests that we may want to have other types of
devices that share the general model of "bind a task to a cpu, then
'activate' a file descriptor on a pseudo-device that gives access to
some hardware resource".  As such, we are using a device rather
than, for example, a syscall, to set up and activate this code.

As part of this change, the compat_ptr() declaration was fixed and used
to pass the compat_ioctl argument to the normal ioctl.  So far we limit
compat code to 2GB, so the difference between zero-extend and sign-extend
(the latter being correct, eventually) had been overlooked.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S
index 207271f0..3404c75 100644
--- a/arch/tile/kernel/intvec_32.S
+++ b/arch/tile/kernel/intvec_32.S
@@ -17,9 +17,9 @@
 #include <linux/linkage.h>
 #include <linux/errno.h>
 #include <linux/init.h>
+#include <linux/unistd.h>
 #include <asm/ptrace.h>
 #include <asm/thread_info.h>
-#include <asm/unistd.h>
 #include <asm/irqflags.h>
 #include <asm/atomic.h>
 #include <asm/asm-offsets.h>
@@ -32,7 +32,7 @@
 # error "No support for kernel preemption currently"
 #endif
 
-#if INT_INTCTRL_1 < 32 || INT_INTCTL_1 >= 48
+#if INT_INTCTRL_1 < 32 || INT_INTCTRL_1 >= 48
 # error INT_INTCTRL_1 coded to set high interrupt mask
 #endif
 
@@ -1941,7 +1941,9 @@
 #define op_handle_perf_interrupt bad_intr
 #define op_handle_aux_perf_interrupt bad_intr
 
+#ifndef CONFIG_HARDWALL
 #define do_hardwall_trap bad_intr
+#endif
 
 	int_hand     INT_ITLB_MISS, ITLB_MISS, \
 		     do_page_fault, handle_interrupt_no_single_step