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>

1 files changed, 14 insertions, 3 deletions

diff --git a/arch/tile/include/asm/processor.h b/arch/tile/include/asm/processor.h
index 96c50d2c4c2b..09584e263b00 100644
--- a/arch/tile/include/asm/processor.h
+++ b/arch/tile/include/asm/processor.h
@@ -21,6 +21,7 @@
  * NOTE: we don't include <linux/ptrace.h> or <linux/percpu.h> as one
  * normally would, due to #include dependencies.
  */
+#include <linux/types.h>
 #include <asm/ptrace.h>
 #include <asm/percpu.h>
 
@@ -29,7 +30,6 @@
 
 struct task_struct;
 struct thread_struct;
-struct list_head;
 
 typedef struct {
         unsigned long seg;
@@ -74,6 +74,9 @@ struct async_tlb {
         unsigned long address;   /* what address faulted? */
 };
 
+#ifdef CONFIG_HARDWALL
+struct hardwall_info;
+#endif
 
 struct thread_struct {
         /* kernel stack pointer */
@@ -100,6 +103,12 @@ struct thread_struct {
         /* Any other miscellaneous processor state bits */
         unsigned long proc_status;
 #endif
+#ifdef CONFIG_HARDWALL
+        /* Is this task tied to an activated hardwall? */
+        struct hardwall_info *hardwall;
+        /* Chains this task into the list at hardwall->list. */
+        struct list_head hardwall_list;
+#endif
 #if CHIP_HAS_TILE_DMA()
         /* Async DMA TLB fault information */
         struct async_tlb dma_async_tlb;
@@ -194,8 +203,6 @@ static inline void release_thread(struct task_struct *dead_task)
 
 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
 
-/* Helper routines for setting home cache modes at exec() time. */
-
 
 /*
  * Return saved (kernel) PC of a blocked thread.
@@ -240,6 +247,10 @@ struct siginfo;
 extern void arch_coredump_signal(struct siginfo *, struct pt_regs *);
 #define arch_coredump_signal arch_coredump_signal
 
+/* Info on this processor (see fs/proc/cpuinfo.c) */
+struct seq_operations;
+extern const struct seq_operations cpuinfo_op;
+
 /* Provide information about the chip model. */
 extern char chip_model[64];