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

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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>
This commit is contained in:
Chris Metcalf
2010-06-25 17:00:56 -04:00
parent fb702b942b
commit 9f9c0382cd
7 changed files with 874 additions and 6 deletions
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17
arch/tile/include/asm/processor.h
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@ -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];